misc/winutils/include/libavcodec/avcodec.h
changeset 7813 7ac83d79b897
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/misc/winutils/include/libavcodec/avcodec.h	Wed Oct 24 14:55:31 2012 +0100
@@ -0,0 +1,4604 @@
+/*
+ * copyright (c) 2001 Fabrice Bellard
+ *
+ * This file is part of Libav.
+ *
+ * Libav is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * Libav is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef AVCODEC_AVCODEC_H
+#define AVCODEC_AVCODEC_H
+
+/**
+ * @file
+ * external API header
+ */
+
+#include <errno.h>
+#include "libavutil/samplefmt.h"
+#include "libavutil/avutil.h"
+#include "libavutil/cpu.h"
+#include "libavutil/dict.h"
+#include "libavutil/log.h"
+#include "libavutil/pixfmt.h"
+#include "libavutil/rational.h"
+
+#include "libavcodec/version.h"
+/**
+ * @defgroup libavc Encoding/Decoding Library
+ * @{
+ *
+ * @defgroup lavc_decoding Decoding
+ * @{
+ * @}
+ *
+ * @defgroup lavc_encoding Encoding
+ * @{
+ * @}
+ *
+ * @defgroup lavc_codec Codecs
+ * @{
+ * @defgroup lavc_codec_native Native Codecs
+ * @{
+ * @}
+ * @defgroup lavc_codec_wrappers External library wrappers
+ * @{
+ * @}
+ * @defgroup lavc_codec_hwaccel Hardware Accelerators bridge
+ * @{
+ * @}
+ * @}
+ * @defgroup lavc_internal Internal
+ * @{
+ * @}
+ * @}
+ *
+ */
+
+/**
+ * @defgroup lavc_core Core functions/structures.
+ * @ingroup libavc
+ *
+ * Basic definitions, functions for querying libavcodec capabilities,
+ * allocating core structures, etc.
+ * @{
+ */
+
+
+/**
+ * Identify the syntax and semantics of the bitstream.
+ * The principle is roughly:
+ * Two decoders with the same ID can decode the same streams.
+ * Two encoders with the same ID can encode compatible streams.
+ * There may be slight deviations from the principle due to implementation
+ * details.
+ *
+ * If you add a codec ID to this list, add it so that
+ * 1. no value of a existing codec ID changes (that would break ABI),
+ * 2. it is as close as possible to similar codecs.
+ *
+ * After adding new codec IDs, do not forget to add an entry to the codec
+ * descriptor list and bump libavcodec minor version.
+ */
+enum AVCodecID {
+    AV_CODEC_ID_NONE,
+
+    /* video codecs */
+    AV_CODEC_ID_MPEG1VIDEO,
+    AV_CODEC_ID_MPEG2VIDEO, ///< preferred ID for MPEG-1/2 video decoding
+    AV_CODEC_ID_MPEG2VIDEO_XVMC,
+    AV_CODEC_ID_H261,
+    AV_CODEC_ID_H263,
+    AV_CODEC_ID_RV10,
+    AV_CODEC_ID_RV20,
+    AV_CODEC_ID_MJPEG,
+    AV_CODEC_ID_MJPEGB,
+    AV_CODEC_ID_LJPEG,
+    AV_CODEC_ID_SP5X,
+    AV_CODEC_ID_JPEGLS,
+    AV_CODEC_ID_MPEG4,
+    AV_CODEC_ID_RAWVIDEO,
+    AV_CODEC_ID_MSMPEG4V1,
+    AV_CODEC_ID_MSMPEG4V2,
+    AV_CODEC_ID_MSMPEG4V3,
+    AV_CODEC_ID_WMV1,
+    AV_CODEC_ID_WMV2,
+    AV_CODEC_ID_H263P,
+    AV_CODEC_ID_H263I,
+    AV_CODEC_ID_FLV1,
+    AV_CODEC_ID_SVQ1,
+    AV_CODEC_ID_SVQ3,
+    AV_CODEC_ID_DVVIDEO,
+    AV_CODEC_ID_HUFFYUV,
+    AV_CODEC_ID_CYUV,
+    AV_CODEC_ID_H264,
+    AV_CODEC_ID_INDEO3,
+    AV_CODEC_ID_VP3,
+    AV_CODEC_ID_THEORA,
+    AV_CODEC_ID_ASV1,
+    AV_CODEC_ID_ASV2,
+    AV_CODEC_ID_FFV1,
+    AV_CODEC_ID_4XM,
+    AV_CODEC_ID_VCR1,
+    AV_CODEC_ID_CLJR,
+    AV_CODEC_ID_MDEC,
+    AV_CODEC_ID_ROQ,
+    AV_CODEC_ID_INTERPLAY_VIDEO,
+    AV_CODEC_ID_XAN_WC3,
+    AV_CODEC_ID_XAN_WC4,
+    AV_CODEC_ID_RPZA,
+    AV_CODEC_ID_CINEPAK,
+    AV_CODEC_ID_WS_VQA,
+    AV_CODEC_ID_MSRLE,
+    AV_CODEC_ID_MSVIDEO1,
+    AV_CODEC_ID_IDCIN,
+    AV_CODEC_ID_8BPS,
+    AV_CODEC_ID_SMC,
+    AV_CODEC_ID_FLIC,
+    AV_CODEC_ID_TRUEMOTION1,
+    AV_CODEC_ID_VMDVIDEO,
+    AV_CODEC_ID_MSZH,
+    AV_CODEC_ID_ZLIB,
+    AV_CODEC_ID_QTRLE,
+    AV_CODEC_ID_SNOW,
+    AV_CODEC_ID_TSCC,
+    AV_CODEC_ID_ULTI,
+    AV_CODEC_ID_QDRAW,
+    AV_CODEC_ID_VIXL,
+    AV_CODEC_ID_QPEG,
+    AV_CODEC_ID_PNG,
+    AV_CODEC_ID_PPM,
+    AV_CODEC_ID_PBM,
+    AV_CODEC_ID_PGM,
+    AV_CODEC_ID_PGMYUV,
+    AV_CODEC_ID_PAM,
+    AV_CODEC_ID_FFVHUFF,
+    AV_CODEC_ID_RV30,
+    AV_CODEC_ID_RV40,
+    AV_CODEC_ID_VC1,
+    AV_CODEC_ID_WMV3,
+    AV_CODEC_ID_LOCO,
+    AV_CODEC_ID_WNV1,
+    AV_CODEC_ID_AASC,
+    AV_CODEC_ID_INDEO2,
+    AV_CODEC_ID_FRAPS,
+    AV_CODEC_ID_TRUEMOTION2,
+    AV_CODEC_ID_BMP,
+    AV_CODEC_ID_CSCD,
+    AV_CODEC_ID_MMVIDEO,
+    AV_CODEC_ID_ZMBV,
+    AV_CODEC_ID_AVS,
+    AV_CODEC_ID_SMACKVIDEO,
+    AV_CODEC_ID_NUV,
+    AV_CODEC_ID_KMVC,
+    AV_CODEC_ID_FLASHSV,
+    AV_CODEC_ID_CAVS,
+    AV_CODEC_ID_JPEG2000,
+    AV_CODEC_ID_VMNC,
+    AV_CODEC_ID_VP5,
+    AV_CODEC_ID_VP6,
+    AV_CODEC_ID_VP6F,
+    AV_CODEC_ID_TARGA,
+    AV_CODEC_ID_DSICINVIDEO,
+    AV_CODEC_ID_TIERTEXSEQVIDEO,
+    AV_CODEC_ID_TIFF,
+    AV_CODEC_ID_GIF,
+    AV_CODEC_ID_DXA,
+    AV_CODEC_ID_DNXHD,
+    AV_CODEC_ID_THP,
+    AV_CODEC_ID_SGI,
+    AV_CODEC_ID_C93,
+    AV_CODEC_ID_BETHSOFTVID,
+    AV_CODEC_ID_PTX,
+    AV_CODEC_ID_TXD,
+    AV_CODEC_ID_VP6A,
+    AV_CODEC_ID_AMV,
+    AV_CODEC_ID_VB,
+    AV_CODEC_ID_PCX,
+    AV_CODEC_ID_SUNRAST,
+    AV_CODEC_ID_INDEO4,
+    AV_CODEC_ID_INDEO5,
+    AV_CODEC_ID_MIMIC,
+    AV_CODEC_ID_RL2,
+    AV_CODEC_ID_ESCAPE124,
+    AV_CODEC_ID_DIRAC,
+    AV_CODEC_ID_BFI,
+    AV_CODEC_ID_CMV,
+    AV_CODEC_ID_MOTIONPIXELS,
+    AV_CODEC_ID_TGV,
+    AV_CODEC_ID_TGQ,
+    AV_CODEC_ID_TQI,
+    AV_CODEC_ID_AURA,
+    AV_CODEC_ID_AURA2,
+    AV_CODEC_ID_V210X,
+    AV_CODEC_ID_TMV,
+    AV_CODEC_ID_V210,
+    AV_CODEC_ID_DPX,
+    AV_CODEC_ID_MAD,
+    AV_CODEC_ID_FRWU,
+    AV_CODEC_ID_FLASHSV2,
+    AV_CODEC_ID_CDGRAPHICS,
+    AV_CODEC_ID_R210,
+    AV_CODEC_ID_ANM,
+    AV_CODEC_ID_BINKVIDEO,
+    AV_CODEC_ID_IFF_ILBM,
+    AV_CODEC_ID_IFF_BYTERUN1,
+    AV_CODEC_ID_KGV1,
+    AV_CODEC_ID_YOP,
+    AV_CODEC_ID_VP8,
+    AV_CODEC_ID_PICTOR,
+    AV_CODEC_ID_ANSI,
+    AV_CODEC_ID_A64_MULTI,
+    AV_CODEC_ID_A64_MULTI5,
+    AV_CODEC_ID_R10K,
+    AV_CODEC_ID_MXPEG,
+    AV_CODEC_ID_LAGARITH,
+    AV_CODEC_ID_PRORES,
+    AV_CODEC_ID_JV,
+    AV_CODEC_ID_DFA,
+    AV_CODEC_ID_WMV3IMAGE,
+    AV_CODEC_ID_VC1IMAGE,
+    AV_CODEC_ID_UTVIDEO,
+    AV_CODEC_ID_BMV_VIDEO,
+    AV_CODEC_ID_VBLE,
+    AV_CODEC_ID_DXTORY,
+    AV_CODEC_ID_V410,
+    AV_CODEC_ID_XWD,
+    AV_CODEC_ID_CDXL,
+    AV_CODEC_ID_XBM,
+    AV_CODEC_ID_ZEROCODEC,
+    AV_CODEC_ID_MSS1,
+    AV_CODEC_ID_MSA1,
+    AV_CODEC_ID_TSCC2,
+    AV_CODEC_ID_MTS2,
+    AV_CODEC_ID_CLLC,
+    AV_CODEC_ID_MSS2,
+
+    /* various PCM "codecs" */
+    AV_CODEC_ID_FIRST_AUDIO = 0x10000,     ///< A dummy id pointing at the start of audio codecs
+    AV_CODEC_ID_PCM_S16LE = 0x10000,
+    AV_CODEC_ID_PCM_S16BE,
+    AV_CODEC_ID_PCM_U16LE,
+    AV_CODEC_ID_PCM_U16BE,
+    AV_CODEC_ID_PCM_S8,
+    AV_CODEC_ID_PCM_U8,
+    AV_CODEC_ID_PCM_MULAW,
+    AV_CODEC_ID_PCM_ALAW,
+    AV_CODEC_ID_PCM_S32LE,
+    AV_CODEC_ID_PCM_S32BE,
+    AV_CODEC_ID_PCM_U32LE,
+    AV_CODEC_ID_PCM_U32BE,
+    AV_CODEC_ID_PCM_S24LE,
+    AV_CODEC_ID_PCM_S24BE,
+    AV_CODEC_ID_PCM_U24LE,
+    AV_CODEC_ID_PCM_U24BE,
+    AV_CODEC_ID_PCM_S24DAUD,
+    AV_CODEC_ID_PCM_ZORK,
+    AV_CODEC_ID_PCM_S16LE_PLANAR,
+    AV_CODEC_ID_PCM_DVD,
+    AV_CODEC_ID_PCM_F32BE,
+    AV_CODEC_ID_PCM_F32LE,
+    AV_CODEC_ID_PCM_F64BE,
+    AV_CODEC_ID_PCM_F64LE,
+    AV_CODEC_ID_PCM_BLURAY,
+    AV_CODEC_ID_PCM_LXF,
+    AV_CODEC_ID_S302M,
+    AV_CODEC_ID_PCM_S8_PLANAR,
+
+    /* various ADPCM codecs */
+    AV_CODEC_ID_ADPCM_IMA_QT = 0x11000,
+    AV_CODEC_ID_ADPCM_IMA_WAV,
+    AV_CODEC_ID_ADPCM_IMA_DK3,
+    AV_CODEC_ID_ADPCM_IMA_DK4,
+    AV_CODEC_ID_ADPCM_IMA_WS,
+    AV_CODEC_ID_ADPCM_IMA_SMJPEG,
+    AV_CODEC_ID_ADPCM_MS,
+    AV_CODEC_ID_ADPCM_4XM,
+    AV_CODEC_ID_ADPCM_XA,
+    AV_CODEC_ID_ADPCM_ADX,
+    AV_CODEC_ID_ADPCM_EA,
+    AV_CODEC_ID_ADPCM_G726,
+    AV_CODEC_ID_ADPCM_CT,
+    AV_CODEC_ID_ADPCM_SWF,
+    AV_CODEC_ID_ADPCM_YAMAHA,
+    AV_CODEC_ID_ADPCM_SBPRO_4,
+    AV_CODEC_ID_ADPCM_SBPRO_3,
+    AV_CODEC_ID_ADPCM_SBPRO_2,
+    AV_CODEC_ID_ADPCM_THP,
+    AV_CODEC_ID_ADPCM_IMA_AMV,
+    AV_CODEC_ID_ADPCM_EA_R1,
+    AV_CODEC_ID_ADPCM_EA_R3,
+    AV_CODEC_ID_ADPCM_EA_R2,
+    AV_CODEC_ID_ADPCM_IMA_EA_SEAD,
+    AV_CODEC_ID_ADPCM_IMA_EA_EACS,
+    AV_CODEC_ID_ADPCM_EA_XAS,
+    AV_CODEC_ID_ADPCM_EA_MAXIS_XA,
+    AV_CODEC_ID_ADPCM_IMA_ISS,
+    AV_CODEC_ID_ADPCM_G722,
+    AV_CODEC_ID_ADPCM_IMA_APC,
+
+    /* AMR */
+    AV_CODEC_ID_AMR_NB = 0x12000,
+    AV_CODEC_ID_AMR_WB,
+
+    /* RealAudio codecs*/
+    AV_CODEC_ID_RA_144 = 0x13000,
+    AV_CODEC_ID_RA_288,
+
+    /* various DPCM codecs */
+    AV_CODEC_ID_ROQ_DPCM = 0x14000,
+    AV_CODEC_ID_INTERPLAY_DPCM,
+    AV_CODEC_ID_XAN_DPCM,
+    AV_CODEC_ID_SOL_DPCM,
+
+    /* audio codecs */
+    AV_CODEC_ID_MP2 = 0x15000,
+    AV_CODEC_ID_MP3, ///< preferred ID for decoding MPEG audio layer 1, 2 or 3
+    AV_CODEC_ID_AAC,
+    AV_CODEC_ID_AC3,
+    AV_CODEC_ID_DTS,
+    AV_CODEC_ID_VORBIS,
+    AV_CODEC_ID_DVAUDIO,
+    AV_CODEC_ID_WMAV1,
+    AV_CODEC_ID_WMAV2,
+    AV_CODEC_ID_MACE3,
+    AV_CODEC_ID_MACE6,
+    AV_CODEC_ID_VMDAUDIO,
+    AV_CODEC_ID_FLAC,
+    AV_CODEC_ID_MP3ADU,
+    AV_CODEC_ID_MP3ON4,
+    AV_CODEC_ID_SHORTEN,
+    AV_CODEC_ID_ALAC,
+    AV_CODEC_ID_WESTWOOD_SND1,
+    AV_CODEC_ID_GSM, ///< as in Berlin toast format
+    AV_CODEC_ID_QDM2,
+    AV_CODEC_ID_COOK,
+    AV_CODEC_ID_TRUESPEECH,
+    AV_CODEC_ID_TTA,
+    AV_CODEC_ID_SMACKAUDIO,
+    AV_CODEC_ID_QCELP,
+    AV_CODEC_ID_WAVPACK,
+    AV_CODEC_ID_DSICINAUDIO,
+    AV_CODEC_ID_IMC,
+    AV_CODEC_ID_MUSEPACK7,
+    AV_CODEC_ID_MLP,
+    AV_CODEC_ID_GSM_MS, /* as found in WAV */
+    AV_CODEC_ID_ATRAC3,
+    AV_CODEC_ID_VOXWARE,
+    AV_CODEC_ID_APE,
+    AV_CODEC_ID_NELLYMOSER,
+    AV_CODEC_ID_MUSEPACK8,
+    AV_CODEC_ID_SPEEX,
+    AV_CODEC_ID_WMAVOICE,
+    AV_CODEC_ID_WMAPRO,
+    AV_CODEC_ID_WMALOSSLESS,
+    AV_CODEC_ID_ATRAC3P,
+    AV_CODEC_ID_EAC3,
+    AV_CODEC_ID_SIPR,
+    AV_CODEC_ID_MP1,
+    AV_CODEC_ID_TWINVQ,
+    AV_CODEC_ID_TRUEHD,
+    AV_CODEC_ID_MP4ALS,
+    AV_CODEC_ID_ATRAC1,
+    AV_CODEC_ID_BINKAUDIO_RDFT,
+    AV_CODEC_ID_BINKAUDIO_DCT,
+    AV_CODEC_ID_AAC_LATM,
+    AV_CODEC_ID_QDMC,
+    AV_CODEC_ID_CELT,
+    AV_CODEC_ID_G723_1,
+    AV_CODEC_ID_G729,
+    AV_CODEC_ID_8SVX_EXP,
+    AV_CODEC_ID_8SVX_FIB,
+    AV_CODEC_ID_BMV_AUDIO,
+    AV_CODEC_ID_RALF,
+    AV_CODEC_ID_IAC,
+    AV_CODEC_ID_ILBC,
+    AV_CODEC_ID_OPUS,
+
+    /* subtitle codecs */
+    AV_CODEC_ID_FIRST_SUBTITLE = 0x17000,          ///< A dummy ID pointing at the start of subtitle codecs.
+    AV_CODEC_ID_DVD_SUBTITLE = 0x17000,
+    AV_CODEC_ID_DVB_SUBTITLE,
+    AV_CODEC_ID_TEXT,  ///< raw UTF-8 text
+    AV_CODEC_ID_XSUB,
+    AV_CODEC_ID_SSA,
+    AV_CODEC_ID_MOV_TEXT,
+    AV_CODEC_ID_HDMV_PGS_SUBTITLE,
+    AV_CODEC_ID_DVB_TELETEXT,
+    AV_CODEC_ID_SRT,
+
+    /* other specific kind of codecs (generally used for attachments) */
+    AV_CODEC_ID_FIRST_UNKNOWN = 0x18000,           ///< A dummy ID pointing at the start of various fake codecs.
+    AV_CODEC_ID_TTF = 0x18000,
+
+    AV_CODEC_ID_PROBE = 0x19000, ///< codec_id is not known (like AV_CODEC_ID_NONE) but lavf should attempt to identify it
+
+    AV_CODEC_ID_MPEG2TS = 0x20000, /**< _FAKE_ codec to indicate a raw MPEG-2 TS
+                                * stream (only used by libavformat) */
+    AV_CODEC_ID_MPEG4SYSTEMS = 0x20001, /**< _FAKE_ codec to indicate a MPEG-4 Systems
+                                * stream (only used by libavformat) */
+    AV_CODEC_ID_FFMETADATA = 0x21000,   ///< Dummy codec for streams containing only metadata information.
+
+#if FF_API_CODEC_ID
+#include "old_codec_ids.h"
+#endif
+};
+
+#if FF_API_CODEC_ID
+#define CodecID AVCodecID
+#endif
+
+/**
+ * This struct describes the properties of a single codec described by an
+ * AVCodecID.
+ * @see avcodec_get_descriptor()
+ */
+typedef struct AVCodecDescriptor {
+    enum AVCodecID     id;
+    enum AVMediaType type;
+    /**
+     * Name of the codec described by this descriptor. It is non-empty and
+     * unique for each codec descriptor. It should contain alphanumeric
+     * characters and '_' only.
+     */
+    const char      *name;
+    /**
+     * A more descriptive name for this codec. May be NULL.
+     */
+    const char *long_name;
+    /**
+     * Codec properties, a combination of AV_CODEC_PROP_* flags.
+     */
+    int             props;
+} AVCodecDescriptor;
+
+/**
+ * Codec uses only intra compression.
+ * Video codecs only.
+ */
+#define AV_CODEC_PROP_INTRA_ONLY    (1 << 0)
+/**
+ * Codec supports lossy compression. Audio and video codecs only.
+ * @note a codec may support both lossy and lossless
+ * compression modes
+ */
+#define AV_CODEC_PROP_LOSSY         (1 << 1)
+/**
+ * Codec supports lossless compression. Audio and video codecs only.
+ */
+#define AV_CODEC_PROP_LOSSLESS      (1 << 2)
+
+#if FF_API_OLD_DECODE_AUDIO
+/* in bytes */
+#define AVCODEC_MAX_AUDIO_FRAME_SIZE 192000 // 1 second of 48khz 32bit audio
+#endif
+
+/**
+ * @ingroup lavc_decoding
+ * Required number of additionally allocated bytes at the end of the input bitstream for decoding.
+ * This is mainly needed because some optimized bitstream readers read
+ * 32 or 64 bit at once and could read over the end.<br>
+ * Note: If the first 23 bits of the additional bytes are not 0, then damaged
+ * MPEG bitstreams could cause overread and segfault.
+ */
+#define FF_INPUT_BUFFER_PADDING_SIZE 8
+
+/**
+ * @ingroup lavc_encoding
+ * minimum encoding buffer size
+ * Used to avoid some checks during header writing.
+ */
+#define FF_MIN_BUFFER_SIZE 16384
+
+
+/**
+ * @ingroup lavc_encoding
+ * motion estimation type.
+ */
+enum Motion_Est_ID {
+    ME_ZERO = 1,    ///< no search, that is use 0,0 vector whenever one is needed
+    ME_FULL,
+    ME_LOG,
+    ME_PHODS,
+    ME_EPZS,        ///< enhanced predictive zonal search
+    ME_X1,          ///< reserved for experiments
+    ME_HEX,         ///< hexagon based search
+    ME_UMH,         ///< uneven multi-hexagon search
+    ME_ITER,        ///< iterative search
+    ME_TESA,        ///< transformed exhaustive search algorithm
+};
+
+/**
+ * @ingroup lavc_decoding
+ */
+enum AVDiscard{
+    /* We leave some space between them for extensions (drop some
+     * keyframes for intra-only or drop just some bidir frames). */
+    AVDISCARD_NONE    =-16, ///< discard nothing
+    AVDISCARD_DEFAULT =  0, ///< discard useless packets like 0 size packets in avi
+    AVDISCARD_NONREF  =  8, ///< discard all non reference
+    AVDISCARD_BIDIR   = 16, ///< discard all bidirectional frames
+    AVDISCARD_NONKEY  = 32, ///< discard all frames except keyframes
+    AVDISCARD_ALL     = 48, ///< discard all
+};
+
+enum AVColorPrimaries{
+    AVCOL_PRI_BT709       = 1, ///< also ITU-R BT1361 / IEC 61966-2-4 / SMPTE RP177 Annex B
+    AVCOL_PRI_UNSPECIFIED = 2,
+    AVCOL_PRI_BT470M      = 4,
+    AVCOL_PRI_BT470BG     = 5, ///< also ITU-R BT601-6 625 / ITU-R BT1358 625 / ITU-R BT1700 625 PAL & SECAM
+    AVCOL_PRI_SMPTE170M   = 6, ///< also ITU-R BT601-6 525 / ITU-R BT1358 525 / ITU-R BT1700 NTSC
+    AVCOL_PRI_SMPTE240M   = 7, ///< functionally identical to above
+    AVCOL_PRI_FILM        = 8,
+    AVCOL_PRI_NB             , ///< Not part of ABI
+};
+
+enum AVColorTransferCharacteristic{
+    AVCOL_TRC_BT709       = 1, ///< also ITU-R BT1361
+    AVCOL_TRC_UNSPECIFIED = 2,
+    AVCOL_TRC_GAMMA22     = 4, ///< also ITU-R BT470M / ITU-R BT1700 625 PAL & SECAM
+    AVCOL_TRC_GAMMA28     = 5, ///< also ITU-R BT470BG
+    AVCOL_TRC_SMPTE240M   = 7,
+    AVCOL_TRC_NB             , ///< Not part of ABI
+};
+
+enum AVColorSpace{
+    AVCOL_SPC_RGB         = 0,
+    AVCOL_SPC_BT709       = 1, ///< also ITU-R BT1361 / IEC 61966-2-4 xvYCC709 / SMPTE RP177 Annex B
+    AVCOL_SPC_UNSPECIFIED = 2,
+    AVCOL_SPC_FCC         = 4,
+    AVCOL_SPC_BT470BG     = 5, ///< also ITU-R BT601-6 625 / ITU-R BT1358 625 / ITU-R BT1700 625 PAL & SECAM / IEC 61966-2-4 xvYCC601
+    AVCOL_SPC_SMPTE170M   = 6, ///< also ITU-R BT601-6 525 / ITU-R BT1358 525 / ITU-R BT1700 NTSC / functionally identical to above
+    AVCOL_SPC_SMPTE240M   = 7,
+    AVCOL_SPC_YCOCG       = 8, ///< Used by Dirac / VC-2 and H.264 FRext, see ITU-T SG16
+    AVCOL_SPC_NB             , ///< Not part of ABI
+};
+
+enum AVColorRange{
+    AVCOL_RANGE_UNSPECIFIED = 0,
+    AVCOL_RANGE_MPEG        = 1, ///< the normal 219*2^(n-8) "MPEG" YUV ranges
+    AVCOL_RANGE_JPEG        = 2, ///< the normal     2^n-1   "JPEG" YUV ranges
+    AVCOL_RANGE_NB             , ///< Not part of ABI
+};
+
+/**
+ *  X   X      3 4 X      X are luma samples,
+ *             1 2        1-6 are possible chroma positions
+ *  X   X      5 6 X      0 is undefined/unknown position
+ */
+enum AVChromaLocation{
+    AVCHROMA_LOC_UNSPECIFIED = 0,
+    AVCHROMA_LOC_LEFT        = 1, ///< mpeg2/4, h264 default
+    AVCHROMA_LOC_CENTER      = 2, ///< mpeg1, jpeg, h263
+    AVCHROMA_LOC_TOPLEFT     = 3, ///< DV
+    AVCHROMA_LOC_TOP         = 4,
+    AVCHROMA_LOC_BOTTOMLEFT  = 5,
+    AVCHROMA_LOC_BOTTOM      = 6,
+    AVCHROMA_LOC_NB             , ///< Not part of ABI
+};
+
+enum AVAudioServiceType {
+    AV_AUDIO_SERVICE_TYPE_MAIN              = 0,
+    AV_AUDIO_SERVICE_TYPE_EFFECTS           = 1,
+    AV_AUDIO_SERVICE_TYPE_VISUALLY_IMPAIRED = 2,
+    AV_AUDIO_SERVICE_TYPE_HEARING_IMPAIRED  = 3,
+    AV_AUDIO_SERVICE_TYPE_DIALOGUE          = 4,
+    AV_AUDIO_SERVICE_TYPE_COMMENTARY        = 5,
+    AV_AUDIO_SERVICE_TYPE_EMERGENCY         = 6,
+    AV_AUDIO_SERVICE_TYPE_VOICE_OVER        = 7,
+    AV_AUDIO_SERVICE_TYPE_KARAOKE           = 8,
+    AV_AUDIO_SERVICE_TYPE_NB                   , ///< Not part of ABI
+};
+
+/**
+ * @ingroup lavc_encoding
+ */
+typedef struct RcOverride{
+    int start_frame;
+    int end_frame;
+    int qscale; // If this is 0 then quality_factor will be used instead.
+    float quality_factor;
+} RcOverride;
+
+#define FF_MAX_B_FRAMES 16
+
+/* encoding support
+   These flags can be passed in AVCodecContext.flags before initialization.
+   Note: Not everything is supported yet.
+*/
+
+#define CODEC_FLAG_QSCALE 0x0002  ///< Use fixed qscale.
+#define CODEC_FLAG_4MV    0x0004  ///< 4 MV per MB allowed / advanced prediction for H.263.
+#define CODEC_FLAG_QPEL   0x0010  ///< Use qpel MC.
+#define CODEC_FLAG_GMC    0x0020  ///< Use GMC.
+#define CODEC_FLAG_MV0    0x0040  ///< Always try a MB with MV=<0,0>.
+/**
+ * The parent program guarantees that the input for B-frames containing
+ * streams is not written to for at least s->max_b_frames+1 frames, if
+ * this is not set the input will be copied.
+ */
+#define CODEC_FLAG_INPUT_PRESERVED 0x0100
+#define CODEC_FLAG_PASS1           0x0200   ///< Use internal 2pass ratecontrol in first pass mode.
+#define CODEC_FLAG_PASS2           0x0400   ///< Use internal 2pass ratecontrol in second pass mode.
+#define CODEC_FLAG_GRAY            0x2000   ///< Only decode/encode grayscale.
+#define CODEC_FLAG_EMU_EDGE        0x4000   ///< Don't draw edges.
+#define CODEC_FLAG_PSNR            0x8000   ///< error[?] variables will be set during encoding.
+#define CODEC_FLAG_TRUNCATED       0x00010000 /** Input bitstream might be truncated at a random
+                                                  location instead of only at frame boundaries. */
+#define CODEC_FLAG_NORMALIZE_AQP  0x00020000 ///< Normalize adaptive quantization.
+#define CODEC_FLAG_INTERLACED_DCT 0x00040000 ///< Use interlaced DCT.
+#define CODEC_FLAG_LOW_DELAY      0x00080000 ///< Force low delay.
+#define CODEC_FLAG_GLOBAL_HEADER  0x00400000 ///< Place global headers in extradata instead of every keyframe.
+#define CODEC_FLAG_BITEXACT       0x00800000 ///< Use only bitexact stuff (except (I)DCT).
+/* Fx : Flag for h263+ extra options */
+#define CODEC_FLAG_AC_PRED        0x01000000 ///< H.263 advanced intra coding / MPEG-4 AC prediction
+#define CODEC_FLAG_LOOP_FILTER    0x00000800 ///< loop filter
+#define CODEC_FLAG_INTERLACED_ME  0x20000000 ///< interlaced motion estimation
+#define CODEC_FLAG_CLOSED_GOP     0x80000000
+#define CODEC_FLAG2_FAST          0x00000001 ///< Allow non spec compliant speedup tricks.
+#define CODEC_FLAG2_NO_OUTPUT     0x00000004 ///< Skip bitstream encoding.
+#define CODEC_FLAG2_LOCAL_HEADER  0x00000008 ///< Place global headers at every keyframe instead of in extradata.
+#if FF_API_MPV_GLOBAL_OPTS
+#define CODEC_FLAG_CBP_RD         0x04000000 ///< Use rate distortion optimization for cbp.
+#define CODEC_FLAG_QP_RD          0x08000000 ///< Use rate distortion optimization for qp selectioon.
+#define CODEC_FLAG2_STRICT_GOP    0x00000002 ///< Strictly enforce GOP size.
+#define CODEC_FLAG2_SKIP_RD       0x00004000 ///< RD optimal MB level residual skipping
+#endif
+#define CODEC_FLAG2_CHUNKS        0x00008000 ///< Input bitstream might be truncated at a packet boundaries instead of only at frame boundaries.
+
+/* Unsupported options :
+ *              Syntax Arithmetic coding (SAC)
+ *              Reference Picture Selection
+ *              Independent Segment Decoding */
+/* /Fx */
+/* codec capabilities */
+
+#define CODEC_CAP_DRAW_HORIZ_BAND 0x0001 ///< Decoder can use draw_horiz_band callback.
+/**
+ * Codec uses get_buffer() for allocating buffers and supports custom allocators.
+ * If not set, it might not use get_buffer() at all or use operations that
+ * assume the buffer was allocated by avcodec_default_get_buffer.
+ */
+#define CODEC_CAP_DR1             0x0002
+#define CODEC_CAP_TRUNCATED       0x0008
+/* Codec can export data for HW decoding (XvMC). */
+#define CODEC_CAP_HWACCEL         0x0010
+/**
+ * Encoder or decoder requires flushing with NULL input at the end in order to
+ * give the complete and correct output.
+ *
+ * NOTE: If this flag is not set, the codec is guaranteed to never be fed with
+ *       with NULL data. The user can still send NULL data to the public encode
+ *       or decode function, but libavcodec will not pass it along to the codec
+ *       unless this flag is set.
+ *
+ * Decoders:
+ * The decoder has a non-zero delay and needs to be fed with avpkt->data=NULL,
+ * avpkt->size=0 at the end to get the delayed data until the decoder no longer
+ * returns frames.
+ *
+ * Encoders:
+ * The encoder needs to be fed with NULL data at the end of encoding until the
+ * encoder no longer returns data.
+ *
+ * NOTE: For encoders implementing the AVCodec.encode2() function, setting this
+ *       flag also means that the encoder must set the pts and duration for
+ *       each output packet. If this flag is not set, the pts and duration will
+ *       be determined by libavcodec from the input frame.
+ */
+#define CODEC_CAP_DELAY           0x0020
+/**
+ * Codec can be fed a final frame with a smaller size.
+ * This can be used to prevent truncation of the last audio samples.
+ */
+#define CODEC_CAP_SMALL_LAST_FRAME 0x0040
+/**
+ * Codec can export data for HW decoding (VDPAU).
+ */
+#define CODEC_CAP_HWACCEL_VDPAU    0x0080
+/**
+ * Codec can output multiple frames per AVPacket
+ * Normally demuxers return one frame at a time, demuxers which do not do
+ * are connected to a parser to split what they return into proper frames.
+ * This flag is reserved to the very rare category of codecs which have a
+ * bitstream that cannot be split into frames without timeconsuming
+ * operations like full decoding. Demuxers carring such bitstreams thus
+ * may return multiple frames in a packet. This has many disadvantages like
+ * prohibiting stream copy in many cases thus it should only be considered
+ * as a last resort.
+ */
+#define CODEC_CAP_SUBFRAMES        0x0100
+/**
+ * Codec is experimental and is thus avoided in favor of non experimental
+ * encoders
+ */
+#define CODEC_CAP_EXPERIMENTAL     0x0200
+/**
+ * Codec should fill in channel configuration and samplerate instead of container
+ */
+#define CODEC_CAP_CHANNEL_CONF     0x0400
+/**
+ * Codec is able to deal with negative linesizes
+ */
+#define CODEC_CAP_NEG_LINESIZES    0x0800
+/**
+ * Codec supports frame-level multithreading.
+ */
+#define CODEC_CAP_FRAME_THREADS    0x1000
+/**
+ * Codec supports slice-based (or partition-based) multithreading.
+ */
+#define CODEC_CAP_SLICE_THREADS    0x2000
+/**
+ * Codec supports changed parameters at any point.
+ */
+#define CODEC_CAP_PARAM_CHANGE     0x4000
+/**
+ * Codec supports avctx->thread_count == 0 (auto).
+ */
+#define CODEC_CAP_AUTO_THREADS     0x8000
+/**
+ * Audio encoder supports receiving a different number of samples in each call.
+ */
+#define CODEC_CAP_VARIABLE_FRAME_SIZE 0x10000
+
+//The following defines may change, don't expect compatibility if you use them.
+#define MB_TYPE_INTRA4x4   0x0001
+#define MB_TYPE_INTRA16x16 0x0002 //FIXME H.264-specific
+#define MB_TYPE_INTRA_PCM  0x0004 //FIXME H.264-specific
+#define MB_TYPE_16x16      0x0008
+#define MB_TYPE_16x8       0x0010
+#define MB_TYPE_8x16       0x0020
+#define MB_TYPE_8x8        0x0040
+#define MB_TYPE_INTERLACED 0x0080
+#define MB_TYPE_DIRECT2    0x0100 //FIXME
+#define MB_TYPE_ACPRED     0x0200
+#define MB_TYPE_GMC        0x0400
+#define MB_TYPE_SKIP       0x0800
+#define MB_TYPE_P0L0       0x1000
+#define MB_TYPE_P1L0       0x2000
+#define MB_TYPE_P0L1       0x4000
+#define MB_TYPE_P1L1       0x8000
+#define MB_TYPE_L0         (MB_TYPE_P0L0 | MB_TYPE_P1L0)
+#define MB_TYPE_L1         (MB_TYPE_P0L1 | MB_TYPE_P1L1)
+#define MB_TYPE_L0L1       (MB_TYPE_L0   | MB_TYPE_L1)
+#define MB_TYPE_QUANT      0x00010000
+#define MB_TYPE_CBP        0x00020000
+//Note bits 24-31 are reserved for codec specific use (h264 ref0, mpeg1 0mv, ...)
+
+/**
+ * Pan Scan area.
+ * This specifies the area which should be displayed.
+ * Note there may be multiple such areas for one frame.
+ */
+typedef struct AVPanScan{
+    /**
+     * id
+     * - encoding: Set by user.
+     * - decoding: Set by libavcodec.
+     */
+    int id;
+
+    /**
+     * width and height in 1/16 pel
+     * - encoding: Set by user.
+     * - decoding: Set by libavcodec.
+     */
+    int width;
+    int height;
+
+    /**
+     * position of the top left corner in 1/16 pel for up to 3 fields/frames
+     * - encoding: Set by user.
+     * - decoding: Set by libavcodec.
+     */
+    int16_t position[3][2];
+}AVPanScan;
+
+#define FF_QSCALE_TYPE_MPEG1 0
+#define FF_QSCALE_TYPE_MPEG2 1
+#define FF_QSCALE_TYPE_H264  2
+#define FF_QSCALE_TYPE_VP56  3
+
+#define FF_BUFFER_TYPE_INTERNAL 1
+#define FF_BUFFER_TYPE_USER     2 ///< direct rendering buffers (image is (de)allocated by user)
+#define FF_BUFFER_TYPE_SHARED   4 ///< Buffer from somewhere else; don't deallocate image (data/base), all other tables are not shared.
+#define FF_BUFFER_TYPE_COPY     8 ///< Just a (modified) copy of some other buffer, don't deallocate anything.
+
+#define FF_BUFFER_HINTS_VALID    0x01 // Buffer hints value is meaningful (if 0 ignore).
+#define FF_BUFFER_HINTS_READABLE 0x02 // Codec will read from buffer.
+#define FF_BUFFER_HINTS_PRESERVE 0x04 // User must not alter buffer content.
+#define FF_BUFFER_HINTS_REUSABLE 0x08 // Codec will reuse the buffer (update).
+
+/**
+ * @defgroup lavc_packet AVPacket
+ *
+ * Types and functions for working with AVPacket.
+ * @{
+ */
+enum AVPacketSideDataType {
+    AV_PKT_DATA_PALETTE,
+    AV_PKT_DATA_NEW_EXTRADATA,
+
+    /**
+     * An AV_PKT_DATA_PARAM_CHANGE side data packet is laid out as follows:
+     * @code
+     * u32le param_flags
+     * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_COUNT)
+     *     s32le channel_count
+     * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_LAYOUT)
+     *     u64le channel_layout
+     * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_SAMPLE_RATE)
+     *     s32le sample_rate
+     * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_DIMENSIONS)
+     *     s32le width
+     *     s32le height
+     * @endcode
+     */
+    AV_PKT_DATA_PARAM_CHANGE,
+
+    /**
+     * An AV_PKT_DATA_H263_MB_INFO side data packet contains a number of
+     * structures with info about macroblocks relevant to splitting the
+     * packet into smaller packets on macroblock edges (e.g. as for RFC 2190).
+     * That is, it does not necessarily contain info about all macroblocks,
+     * as long as the distance between macroblocks in the info is smaller
+     * than the target payload size.
+     * Each MB info structure is 12 bytes, and is laid out as follows:
+     * @code
+     * u32le bit offset from the start of the packet
+     * u8    current quantizer at the start of the macroblock
+     * u8    GOB number
+     * u16le macroblock address within the GOB
+     * u8    horizontal MV predictor
+     * u8    vertical MV predictor
+     * u8    horizontal MV predictor for block number 3
+     * u8    vertical MV predictor for block number 3
+     * @endcode
+     */
+    AV_PKT_DATA_H263_MB_INFO,
+};
+
+typedef struct AVPacket {
+    /**
+     * Presentation timestamp in AVStream->time_base units; the time at which
+     * the decompressed packet will be presented to the user.
+     * Can be AV_NOPTS_VALUE if it is not stored in the file.
+     * pts MUST be larger or equal to dts as presentation cannot happen before
+     * decompression, unless one wants to view hex dumps. Some formats misuse
+     * the terms dts and pts/cts to mean something different. Such timestamps
+     * must be converted to true pts/dts before they are stored in AVPacket.
+     */
+    int64_t pts;
+    /**
+     * Decompression timestamp in AVStream->time_base units; the time at which
+     * the packet is decompressed.
+     * Can be AV_NOPTS_VALUE if it is not stored in the file.
+     */
+    int64_t dts;
+    uint8_t *data;
+    int   size;
+    int   stream_index;
+    /**
+     * A combination of AV_PKT_FLAG values
+     */
+    int   flags;
+    /**
+     * Additional packet data that can be provided by the container.
+     * Packet can contain several types of side information.
+     */
+    struct {
+        uint8_t *data;
+        int      size;
+        enum AVPacketSideDataType type;
+    } *side_data;
+    int side_data_elems;
+
+    /**
+     * Duration of this packet in AVStream->time_base units, 0 if unknown.
+     * Equals next_pts - this_pts in presentation order.
+     */
+    int   duration;
+    void  (*destruct)(struct AVPacket *);
+    void  *priv;
+    int64_t pos;                            ///< byte position in stream, -1 if unknown
+
+    /**
+     * Time difference in AVStream->time_base units from the pts of this
+     * packet to the point at which the output from the decoder has converged
+     * independent from the availability of previous frames. That is, the
+     * frames are virtually identical no matter if decoding started from
+     * the very first frame or from this keyframe.
+     * Is AV_NOPTS_VALUE if unknown.
+     * This field is not the display duration of the current packet.
+     * This field has no meaning if the packet does not have AV_PKT_FLAG_KEY
+     * set.
+     *
+     * The purpose of this field is to allow seeking in streams that have no
+     * keyframes in the conventional sense. It corresponds to the
+     * recovery point SEI in H.264 and match_time_delta in NUT. It is also
+     * essential for some types of subtitle streams to ensure that all
+     * subtitles are correctly displayed after seeking.
+     */
+    int64_t convergence_duration;
+} AVPacket;
+#define AV_PKT_FLAG_KEY     0x0001 ///< The packet contains a keyframe
+#define AV_PKT_FLAG_CORRUPT 0x0002 ///< The packet content is corrupted
+
+enum AVSideDataParamChangeFlags {
+    AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_COUNT  = 0x0001,
+    AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_LAYOUT = 0x0002,
+    AV_SIDE_DATA_PARAM_CHANGE_SAMPLE_RATE    = 0x0004,
+    AV_SIDE_DATA_PARAM_CHANGE_DIMENSIONS     = 0x0008,
+};
+/**
+ * @}
+ */
+
+/**
+ * Audio Video Frame.
+ * New fields can be added to the end of AVFRAME with minor version
+ * bumps. Removal, reordering and changes to existing fields require
+ * a major version bump.
+ * sizeof(AVFrame) must not be used outside libav*.
+ */
+typedef struct AVFrame {
+#define AV_NUM_DATA_POINTERS 8
+    /**
+     * pointer to the picture/channel planes.
+     * This might be different from the first allocated byte
+     * - encoding: Set by user
+     * - decoding: set by AVCodecContext.get_buffer()
+     */
+    uint8_t *data[AV_NUM_DATA_POINTERS];
+
+    /**
+     * Size, in bytes, of the data for each picture/channel plane.
+     *
+     * For audio, only linesize[0] may be set. For planar audio, each channel
+     * plane must be the same size.
+     *
+     * - encoding: Set by user
+     * - decoding: set by AVCodecContext.get_buffer()
+     */
+    int linesize[AV_NUM_DATA_POINTERS];
+
+    /**
+     * pointers to the data planes/channels.
+     *
+     * For video, this should simply point to data[].
+     *
+     * For planar audio, each channel has a separate data pointer, and
+     * linesize[0] contains the size of each channel buffer.
+     * For packed audio, there is just one data pointer, and linesize[0]
+     * contains the total size of the buffer for all channels.
+     *
+     * Note: Both data and extended_data will always be set by get_buffer(),
+     * but for planar audio with more channels that can fit in data,
+     * extended_data must be used by the decoder in order to access all
+     * channels.
+     *
+     * encoding: set by user
+     * decoding: set by AVCodecContext.get_buffer()
+     */
+    uint8_t **extended_data;
+
+    /**
+     * width and height of the video frame
+     * - encoding: unused
+     * - decoding: Read by user.
+     */
+    int width, height;
+
+    /**
+     * number of audio samples (per channel) described by this frame
+     * - encoding: Set by user
+     * - decoding: Set by libavcodec
+     */
+    int nb_samples;
+
+    /**
+     * format of the frame, -1 if unknown or unset
+     * Values correspond to enum AVPixelFormat for video frames,
+     * enum AVSampleFormat for audio)
+     * - encoding: unused
+     * - decoding: Read by user.
+     */
+    int format;
+
+    /**
+     * 1 -> keyframe, 0-> not
+     * - encoding: Set by libavcodec.
+     * - decoding: Set by libavcodec.
+     */
+    int key_frame;
+
+    /**
+     * Picture type of the frame, see ?_TYPE below.
+     * - encoding: Set by libavcodec. for coded_picture (and set by user for input).
+     * - decoding: Set by libavcodec.
+     */
+    enum AVPictureType pict_type;
+
+    /**
+     * pointer to the first allocated byte of the picture. Can be used in get_buffer/release_buffer.
+     * This isn't used by libavcodec unless the default get/release_buffer() is used.
+     * - encoding:
+     * - decoding:
+     */
+    uint8_t *base[AV_NUM_DATA_POINTERS];
+
+    /**
+     * sample aspect ratio for the video frame, 0/1 if unknown/unspecified
+     * - encoding: unused
+     * - decoding: Read by user.
+     */
+    AVRational sample_aspect_ratio;
+
+    /**
+     * presentation timestamp in time_base units (time when frame should be shown to user)
+     * If AV_NOPTS_VALUE then frame_rate = 1/time_base will be assumed.
+     * - encoding: MUST be set by user.
+     * - decoding: Set by libavcodec.
+     */
+    int64_t pts;
+
+    /**
+     * reordered pts from the last AVPacket that has been input into the decoder
+     * - encoding: unused
+     * - decoding: Read by user.
+     */
+    int64_t pkt_pts;
+
+    /**
+     * dts from the last AVPacket that has been input into the decoder
+     * - encoding: unused
+     * - decoding: Read by user.
+     */
+    int64_t pkt_dts;
+
+    /**
+     * picture number in bitstream order
+     * - encoding: set by
+     * - decoding: Set by libavcodec.
+     */
+    int coded_picture_number;
+    /**
+     * picture number in display order
+     * - encoding: set by
+     * - decoding: Set by libavcodec.
+     */
+    int display_picture_number;
+
+    /**
+     * quality (between 1 (good) and FF_LAMBDA_MAX (bad))
+     * - encoding: Set by libavcodec. for coded_picture (and set by user for input).
+     * - decoding: Set by libavcodec.
+     */
+    int quality;
+
+    /**
+     * is this picture used as reference
+     * The values for this are the same as the MpegEncContext.picture_structure
+     * variable, that is 1->top field, 2->bottom field, 3->frame/both fields.
+     * Set to 4 for delayed, non-reference frames.
+     * - encoding: unused
+     * - decoding: Set by libavcodec. (before get_buffer() call)).
+     */
+    int reference;
+
+    /**
+     * QP table
+     * - encoding: unused
+     * - decoding: Set by libavcodec.
+     */
+    int8_t *qscale_table;
+    /**
+     * QP store stride
+     * - encoding: unused
+     * - decoding: Set by libavcodec.
+     */
+    int qstride;
+
+    /**
+     *
+     */
+    int qscale_type;
+
+    /**
+     * mbskip_table[mb]>=1 if MB didn't change
+     * stride= mb_width = (width+15)>>4
+     * - encoding: unused
+     * - decoding: Set by libavcodec.
+     */
+    uint8_t *mbskip_table;
+
+    /**
+     * motion vector table
+     * @code
+     * example:
+     * int mv_sample_log2= 4 - motion_subsample_log2;
+     * int mb_width= (width+15)>>4;
+     * int mv_stride= (mb_width << mv_sample_log2) + 1;
+     * motion_val[direction][x + y*mv_stride][0->mv_x, 1->mv_y];
+     * @endcode
+     * - encoding: Set by user.
+     * - decoding: Set by libavcodec.
+     */
+    int16_t (*motion_val[2])[2];
+
+    /**
+     * macroblock type table
+     * mb_type_base + mb_width + 2
+     * - encoding: Set by user.
+     * - decoding: Set by libavcodec.
+     */
+    uint32_t *mb_type;
+
+    /**
+     * DCT coefficients
+     * - encoding: unused
+     * - decoding: Set by libavcodec.
+     */
+    short *dct_coeff;
+
+    /**
+     * motion reference frame index
+     * the order in which these are stored can depend on the codec.
+     * - encoding: Set by user.
+     * - decoding: Set by libavcodec.
+     */
+    int8_t *ref_index[2];
+
+    /**
+     * for some private data of the user
+     * - encoding: unused
+     * - decoding: Set by user.
+     */
+    void *opaque;
+
+    /**
+     * error
+     * - encoding: Set by libavcodec. if flags&CODEC_FLAG_PSNR.
+     * - decoding: unused
+     */
+    uint64_t error[AV_NUM_DATA_POINTERS];
+
+    /**
+     * type of the buffer (to keep track of who has to deallocate data[*])
+     * - encoding: Set by the one who allocates it.
+     * - decoding: Set by the one who allocates it.
+     * Note: User allocated (direct rendering) & internal buffers cannot coexist currently.
+     */
+    int type;
+
+    /**
+     * When decoding, this signals how much the picture must be delayed.
+     * extra_delay = repeat_pict / (2*fps)
+     * - encoding: unused
+     * - decoding: Set by libavcodec.
+     */
+    int repeat_pict;
+
+    /**
+     * The content of the picture is interlaced.
+     * - encoding: Set by user.
+     * - decoding: Set by libavcodec. (default 0)
+     */
+    int interlaced_frame;
+
+    /**
+     * If the content is interlaced, is top field displayed first.
+     * - encoding: Set by user.
+     * - decoding: Set by libavcodec.
+     */
+    int top_field_first;
+
+    /**
+     * Tell user application that palette has changed from previous frame.
+     * - encoding: ??? (no palette-enabled encoder yet)
+     * - decoding: Set by libavcodec. (default 0).
+     */
+    int palette_has_changed;
+
+    /**
+     * codec suggestion on buffer type if != 0
+     * - encoding: unused
+     * - decoding: Set by libavcodec. (before get_buffer() call)).
+     */
+    int buffer_hints;
+
+    /**
+     * Pan scan.
+     * - encoding: Set by user.
+     * - decoding: Set by libavcodec.
+     */
+    AVPanScan *pan_scan;
+
+    /**
+     * reordered opaque 64bit (generally an integer or a double precision float
+     * PTS but can be anything).
+     * The user sets AVCodecContext.reordered_opaque to represent the input at
+     * that time,
+     * the decoder reorders values as needed and sets AVFrame.reordered_opaque
+     * to exactly one of the values provided by the user through AVCodecContext.reordered_opaque
+     * @deprecated in favor of pkt_pts
+     * - encoding: unused
+     * - decoding: Read by user.
+     */
+    int64_t reordered_opaque;
+
+    /**
+     * hardware accelerator private data (Libav-allocated)
+     * - encoding: unused
+     * - decoding: Set by libavcodec
+     */
+    void *hwaccel_picture_private;
+
+    /**
+     * the AVCodecContext which ff_thread_get_buffer() was last called on
+     * - encoding: Set by libavcodec.
+     * - decoding: Set by libavcodec.
+     */
+    struct AVCodecContext *owner;
+
+    /**
+     * used by multithreading to store frame-specific info
+     * - encoding: Set by libavcodec.
+     * - decoding: Set by libavcodec.
+     */
+    void *thread_opaque;
+
+    /**
+     * log2 of the size of the block which a single vector in motion_val represents:
+     * (4->16x16, 3->8x8, 2-> 4x4, 1-> 2x2)
+     * - encoding: unused
+     * - decoding: Set by libavcodec.
+     */
+    uint8_t motion_subsample_log2;
+
+    /**
+     * Sample rate of the audio data.
+     *
+     * - encoding: unused
+     * - decoding: set by get_buffer()
+     */
+    int sample_rate;
+
+    /**
+     * Channel layout of the audio data.
+     *
+     * - encoding: unused
+     * - decoding: set by get_buffer()
+     */
+    uint64_t channel_layout;
+} AVFrame;
+
+struct AVCodecInternal;
+
+enum AVFieldOrder {
+    AV_FIELD_UNKNOWN,
+    AV_FIELD_PROGRESSIVE,
+    AV_FIELD_TT,          //< Top coded_first, top displayed first
+    AV_FIELD_BB,          //< Bottom coded first, bottom displayed first
+    AV_FIELD_TB,          //< Top coded first, bottom displayed first
+    AV_FIELD_BT,          //< Bottom coded first, top displayed first
+};
+
+/**
+ * main external API structure.
+ * New fields can be added to the end with minor version bumps.
+ * Removal, reordering and changes to existing fields require a major
+ * version bump.
+ * sizeof(AVCodecContext) must not be used outside libav*.
+ */
+typedef struct AVCodecContext {
+    /**
+     * information on struct for av_log
+     * - set by avcodec_alloc_context3
+     */
+    const AVClass *av_class;
+    int log_level_offset;
+
+    enum AVMediaType codec_type; /* see AVMEDIA_TYPE_xxx */
+    const struct AVCodec  *codec;
+    char             codec_name[32];
+    enum AVCodecID     codec_id; /* see AV_CODEC_ID_xxx */
+
+    /**
+     * fourcc (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
+     * This is used to work around some encoder bugs.
+     * A demuxer should set this to what is stored in the field used to identify the codec.
+     * If there are multiple such fields in a container then the demuxer should choose the one
+     * which maximizes the information about the used codec.
+     * If the codec tag field in a container is larger than 32 bits then the demuxer should
+     * remap the longer ID to 32 bits with a table or other structure. Alternatively a new
+     * extra_codec_tag + size could be added but for this a clear advantage must be demonstrated
+     * first.
+     * - encoding: Set by user, if not then the default based on codec_id will be used.
+     * - decoding: Set by user, will be converted to uppercase by libavcodec during init.
+     */
+    unsigned int codec_tag;
+
+    /**
+     * fourcc from the AVI stream header (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
+     * This is used to work around some encoder bugs.
+     * - encoding: unused
+     * - decoding: Set by user, will be converted to uppercase by libavcodec during init.
+     */
+    unsigned int stream_codec_tag;
+
+#if FF_API_SUB_ID
+    /**
+     * @deprecated this field is unused
+     */
+    attribute_deprecated int sub_id;
+#endif
+
+    void *priv_data;
+
+    /**
+     * Private context used for internal data.
+     *
+     * Unlike priv_data, this is not codec-specific. It is used in general
+     * libavcodec functions.
+     */
+    struct AVCodecInternal *internal;
+
+    /**
+     * Private data of the user, can be used to carry app specific stuff.
+     * - encoding: Set by user.
+     * - decoding: Set by user.
+     */
+    void *opaque;
+
+    /**
+     * the average bitrate
+     * - encoding: Set by user; unused for constant quantizer encoding.
+     * - decoding: Set by libavcodec. 0 or some bitrate if this info is available in the stream.
+     */
+    int bit_rate;
+
+    /**
+     * number of bits the bitstream is allowed to diverge from the reference.
+     *           the reference can be CBR (for CBR pass1) or VBR (for pass2)
+     * - encoding: Set by user; unused for constant quantizer encoding.
+     * - decoding: unused
+     */
+    int bit_rate_tolerance;
+
+    /**
+     * Global quality for codecs which cannot change it per frame.
+     * This should be proportional to MPEG-1/2/4 qscale.
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int global_quality;
+
+    /**
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int compression_level;
+#define FF_COMPRESSION_DEFAULT -1
+
+    /**
+     * CODEC_FLAG_*.
+     * - encoding: Set by user.
+     * - decoding: Set by user.
+     */
+    int flags;
+
+    /**
+     * CODEC_FLAG2_*
+     * - encoding: Set by user.
+     * - decoding: Set by user.
+     */
+    int flags2;
+
+    /**
+     * some codecs need / can use extradata like Huffman tables.
+     * mjpeg: Huffman tables
+     * rv10: additional flags
+     * mpeg4: global headers (they can be in the bitstream or here)
+     * The allocated memory should be FF_INPUT_BUFFER_PADDING_SIZE bytes larger
+     * than extradata_size to avoid prolems if it is read with the bitstream reader.
+     * The bytewise contents of extradata must not depend on the architecture or CPU endianness.
+     * - encoding: Set/allocated/freed by libavcodec.
+     * - decoding: Set/allocated/freed by user.
+     */
+    uint8_t *extradata;
+    int extradata_size;
+
+    /**
+     * This is the fundamental unit of time (in seconds) in terms
+     * of which frame timestamps are represented. For fixed-fps content,
+     * timebase should be 1/framerate and timestamp increments should be
+     * identically 1.
+     * - encoding: MUST be set by user.
+     * - decoding: Set by libavcodec.
+     */
+    AVRational time_base;
+
+    /**
+     * For some codecs, the time base is closer to the field rate than the frame rate.
+     * Most notably, H.264 and MPEG-2 specify time_base as half of frame duration
+     * if no telecine is used ...
+     *
+     * Set to time_base ticks per frame. Default 1, e.g., H.264/MPEG-2 set it to 2.
+     */
+    int ticks_per_frame;
+
+    /**
+     * Encoder delay.
+     *
+     * Video:
+     *   Number of frames the decoded output will be delayed relative to the
+     *   encoded input.
+     *
+     * Audio:
+     *   For encoding, this is the number of "priming" samples added to the
+     *   beginning of the stream. The decoded output will be delayed by this
+     *   many samples relative to the input to the encoder. Note that this
+     *   field is purely informational and does not directly affect the pts
+     *   output by the encoder, which should always be based on the actual
+     *   presentation time, including any delay.
+     *   For decoding, this is the number of samples the decoder needs to
+     *   output before the decoder's output is valid. When seeking, you should
+     *   start decoding this many samples prior to your desired seek point.
+     *
+     * - encoding: Set by libavcodec.
+     * - decoding: Set by libavcodec.
+     */
+    int delay;
+
+
+    /* video only */
+    /**
+     * picture width / height.
+     * - encoding: MUST be set by user.
+     * - decoding: Set by libavcodec.
+     * Note: For compatibility it is possible to set this instead of
+     * coded_width/height before decoding.
+     */
+    int width, height;
+
+    /**
+     * Bitstream width / height, may be different from width/height.
+     * - encoding: unused
+     * - decoding: Set by user before init if known. Codec should override / dynamically change if needed.
+     */
+    int coded_width, coded_height;
+
+#define FF_ASPECT_EXTENDED 15
+
+    /**
+     * the number of pictures in a group of pictures, or 0 for intra_only
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int gop_size;
+
+    /**
+     * Pixel format, see AV_PIX_FMT_xxx.
+     * May be set by the demuxer if known from headers.
+     * May be overriden by the decoder if it knows better.
+     * - encoding: Set by user.
+     * - decoding: Set by user if known, overridden by libavcodec if known
+     */
+    enum AVPixelFormat pix_fmt;
+
+    /**
+     * Motion estimation algorithm used for video coding.
+     * 1 (zero), 2 (full), 3 (log), 4 (phods), 5 (epzs), 6 (x1), 7 (hex),
+     * 8 (umh), 9 (iter), 10 (tesa) [7, 8, 10 are x264 specific, 9 is snow specific]
+     * - encoding: MUST be set by user.
+     * - decoding: unused
+     */
+    int me_method;
+
+    /**
+     * If non NULL, 'draw_horiz_band' is called by the libavcodec
+     * decoder to draw a horizontal band. It improves cache usage. Not
+     * all codecs can do that. You must check the codec capabilities
+     * beforehand.
+     * When multithreading is used, it may be called from multiple threads
+     * at the same time; threads might draw different parts of the same AVFrame,
+     * or multiple AVFrames, and there is no guarantee that slices will be drawn
+     * in order.
+     * The function is also used by hardware acceleration APIs.
+     * It is called at least once during frame decoding to pass
+     * the data needed for hardware render.
+     * In that mode instead of pixel data, AVFrame points to
+     * a structure specific to the acceleration API. The application
+     * reads the structure and can change some fields to indicate progress
+     * or mark state.
+     * - encoding: unused
+     * - decoding: Set by user.
+     * @param height the height of the slice
+     * @param y the y position of the slice
+     * @param type 1->top field, 2->bottom field, 3->frame
+     * @param offset offset into the AVFrame.data from which the slice should be read
+     */
+    void (*draw_horiz_band)(struct AVCodecContext *s,
+                            const AVFrame *src, int offset[AV_NUM_DATA_POINTERS],
+                            int y, int type, int height);
+
+    /**
+     * callback to negotiate the pixelFormat
+     * @param fmt is the list of formats which are supported by the codec,
+     * it is terminated by -1 as 0 is a valid format, the formats are ordered by quality.
+     * The first is always the native one.
+     * @return the chosen format
+     * - encoding: unused
+     * - decoding: Set by user, if not set the native format will be chosen.
+     */
+    enum AVPixelFormat (*get_format)(struct AVCodecContext *s, const enum AVPixelFormat * fmt);
+
+    /**
+     * maximum number of B-frames between non-B-frames
+     * Note: The output will be delayed by max_b_frames+1 relative to the input.
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int max_b_frames;
+
+    /**
+     * qscale factor between IP and B-frames
+     * If > 0 then the last P-frame quantizer will be used (q= lastp_q*factor+offset).
+     * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    float b_quant_factor;
+
+    /** obsolete FIXME remove */
+    int rc_strategy;
+#define FF_RC_STRATEGY_XVID 1
+
+    int b_frame_strategy;
+
+#if FF_API_MPV_GLOBAL_OPTS
+    /**
+     * luma single coefficient elimination threshold
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    attribute_deprecated int luma_elim_threshold;
+
+    /**
+     * chroma single coeff elimination threshold
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    attribute_deprecated int chroma_elim_threshold;
+#endif
+
+    /**
+     * qscale offset between IP and B-frames
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    float b_quant_offset;
+
+    /**
+     * Size of the frame reordering buffer in the decoder.
+     * For MPEG-2 it is 1 IPB or 0 low delay IP.
+     * - encoding: Set by libavcodec.
+     * - decoding: Set by libavcodec.
+     */
+    int has_b_frames;
+
+    /**
+     * 0-> h263 quant 1-> mpeg quant
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int mpeg_quant;
+
+    /**
+     * qscale factor between P and I-frames
+     * If > 0 then the last p frame quantizer will be used (q= lastp_q*factor+offset).
+     * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    float i_quant_factor;
+
+    /**
+     * qscale offset between P and I-frames
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    float i_quant_offset;
+
+    /**
+     * luminance masking (0-> disabled)
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    float lumi_masking;
+
+    /**
+     * temporary complexity masking (0-> disabled)
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    float temporal_cplx_masking;
+
+    /**
+     * spatial complexity masking (0-> disabled)
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    float spatial_cplx_masking;
+
+    /**
+     * p block masking (0-> disabled)
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    float p_masking;
+
+    /**
+     * darkness masking (0-> disabled)
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    float dark_masking;
+
+    /**
+     * slice count
+     * - encoding: Set by libavcodec.
+     * - decoding: Set by user (or 0).
+     */
+    int slice_count;
+    /**
+     * prediction method (needed for huffyuv)
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+     int prediction_method;
+#define FF_PRED_LEFT   0
+#define FF_PRED_PLANE  1
+#define FF_PRED_MEDIAN 2
+
+    /**
+     * slice offsets in the frame in bytes
+     * - encoding: Set/allocated by libavcodec.
+     * - decoding: Set/allocated by user (or NULL).
+     */
+    int *slice_offset;
+
+    /**
+     * sample aspect ratio (0 if unknown)
+     * That is the width of a pixel divided by the height of the pixel.
+     * Numerator and denominator must be relatively prime and smaller than 256 for some video standards.
+     * - encoding: Set by user.
+     * - decoding: Set by libavcodec.
+     */
+    AVRational sample_aspect_ratio;
+
+    /**
+     * motion estimation comparison function
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int me_cmp;
+    /**
+     * subpixel motion estimation comparison function
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int me_sub_cmp;
+    /**
+     * macroblock comparison function (not supported yet)
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int mb_cmp;
+    /**
+     * interlaced DCT comparison function
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int ildct_cmp;
+#define FF_CMP_SAD    0
+#define FF_CMP_SSE    1
+#define FF_CMP_SATD   2
+#define FF_CMP_DCT    3
+#define FF_CMP_PSNR   4
+#define FF_CMP_BIT    5
+#define FF_CMP_RD     6
+#define FF_CMP_ZERO   7
+#define FF_CMP_VSAD   8
+#define FF_CMP_VSSE   9
+#define FF_CMP_NSSE   10
+#define FF_CMP_W53    11
+#define FF_CMP_W97    12
+#define FF_CMP_DCTMAX 13
+#define FF_CMP_DCT264 14
+#define FF_CMP_CHROMA 256
+
+    /**
+     * ME diamond size & shape
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int dia_size;
+
+    /**
+     * amount of previous MV predictors (2a+1 x 2a+1 square)
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int last_predictor_count;
+
+    /**
+     * prepass for motion estimation
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int pre_me;
+
+    /**
+     * motion estimation prepass comparison function
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int me_pre_cmp;
+
+    /**
+     * ME prepass diamond size & shape
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int pre_dia_size;
+
+    /**
+     * subpel ME quality
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int me_subpel_quality;
+
+    /**
+     * DTG active format information (additional aspect ratio
+     * information only used in DVB MPEG-2 transport streams)
+     * 0 if not set.
+     *
+     * - encoding: unused
+     * - decoding: Set by decoder.
+     */
+    int dtg_active_format;
+#define FF_DTG_AFD_SAME         8
+#define FF_DTG_AFD_4_3          9
+#define FF_DTG_AFD_16_9         10
+#define FF_DTG_AFD_14_9         11
+#define FF_DTG_AFD_4_3_SP_14_9  13
+#define FF_DTG_AFD_16_9_SP_14_9 14
+#define FF_DTG_AFD_SP_4_3       15
+
+    /**
+     * maximum motion estimation search range in subpel units
+     * If 0 then no limit.
+     *
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int me_range;
+
+    /**
+     * intra quantizer bias
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int intra_quant_bias;
+#define FF_DEFAULT_QUANT_BIAS 999999
+
+    /**
+     * inter quantizer bias
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int inter_quant_bias;
+
+#if FF_API_COLOR_TABLE_ID
+    /**
+     * color table ID
+     * - encoding: unused
+     * - decoding: Which clrtable should be used for 8bit RGB images.
+     *             Tables have to be stored somewhere. FIXME
+     */
+    attribute_deprecated int color_table_id;
+#endif
+
+    /**
+     * slice flags
+     * - encoding: unused
+     * - decoding: Set by user.
+     */
+    int slice_flags;
+#define SLICE_FLAG_CODED_ORDER    0x0001 ///< draw_horiz_band() is called in coded order instead of display
+#define SLICE_FLAG_ALLOW_FIELD    0x0002 ///< allow draw_horiz_band() with field slices (MPEG2 field pics)
+#define SLICE_FLAG_ALLOW_PLANE    0x0004 ///< allow draw_horiz_band() with 1 component at a time (SVQ1)
+
+    /**
+     * XVideo Motion Acceleration
+     * - encoding: forbidden
+     * - decoding: set by decoder
+     */
+    int xvmc_acceleration;
+
+    /**
+     * macroblock decision mode
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int mb_decision;
+#define FF_MB_DECISION_SIMPLE 0        ///< uses mb_cmp
+#define FF_MB_DECISION_BITS   1        ///< chooses the one which needs the fewest bits
+#define FF_MB_DECISION_RD     2        ///< rate distortion
+
+    /**
+     * custom intra quantization matrix
+     * - encoding: Set by user, can be NULL.
+     * - decoding: Set by libavcodec.
+     */
+    uint16_t *intra_matrix;
+
+    /**
+     * custom inter quantization matrix
+     * - encoding: Set by user, can be NULL.
+     * - decoding: Set by libavcodec.
+     */
+    uint16_t *inter_matrix;
+
+    /**
+     * scene change detection threshold
+     * 0 is default, larger means fewer detected scene changes.
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int scenechange_threshold;
+
+    /**
+     * noise reduction strength
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int noise_reduction;
+
+#if FF_API_INTER_THRESHOLD
+    /**
+     * @deprecated this field is unused
+     */
+    attribute_deprecated int inter_threshold;
+#endif
+
+#if FF_API_MPV_GLOBAL_OPTS
+    /**
+     * @deprecated use mpegvideo private options instead
+     */
+    attribute_deprecated int quantizer_noise_shaping;
+#endif
+
+    /**
+     * Motion estimation threshold below which no motion estimation is
+     * performed, but instead the user specified motion vectors are used.
+     *
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int me_threshold;
+
+    /**
+     * Macroblock threshold below which the user specified macroblock types will be used.
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int mb_threshold;
+
+    /**
+     * precision of the intra DC coefficient - 8
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int intra_dc_precision;
+
+    /**
+     * Number of macroblock rows at the top which are skipped.
+     * - encoding: unused
+     * - decoding: Set by user.
+     */
+    int skip_top;
+
+    /**
+     * Number of macroblock rows at the bottom which are skipped.
+     * - encoding: unused
+     * - decoding: Set by user.
+     */
+    int skip_bottom;
+
+    /**
+     * Border processing masking, raises the quantizer for mbs on the borders
+     * of the picture.
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    float border_masking;
+
+    /**
+     * minimum MB lagrange multipler
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int mb_lmin;
+
+    /**
+     * maximum MB lagrange multipler
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int mb_lmax;
+
+    /**
+     *
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int me_penalty_compensation;
+
+    /**
+     *
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int bidir_refine;
+
+    /**
+     *
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int brd_scale;
+
+    /**
+     * minimum GOP size
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int keyint_min;
+
+    /**
+     * number of reference frames
+     * - encoding: Set by user.
+     * - decoding: Set by lavc.
+     */
+    int refs;
+
+    /**
+     * chroma qp offset from luma
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int chromaoffset;
+
+    /**
+     * Multiplied by qscale for each frame and added to scene_change_score.
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int scenechange_factor;
+
+    /**
+     *
+     * Note: Value depends upon the compare function used for fullpel ME.
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int mv0_threshold;
+
+    /**
+     * Adjust sensitivity of b_frame_strategy 1.
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int b_sensitivity;
+
+    /**
+     * Chromaticity coordinates of the source primaries.
+     * - encoding: Set by user
+     * - decoding: Set by libavcodec
+     */
+    enum AVColorPrimaries color_primaries;
+
+    /**
+     * Color Transfer Characteristic.
+     * - encoding: Set by user
+     * - decoding: Set by libavcodec
+     */
+    enum AVColorTransferCharacteristic color_trc;
+
+    /**
+     * YUV colorspace type.
+     * - encoding: Set by user
+     * - decoding: Set by libavcodec
+     */
+    enum AVColorSpace colorspace;
+
+    /**
+     * MPEG vs JPEG YUV range.
+     * - encoding: Set by user
+     * - decoding: Set by libavcodec
+     */
+    enum AVColorRange color_range;
+
+    /**
+     * This defines the location of chroma samples.
+     * - encoding: Set by user
+     * - decoding: Set by libavcodec
+     */
+    enum AVChromaLocation chroma_sample_location;
+
+    /**
+     * Number of slices.
+     * Indicates number of picture subdivisions. Used for parallelized
+     * decoding.
+     * - encoding: Set by user
+     * - decoding: unused
+     */
+    int slices;
+
+    /** Field order
+     * - encoding: set by libavcodec
+     * - decoding: Set by libavcodec
+     */
+    enum AVFieldOrder field_order;
+
+    /* audio only */
+    int sample_rate; ///< samples per second
+    int channels;    ///< number of audio channels
+
+    /**
+     * audio sample format
+     * - encoding: Set by user.
+     * - decoding: Set by libavcodec.
+     */
+    enum AVSampleFormat sample_fmt;  ///< sample format
+
+    /* The following data should not be initialized. */
+    /**
+     * Samples per packet, initialized when calling 'init'.
+     */
+    int frame_size;
+
+    /**
+     * Frame counter, set by libavcodec.
+     *
+     * - decoding: total number of frames returned from the decoder so far.
+     * - encoding: total number of frames passed to the encoder so far.
+     *
+     *   @note the counter is not incremented if encoding/decoding resulted in
+     *   an error.
+     */
+    int frame_number;
+
+    /**
+     * number of bytes per packet if constant and known or 0
+     * Used by some WAV based audio codecs.
+     */
+    int block_align;
+
+    /**
+     * Audio cutoff bandwidth (0 means "automatic")
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int cutoff;
+
+#if FF_API_REQUEST_CHANNELS
+    /**
+     * Decoder should decode to this many channels if it can (0 for default)
+     * - encoding: unused
+     * - decoding: Set by user.
+     * @deprecated Deprecated in favor of request_channel_layout.
+     */
+    int request_channels;
+#endif
+
+    /**
+     * Audio channel layout.
+     * - encoding: set by user.
+     * - decoding: set by libavcodec.
+     */
+    uint64_t channel_layout;
+
+    /**
+     * Request decoder to use this channel layout if it can (0 for default)
+     * - encoding: unused
+     * - decoding: Set by user.
+     */
+    uint64_t request_channel_layout;
+
+    /**
+     * Type of service that the audio stream conveys.
+     * - encoding: Set by user.
+     * - decoding: Set by libavcodec.
+     */
+    enum AVAudioServiceType audio_service_type;
+
+    /**
+     * Used to request a sample format from the decoder.
+     * - encoding: unused.
+     * - decoding: Set by user.
+     */
+    enum AVSampleFormat request_sample_fmt;
+
+    /**
+     * Called at the beginning of each frame to get a buffer for it.
+     *
+     * The function will set AVFrame.data[], AVFrame.linesize[].
+     * AVFrame.extended_data[] must also be set, but it should be the same as
+     * AVFrame.data[] except for planar audio with more channels than can fit
+     * in AVFrame.data[]. In that case, AVFrame.data[] shall still contain as
+     * many data pointers as it can hold.
+     *
+     * if CODEC_CAP_DR1 is not set then get_buffer() must call
+     * avcodec_default_get_buffer() instead of providing buffers allocated by
+     * some other means.
+     *
+     * AVFrame.data[] should be 32- or 16-byte-aligned unless the CPU doesn't
+     * need it. avcodec_default_get_buffer() aligns the output buffer properly,
+     * but if get_buffer() is overridden then alignment considerations should
+     * be taken into account.
+     *
+     * @see avcodec_default_get_buffer()
+     *
+     * Video:
+     *
+     * If pic.reference is set then the frame will be read later by libavcodec.
+     * avcodec_align_dimensions2() should be used to find the required width and
+     * height, as they normally need to be rounded up to the next multiple of 16.
+     *
+     * If frame multithreading is used and thread_safe_callbacks is set,
+     * it may be called from a different thread, but not from more than one at
+     * once. Does not need to be reentrant.
+     *
+     * @see release_buffer(), reget_buffer()
+     * @see avcodec_align_dimensions2()
+     *
+     * Audio:
+     *
+     * Decoders request a buffer of a particular size by setting
+     * AVFrame.nb_samples prior to calling get_buffer(). The decoder may,
+     * however, utilize only part of the buffer by setting AVFrame.nb_samples
+     * to a smaller value in the output frame.
+     *
+     * Decoders cannot use the buffer after returning from
+     * avcodec_decode_audio4(), so they will not call release_buffer(), as it
+     * is assumed to be released immediately upon return.
+     *
+     * As a convenience, av_samples_get_buffer_size() and
+     * av_samples_fill_arrays() in libavutil may be used by custom get_buffer()
+     * functions to find the required data size and to fill data pointers and
+     * linesize. In AVFrame.linesize, only linesize[0] may be set for audio
+     * since all planes must be the same size.
+     *
+     * @see av_samples_get_buffer_size(), av_samples_fill_arrays()
+     *
+     * - encoding: unused
+     * - decoding: Set by libavcodec, user can override.
+     */
+    int (*get_buffer)(struct AVCodecContext *c, AVFrame *pic);
+
+    /**
+     * Called to release buffers which were allocated with get_buffer.
+     * A released buffer can be reused in get_buffer().
+     * pic.data[*] must be set to NULL.
+     * May be called from a different thread if frame multithreading is used,
+     * but not by more than one thread at once, so does not need to be reentrant.
+     * - encoding: unused
+     * - decoding: Set by libavcodec, user can override.
+     */
+    void (*release_buffer)(struct AVCodecContext *c, AVFrame *pic);
+
+    /**
+     * Called at the beginning of a frame to get cr buffer for it.
+     * Buffer type (size, hints) must be the same. libavcodec won't check it.
+     * libavcodec will pass previous buffer in pic, function should return
+     * same buffer or new buffer with old frame "painted" into it.
+     * If pic.data[0] == NULL must behave like get_buffer().
+     * if CODEC_CAP_DR1 is not set then reget_buffer() must call
+     * avcodec_default_reget_buffer() instead of providing buffers allocated by
+     * some other means.
+     * - encoding: unused
+     * - decoding: Set by libavcodec, user can override.
+     */
+    int (*reget_buffer)(struct AVCodecContext *c, AVFrame *pic);
+
+
+    /* - encoding parameters */
+    float qcompress;  ///< amount of qscale change between easy & hard scenes (0.0-1.0)
+    float qblur;      ///< amount of qscale smoothing over time (0.0-1.0)
+
+    /**
+     * minimum quantizer
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int qmin;
+
+    /**
+     * maximum quantizer
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int qmax;
+
+    /**
+     * maximum quantizer difference between frames
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int max_qdiff;
+
+    /**
+     * ratecontrol qmin qmax limiting method
+     * 0-> clipping, 1-> use a nice continous function to limit qscale wthin qmin/qmax.
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    float rc_qsquish;
+
+    float rc_qmod_amp;
+    int rc_qmod_freq;
+
+    /**
+     * decoder bitstream buffer size
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int rc_buffer_size;
+
+    /**
+     * ratecontrol override, see RcOverride
+     * - encoding: Allocated/set/freed by user.
+     * - decoding: unused
+     */
+    int rc_override_count;
+    RcOverride *rc_override;
+
+    /**
+     * rate control equation
+     * - encoding: Set by user
+     * - decoding: unused
+     */
+    const char *rc_eq;
+
+    /**
+     * maximum bitrate
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int rc_max_rate;
+
+    /**
+     * minimum bitrate
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int rc_min_rate;
+
+    float rc_buffer_aggressivity;
+
+    /**
+     * initial complexity for pass1 ratecontrol
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    float rc_initial_cplx;
+
+    /**
+     * Ratecontrol attempt to use, at maximum, <value> of what can be used without an underflow.
+     * - encoding: Set by user.
+     * - decoding: unused.
+     */
+    float rc_max_available_vbv_use;
+
+    /**
+     * Ratecontrol attempt to use, at least, <value> times the amount needed to prevent a vbv overflow.
+     * - encoding: Set by user.
+     * - decoding: unused.
+     */
+    float rc_min_vbv_overflow_use;
+
+    /**
+     * Number of bits which should be loaded into the rc buffer before decoding starts.
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int rc_initial_buffer_occupancy;
+
+#define FF_CODER_TYPE_VLC       0
+#define FF_CODER_TYPE_AC        1
+#define FF_CODER_TYPE_RAW       2
+#define FF_CODER_TYPE_RLE       3
+#define FF_CODER_TYPE_DEFLATE   4
+    /**
+     * coder type
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int coder_type;
+
+    /**
+     * context model
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int context_model;
+
+    /**
+     * minimum Lagrange multipler
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int lmin;
+
+    /**
+     * maximum Lagrange multipler
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int lmax;
+
+    /**
+     * frame skip threshold
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int frame_skip_threshold;
+
+    /**
+     * frame skip factor
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int frame_skip_factor;
+
+    /**
+     * frame skip exponent
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int frame_skip_exp;
+
+    /**
+     * frame skip comparison function
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int frame_skip_cmp;
+
+    /**
+     * trellis RD quantization
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int trellis;
+
+    /**
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int min_prediction_order;
+
+    /**
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int max_prediction_order;
+
+    /**
+     * GOP timecode frame start number, in non drop frame format
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int64_t timecode_frame_start;
+
+    /* The RTP callback: This function is called    */
+    /* every time the encoder has a packet to send. */
+    /* It depends on the encoder if the data starts */
+    /* with a Start Code (it should). H.263 does.   */
+    /* mb_nb contains the number of macroblocks     */
+    /* encoded in the RTP payload.                  */
+    void (*rtp_callback)(struct AVCodecContext *avctx, void *data, int size, int mb_nb);
+
+    int rtp_payload_size;   /* The size of the RTP payload: the coder will  */
+                            /* do its best to deliver a chunk with size     */
+                            /* below rtp_payload_size, the chunk will start */
+                            /* with a start code on some codecs like H.263. */
+                            /* This doesn't take account of any particular  */
+                            /* headers inside the transmitted RTP payload.  */
+
+    /* statistics, used for 2-pass encoding */
+    int mv_bits;
+    int header_bits;
+    int i_tex_bits;
+    int p_tex_bits;
+    int i_count;
+    int p_count;
+    int skip_count;
+    int misc_bits;
+
+    /**
+     * number of bits used for the previously encoded frame
+     * - encoding: Set by libavcodec.
+     * - decoding: unused
+     */
+    int frame_bits;
+
+    /**
+     * pass1 encoding statistics output buffer
+     * - encoding: Set by libavcodec.
+     * - decoding: unused
+     */
+    char *stats_out;
+
+    /**
+     * pass2 encoding statistics input buffer
+     * Concatenated stuff from stats_out of pass1 should be placed here.
+     * - encoding: Allocated/set/freed by user.
+     * - decoding: unused
+     */
+    char *stats_in;
+
+    /**
+     * Work around bugs in encoders which sometimes cannot be detected automatically.
+     * - encoding: Set by user
+     * - decoding: Set by user
+     */
+    int workaround_bugs;
+#define FF_BUG_AUTODETECT       1  ///< autodetection
+#define FF_BUG_OLD_MSMPEG4      2
+#define FF_BUG_XVID_ILACE       4
+#define FF_BUG_UMP4             8
+#define FF_BUG_NO_PADDING       16
+#define FF_BUG_AMV              32
+#define FF_BUG_AC_VLC           0  ///< Will be removed, libavcodec can now handle these non-compliant files by default.
+#define FF_BUG_QPEL_CHROMA      64
+#define FF_BUG_STD_QPEL         128
+#define FF_BUG_QPEL_CHROMA2     256
+#define FF_BUG_DIRECT_BLOCKSIZE 512
+#define FF_BUG_EDGE             1024
+#define FF_BUG_HPEL_CHROMA      2048
+#define FF_BUG_DC_CLIP          4096
+#define FF_BUG_MS               8192 ///< Work around various bugs in Microsoft's broken decoders.
+#define FF_BUG_TRUNCATED       16384
+
+    /**
+     * strictly follow the standard (MPEG4, ...).
+     * - encoding: Set by user.
+     * - decoding: Set by user.
+     * Setting this to STRICT or higher means the encoder and decoder will
+     * generally do stupid things, whereas setting it to unofficial or lower
+     * will mean the encoder might produce output that is not supported by all
+     * spec-compliant decoders. Decoders don't differentiate between normal,
+     * unofficial and experimental (that is, they always try to decode things
+     * when they can) unless they are explicitly asked to behave stupidly
+     * (=strictly conform to the specs)
+     */
+    int strict_std_compliance;
+#define FF_COMPLIANCE_VERY_STRICT   2 ///< Strictly conform to an older more strict version of the spec or reference software.
+#define FF_COMPLIANCE_STRICT        1 ///< Strictly conform to all the things in the spec no matter what consequences.
+#define FF_COMPLIANCE_NORMAL        0
+#define FF_COMPLIANCE_UNOFFICIAL   -1 ///< Allow unofficial extensions
+#define FF_COMPLIANCE_EXPERIMENTAL -2 ///< Allow nonstandardized experimental things.
+
+    /**
+     * error concealment flags
+     * - encoding: unused
+     * - decoding: Set by user.
+     */
+    int error_concealment;
+#define FF_EC_GUESS_MVS   1
+#define FF_EC_DEBLOCK     2
+
+    /**
+     * debug
+     * - encoding: Set by user.
+     * - decoding: Set by user.
+     */
+    int debug;
+#define FF_DEBUG_PICT_INFO   1
+#define FF_DEBUG_RC          2
+#define FF_DEBUG_BITSTREAM   4
+#define FF_DEBUG_MB_TYPE     8
+#define FF_DEBUG_QP          16
+#define FF_DEBUG_MV          32
+#define FF_DEBUG_DCT_COEFF   0x00000040
+#define FF_DEBUG_SKIP        0x00000080
+#define FF_DEBUG_STARTCODE   0x00000100
+#define FF_DEBUG_PTS         0x00000200
+#define FF_DEBUG_ER          0x00000400
+#define FF_DEBUG_MMCO        0x00000800
+#define FF_DEBUG_BUGS        0x00001000
+#define FF_DEBUG_VIS_QP      0x00002000
+#define FF_DEBUG_VIS_MB_TYPE 0x00004000
+#define FF_DEBUG_BUFFERS     0x00008000
+#define FF_DEBUG_THREADS     0x00010000
+
+    /**
+     * debug
+     * - encoding: Set by user.
+     * - decoding: Set by user.
+     */
+    int debug_mv;
+#define FF_DEBUG_VIS_MV_P_FOR  0x00000001 //visualize forward predicted MVs of P frames
+#define FF_DEBUG_VIS_MV_B_FOR  0x00000002 //visualize forward predicted MVs of B frames
+#define FF_DEBUG_VIS_MV_B_BACK 0x00000004 //visualize backward predicted MVs of B frames
+
+    /**
+     * Error recognition; may misdetect some more or less valid parts as errors.
+     * - encoding: unused
+     * - decoding: Set by user.
+     */
+    int err_recognition;
+#define AV_EF_CRCCHECK  (1<<0)
+#define AV_EF_BITSTREAM (1<<1)
+#define AV_EF_BUFFER    (1<<2)
+#define AV_EF_EXPLODE   (1<<3)
+
+    /**
+     * opaque 64bit number (generally a PTS) that will be reordered and
+     * output in AVFrame.reordered_opaque
+     * @deprecated in favor of pkt_pts
+     * - encoding: unused
+     * - decoding: Set by user.
+     */
+    int64_t reordered_opaque;
+
+    /**
+     * Hardware accelerator in use
+     * - encoding: unused.
+     * - decoding: Set by libavcodec
+     */
+    struct AVHWAccel *hwaccel;
+
+    /**
+     * Hardware accelerator context.
+     * For some hardware accelerators, a global context needs to be
+     * provided by the user. In that case, this holds display-dependent
+     * data Libav cannot instantiate itself. Please refer to the
+     * Libav HW accelerator documentation to know how to fill this
+     * is. e.g. for VA API, this is a struct vaapi_context.
+     * - encoding: unused
+     * - decoding: Set by user
+     */
+    void *hwaccel_context;
+
+    /**
+     * error
+     * - encoding: Set by libavcodec if flags&CODEC_FLAG_PSNR.
+     * - decoding: unused
+     */
+    uint64_t error[AV_NUM_DATA_POINTERS];
+
+    /**
+     * DCT algorithm, see FF_DCT_* below
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int dct_algo;
+#define FF_DCT_AUTO    0
+#define FF_DCT_FASTINT 1
+#define FF_DCT_INT     2
+#define FF_DCT_MMX     3
+#define FF_DCT_ALTIVEC 5
+#define FF_DCT_FAAN    6
+
+    /**
+     * IDCT algorithm, see FF_IDCT_* below.
+     * - encoding: Set by user.
+     * - decoding: Set by user.
+     */
+    int idct_algo;
+#define FF_IDCT_AUTO          0
+#define FF_IDCT_INT           1
+#define FF_IDCT_SIMPLE        2
+#define FF_IDCT_SIMPLEMMX     3
+#if FF_API_LIBMPEG2
+#define FF_IDCT_LIBMPEG2MMX   4
+#endif
+#if FF_API_MMI
+#define FF_IDCT_MMI           5
+#endif
+#define FF_IDCT_ARM           7
+#define FF_IDCT_ALTIVEC       8
+#define FF_IDCT_SH4           9
+#define FF_IDCT_SIMPLEARM     10
+#define FF_IDCT_H264          11
+#define FF_IDCT_VP3           12
+#define FF_IDCT_IPP           13
+#define FF_IDCT_XVIDMMX       14
+#define FF_IDCT_CAVS          15
+#define FF_IDCT_SIMPLEARMV5TE 16
+#define FF_IDCT_SIMPLEARMV6   17
+#define FF_IDCT_SIMPLEVIS     18
+#define FF_IDCT_WMV2          19
+#define FF_IDCT_FAAN          20
+#define FF_IDCT_EA            21
+#define FF_IDCT_SIMPLENEON    22
+#define FF_IDCT_SIMPLEALPHA   23
+#define FF_IDCT_BINK          24
+
+#if FF_API_DSP_MASK
+    /**
+     * Unused.
+     * @deprecated use av_set_cpu_flags_mask() instead.
+     */
+    attribute_deprecated unsigned dsp_mask;
+#endif
+
+    /**
+     * bits per sample/pixel from the demuxer (needed for huffyuv).
+     * - encoding: Set by libavcodec.
+     * - decoding: Set by user.
+     */
+     int bits_per_coded_sample;
+
+    /**
+     * Bits per sample/pixel of internal libavcodec pixel/sample format.
+     * - encoding: set by user.
+     * - decoding: set by libavcodec.
+     */
+    int bits_per_raw_sample;
+
+    /**
+     * low resolution decoding, 1-> 1/2 size, 2->1/4 size
+     * - encoding: unused
+     * - decoding: Set by user.
+     */
+    attribute_deprecated int lowres;
+
+    /**
+     * the picture in the bitstream
+     * - encoding: Set by libavcodec.
+     * - decoding: Set by libavcodec.
+     */
+    AVFrame *coded_frame;
+
+    /**
+     * thread count
+     * is used to decide how many independent tasks should be passed to execute()
+     * - encoding: Set by user.
+     * - decoding: Set by user.
+     */
+    int thread_count;
+
+    /**
+     * Which multithreading methods to use.
+     * Use of FF_THREAD_FRAME will increase decoding delay by one frame per thread,
+     * so clients which cannot provide future frames should not use it.
+     *
+     * - encoding: Set by user, otherwise the default is used.
+     * - decoding: Set by user, otherwise the default is used.
+     */
+    int thread_type;
+#define FF_THREAD_FRAME   1 ///< Decode more than one frame at once
+#define FF_THREAD_SLICE   2 ///< Decode more than one part of a single frame at once
+
+    /**
+     * Which multithreading methods are in use by the codec.
+     * - encoding: Set by libavcodec.
+     * - decoding: Set by libavcodec.
+     */
+    int active_thread_type;
+
+    /**
+     * Set by the client if its custom get_buffer() callback can be called
+     * synchronously from another thread, which allows faster multithreaded decoding.
+     * draw_horiz_band() will be called from other threads regardless of this setting.
+     * Ignored if the default get_buffer() is used.
+     * - encoding: Set by user.
+     * - decoding: Set by user.
+     */
+    int thread_safe_callbacks;
+
+    /**
+     * The codec may call this to execute several independent things.
+     * It will return only after finishing all tasks.
+     * The user may replace this with some multithreaded implementation,
+     * the default implementation will execute the parts serially.
+     * @param count the number of things to execute
+     * - encoding: Set by libavcodec, user can override.
+     * - decoding: Set by libavcodec, user can override.
+     */
+    int (*execute)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg), void *arg2, int *ret, int count, int size);
+
+    /**
+     * The codec may call this to execute several independent things.
+     * It will return only after finishing all tasks.
+     * The user may replace this with some multithreaded implementation,
+     * the default implementation will execute the parts serially.
+     * Also see avcodec_thread_init and e.g. the --enable-pthread configure option.
+     * @param c context passed also to func
+     * @param count the number of things to execute
+     * @param arg2 argument passed unchanged to func
+     * @param ret return values of executed functions, must have space for "count" values. May be NULL.
+     * @param func function that will be called count times, with jobnr from 0 to count-1.
+     *             threadnr will be in the range 0 to c->thread_count-1 < MAX_THREADS and so that no
+     *             two instances of func executing at the same time will have the same threadnr.
+     * @return always 0 currently, but code should handle a future improvement where when any call to func
+     *         returns < 0 no further calls to func may be done and < 0 is returned.
+     * - encoding: Set by libavcodec, user can override.
+     * - decoding: Set by libavcodec, user can override.
+     */
+    int (*execute2)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg, int jobnr, int threadnr), void *arg2, int *ret, int count);
+
+    /**
+     * thread opaque
+     * Can be used by execute() to store some per AVCodecContext stuff.
+     * - encoding: set by execute()
+     * - decoding: set by execute()
+     */
+    void *thread_opaque;
+
+    /**
+     * noise vs. sse weight for the nsse comparsion function
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+     int nsse_weight;
+
+    /**
+     * profile
+     * - encoding: Set by user.
+     * - decoding: Set by libavcodec.
+     */
+     int profile;
+#define FF_PROFILE_UNKNOWN -99
+#define FF_PROFILE_RESERVED -100
+
+#define FF_PROFILE_AAC_MAIN 0
+#define FF_PROFILE_AAC_LOW  1
+#define FF_PROFILE_AAC_SSR  2
+#define FF_PROFILE_AAC_LTP  3
+#define FF_PROFILE_AAC_HE   4
+#define FF_PROFILE_AAC_HE_V2 28
+#define FF_PROFILE_AAC_LD   22
+#define FF_PROFILE_AAC_ELD  38
+
+#define FF_PROFILE_DTS         20
+#define FF_PROFILE_DTS_ES      30
+#define FF_PROFILE_DTS_96_24   40
+#define FF_PROFILE_DTS_HD_HRA  50
+#define FF_PROFILE_DTS_HD_MA   60
+
+#define FF_PROFILE_MPEG2_422    0
+#define FF_PROFILE_MPEG2_HIGH   1
+#define FF_PROFILE_MPEG2_SS     2
+#define FF_PROFILE_MPEG2_SNR_SCALABLE  3
+#define FF_PROFILE_MPEG2_MAIN   4
+#define FF_PROFILE_MPEG2_SIMPLE 5
+
+#define FF_PROFILE_H264_CONSTRAINED  (1<<9)  // 8+1; constraint_set1_flag
+#define FF_PROFILE_H264_INTRA        (1<<11) // 8+3; constraint_set3_flag
+
+#define FF_PROFILE_H264_BASELINE             66
+#define FF_PROFILE_H264_CONSTRAINED_BASELINE (66|FF_PROFILE_H264_CONSTRAINED)
+#define FF_PROFILE_H264_MAIN                 77
+#define FF_PROFILE_H264_EXTENDED             88
+#define FF_PROFILE_H264_HIGH                 100
+#define FF_PROFILE_H264_HIGH_10              110
+#define FF_PROFILE_H264_HIGH_10_INTRA        (110|FF_PROFILE_H264_INTRA)
+#define FF_PROFILE_H264_HIGH_422             122
+#define FF_PROFILE_H264_HIGH_422_INTRA       (122|FF_PROFILE_H264_INTRA)
+#define FF_PROFILE_H264_HIGH_444             144
+#define FF_PROFILE_H264_HIGH_444_PREDICTIVE  244
+#define FF_PROFILE_H264_HIGH_444_INTRA       (244|FF_PROFILE_H264_INTRA)
+#define FF_PROFILE_H264_CAVLC_444            44
+
+#define FF_PROFILE_VC1_SIMPLE   0
+#define FF_PROFILE_VC1_MAIN     1
+#define FF_PROFILE_VC1_COMPLEX  2
+#define FF_PROFILE_VC1_ADVANCED 3
+
+#define FF_PROFILE_MPEG4_SIMPLE                     0
+#define FF_PROFILE_MPEG4_SIMPLE_SCALABLE            1
+#define FF_PROFILE_MPEG4_CORE                       2
+#define FF_PROFILE_MPEG4_MAIN                       3
+#define FF_PROFILE_MPEG4_N_BIT                      4
+#define FF_PROFILE_MPEG4_SCALABLE_TEXTURE           5
+#define FF_PROFILE_MPEG4_SIMPLE_FACE_ANIMATION      6
+#define FF_PROFILE_MPEG4_BASIC_ANIMATED_TEXTURE     7
+#define FF_PROFILE_MPEG4_HYBRID                     8
+#define FF_PROFILE_MPEG4_ADVANCED_REAL_TIME         9
+#define FF_PROFILE_MPEG4_CORE_SCALABLE             10
+#define FF_PROFILE_MPEG4_ADVANCED_CODING           11
+#define FF_PROFILE_MPEG4_ADVANCED_CORE             12
+#define FF_PROFILE_MPEG4_ADVANCED_SCALABLE_TEXTURE 13
+#define FF_PROFILE_MPEG4_SIMPLE_STUDIO             14
+#define FF_PROFILE_MPEG4_ADVANCED_SIMPLE           15
+
+    /**
+     * level
+     * - encoding: Set by user.
+     * - decoding: Set by libavcodec.
+     */
+     int level;
+#define FF_LEVEL_UNKNOWN -99
+
+    /**
+     *
+     * - encoding: unused
+     * - decoding: Set by user.
+     */
+    enum AVDiscard skip_loop_filter;
+
+    /**
+     *
+     * - encoding: unused
+     * - decoding: Set by user.
+     */
+    enum AVDiscard skip_idct;
+
+    /**
+     *
+     * - encoding: unused
+     * - decoding: Set by user.
+     */
+    enum AVDiscard skip_frame;
+
+    /**
+     * Header containing style information for text subtitles.
+     * For SUBTITLE_ASS subtitle type, it should contain the whole ASS
+     * [Script Info] and [V4+ Styles] section, plus the [Events] line and
+     * the Format line following. It shouldn't include any Dialogue line.
+     * - encoding: Set/allocated/freed by user (before avcodec_open2())
+     * - decoding: Set/allocated/freed by libavcodec (by avcodec_open2())
+     */
+    uint8_t *subtitle_header;
+    int subtitle_header_size;
+
+    /**
+     * Simulates errors in the bitstream to test error concealment.
+     * - encoding: Set by user.
+     * - decoding: unused
+     */
+    int error_rate;
+
+    /**
+     * Current packet as passed into the decoder, to avoid having
+     * to pass the packet into every function. Currently only valid
+     * inside lavc and get/release_buffer callbacks.
+     * - decoding: set by avcodec_decode_*, read by get_buffer() for setting pkt_pts
+     * - encoding: unused
+     */
+    AVPacket *pkt;
+
+    /**
+     * VBV delay coded in the last frame (in periods of a 27 MHz clock).
+     * Used for compliant TS muxing.
+     * - encoding: Set by libavcodec.
+     * - decoding: unused.
+     */
+    uint64_t vbv_delay;
+} AVCodecContext;
+
+/**
+ * AVProfile.
+ */
+typedef struct AVProfile {
+    int profile;
+    const char *name; ///< short name for the profile
+} AVProfile;
+
+typedef struct AVCodecDefault AVCodecDefault;
+
+struct AVSubtitle;
+
+/**
+ * AVCodec.
+ */
+typedef struct AVCodec {
+    /**
+     * Name of the codec implementation.
+     * The name is globally unique among encoders and among decoders (but an
+     * encoder and a decoder can share the same name).
+     * This is the primary way to find a codec from the user perspective.
+     */
+    const char *name;
+    /**
+     * Descriptive name for the codec, meant to be more human readable than name.
+     * You should use the NULL_IF_CONFIG_SMALL() macro to define it.
+     */
+    const char *long_name;
+    enum AVMediaType type;
+    enum AVCodecID id;
+    /**
+     * Codec capabilities.
+     * see CODEC_CAP_*
+     */
+    int capabilities;
+    const AVRational *supported_framerates; ///< array of supported framerates, or NULL if any, array is terminated by {0,0}
+    const enum AVPixelFormat *pix_fmts;     ///< array of supported pixel formats, or NULL if unknown, array is terminated by -1
+    const int *supported_samplerates;       ///< array of supported audio samplerates, or NULL if unknown, array is terminated by 0
+    const enum AVSampleFormat *sample_fmts; ///< array of supported sample formats, or NULL if unknown, array is terminated by -1
+    const uint64_t *channel_layouts;         ///< array of support channel layouts, or NULL if unknown. array is terminated by 0
+    attribute_deprecated uint8_t max_lowres; ///< maximum value for lowres supported by the decoder
+    const AVClass *priv_class;              ///< AVClass for the private context
+    const AVProfile *profiles;              ///< array of recognized profiles, or NULL if unknown, array is terminated by {FF_PROFILE_UNKNOWN}
+
+    /*****************************************************************
+     * No fields below this line are part of the public API. They
+     * may not be used outside of libavcodec and can be changed and
+     * removed at will.
+     * New public fields should be added right above.
+     *****************************************************************
+     */
+    int priv_data_size;
+    struct AVCodec *next;
+    /**
+     * @name Frame-level threading support functions
+     * @{
+     */
+    /**
+     * If defined, called on thread contexts when they are created.
+     * If the codec allocates writable tables in init(), re-allocate them here.
+     * priv_data will be set to a copy of the original.
+     */
+    int (*init_thread_copy)(AVCodecContext *);
+    /**
+     * Copy necessary context variables from a previous thread context to the current one.
+     * If not defined, the next thread will start automatically; otherwise, the codec
+     * must call ff_thread_finish_setup().
+     *
+     * dst and src will (rarely) point to the same context, in which case memcpy should be skipped.
+     */
+    int (*update_thread_context)(AVCodecContext *dst, const AVCodecContext *src);
+    /** @} */
+
+    /**
+     * Private codec-specific defaults.
+     */
+    const AVCodecDefault *defaults;
+
+    /**
+     * Initialize codec static data, called from avcodec_register().
+     */
+    void (*init_static_data)(struct AVCodec *codec);
+
+    int (*init)(AVCodecContext *);
+    int (*encode_sub)(AVCodecContext *, uint8_t *buf, int buf_size,
+                      const struct AVSubtitle *sub);
+    /**
+     * Encode data to an AVPacket.
+     *
+     * @param      avctx          codec context
+     * @param      avpkt          output AVPacket (may contain a user-provided buffer)
+     * @param[in]  frame          AVFrame containing the raw data to be encoded
+     * @param[out] got_packet_ptr encoder sets to 0 or 1 to indicate that a
+     *                            non-empty packet was returned in avpkt.
+     * @return 0 on success, negative error code on failure
+     */
+    int (*encode2)(AVCodecContext *avctx, AVPacket *avpkt, const AVFrame *frame,
+                   int *got_packet_ptr);
+    int (*decode)(AVCodecContext *, void *outdata, int *outdata_size, AVPacket *avpkt);
+    int (*close)(AVCodecContext *);
+    /**
+     * Flush buffers.
+     * Will be called when seeking
+     */
+    void (*flush)(AVCodecContext *);
+} AVCodec;
+
+/**
+ * AVHWAccel.
+ */
+typedef struct AVHWAccel {
+    /**
+     * Name of the hardware accelerated codec.
+     * The name is globally unique among encoders and among decoders (but an
+     * encoder and a decoder can share the same name).
+     */
+    const char *name;
+
+    /**
+     * Type of codec implemented by the hardware accelerator.
+     *
+     * See AVMEDIA_TYPE_xxx
+     */
+    enum AVMediaType type;
+
+    /**
+     * Codec implemented by the hardware accelerator.
+     *
+     * See AV_CODEC_ID_xxx
+     */
+    enum AVCodecID id;
+
+    /**
+     * Supported pixel format.
+     *
+     * Only hardware accelerated formats are supported here.
+     */
+    enum AVPixelFormat pix_fmt;
+
+    /**
+     * Hardware accelerated codec capabilities.
+     * see FF_HWACCEL_CODEC_CAP_*
+     */
+    int capabilities;
+
+    struct AVHWAccel *next;
+
+    /**
+     * Called at the beginning of each frame or field picture.
+     *
+     * Meaningful frame information (codec specific) is guaranteed to
+     * be parsed at this point. This function is mandatory.
+     *
+     * Note that buf can be NULL along with buf_size set to 0.
+     * Otherwise, this means the whole frame is available at this point.
+     *
+     * @param avctx the codec context
+     * @param buf the frame data buffer base
+     * @param buf_size the size of the frame in bytes
+     * @return zero if successful, a negative value otherwise
+     */
+    int (*start_frame)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);
+
+    /**
+     * Callback for each slice.
+     *
+     * Meaningful slice information (codec specific) is guaranteed to
+     * be parsed at this point. This function is mandatory.
+     *
+     * @param avctx the codec context
+     * @param buf the slice data buffer base
+     * @param buf_size the size of the slice in bytes
+     * @return zero if successful, a negative value otherwise
+     */
+    int (*decode_slice)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);
+
+    /**
+     * Called at the end of each frame or field picture.
+     *
+     * The whole picture is parsed at this point and can now be sent
+     * to the hardware accelerator. This function is mandatory.
+     *
+     * @param avctx the codec context
+     * @return zero if successful, a negative value otherwise
+     */
+    int (*end_frame)(AVCodecContext *avctx);
+
+    /**
+     * Size of HW accelerator private data.
+     *
+     * Private data is allocated with av_mallocz() before
+     * AVCodecContext.get_buffer() and deallocated after
+     * AVCodecContext.release_buffer().
+     */
+    int priv_data_size;
+} AVHWAccel;
+
+/**
+ * @defgroup lavc_picture AVPicture
+ *
+ * Functions for working with AVPicture
+ * @{
+ */
+
+/**
+ * four components are given, that's all.
+ * the last component is alpha
+ */
+typedef struct AVPicture {
+    uint8_t *data[AV_NUM_DATA_POINTERS];
+    int linesize[AV_NUM_DATA_POINTERS];     ///< number of bytes per line
+} AVPicture;
+
+/**
+ * @}
+ */
+
+#define AVPALETTE_SIZE 1024
+#define AVPALETTE_COUNT 256
+
+enum AVSubtitleType {
+    SUBTITLE_NONE,
+
+    SUBTITLE_BITMAP,                ///< A bitmap, pict will be set
+
+    /**
+     * Plain text, the text field must be set by the decoder and is
+     * authoritative. ass and pict fields may contain approximations.
+     */
+    SUBTITLE_TEXT,
+
+    /**
+     * Formatted text, the ass field must be set by the decoder and is
+     * authoritative. pict and text fields may contain approximations.
+     */
+    SUBTITLE_ASS,
+};
+
+typedef struct AVSubtitleRect {
+    int x;         ///< top left corner  of pict, undefined when pict is not set
+    int y;         ///< top left corner  of pict, undefined when pict is not set
+    int w;         ///< width            of pict, undefined when pict is not set
+    int h;         ///< height           of pict, undefined when pict is not set
+    int nb_colors; ///< number of colors in pict, undefined when pict is not set
+
+    /**
+     * data+linesize for the bitmap of this subtitle.
+     * can be set for text/ass as well once they where rendered
+     */
+    AVPicture pict;
+    enum AVSubtitleType type;
+
+    char *text;                     ///< 0 terminated plain UTF-8 text
+
+    /**
+     * 0 terminated ASS/SSA compatible event line.
+     * The pressentation of this is unaffected by the other values in this
+     * struct.
+     */
+    char *ass;
+} AVSubtitleRect;
+
+typedef struct AVSubtitle {
+    uint16_t format; /* 0 = graphics */
+    uint32_t start_display_time; /* relative to packet pts, in ms */
+    uint32_t end_display_time; /* relative to packet pts, in ms */
+    unsigned num_rects;
+    AVSubtitleRect **rects;
+    int64_t pts;    ///< Same as packet pts, in AV_TIME_BASE
+} AVSubtitle;
+
+/**
+ * If c is NULL, returns the first registered codec,
+ * if c is non-NULL, returns the next registered codec after c,
+ * or NULL if c is the last one.
+ */
+AVCodec *av_codec_next(const AVCodec *c);
+
+/**
+ * Return the LIBAVCODEC_VERSION_INT constant.
+ */
+unsigned avcodec_version(void);
+
+/**
+ * Return the libavcodec build-time configuration.
+ */
+const char *avcodec_configuration(void);
+
+/**
+ * Return the libavcodec license.
+ */
+const char *avcodec_license(void);
+
+/**
+ * Register the codec codec and initialize libavcodec.
+ *
+ * @warning either this function or avcodec_register_all() must be called
+ * before any other libavcodec functions.
+ *
+ * @see avcodec_register_all()
+ */
+void avcodec_register(AVCodec *codec);
+
+/**
+ * Register all the codecs, parsers and bitstream filters which were enabled at
+ * configuration time. If you do not call this function you can select exactly
+ * which formats you want to support, by using the individual registration
+ * functions.
+ *
+ * @see avcodec_register
+ * @see av_register_codec_parser
+ * @see av_register_bitstream_filter
+ */
+void avcodec_register_all(void);
+
+/**
+ * Allocate an AVCodecContext and set its fields to default values.  The
+ * resulting struct can be deallocated by calling avcodec_close() on it followed
+ * by av_free().
+ *
+ * @param codec if non-NULL, allocate private data and initialize defaults
+ *              for the given codec. It is illegal to then call avcodec_open2()
+ *              with a different codec.
+ *              If NULL, then the codec-specific defaults won't be initialized,
+ *              which may result in suboptimal default settings (this is
+ *              important mainly for encoders, e.g. libx264).
+ *
+ * @return An AVCodecContext filled with default values or NULL on failure.
+ * @see avcodec_get_context_defaults
+ */
+AVCodecContext *avcodec_alloc_context3(const AVCodec *codec);
+
+/**
+ * Set the fields of the given AVCodecContext to default values corresponding
+ * to the given codec (defaults may be codec-dependent).
+ *
+ * Do not call this function if a non-NULL codec has been passed
+ * to avcodec_alloc_context3() that allocated this AVCodecContext.
+ * If codec is non-NULL, it is illegal to call avcodec_open2() with a
+ * different codec on this AVCodecContext.
+ */
+int avcodec_get_context_defaults3(AVCodecContext *s, const AVCodec *codec);
+
+/**
+ * Get the AVClass for AVCodecContext. It can be used in combination with
+ * AV_OPT_SEARCH_FAKE_OBJ for examining options.
+ *
+ * @see av_opt_find().
+ */
+const AVClass *avcodec_get_class(void);
+
+/**
+ * Copy the settings of the source AVCodecContext into the destination
+ * AVCodecContext. The resulting destination codec context will be
+ * unopened, i.e. you are required to call avcodec_open2() before you
+ * can use this AVCodecContext to decode/encode video/audio data.
+ *
+ * @param dest target codec context, should be initialized with
+ *             avcodec_alloc_context3(), but otherwise uninitialized
+ * @param src source codec context
+ * @return AVERROR() on error (e.g. memory allocation error), 0 on success
+ */
+int avcodec_copy_context(AVCodecContext *dest, const AVCodecContext *src);
+
+/**
+ * Allocate an AVFrame and set its fields to default values.  The resulting
+ * struct must be freed using avcodec_free_frame().
+ *
+ * @return An AVFrame filled with default values or NULL on failure.
+ * @see avcodec_get_frame_defaults
+ */
+AVFrame *avcodec_alloc_frame(void);
+
+/**
+ * Set the fields of the given AVFrame to default values.
+ *
+ * @param frame The AVFrame of which the fields should be set to default values.
+ */
+void avcodec_get_frame_defaults(AVFrame *frame);
+
+/**
+ * Free the frame and any dynamically allocated objects in it,
+ * e.g. extended_data.
+ *
+ * @param frame frame to be freed. The pointer will be set to NULL.
+ *
+ * @warning this function does NOT free the data buffers themselves
+ * (it does not know how, since they might have been allocated with
+ *  a custom get_buffer()).
+ */
+void avcodec_free_frame(AVFrame **frame);
+
+/**
+ * Initialize the AVCodecContext to use the given AVCodec. Prior to using this
+ * function the context has to be allocated with avcodec_alloc_context3().
+ *
+ * The functions avcodec_find_decoder_by_name(), avcodec_find_encoder_by_name(),
+ * avcodec_find_decoder() and avcodec_find_encoder() provide an easy way for
+ * retrieving a codec.
+ *
+ * @warning This function is not thread safe!
+ *
+ * @code
+ * avcodec_register_all();
+ * av_dict_set(&opts, "b", "2.5M", 0);
+ * codec = avcodec_find_decoder(AV_CODEC_ID_H264);
+ * if (!codec)
+ *     exit(1);
+ *
+ * context = avcodec_alloc_context3(codec);
+ *
+ * if (avcodec_open2(context, codec, opts) < 0)
+ *     exit(1);
+ * @endcode
+ *
+ * @param avctx The context to initialize.
+ * @param codec The codec to open this context for. If a non-NULL codec has been
+ *              previously passed to avcodec_alloc_context3() or
+ *              avcodec_get_context_defaults3() for this context, then this
+ *              parameter MUST be either NULL or equal to the previously passed
+ *              codec.
+ * @param options A dictionary filled with AVCodecContext and codec-private options.
+ *                On return this object will be filled with options that were not found.
+ *
+ * @return zero on success, a negative value on error
+ * @see avcodec_alloc_context3(), avcodec_find_decoder(), avcodec_find_encoder(),
+ *      av_dict_set(), av_opt_find().
+ */
+int avcodec_open2(AVCodecContext *avctx, const AVCodec *codec, AVDictionary **options);
+
+/**
+ * Close a given AVCodecContext and free all the data associated with it
+ * (but not the AVCodecContext itself).
+ *
+ * Calling this function on an AVCodecContext that hasn't been opened will free
+ * the codec-specific data allocated in avcodec_alloc_context3() /
+ * avcodec_get_context_defaults3() with a non-NULL codec. Subsequent calls will
+ * do nothing.
+ */
+int avcodec_close(AVCodecContext *avctx);
+
+/**
+ * Free all allocated data in the given subtitle struct.
+ *
+ * @param sub AVSubtitle to free.
+ */
+void avsubtitle_free(AVSubtitle *sub);
+
+/**
+ * @}
+ */
+
+/**
+ * @addtogroup lavc_packet
+ * @{
+ */
+
+/**
+ * Default packet destructor.
+ */
+void av_destruct_packet(AVPacket *pkt);
+
+/**
+ * Initialize optional fields of a packet with default values.
+ *
+ * Note, this does not touch the data and size members, which have to be
+ * initialized separately.
+ *
+ * @param pkt packet
+ */
+void av_init_packet(AVPacket *pkt);
+
+/**
+ * Allocate the payload of a packet and initialize its fields with
+ * default values.
+ *
+ * @param pkt packet
+ * @param size wanted payload size
+ * @return 0 if OK, AVERROR_xxx otherwise
+ */
+int av_new_packet(AVPacket *pkt, int size);
+
+/**
+ * Reduce packet size, correctly zeroing padding
+ *
+ * @param pkt packet
+ * @param size new size
+ */
+void av_shrink_packet(AVPacket *pkt, int size);
+
+/**
+ * Increase packet size, correctly zeroing padding
+ *
+ * @param pkt packet
+ * @param grow_by number of bytes by which to increase the size of the packet
+ */
+int av_grow_packet(AVPacket *pkt, int grow_by);
+
+/**
+ * @warning This is a hack - the packet memory allocation stuff is broken. The
+ * packet is allocated if it was not really allocated.
+ */
+int av_dup_packet(AVPacket *pkt);
+
+/**
+ * Free a packet.
+ *
+ * @param pkt packet to free
+ */
+void av_free_packet(AVPacket *pkt);
+
+/**
+ * Allocate new information of a packet.
+ *
+ * @param pkt packet
+ * @param type side information type
+ * @param size side information size
+ * @return pointer to fresh allocated data or NULL otherwise
+ */
+uint8_t* av_packet_new_side_data(AVPacket *pkt, enum AVPacketSideDataType type,
+                                 int size);
+
+/**
+ * Shrink the already allocated side data buffer
+ *
+ * @param pkt packet
+ * @param type side information type
+ * @param size new side information size
+ * @return 0 on success, < 0 on failure
+ */
+int av_packet_shrink_side_data(AVPacket *pkt, enum AVPacketSideDataType type,
+                               int size);
+
+/**
+ * Get side information from packet.
+ *
+ * @param pkt packet
+ * @param type desired side information type
+ * @param size pointer for side information size to store (optional)
+ * @return pointer to data if present or NULL otherwise
+ */
+uint8_t* av_packet_get_side_data(AVPacket *pkt, enum AVPacketSideDataType type,
+                                 int *size);
+
+/**
+ * @}
+ */
+
+/**
+ * @addtogroup lavc_decoding
+ * @{
+ */
+
+/**
+ * Find a registered decoder with a matching codec ID.
+ *
+ * @param id AVCodecID of the requested decoder
+ * @return A decoder if one was found, NULL otherwise.
+ */
+AVCodec *avcodec_find_decoder(enum AVCodecID id);
+
+/**
+ * Find a registered decoder with the specified name.
+ *
+ * @param name name of the requested decoder
+ * @return A decoder if one was found, NULL otherwise.
+ */
+AVCodec *avcodec_find_decoder_by_name(const char *name);
+
+int avcodec_default_get_buffer(AVCodecContext *s, AVFrame *pic);
+void avcodec_default_release_buffer(AVCodecContext *s, AVFrame *pic);
+int avcodec_default_reget_buffer(AVCodecContext *s, AVFrame *pic);
+
+/**
+ * Return the amount of padding in pixels which the get_buffer callback must
+ * provide around the edge of the image for codecs which do not have the
+ * CODEC_FLAG_EMU_EDGE flag.
+ *
+ * @return Required padding in pixels.
+ */
+unsigned avcodec_get_edge_width(void);
+
+/**
+ * Modify width and height values so that they will result in a memory
+ * buffer that is acceptable for the codec if you do not use any horizontal
+ * padding.
+ *
+ * May only be used if a codec with CODEC_CAP_DR1 has been opened.
+ * If CODEC_FLAG_EMU_EDGE is not set, the dimensions must have been increased
+ * according to avcodec_get_edge_width() before.
+ */
+void avcodec_align_dimensions(AVCodecContext *s, int *width, int *height);
+
+/**
+ * Modify width and height values so that they will result in a memory
+ * buffer that is acceptable for the codec if you also ensure that all
+ * line sizes are a multiple of the respective linesize_align[i].
+ *
+ * May only be used if a codec with CODEC_CAP_DR1 has been opened.
+ * If CODEC_FLAG_EMU_EDGE is not set, the dimensions must have been increased
+ * according to avcodec_get_edge_width() before.
+ */
+void avcodec_align_dimensions2(AVCodecContext *s, int *width, int *height,
+                               int linesize_align[AV_NUM_DATA_POINTERS]);
+
+#if FF_API_OLD_DECODE_AUDIO
+/**
+ * Wrapper function which calls avcodec_decode_audio4.
+ *
+ * @deprecated Use avcodec_decode_audio4 instead.
+ *
+ * Decode the audio frame of size avpkt->size from avpkt->data into samples.
+ * Some decoders may support multiple frames in a single AVPacket, such
+ * decoders would then just decode the first frame. In this case,
+ * avcodec_decode_audio3 has to be called again with an AVPacket that contains
+ * the remaining data in order to decode the second frame etc.
+ * If no frame
+ * could be outputted, frame_size_ptr is zero. Otherwise, it is the
+ * decompressed frame size in bytes.
+ *
+ * @warning You must set frame_size_ptr to the allocated size of the
+ * output buffer before calling avcodec_decode_audio3().
+ *
+ * @warning The input buffer must be FF_INPUT_BUFFER_PADDING_SIZE larger than
+ * the actual read bytes because some optimized bitstream readers read 32 or 64
+ * bits at once and could read over the end.
+ *
+ * @warning The end of the input buffer avpkt->data should be set to 0 to ensure that
+ * no overreading happens for damaged MPEG streams.
+ *
+ * @warning You must not provide a custom get_buffer() when using
+ * avcodec_decode_audio3().  Doing so will override it with
+ * avcodec_default_get_buffer.  Use avcodec_decode_audio4() instead,
+ * which does allow the application to provide a custom get_buffer().
+ *
+ * @note You might have to align the input buffer avpkt->data and output buffer
+ * samples. The alignment requirements depend on the CPU: On some CPUs it isn't
+ * necessary at all, on others it won't work at all if not aligned and on others
+ * it will work but it will have an impact on performance.
+ *
+ * In practice, avpkt->data should have 4 byte alignment at minimum and
+ * samples should be 16 byte aligned unless the CPU doesn't need it
+ * (AltiVec and SSE do).
+ *
+ * @note Codecs which have the CODEC_CAP_DELAY capability set have a delay
+ * between input and output, these need to be fed with avpkt->data=NULL,
+ * avpkt->size=0 at the end to return the remaining frames.
+ *
+ * @param avctx the codec context
+ * @param[out] samples the output buffer, sample type in avctx->sample_fmt
+ *                     If the sample format is planar, each channel plane will
+ *                     be the same size, with no padding between channels.
+ * @param[in,out] frame_size_ptr the output buffer size in bytes
+ * @param[in] avpkt The input AVPacket containing the input buffer.
+ *            You can create such packet with av_init_packet() and by then setting
+ *            data and size, some decoders might in addition need other fields.
+ *            All decoders are designed to use the least fields possible though.
+ * @return On error a negative value is returned, otherwise the number of bytes
+ * used or zero if no frame data was decompressed (used) from the input AVPacket.
+ */
+attribute_deprecated int avcodec_decode_audio3(AVCodecContext *avctx, int16_t *samples,
+                         int *frame_size_ptr,
+                         AVPacket *avpkt);
+#endif
+
+/**
+ * Decode the audio frame of size avpkt->size from avpkt->data into frame.
+ *
+ * Some decoders may support multiple frames in a single AVPacket. Such
+ * decoders would then just decode the first frame. In this case,
+ * avcodec_decode_audio4 has to be called again with an AVPacket containing
+ * the remaining data in order to decode the second frame, etc...
+ * Even if no frames are returned, the packet needs to be fed to the decoder
+ * with remaining data until it is completely consumed or an error occurs.
+ *
+ * @warning The input buffer, avpkt->data must be FF_INPUT_BUFFER_PADDING_SIZE
+ *          larger than the actual read bytes because some optimized bitstream
+ *          readers read 32 or 64 bits at once and could read over the end.
+ *
+ * @note You might have to align the input buffer. The alignment requirements
+ *       depend on the CPU and the decoder.
+ *
+ * @param      avctx the codec context
+ * @param[out] frame The AVFrame in which to store decoded audio samples.
+ *                   Decoders request a buffer of a particular size by setting
+ *                   AVFrame.nb_samples prior to calling get_buffer(). The
+ *                   decoder may, however, only utilize part of the buffer by
+ *                   setting AVFrame.nb_samples to a smaller value in the
+ *                   output frame.
+ * @param[out] got_frame_ptr Zero if no frame could be decoded, otherwise it is
+ *                           non-zero.
+ * @param[in]  avpkt The input AVPacket containing the input buffer.
+ *                   At least avpkt->data and avpkt->size should be set. Some
+ *                   decoders might also require additional fields to be set.
+ * @return A negative error code is returned if an error occurred during
+ *         decoding, otherwise the number of bytes consumed from the input
+ *         AVPacket is returned.
+ */
+int avcodec_decode_audio4(AVCodecContext *avctx, AVFrame *frame,
+                          int *got_frame_ptr, AVPacket *avpkt);
+
+/**
+ * Decode the video frame of size avpkt->size from avpkt->data into picture.
+ * Some decoders may support multiple frames in a single AVPacket, such
+ * decoders would then just decode the first frame.
+ *
+ * @warning The input buffer must be FF_INPUT_BUFFER_PADDING_SIZE larger than
+ * the actual read bytes because some optimized bitstream readers read 32 or 64
+ * bits at once and could read over the end.
+ *
+ * @warning The end of the input buffer buf should be set to 0 to ensure that
+ * no overreading happens for damaged MPEG streams.
+ *
+ * @note You might have to align the input buffer avpkt->data.
+ * The alignment requirements depend on the CPU: on some CPUs it isn't
+ * necessary at all, on others it won't work at all if not aligned and on others
+ * it will work but it will have an impact on performance.
+ *
+ * In practice, avpkt->data should have 4 byte alignment at minimum.
+ *
+ * @note Codecs which have the CODEC_CAP_DELAY capability set have a delay
+ * between input and output, these need to be fed with avpkt->data=NULL,
+ * avpkt->size=0 at the end to return the remaining frames.
+ *
+ * @param avctx the codec context
+ * @param[out] picture The AVFrame in which the decoded video frame will be stored.
+ *             Use avcodec_alloc_frame to get an AVFrame, the codec will
+ *             allocate memory for the actual bitmap.
+ *             with default get/release_buffer(), the decoder frees/reuses the bitmap as it sees fit.
+ *             with overridden get/release_buffer() (needs CODEC_CAP_DR1) the user decides into what buffer the decoder
+ *                   decodes and the decoder tells the user once it does not need the data anymore,
+ *                   the user app can at this point free/reuse/keep the memory as it sees fit.
+ *
+ * @param[in] avpkt The input AVpacket containing the input buffer.
+ *            You can create such packet with av_init_packet() and by then setting
+ *            data and size, some decoders might in addition need other fields like
+ *            flags&AV_PKT_FLAG_KEY. All decoders are designed to use the least
+ *            fields possible.
+ * @param[in,out] got_picture_ptr Zero if no frame could be decompressed, otherwise, it is nonzero.
+ * @return On error a negative value is returned, otherwise the number of bytes
+ * used or zero if no frame could be decompressed.
+ */
+int avcodec_decode_video2(AVCodecContext *avctx, AVFrame *picture,
+                         int *got_picture_ptr,
+                         AVPacket *avpkt);
+
+/**
+ * Decode a subtitle message.
+ * Return a negative value on error, otherwise return the number of bytes used.
+ * If no subtitle could be decompressed, got_sub_ptr is zero.
+ * Otherwise, the subtitle is stored in *sub.
+ * Note that CODEC_CAP_DR1 is not available for subtitle codecs. This is for
+ * simplicity, because the performance difference is expect to be negligible
+ * and reusing a get_buffer written for video codecs would probably perform badly
+ * due to a potentially very different allocation pattern.
+ *
+ * @param avctx the codec context
+ * @param[out] sub The AVSubtitle in which the decoded subtitle will be stored, must be
+                   freed with avsubtitle_free if *got_sub_ptr is set.
+ * @param[in,out] got_sub_ptr Zero if no subtitle could be decompressed, otherwise, it is nonzero.
+ * @param[in] avpkt The input AVPacket containing the input buffer.
+ */
+int avcodec_decode_subtitle2(AVCodecContext *avctx, AVSubtitle *sub,
+                            int *got_sub_ptr,
+                            AVPacket *avpkt);
+
+/**
+ * @defgroup lavc_parsing Frame parsing
+ * @{
+ */
+
+typedef struct AVCodecParserContext {
+    void *priv_data;
+    struct AVCodecParser *parser;
+    int64_t frame_offset; /* offset of the current frame */
+    int64_t cur_offset; /* current offset
+                           (incremented by each av_parser_parse()) */
+    int64_t next_frame_offset; /* offset of the next frame */
+    /* video info */
+    int pict_type; /* XXX: Put it back in AVCodecContext. */
+    /**
+     * This field is used for proper frame duration computation in lavf.
+     * It signals, how much longer the frame duration of the current frame
+     * is compared to normal frame duration.
+     *
+     * frame_duration = (1 + repeat_pict) * time_base
+     *
+     * It is used by codecs like H.264 to display telecined material.
+     */
+    int repeat_pict; /* XXX: Put it back in AVCodecContext. */
+    int64_t pts;     /* pts of the current frame */
+    int64_t dts;     /* dts of the current frame */
+
+    /* private data */
+    int64_t last_pts;
+    int64_t last_dts;
+    int fetch_timestamp;
+
+#define AV_PARSER_PTS_NB 4
+    int cur_frame_start_index;
+    int64_t cur_frame_offset[AV_PARSER_PTS_NB];
+    int64_t cur_frame_pts[AV_PARSER_PTS_NB];
+    int64_t cur_frame_dts[AV_PARSER_PTS_NB];
+
+    int flags;
+#define PARSER_FLAG_COMPLETE_FRAMES           0x0001
+#define PARSER_FLAG_ONCE                      0x0002
+/// Set if the parser has a valid file offset
+#define PARSER_FLAG_FETCHED_OFFSET            0x0004
+
+    int64_t offset;      ///< byte offset from starting packet start
+    int64_t cur_frame_end[AV_PARSER_PTS_NB];
+
+    /**
+     * Set by parser to 1 for key frames and 0 for non-key frames.
+     * It is initialized to -1, so if the parser doesn't set this flag,
+     * old-style fallback using AV_PICTURE_TYPE_I picture type as key frames
+     * will be used.
+     */
+    int key_frame;
+
+    /**
+     * Time difference in stream time base units from the pts of this
+     * packet to the point at which the output from the decoder has converged
+     * independent from the availability of previous frames. That is, the
+     * frames are virtually identical no matter if decoding started from
+     * the very first frame or from this keyframe.
+     * Is AV_NOPTS_VALUE if unknown.
+     * This field is not the display duration of the current frame.
+     * This field has no meaning if the packet does not have AV_PKT_FLAG_KEY
+     * set.
+     *
+     * The purpose of this field is to allow seeking in streams that have no
+     * keyframes in the conventional sense. It corresponds to the
+     * recovery point SEI in H.264 and match_time_delta in NUT. It is also
+     * essential for some types of subtitle streams to ensure that all
+     * subtitles are correctly displayed after seeking.
+     */
+    int64_t convergence_duration;
+
+    // Timestamp generation support:
+    /**
+     * Synchronization point for start of timestamp generation.
+     *
+     * Set to >0 for sync point, 0 for no sync point and <0 for undefined
+     * (default).
+     *
+     * For example, this corresponds to presence of H.264 buffering period
+     * SEI message.
+     */
+    int dts_sync_point;
+
+    /**
+     * Offset of the current timestamp against last timestamp sync point in
+     * units of AVCodecContext.time_base.
+     *
+     * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
+     * contain a valid timestamp offset.
+     *
+     * Note that the timestamp of sync point has usually a nonzero
+     * dts_ref_dts_delta, which refers to the previous sync point. Offset of
+     * the next frame after timestamp sync point will be usually 1.
+     *
+     * For example, this corresponds to H.264 cpb_removal_delay.
+     */
+    int dts_ref_dts_delta;
+
+    /**
+     * Presentation delay of current frame in units of AVCodecContext.time_base.
+     *
+     * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
+     * contain valid non-negative timestamp delta (presentation time of a frame
+     * must not lie in the past).
+     *
+     * This delay represents the difference between decoding and presentation
+     * time of the frame.
+     *
+     * For example, this corresponds to H.264 dpb_output_delay.
+     */
+    int pts_dts_delta;
+
+    /**
+     * Position of the packet in file.
+     *
+     * Analogous to cur_frame_pts/dts
+     */
+    int64_t cur_frame_pos[AV_PARSER_PTS_NB];
+
+    /**
+     * Byte position of currently parsed frame in stream.
+     */
+    int64_t pos;
+
+    /**
+     * Previous frame byte position.
+     */
+    int64_t last_pos;
+
+    /**
+     * Duration of the current frame.
+     * For audio, this is in units of 1 / AVCodecContext.sample_rate.
+     * For all other types, this is in units of AVCodecContext.time_base.
+     */
+    int duration;
+} AVCodecParserContext;
+
+typedef struct AVCodecParser {
+    int codec_ids[5]; /* several codec IDs are permitted */
+    int priv_data_size;
+    int (*parser_init)(AVCodecParserContext *s);
+    int (*parser_parse)(AVCodecParserContext *s,
+                        AVCodecContext *avctx,
+                        const uint8_t **poutbuf, int *poutbuf_size,
+                        const uint8_t *buf, int buf_size);
+    void (*parser_close)(AVCodecParserContext *s);
+    int (*split)(AVCodecContext *avctx, const uint8_t *buf, int buf_size);
+    struct AVCodecParser *next;
+} AVCodecParser;
+
+AVCodecParser *av_parser_next(AVCodecParser *c);
+
+void av_register_codec_parser(AVCodecParser *parser);
+AVCodecParserContext *av_parser_init(int codec_id);
+
+/**
+ * Parse a packet.
+ *
+ * @param s             parser context.
+ * @param avctx         codec context.
+ * @param poutbuf       set to pointer to parsed buffer or NULL if not yet finished.
+ * @param poutbuf_size  set to size of parsed buffer or zero if not yet finished.
+ * @param buf           input buffer.
+ * @param buf_size      input length, to signal EOF, this should be 0 (so that the last frame can be output).
+ * @param pts           input presentation timestamp.
+ * @param dts           input decoding timestamp.
+ * @param pos           input byte position in stream.
+ * @return the number of bytes of the input bitstream used.
+ *
+ * Example:
+ * @code
+ *   while(in_len){
+ *       len = av_parser_parse2(myparser, AVCodecContext, &data, &size,
+ *                                        in_data, in_len,
+ *                                        pts, dts, pos);
+ *       in_data += len;
+ *       in_len  -= len;
+ *
+ *       if(size)
+ *          decode_frame(data, size);
+ *   }
+ * @endcode
+ */
+int av_parser_parse2(AVCodecParserContext *s,
+                     AVCodecContext *avctx,
+                     uint8_t **poutbuf, int *poutbuf_size,
+                     const uint8_t *buf, int buf_size,
+                     int64_t pts, int64_t dts,
+                     int64_t pos);
+
+int av_parser_change(AVCodecParserContext *s,
+                     AVCodecContext *avctx,
+                     uint8_t **poutbuf, int *poutbuf_size,
+                     const uint8_t *buf, int buf_size, int keyframe);
+void av_parser_close(AVCodecParserContext *s);
+
+/**
+ * @}
+ * @}
+ */
+
+/**
+ * @addtogroup lavc_encoding
+ * @{
+ */
+
+/**
+ * Find a registered encoder with a matching codec ID.
+ *
+ * @param id AVCodecID of the requested encoder
+ * @return An encoder if one was found, NULL otherwise.
+ */
+AVCodec *avcodec_find_encoder(enum AVCodecID id);
+
+/**
+ * Find a registered encoder with the specified name.
+ *
+ * @param name name of the requested encoder
+ * @return An encoder if one was found, NULL otherwise.
+ */
+AVCodec *avcodec_find_encoder_by_name(const char *name);
+
+#if FF_API_OLD_ENCODE_AUDIO
+/**
+ * Encode an audio frame from samples into buf.
+ *
+ * @deprecated Use avcodec_encode_audio2 instead.
+ *
+ * @note The output buffer should be at least FF_MIN_BUFFER_SIZE bytes large.
+ * However, for codecs with avctx->frame_size equal to 0 (e.g. PCM) the user
+ * will know how much space is needed because it depends on the value passed
+ * in buf_size as described below. In that case a lower value can be used.
+ *
+ * @param avctx the codec context
+ * @param[out] buf the output buffer
+ * @param[in] buf_size the output buffer size
+ * @param[in] samples the input buffer containing the samples
+ * The number of samples read from this buffer is frame_size*channels,
+ * both of which are defined in avctx.
+ * For codecs which have avctx->frame_size equal to 0 (e.g. PCM) the number of
+ * samples read from samples is equal to:
+ * buf_size * 8 / (avctx->channels * av_get_bits_per_sample(avctx->codec_id))
+ * This also implies that av_get_bits_per_sample() must not return 0 for these
+ * codecs.
+ * @return On error a negative value is returned, on success zero or the number
+ * of bytes used to encode the data read from the input buffer.
+ */
+int attribute_deprecated avcodec_encode_audio(AVCodecContext *avctx,
+                                              uint8_t *buf, int buf_size,
+                                              const short *samples);
+#endif
+
+/**
+ * Encode a frame of audio.
+ *
+ * Takes input samples from frame and writes the next output packet, if
+ * available, to avpkt. The output packet does not necessarily contain data for
+ * the most recent frame, as encoders can delay, split, and combine input frames
+ * internally as needed.
+ *
+ * @param avctx     codec context
+ * @param avpkt     output AVPacket.
+ *                  The user can supply an output buffer by setting
+ *                  avpkt->data and avpkt->size prior to calling the
+ *                  function, but if the size of the user-provided data is not
+ *                  large enough, encoding will fail. All other AVPacket fields
+ *                  will be reset by the encoder using av_init_packet(). If
+ *                  avpkt->data is NULL, the encoder will allocate it.
+ *                  The encoder will set avpkt->size to the size of the
+ *                  output packet.
+ *
+ *                  If this function fails or produces no output, avpkt will be
+ *                  freed using av_free_packet() (i.e. avpkt->destruct will be
+ *                  called to free the user supplied buffer).
+ * @param[in] frame AVFrame containing the raw audio data to be encoded.
+ *                  May be NULL when flushing an encoder that has the
+ *                  CODEC_CAP_DELAY capability set.
+ *                  If CODEC_CAP_VARIABLE_FRAME_SIZE is set, then each frame
+ *                  can have any number of samples.
+ *                  If it is not set, frame->nb_samples must be equal to
+ *                  avctx->frame_size for all frames except the last.
+ *                  The final frame may be smaller than avctx->frame_size.
+ * @param[out] got_packet_ptr This field is set to 1 by libavcodec if the
+ *                            output packet is non-empty, and to 0 if it is
+ *                            empty. If the function returns an error, the
+ *                            packet can be assumed to be invalid, and the
+ *                            value of got_packet_ptr is undefined and should
+ *                            not be used.
+ * @return          0 on success, negative error code on failure
+ */
+int avcodec_encode_audio2(AVCodecContext *avctx, AVPacket *avpkt,
+                          const AVFrame *frame, int *got_packet_ptr);
+
+#if FF_API_OLD_ENCODE_VIDEO
+/**
+ * @deprecated use avcodec_encode_video2() instead.
+ *
+ * Encode a video frame from pict into buf.
+ * The input picture should be
+ * stored using a specific format, namely avctx.pix_fmt.
+ *
+ * @param avctx the codec context
+ * @param[out] buf the output buffer for the bitstream of encoded frame
+ * @param[in] buf_size the size of the output buffer in bytes
+ * @param[in] pict the input picture to encode
+ * @return On error a negative value is returned, on success zero or the number
+ * of bytes used from the output buffer.
+ */
+attribute_deprecated
+int avcodec_encode_video(AVCodecContext *avctx, uint8_t *buf, int buf_size,
+                         const AVFrame *pict);
+#endif
+
+/**
+ * Encode a frame of video.
+ *
+ * Takes input raw video data from frame and writes the next output packet, if
+ * available, to avpkt. The output packet does not necessarily contain data for
+ * the most recent frame, as encoders can delay and reorder input frames
+ * internally as needed.
+ *
+ * @param avctx     codec context
+ * @param avpkt     output AVPacket.
+ *                  The user can supply an output buffer by setting
+ *                  avpkt->data and avpkt->size prior to calling the
+ *                  function, but if the size of the user-provided data is not
+ *                  large enough, encoding will fail. All other AVPacket fields
+ *                  will be reset by the encoder using av_init_packet(). If
+ *                  avpkt->data is NULL, the encoder will allocate it.
+ *                  The encoder will set avpkt->size to the size of the
+ *                  output packet. The returned data (if any) belongs to the
+ *                  caller, he is responsible for freeing it.
+ *
+ *                  If this function fails or produces no output, avpkt will be
+ *                  freed using av_free_packet() (i.e. avpkt->destruct will be
+ *                  called to free the user supplied buffer).
+ * @param[in] frame AVFrame containing the raw video data to be encoded.
+ *                  May be NULL when flushing an encoder that has the
+ *                  CODEC_CAP_DELAY capability set.
+ * @param[out] got_packet_ptr This field is set to 1 by libavcodec if the
+ *                            output packet is non-empty, and to 0 if it is
+ *                            empty. If the function returns an error, the
+ *                            packet can be assumed to be invalid, and the
+ *                            value of got_packet_ptr is undefined and should
+ *                            not be used.
+ * @return          0 on success, negative error code on failure
+ */
+int avcodec_encode_video2(AVCodecContext *avctx, AVPacket *avpkt,
+                          const AVFrame *frame, int *got_packet_ptr);
+
+int avcodec_encode_subtitle(AVCodecContext *avctx, uint8_t *buf, int buf_size,
+                            const AVSubtitle *sub);
+
+
+/**
+ * @}
+ */
+
+#if FF_API_AVCODEC_RESAMPLE
+/**
+ * @defgroup lavc_resample Audio resampling
+ * @ingroup libavc
+ * @deprecated use libavresample instead
+ *
+ * @{
+ */
+struct ReSampleContext;
+struct AVResampleContext;
+
+typedef struct ReSampleContext ReSampleContext;
+
+/**
+ *  Initialize audio resampling context.
+ *
+ * @param output_channels  number of output channels
+ * @param input_channels   number of input channels
+ * @param output_rate      output sample rate
+ * @param input_rate       input sample rate
+ * @param sample_fmt_out   requested output sample format
+ * @param sample_fmt_in    input sample format
+ * @param filter_length    length of each FIR filter in the filterbank relative to the cutoff frequency
+ * @param log2_phase_count log2 of the number of entries in the polyphase filterbank
+ * @param linear           if 1 then the used FIR filter will be linearly interpolated
+                           between the 2 closest, if 0 the closest will be used
+ * @param cutoff           cutoff frequency, 1.0 corresponds to half the output sampling rate
+ * @return allocated ReSampleContext, NULL if error occurred
+ */
+attribute_deprecated
+ReSampleContext *av_audio_resample_init(int output_channels, int input_channels,
+                                        int output_rate, int input_rate,
+                                        enum AVSampleFormat sample_fmt_out,
+                                        enum AVSampleFormat sample_fmt_in,
+                                        int filter_length, int log2_phase_count,
+                                        int linear, double cutoff);
+
+attribute_deprecated
+int audio_resample(ReSampleContext *s, short *output, short *input, int nb_samples);
+
+/**
+ * Free resample context.
+ *
+ * @param s a non-NULL pointer to a resample context previously
+ *          created with av_audio_resample_init()
+ */
+attribute_deprecated
+void audio_resample_close(ReSampleContext *s);
+
+
+/**
+ * Initialize an audio resampler.
+ * Note, if either rate is not an integer then simply scale both rates up so they are.
+ * @param filter_length length of each FIR filter in the filterbank relative to the cutoff freq
+ * @param log2_phase_count log2 of the number of entries in the polyphase filterbank
+ * @param linear If 1 then the used FIR filter will be linearly interpolated
+                 between the 2 closest, if 0 the closest will be used
+ * @param cutoff cutoff frequency, 1.0 corresponds to half the output sampling rate
+ */
+attribute_deprecated
+struct AVResampleContext *av_resample_init(int out_rate, int in_rate, int filter_length, int log2_phase_count, int linear, double cutoff);
+
+/**
+ * Resample an array of samples using a previously configured context.
+ * @param src an array of unconsumed samples
+ * @param consumed the number of samples of src which have been consumed are returned here
+ * @param src_size the number of unconsumed samples available
+ * @param dst_size the amount of space in samples available in dst
+ * @param update_ctx If this is 0 then the context will not be modified, that way several channels can be resampled with the same context.
+ * @return the number of samples written in dst or -1 if an error occurred
+ */
+attribute_deprecated
+int av_resample(struct AVResampleContext *c, short *dst, short *src, int *consumed, int src_size, int dst_size, int update_ctx);
+
+
+/**
+ * Compensate samplerate/timestamp drift. The compensation is done by changing
+ * the resampler parameters, so no audible clicks or similar distortions occur
+ * @param compensation_distance distance in output samples over which the compensation should be performed
+ * @param sample_delta number of output samples which should be output less
+ *
+ * example: av_resample_compensate(c, 10, 500)
+ * here instead of 510 samples only 500 samples would be output
+ *
+ * note, due to rounding the actual compensation might be slightly different,
+ * especially if the compensation_distance is large and the in_rate used during init is small
+ */
+attribute_deprecated
+void av_resample_compensate(struct AVResampleContext *c, int sample_delta, int compensation_distance);
+attribute_deprecated
+void av_resample_close(struct AVResampleContext *c);
+
+/**
+ * @}
+ */
+#endif
+
+/**
+ * @addtogroup lavc_picture
+ * @{
+ */
+
+/**
+ * Allocate memory for a picture.  Call avpicture_free() to free it.
+ *
+ * @see avpicture_fill()
+ *
+ * @param picture the picture to be filled in
+ * @param pix_fmt the format of the picture
+ * @param width the width of the picture
+ * @param height the height of the picture
+ * @return zero if successful, a negative value if not
+ */
+int avpicture_alloc(AVPicture *picture, enum AVPixelFormat pix_fmt, int width, int height);
+
+/**
+ * Free a picture previously allocated by avpicture_alloc().
+ * The data buffer used by the AVPicture is freed, but the AVPicture structure
+ * itself is not.
+ *
+ * @param picture the AVPicture to be freed
+ */
+void avpicture_free(AVPicture *picture);
+
+/**
+ * Fill in the AVPicture fields.
+ * The fields of the given AVPicture are filled in by using the 'ptr' address
+ * which points to the image data buffer. Depending on the specified picture
+ * format, one or multiple image data pointers and line sizes will be set.
+ * If a planar format is specified, several pointers will be set pointing to
+ * the different picture planes and the line sizes of the different planes
+ * will be stored in the lines_sizes array.
+ * Call with ptr == NULL to get the required size for the ptr buffer.
+ *
+ * To allocate the buffer and fill in the AVPicture fields in one call,
+ * use avpicture_alloc().
+ *
+ * @param picture AVPicture whose fields are to be filled in
+ * @param ptr Buffer which will contain or contains the actual image data
+ * @param pix_fmt The format in which the picture data is stored.
+ * @param width the width of the image in pixels
+ * @param height the height of the image in pixels
+ * @return size of the image data in bytes
+ */
+int avpicture_fill(AVPicture *picture, uint8_t *ptr,
+                   enum AVPixelFormat pix_fmt, int width, int height);
+
+/**
+ * Copy pixel data from an AVPicture into a buffer.
+ * The data is stored compactly, without any gaps for alignment or padding
+ * which may be applied by avpicture_fill().
+ *
+ * @see avpicture_get_size()
+ *
+ * @param[in] src AVPicture containing image data
+ * @param[in] pix_fmt The format in which the picture data is stored.
+ * @param[in] width the width of the image in pixels.
+ * @param[in] height the height of the image in pixels.
+ * @param[out] dest A buffer into which picture data will be copied.
+ * @param[in] dest_size The size of 'dest'.
+ * @return The number of bytes written to dest, or a negative value (error code) on error.
+ */
+int avpicture_layout(const AVPicture* src, enum AVPixelFormat pix_fmt,
+                     int width, int height,
+                     unsigned char *dest, int dest_size);
+
+/**
+ * Calculate the size in bytes that a picture of the given width and height
+ * would occupy if stored in the given picture format.
+ * Note that this returns the size of a compact representation as generated
+ * by avpicture_layout(), which can be smaller than the size required for e.g.
+ * avpicture_fill().
+ *
+ * @param pix_fmt the given picture format
+ * @param width the width of the image
+ * @param height the height of the image
+ * @return Image data size in bytes or -1 on error (e.g. too large dimensions).
+ */
+int avpicture_get_size(enum AVPixelFormat pix_fmt, int width, int height);
+
+/**
+ *  deinterlace - if not supported return -1
+ */
+int avpicture_deinterlace(AVPicture *dst, const AVPicture *src,
+                          enum AVPixelFormat pix_fmt, int width, int height);
+/**
+ * Copy image src to dst. Wraps av_picture_data_copy() above.
+ */
+void av_picture_copy(AVPicture *dst, const AVPicture *src,
+                     enum AVPixelFormat pix_fmt, int width, int height);
+
+/**
+ * Crop image top and left side.
+ */
+int av_picture_crop(AVPicture *dst, const AVPicture *src,
+                    enum AVPixelFormat pix_fmt, int top_band, int left_band);
+
+/**
+ * Pad image.
+ */
+int av_picture_pad(AVPicture *dst, const AVPicture *src, int height, int width, enum AVPixelFormat pix_fmt,
+            int padtop, int padbottom, int padleft, int padright, int *color);
+
+/**
+ * @}
+ */
+
+/**
+ * @defgroup lavc_misc Utility functions
+ * @ingroup libavc
+ *
+ * Miscellaneous utility functions related to both encoding and decoding
+ * (or neither).
+ * @{
+ */
+
+/**
+ * @defgroup lavc_misc_pixfmt Pixel formats
+ *
+ * Functions for working with pixel formats.
+ * @{
+ */
+
+void avcodec_get_chroma_sub_sample(enum AVPixelFormat pix_fmt, int *h_shift, int *v_shift);
+
+/**
+ * Return a value representing the fourCC code associated to the
+ * pixel format pix_fmt, or 0 if no associated fourCC code can be
+ * found.
+ */
+unsigned int avcodec_pix_fmt_to_codec_tag(enum AVPixelFormat pix_fmt);
+
+#define FF_LOSS_RESOLUTION  0x0001 /**< loss due to resolution change */
+#define FF_LOSS_DEPTH       0x0002 /**< loss due to color depth change */
+#define FF_LOSS_COLORSPACE  0x0004 /**< loss due to color space conversion */
+#define FF_LOSS_ALPHA       0x0008 /**< loss of alpha bits */
+#define FF_LOSS_COLORQUANT  0x0010 /**< loss due to color quantization */
+#define FF_LOSS_CHROMA      0x0020 /**< loss of chroma (e.g. RGB to gray conversion) */
+
+/**
+ * Compute what kind of losses will occur when converting from one specific
+ * pixel format to another.
+ * When converting from one pixel format to another, information loss may occur.
+ * For example, when converting from RGB24 to GRAY, the color information will
+ * be lost. Similarly, other losses occur when converting from some formats to
+ * other formats. These losses can involve loss of chroma, but also loss of
+ * resolution, loss of color depth, loss due to the color space conversion, loss
+ * of the alpha bits or loss due to color quantization.
+ * avcodec_get_fix_fmt_loss() informs you about the various types of losses
+ * which will occur when converting from one pixel format to another.
+ *
+ * @param[in] dst_pix_fmt destination pixel format
+ * @param[in] src_pix_fmt source pixel format
+ * @param[in] has_alpha Whether the source pixel format alpha channel is used.
+ * @return Combination of flags informing you what kind of losses will occur.
+ */
+int avcodec_get_pix_fmt_loss(enum AVPixelFormat dst_pix_fmt, enum AVPixelFormat src_pix_fmt,
+                             int has_alpha);
+
+#if FF_API_FIND_BEST_PIX_FMT
+/**
+ * @deprecated use avcodec_find_best_pix_fmt2() instead.
+ *
+ * Find the best pixel format to convert to given a certain source pixel
+ * format.  When converting from one pixel format to another, information loss
+ * may occur.  For example, when converting from RGB24 to GRAY, the color
+ * information will be lost. Similarly, other losses occur when converting from
+ * some formats to other formats. avcodec_find_best_pix_fmt() searches which of
+ * the given pixel formats should be used to suffer the least amount of loss.
+ * The pixel formats from which it chooses one, are determined by the
+ * pix_fmt_mask parameter.
+ *
+ * @code
+ * src_pix_fmt = AV_PIX_FMT_YUV420P;
+ * pix_fmt_mask = (1 << AV_PIX_FMT_YUV422P) || (1 << AV_PIX_FMT_RGB24);
+ * dst_pix_fmt = avcodec_find_best_pix_fmt(pix_fmt_mask, src_pix_fmt, alpha, &loss);
+ * @endcode
+ *
+ * @param[in] pix_fmt_mask bitmask determining which pixel format to choose from
+ * @param[in] src_pix_fmt source pixel format
+ * @param[in] has_alpha Whether the source pixel format alpha channel is used.
+ * @param[out] loss_ptr Combination of flags informing you what kind of losses will occur.
+ * @return The best pixel format to convert to or -1 if none was found.
+ */
+attribute_deprecated
+enum AVPixelFormat avcodec_find_best_pix_fmt(int64_t pix_fmt_mask, enum AVPixelFormat src_pix_fmt,
+                              int has_alpha, int *loss_ptr);
+#endif /* FF_API_FIND_BEST_PIX_FMT */
+
+/**
+ * Find the best pixel format to convert to given a certain source pixel
+ * format.  When converting from one pixel format to another, information loss
+ * may occur.  For example, when converting from RGB24 to GRAY, the color
+ * information will be lost. Similarly, other losses occur when converting from
+ * some formats to other formats. avcodec_find_best_pix_fmt2() searches which of
+ * the given pixel formats should be used to suffer the least amount of loss.
+ * The pixel formats from which it chooses one, are determined by the
+ * pix_fmt_list parameter.
+ *
+ *
+ * @param[in] pix_fmt_list AV_PIX_FMT_NONE terminated array of pixel formats to choose from
+ * @param[in] src_pix_fmt source pixel format
+ * @param[in] has_alpha Whether the source pixel format alpha channel is used.
+ * @param[out] loss_ptr Combination of flags informing you what kind of losses will occur.
+ * @return The best pixel format to convert to or -1 if none was found.
+ */
+enum AVPixelFormat avcodec_find_best_pix_fmt2(enum AVPixelFormat *pix_fmt_list,
+                                              enum AVPixelFormat src_pix_fmt,
+                                              int has_alpha, int *loss_ptr);
+
+enum AVPixelFormat avcodec_default_get_format(struct AVCodecContext *s, const enum AVPixelFormat * fmt);
+
+/**
+ * @}
+ */
+
+void avcodec_set_dimensions(AVCodecContext *s, int width, int height);
+
+/**
+ * Put a string representing the codec tag codec_tag in buf.
+ *
+ * @param buf_size size in bytes of buf
+ * @return the length of the string that would have been generated if
+ * enough space had been available, excluding the trailing null
+ */
+size_t av_get_codec_tag_string(char *buf, size_t buf_size, unsigned int codec_tag);
+
+void avcodec_string(char *buf, int buf_size, AVCodecContext *enc, int encode);
+
+/**
+ * Return a name for the specified profile, if available.
+ *
+ * @param codec the codec that is searched for the given profile
+ * @param profile the profile value for which a name is requested
+ * @return A name for the profile if found, NULL otherwise.
+ */
+const char *av_get_profile_name(const AVCodec *codec, int profile);
+
+int avcodec_default_execute(AVCodecContext *c, int (*func)(AVCodecContext *c2, void *arg2),void *arg, int *ret, int count, int size);
+int avcodec_default_execute2(AVCodecContext *c, int (*func)(AVCodecContext *c2, void *arg2, int, int),void *arg, int *ret, int count);
+//FIXME func typedef
+
+/**
+ * Fill audio frame data and linesize.
+ * AVFrame extended_data channel pointers are allocated if necessary for
+ * planar audio.
+ *
+ * @param frame       the AVFrame
+ *                    frame->nb_samples must be set prior to calling the
+ *                    function. This function fills in frame->data,
+ *                    frame->extended_data, frame->linesize[0].
+ * @param nb_channels channel count
+ * @param sample_fmt  sample format
+ * @param buf         buffer to use for frame data
+ * @param buf_size    size of buffer
+ * @param align       plane size sample alignment (0 = default)
+ * @return            0 on success, negative error code on failure
+ */
+int avcodec_fill_audio_frame(AVFrame *frame, int nb_channels,
+                             enum AVSampleFormat sample_fmt, const uint8_t *buf,
+                             int buf_size, int align);
+
+/**
+ * Flush buffers, should be called when seeking or when switching to a different stream.
+ */
+void avcodec_flush_buffers(AVCodecContext *avctx);
+
+void avcodec_default_free_buffers(AVCodecContext *s);
+
+/**
+ * Return codec bits per sample.
+ *
+ * @param[in] codec_id the codec
+ * @return Number of bits per sample or zero if unknown for the given codec.
+ */
+int av_get_bits_per_sample(enum AVCodecID codec_id);
+
+/**
+ * Return codec bits per sample.
+ * Only return non-zero if the bits per sample is exactly correct, not an
+ * approximation.
+ *
+ * @param[in] codec_id the codec
+ * @return Number of bits per sample or zero if unknown for the given codec.
+ */
+int av_get_exact_bits_per_sample(enum AVCodecID codec_id);
+
+/**
+ * Return audio frame duration.
+ *
+ * @param avctx        codec context
+ * @param frame_bytes  size of the frame, or 0 if unknown
+ * @return             frame duration, in samples, if known. 0 if not able to
+ *                     determine.
+ */
+int av_get_audio_frame_duration(AVCodecContext *avctx, int frame_bytes);
+
+
+typedef struct AVBitStreamFilterContext {
+    void *priv_data;
+    struct AVBitStreamFilter *filter;
+    AVCodecParserContext *parser;
+    struct AVBitStreamFilterContext *next;
+} AVBitStreamFilterContext;
+
+
+typedef struct AVBitStreamFilter {
+    const char *name;
+    int priv_data_size;
+    int (*filter)(AVBitStreamFilterContext *bsfc,
+                  AVCodecContext *avctx, const char *args,
+                  uint8_t **poutbuf, int *poutbuf_size,
+                  const uint8_t *buf, int buf_size, int keyframe);
+    void (*close)(AVBitStreamFilterContext *bsfc);
+    struct AVBitStreamFilter *next;
+} AVBitStreamFilter;
+
+void av_register_bitstream_filter(AVBitStreamFilter *bsf);
+AVBitStreamFilterContext *av_bitstream_filter_init(const char *name);
+int av_bitstream_filter_filter(AVBitStreamFilterContext *bsfc,
+                               AVCodecContext *avctx, const char *args,
+                               uint8_t **poutbuf, int *poutbuf_size,
+                               const uint8_t *buf, int buf_size, int keyframe);
+void av_bitstream_filter_close(AVBitStreamFilterContext *bsf);
+
+AVBitStreamFilter *av_bitstream_filter_next(AVBitStreamFilter *f);
+
+/* memory */
+
+/**
+ * Reallocate the given block if it is not large enough, otherwise do nothing.
+ *
+ * @see av_realloc
+ */
+void *av_fast_realloc(void *ptr, unsigned int *size, size_t min_size);
+
+/**
+ * Allocate a buffer, reusing the given one if large enough.
+ *
+ * Contrary to av_fast_realloc the current buffer contents might not be
+ * preserved and on error the old buffer is freed, thus no special
+ * handling to avoid memleaks is necessary.
+ *
+ * @param ptr pointer to pointer to already allocated buffer, overwritten with pointer to new buffer
+ * @param size size of the buffer *ptr points to
+ * @param min_size minimum size of *ptr buffer after returning, *ptr will be NULL and
+ *                 *size 0 if an error occurred.
+ */
+void av_fast_malloc(void *ptr, unsigned int *size, size_t min_size);
+
+/**
+ * Allocate a buffer with padding, reusing the given one if large enough.
+ *
+ * Same behaviour av_fast_malloc but the buffer has additional
+ * FF_INPUT_PADDING_SIZE at the end which will always memset to 0.
+ *
+ */
+void av_fast_padded_malloc(void *ptr, unsigned int *size, size_t min_size);
+
+/**
+ * Encode extradata length to a buffer. Used by xiph codecs.
+ *
+ * @param s buffer to write to; must be at least (v/255+1) bytes long
+ * @param v size of extradata in bytes
+ * @return number of bytes written to the buffer.
+ */
+unsigned int av_xiphlacing(unsigned char *s, unsigned int v);
+
+/**
+ * Log a generic warning message about a missing feature. This function is
+ * intended to be used internally by Libav (libavcodec, libavformat, etc.)
+ * only, and would normally not be used by applications.
+ * @param[in] avc a pointer to an arbitrary struct of which the first field is
+ * a pointer to an AVClass struct
+ * @param[in] feature string containing the name of the missing feature
+ * @param[in] want_sample indicates if samples are wanted which exhibit this feature.
+ * If want_sample is non-zero, additional verbage will be added to the log
+ * message which tells the user how to report samples to the development
+ * mailing list.
+ */
+void av_log_missing_feature(void *avc, const char *feature, int want_sample);
+
+/**
+ * Log a generic warning message asking for a sample. This function is
+ * intended to be used internally by Libav (libavcodec, libavformat, etc.)
+ * only, and would normally not be used by applications.
+ * @param[in] avc a pointer to an arbitrary struct of which the first field is
+ * a pointer to an AVClass struct
+ * @param[in] msg string containing an optional message, or NULL if no message
+ */
+void av_log_ask_for_sample(void *avc, const char *msg, ...) av_printf_format(2, 3);
+
+/**
+ * Register the hardware accelerator hwaccel.
+ */
+void av_register_hwaccel(AVHWAccel *hwaccel);
+
+/**
+ * If hwaccel is NULL, returns the first registered hardware accelerator,
+ * if hwaccel is non-NULL, returns the next registered hardware accelerator
+ * after hwaccel, or NULL if hwaccel is the last one.
+ */
+AVHWAccel *av_hwaccel_next(AVHWAccel *hwaccel);
+
+
+/**
+ * Lock operation used by lockmgr
+ */
+enum AVLockOp {
+  AV_LOCK_CREATE,  ///< Create a mutex
+  AV_LOCK_OBTAIN,  ///< Lock the mutex
+  AV_LOCK_RELEASE, ///< Unlock the mutex
+  AV_LOCK_DESTROY, ///< Free mutex resources
+};
+
+/**
+ * Register a user provided lock manager supporting the operations
+ * specified by AVLockOp. mutex points to a (void *) where the
+ * lockmgr should store/get a pointer to a user allocated mutex. It's
+ * NULL upon AV_LOCK_CREATE and != NULL for all other ops.
+ *
+ * @param cb User defined callback. Note: Libav may invoke calls to this
+ *           callback during the call to av_lockmgr_register().
+ *           Thus, the application must be prepared to handle that.
+ *           If cb is set to NULL the lockmgr will be unregistered.
+ *           Also note that during unregistration the previously registered
+ *           lockmgr callback may also be invoked.
+ */
+int av_lockmgr_register(int (*cb)(void **mutex, enum AVLockOp op));
+
+/**
+ * Get the type of the given codec.
+ */
+enum AVMediaType avcodec_get_type(enum AVCodecID codec_id);
+
+/**
+ * @return a positive value if s is open (i.e. avcodec_open2() was called on it
+ * with no corresponding avcodec_close()), 0 otherwise.
+ */
+int avcodec_is_open(AVCodecContext *s);
+
+/**
+ * @return a non-zero number if codec is an encoder, zero otherwise
+ */
+int av_codec_is_encoder(const AVCodec *codec);
+
+/**
+ * @return a non-zero number if codec is a decoder, zero otherwise
+ */
+int av_codec_is_decoder(const AVCodec *codec);
+
+/**
+ * @return descriptor for given codec ID or NULL if no descriptor exists.
+ */
+const AVCodecDescriptor *avcodec_descriptor_get(enum AVCodecID id);
+
+/**
+ * Iterate over all codec descriptors known to libavcodec.
+ *
+ * @param prev previous descriptor. NULL to get the first descriptor.
+ *
+ * @return next descriptor or NULL after the last descriptor
+ */
+const AVCodecDescriptor *avcodec_descriptor_next(const AVCodecDescriptor *prev);
+
+/**
+ * @return codec descriptor with the given name or NULL if no such descriptor
+ *         exists.
+ */
+const AVCodecDescriptor *avcodec_descriptor_get_by_name(const char *name);
+
+/**
+ * @}
+ */
+
+#endif /* AVCODEC_AVCODEC_H */