/*

 * Hedgewars, a free turn based strategy game

 * Copyright (c) 2004-2015 Andrey Korotaev <unC0Rr@gmail.com>

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; version 2 of the License

 *

 * This program 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 General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

 */

#include <stdlib.h>

#include <stdio.h>

#include <stdint.h>

#include <string.h>

#include <stdarg.h>

#include "libavcodec/avcodec.h"

#include "libavformat/avformat.h"

#include "libavutil/avutil.h"

#include "libavutil/mathematics.h"

#if (defined _MSC_VER)

#define AVWRAP_DECL __declspec(dllexport)

#elif ((__GNUC__ >= 3) && (!__EMX__) && (!sun))

#define AVWRAP_DECL __attribute__((visibility("default")))

#else

#define AVWRAP_DECL

#endif

static AVFormatContext* g_pContainer;

static AVOutputFormat* g_pFormat;

static AVStream* g_pAStream;

static AVStream* g_pVStream;

static AVFrame* g_pAFrame;

static AVFrame* g_pVFrame;

static AVCodec* g_pACodec;

static AVCodec* g_pVCodec;

static AVCodecContext* g_pAudio;

static AVCodecContext* g_pVideo;

static int g_Width, g_Height;

static uint32_t g_Frequency, g_Channels;

static int g_VQuality;

static AVRational g_Framerate;

static FILE* g_pSoundFile;

static int16_t* g_pSamples;

static int g_NumSamples;

// compatibility section

#if LIBAVCODEC_VERSION_MAJOR < 54

#define OUTBUFFER_SIZE 200000

static uint8_t g_OutBuffer[OUTBUFFER_SIZE];

#define avcodec_open2(x, y, z)              avcodec_open(x, y)

#endif

#if LIBAVCODEC_VERSION_MAJOR < 55

#define avcodec_default_get_buffer2(x, y ,z) avcodec_default_get_buffer(x, y)

#endif

#if LIBAVCODEC_VERSION_MAJOR < 56

#define av_frame_alloc                      avcodec_alloc_frame

#define av_frame_unref                      avcodec_get_frame_defaults

#define av_packet_rescale_ts                rescale_ts

static void rescale_ts(AVPacket *pkt, AVRational ctb, AVRational stb)

{

    if (pkt->pts != AV_NOPTS_VALUE)

        pkt->pts = av_rescale_q(pkt->pts, ctb, stb);

    if (pkt->dts != AV_NOPTS_VALUE)

        pkt->dts = av_rescale_q(pkt->dts, ctb, stb);

    if (pkt->duration > 0)

        pkt->duration = av_rescale_q(pkt->duration, ctb, stb);

}

#endif

#ifndef AV_CODEC_CAP_DELAY

#define AV_CODEC_CAP_DELAY                  CODEC_CAP_DELAY

#endif

#ifndef AV_CODEC_CAP_VARIABLE_FRAME_SIZE

#define AV_CODEC_CAP_VARIABLE_FRAME_SIZE    CODEC_CAP_VARIABLE_FRAME_SIZE

#endif

#ifndef AV_CODEC_FLAG_GLOBAL_HEADER

#define AV_CODEC_FLAG_GLOBAL_HEADER         CODEC_FLAG_GLOBAL_HEADER

#endif

#ifndef AV_CODEC_FLAG_QSCALE

#define AV_CODEC_FLAG_QSCALE                CODEC_FLAG_QSCALE

#endif

#if LIBAVFORMAT_VERSION_MAJOR < 53

#define AVIO_FLAG_WRITE                     AVIO_WRONLY

#endif

#if LIBAVFORMAT_VERSION_MAJOR < 54

#define avformat_new_stream(x, y)           av_new_stream(x, y->type == AVMEDIA_TYPE_AUDIO)

#endif

#if LIBAVUTIL_VERSION_MAJOR < 54

#define AV_PIX_FMT_YUV420P                  PIX_FMT_YUV420P

#endif

// pointer to function from hwengine (uUtils.pas)

static void (*AddFileLogRaw)(const char* pString);

static int FatalError(const char* pFmt, ...)

{

    char Buffer[1024];

    va_list VaArgs;

    va_start(VaArgs, pFmt);

    vsnprintf(Buffer, 1024, pFmt, VaArgs);

    va_end(VaArgs);

    AddFileLogRaw("Error in av-wrapper: ");

    AddFileLogRaw(Buffer);

    AddFileLogRaw("\n");

    return(-1);

}

// Function to be called from libav for logging.

// Note: libav can call LogCallback from different threads

// (there is mutex in AddFileLogRaw).

static void LogCallback(void* p, int Level, const char* pFmt, va_list VaArgs)

{

    char Buffer[1024];

    vsnprintf(Buffer, 1024, pFmt, VaArgs);

    AddFileLogRaw(Buffer);

}

static void Log(const char* pFmt, ...)

{

    char Buffer[1024];

    va_list VaArgs;

    va_start(VaArgs, pFmt);

    vsnprintf(Buffer, 1024, pFmt, VaArgs);

    va_end(VaArgs);

    AddFileLogRaw(Buffer);

}

static void AddAudioStream()

{

    g_pAStream = avformat_new_stream(g_pContainer, g_pACodec);

    if(!g_pAStream)

    {

        Log("Could not allocate audio stream\n");

        return;

    }

    g_pAStream->id = 1;

    g_pAudio = g_pAStream->codec;

    avcodec_get_context_defaults3(g_pAudio, g_pACodec);

    g_pAudio->codec_id = g_pACodec->id;

    // put parameters

    g_pAudio->sample_fmt = AV_SAMPLE_FMT_S16;

    g_pAudio->sample_rate = g_Frequency;

    g_pAudio->channels = g_Channels;

    // set time base as invers of sample rate

    g_pAudio->time_base.den = g_pAStream->time_base.den = g_Frequency;

    g_pAudio->time_base.num = g_pAStream->time_base.num = 1;

    // set quality

    g_pAudio->bit_rate = 160000;

    // for codecs that support variable bitrate use it, it should be better

    g_pAudio->flags |= AV_CODEC_FLAG_QSCALE;

    g_pAudio->global_quality = 1*FF_QP2LAMBDA;

    // some formats want stream headers to be separate

    if (g_pFormat->flags & AVFMT_GLOBALHEADER)

        g_pAudio->flags |= AV_CODEC_FLAG_GLOBAL_HEADER;

    // open it

    if (avcodec_open2(g_pAudio, g_pACodec, NULL) < 0)

    {

        Log("Could not open audio codec %s\n", g_pACodec->long_name);

        return;

    }

#if LIBAVCODEC_VERSION_MAJOR >= 54

    if (g_pACodec->capabilities & AV_CODEC_CAP_VARIABLE_FRAME_SIZE)

#else

    if (g_pAudio->frame_size == 0)

#endif

        g_NumSamples = 4096;

    else

        g_NumSamples = g_pAudio->frame_size;

    g_pSamples = (int16_t*)av_malloc(g_NumSamples*g_Channels*sizeof(int16_t));

    g_pAFrame = av_frame_alloc();

    if (!g_pAFrame)

    {

        Log("Could not allocate frame\n");

        return;

    }

}

// returns non-zero if there is more sound, -1 in case of error

static int WriteAudioFrame()

{

    if (!g_pAStream)

        return 0;

    AVPacket Packet;

    av_init_packet(&Packet);

    Packet.data = NULL;

    Packet.size = 0;

    int NumSamples = fread(g_pSamples, 2*g_Channels, g_NumSamples, g_pSoundFile);

#if LIBAVCODEC_VERSION_MAJOR >= 53

    AVFrame* pFrame = NULL;

    if (NumSamples > 0)

    {

        g_pAFrame->nb_samples = NumSamples;

        avcodec_fill_audio_frame(g_pAFrame, g_Channels, AV_SAMPLE_FMT_S16,

                                 (uint8_t*)g_pSamples, NumSamples*2*g_Channels, 1);

        pFrame = g_pAFrame;

    }

    // when NumSamples == 0 we still need to call encode_audio2 to flush

    int got_packet;

    if (avcodec_encode_audio2(g_pAudio, &Packet, pFrame, &got_packet) != 0)

        return FatalError("avcodec_encode_audio2 failed");

    if (!got_packet)

        return 0;

    av_packet_rescale_ts(&Packet, g_pAudio->time_base, g_pAStream->time_base);

#else

    if (NumSamples == 0)

        return 0;

    int BufferSize = OUTBUFFER_SIZE;

    if (g_pAudio->frame_size == 0)

        BufferSize = NumSamples*g_Channels*2;

    Packet.size = avcodec_encode_audio(g_pAudio, g_OutBuffer, BufferSize, g_pSamples);

    if (Packet.size == 0)

        return 1;

    if (g_pAudio->coded_frame && g_pAudio->coded_frame->pts != AV_NOPTS_VALUE)

        Packet.pts = av_rescale_q(g_pAudio->coded_frame->pts, g_pAudio->time_base, g_pAStream->time_base);

    Packet.flags |= AV_PKT_FLAG_KEY;

    Packet.data = g_OutBuffer;

#endif

    // Write the compressed frame to the media file.

    Packet.stream_index = g_pAStream->index;

    if (av_interleaved_write_frame(g_pContainer, &Packet) != 0)

        return FatalError("Error while writing audio frame");

    return 1;

}

// add a video output stream

static int AddVideoStream()

{

    g_pVStream = avformat_new_stream(g_pContainer, g_pVCodec);

    if (!g_pVStream)

        return FatalError("Could not allocate video stream");

    g_pVideo = g_pVStream->codec;

    avcodec_get_context_defaults3(g_pVideo, g_pVCodec);

    g_pVideo->codec_id = g_pVCodec->id;

    // put parameters

    // resolution must be a multiple of two

    g_pVideo->width  = g_Width  & ~1; // make even (dimensions should be even)

    g_pVideo->height = g_Height & ~1; // make even

    /* time base: 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. */

    g_pVideo->time_base.den = g_pVStream->time_base.den = g_Framerate.num;

    g_pVideo->time_base.num = g_pVStream->time_base.num = g_Framerate.den;

    g_pVideo->pix_fmt = AV_PIX_FMT_YUV420P;

    // set quality

    if (g_VQuality > 100)

        g_pVideo->bit_rate = g_VQuality;

    else

    {

        g_pVideo->flags |= AV_CODEC_FLAG_QSCALE;

        g_pVideo->global_quality = g_VQuality*FF_QP2LAMBDA;

    }

    // some formats want stream headers to be separate

    if (g_pFormat->flags & AVFMT_GLOBALHEADER)

        g_pVideo->flags |= AV_CODEC_FLAG_GLOBAL_HEADER;

#if LIBAVCODEC_VERSION_MAJOR < 53

    // for some versions of ffmpeg x264 options must be set explicitly

    if (strcmp(g_pVCodec->name, "libx264") == 0)

    {

        g_pVideo->coder_type = FF_CODER_TYPE_AC;

        g_pVideo->flags |= CODEC_FLAG_LOOP_FILTER;

        g_pVideo->crf = 23;

        g_pVideo->thread_count = 3;

        g_pVideo->me_cmp = FF_CMP_CHROMA;

        g_pVideo->partitions = X264_PART_I8X8 | X264_PART_I4X4 | X264_PART_P8X8 | X264_PART_B8X8;

        g_pVideo->me_method = ME_HEX;

        g_pVideo->me_subpel_quality = 7;

        g_pVideo->me_range = 16;

        g_pVideo->gop_size = 250;

        g_pVideo->keyint_min = 25;

        g_pVideo->scenechange_threshold = 40;

        g_pVideo->i_quant_factor = 0.71;

        g_pVideo->b_frame_strategy = 1;

        g_pVideo->qcompress = 0.6;

        g_pVideo->qmin = 10;

        g_pVideo->qmax = 51;

        g_pVideo->max_qdiff = 4;

        g_pVideo->max_b_frames = 3;

        g_pVideo->refs = 3;

        g_pVideo->directpred = 1;

        g_pVideo->trellis = 1;

        g_pVideo->flags2 = CODEC_FLAG2_BPYRAMID | CODEC_FLAG2_MIXED_REFS | CODEC_FLAG2_WPRED | CODEC_FLAG2_8X8DCT | CODEC_FLAG2_FASTPSKIP;

        g_pVideo->weighted_p_pred = 2;

    }

#endif

    // open the codec

    if (avcodec_open2(g_pVideo, g_pVCodec, NULL) < 0)

        return FatalError("Could not open video codec %s", g_pVCodec->long_name);

    g_pVFrame = av_frame_alloc();

    if (!g_pVFrame)

        return FatalError("Could not allocate frame");

    av_frame_unref(g_pVFrame);

    g_pVFrame->width = g_Width;

    g_pVFrame->height = g_Height;

    g_pVFrame->format = AV_PIX_FMT_YUV420P;

    return avcodec_default_get_buffer2(g_pVideo, g_pVFrame, 0);

}

static int WriteFrame(AVFrame* pFrame)

{

    double AudioTime, VideoTime;

    int ret;

    // write interleaved audio frame

    if (g_pAStream)

    {

        VideoTime = (double)g_pVFrame->pts * g_pVStream->time_base.num/g_pVStream->time_base.den;

        do

        {

            AudioTime = (double)g_pAFrame->pts * g_pAStream->time_base.num/g_pAStream->time_base.den;

            ret = WriteAudioFrame();

        }

        while (AudioTime < VideoTime && ret);

        if (ret < 0)

            return ret;

    }

    if (!g_pVStream)

        return 0;

    AVPacket Packet;

    av_init_packet(&Packet);

    Packet.data = NULL;

    Packet.size = 0;

    g_pVFrame->pts++;

#if LIBAVCODEC_VERSION_MAJOR < 58

    if (g_pFormat->flags & AVFMT_RAWPICTURE)

    {

        /* raw video case. The API will change slightly in the near

           future for that. */

        Packet.flags |= AV_PKT_FLAG_KEY;

        Packet.stream_index = g_pVStream->index;

        Packet.data = (uint8_t*)pFrame;

        Packet.size = sizeof(AVPicture);

        if (av_interleaved_write_frame(g_pContainer, &Packet) != 0)

            return FatalError("Error while writing video frame");

        return 0;

    }

    else

#endif

    {

#if LIBAVCODEC_VERSION_MAJOR >= 54

        int got_packet;

        if (avcodec_encode_video2(g_pVideo, &Packet, pFrame, &got_packet) < 0)

            return FatalError("avcodec_encode_video2 failed");

        if (!got_packet)

            return 0;

        av_packet_rescale_ts(&Packet, g_pVideo->time_base, g_pVStream->time_base);

#else

        Packet.size = avcodec_encode_video(g_pVideo, g_OutBuffer, OUTBUFFER_SIZE, pFrame);

        if (Packet.size < 0)

            return FatalError("avcodec_encode_video failed");

        if (Packet.size == 0)

            return 0;

        if( g_pVideo->coded_frame->pts != AV_NOPTS_VALUE)

            Packet.pts = av_rescale_q(g_pVideo->coded_frame->pts, g_pVideo->time_base, g_pVStream->time_base);

        if( g_pVideo->coded_frame->key_frame )

            Packet.flags |= AV_PKT_FLAG_KEY;

        Packet.data = g_OutBuffer;

#endif

        // write the compressed frame in the media file

        Packet.stream_index = g_pVStream->index;

        if (av_interleaved_write_frame(g_pContainer, &Packet) != 0)

            return FatalError("Error while writing video frame");

        return 1;

    }

}

AVWRAP_DECL int AVWrapper_WriteFrame(uint8_t *buf)

{

    int x, y, stride = g_Width * 4;

    uint8_t *data[3];

    // copy pointers, prepare source

    memcpy(data, g_pVFrame->data, sizeof(data));

    buf += (g_Height - 1) * stride;

    // convert to YUV 4:2:0

    for (y = 0; y < g_Height; y++) {

        for (x = 0; x < g_Width; x++) {

            int r = buf[x * 4 + 0];

            int g = buf[x * 4 + 1];

            int b = buf[x * 4 + 2];

            int luma = (int)(0.299f * r +  0.587f * g + 0.114f * b);

            data[0][x] = av_clip_uint8(luma);

            if (!(x & 1) && !(y & 1)) {

                int r = (buf[x * 4 + 0]          + buf[(x + 1) * 4 + 0] +

                         buf[x * 4 + 0 + stride] + buf[(x + 1) * 4 + 0 + stride]) / 4;

                int g = (buf[x * 4 + 1]          + buf[(x + 1) * 4 + 1] +

                         buf[x * 4 + 1 + stride] + buf[(x + 1) * 4 + 1 + stride]) / 4;

                int b = (buf[x * 4 + 2]          + buf[(x + 1) * 4 + 2] +

                         buf[x * 4 + 2 + stride] + buf[(x + 1) * 4 + 2 + stride]) / 4;

                int cr = (int)(-0.14713f * r - 0.28886f * g + 0.436f   * b);

                int cb = (int)( 0.615f   * r - 0.51499f * g - 0.10001f * b);

                data[1][x / 2] = av_clip_uint8(128 + cr);

                data[2][x / 2] = av_clip_uint8(128 + cb);

            }

        }

        buf += -stride;

        data[0] += g_pVFrame->linesize[0];

        if (y & 1) {

            data[1] += g_pVFrame->linesize[1];

            data[2] += g_pVFrame->linesize[2];

        }

    }

    return WriteFrame(g_pVFrame);

}

AVWRAP_DECL int AVWrapper_Init(

         void (*pAddFileLogRaw)(const char*),

         const char* pFilename,

         const char* pDesc,

         const char* pSoundFile,

         const char* pFormatName,

         const char* pVCodecName,

         const char* pACodecName,

         int Width, int Height,

         int FramerateNum, int FramerateDen,

         int VQuality)

{

    int ret;

    AddFileLogRaw = pAddFileLogRaw;

    av_log_set_callback( &LogCallback );

    g_Width  = Width;

    g_Height = Height;

    g_Framerate.num = FramerateNum;

    g_Framerate.den = FramerateDen;

    g_VQuality = VQuality;

    // initialize libav and register all codecs and formats

    av_register_all();

    // find format

    g_pFormat = av_guess_format(pFormatName, NULL, NULL);

    if (!g_pFormat)

        return FatalError("Format \"%s\" was not found", pFormatName);

    // allocate the output media context