1 /*

     2  * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>

     3  *

     4  * This file is part of Libav.

     5  *

     6  * Libav is free software; you can redistribute it and/or

     7  * modify it under the terms of the GNU Lesser General Public

     8  * License as published by the Free Software Foundation; either

     9  * version 2.1 of the License, or (at your option) any later version.

    10  *

    11  * Libav is distributed in the hope that it will be useful,

    12  * but WITHOUT ANY WARRANTY; without even the implied warranty of

    13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

    14  * Lesser General Public License for more details.

    15  *

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

    17  * License along with Libav; if not, write to the Free Software

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

    19  */

    20 

    21 /**

    22  * @file

    23  * common internal and external API header

    24  */

    25 

    26 #ifndef AVUTIL_COMMON_H

    27 #define AVUTIL_COMMON_H

    28 

    29 #include <ctype.h>

    30 #include <errno.h>

    31 #include <inttypes.h>

    32 #include <limits.h>

    33 #include <math.h>

    34 #include <stdio.h>

    35 #include <stdlib.h>

    36 #include <string.h>

    37 

    38 #include "attributes.h"

    39 #include "version.h"

    40 #include "libavutil/avconfig.h"

    41 

    42 #if AV_HAVE_BIGENDIAN

    43 #   define AV_NE(be, le) (be)

    44 #else

    45 #   define AV_NE(be, le) (le)

    46 #endif

    47 

    48 //rounded division & shift

    49 #define RSHIFT(a,b) ((a) > 0 ? ((a) + ((1<<(b))>>1))>>(b) : ((a) + ((1<<(b))>>1)-1)>>(b))

    50 /* assume b>0 */

    51 #define ROUNDED_DIV(a,b) (((a)>0 ? (a) + ((b)>>1) : (a) - ((b)>>1))/(b))

    52 #define FFABS(a) ((a) >= 0 ? (a) : (-(a)))

    53 #define FFSIGN(a) ((a) > 0 ? 1 : -1)

    54 

    55 #define FFMAX(a,b) ((a) > (b) ? (a) : (b))

    56 #define FFMAX3(a,b,c) FFMAX(FFMAX(a,b),c)

    57 #define FFMIN(a,b) ((a) > (b) ? (b) : (a))

    58 #define FFMIN3(a,b,c) FFMIN(FFMIN(a,b),c)

    59 

    60 #define FFSWAP(type,a,b) do{type SWAP_tmp= b; b= a; a= SWAP_tmp;}while(0)

    61 #define FF_ARRAY_ELEMS(a) (sizeof(a) / sizeof((a)[0]))

    62 #define FFALIGN(x, a) (((x)+(a)-1)&~((a)-1))

    63 

    64 /* misc math functions */

    65 

    66 #if FF_API_AV_REVERSE

    67 extern attribute_deprecated const uint8_t av_reverse[256];

    68 #endif

    69 

    70 #ifdef HAVE_AV_CONFIG_H

    71 #   include "config.h"

    72 #   include "intmath.h"

    73 #endif

    74 

    75 /* Pull in unguarded fallback defines at the end of this file. */

    76 #include "common.h"

    77 

    78 #ifndef av_log2

    79 av_const int av_log2(unsigned v);

    80 #endif

    81 

    82 #ifndef av_log2_16bit

    83 av_const int av_log2_16bit(unsigned v);

    84 #endif

    85 

    86 /**

    87  * Clip a signed integer value into the amin-amax range.

    88  * @param a value to clip

    89  * @param amin minimum value of the clip range

    90  * @param amax maximum value of the clip range

    91  * @return clipped value

    92  */

    93 static av_always_inline av_const int av_clip_c(int a, int amin, int amax)

    94 {

    95     if      (a < amin) return amin;

    96     else if (a > amax) return amax;

    97     else               return a;

    98 }

    99 

   100 /**

   101  * Clip a signed integer value into the 0-255 range.

   102  * @param a value to clip

   103  * @return clipped value

   104  */

   105 static av_always_inline av_const uint8_t av_clip_uint8_c(int a)

   106 {

   107     if (a&(~0xFF)) return (-a)>>31;

   108     else           return a;

   109 }

   110 

   111 /**

   112  * Clip a signed integer value into the -128,127 range.

   113  * @param a value to clip

   114  * @return clipped value

   115  */

   116 static av_always_inline av_const int8_t av_clip_int8_c(int a)

   117 {

   118     if ((a+0x80) & ~0xFF) return (a>>31) ^ 0x7F;

   119     else                  return a;

   120 }

   121 

   122 /**

   123  * Clip a signed integer value into the 0-65535 range.

   124  * @param a value to clip

   125  * @return clipped value

   126  */

   127 static av_always_inline av_const uint16_t av_clip_uint16_c(int a)

   128 {

   129     if (a&(~0xFFFF)) return (-a)>>31;

   130     else             return a;

   131 }

   132 

   133 /**

   134  * Clip a signed integer value into the -32768,32767 range.

   135  * @param a value to clip

   136  * @return clipped value

   137  */

   138 static av_always_inline av_const int16_t av_clip_int16_c(int a)

   139 {

   140     if ((a+0x8000) & ~0xFFFF) return (a>>31) ^ 0x7FFF;

   141     else                      return a;

   142 }

   143 

   144 /**

   145  * Clip a signed 64-bit integer value into the -2147483648,2147483647 range.

   146  * @param a value to clip

   147  * @return clipped value

   148  */

   149 static av_always_inline av_const int32_t av_clipl_int32_c(int64_t a)

   150 {

   151     if ((a+0x80000000u) & ~UINT64_C(0xFFFFFFFF)) return (a>>63) ^ 0x7FFFFFFF;

   152     else                                         return a;

   153 }

   154 

   155 /**

   156  * Clip a signed integer to an unsigned power of two range.

   157  * @param  a value to clip

   158  * @param  p bit position to clip at

   159  * @return clipped value

   160  */

   161 static av_always_inline av_const unsigned av_clip_uintp2_c(int a, int p)

   162 {

   163     if (a & ~((1<<p) - 1)) return -a >> 31 & ((1<<p) - 1);

   164     else                   return  a;

   165 }

   166 

   167 /**

   168  * Add two signed 32-bit values with saturation.

   169  *

   170  * @param  a one value

   171  * @param  b another value

   172  * @return sum with signed saturation

   173  */

   174 static av_always_inline int av_sat_add32_c(int a, int b)

   175 {

   176     return av_clipl_int32((int64_t)a + b);

   177 }

   178 

   179 /**

   180  * Add a doubled value to another value with saturation at both stages.

   181  *

   182  * @param  a first value

   183  * @param  b value doubled and added to a

   184  * @return sum with signed saturation

   185  */

   186 static av_always_inline int av_sat_dadd32_c(int a, int b)

   187 {

   188     return av_sat_add32(a, av_sat_add32(b, b));

   189 }

   190 

   191 /**

   192  * Clip a float value into the amin-amax range.

   193  * @param a value to clip

   194  * @param amin minimum value of the clip range

   195  * @param amax maximum value of the clip range

   196  * @return clipped value

   197  */

   198 static av_always_inline av_const float av_clipf_c(float a, float amin, float amax)

   199 {

   200     if      (a < amin) return amin;

   201     else if (a > amax) return amax;

   202     else               return a;

   203 }

   204 

   205 /** Compute ceil(log2(x)).

   206  * @param x value used to compute ceil(log2(x))

   207  * @return computed ceiling of log2(x)

   208  */

   209 static av_always_inline av_const int av_ceil_log2_c(int x)

   210 {

   211     return av_log2((x - 1) << 1);

   212 }

   213 

   214 /**

   215  * Count number of bits set to one in x

   216  * @param x value to count bits of

   217  * @return the number of bits set to one in x

   218  */

   219 static av_always_inline av_const int av_popcount_c(uint32_t x)

   220 {

   221     x -= (x >> 1) & 0x55555555;

   222     x = (x & 0x33333333) + ((x >> 2) & 0x33333333);

   223     x = (x + (x >> 4)) & 0x0F0F0F0F;

   224     x += x >> 8;

   225     return (x + (x >> 16)) & 0x3F;

   226 }

   227 

   228 /**

   229  * Count number of bits set to one in x

   230  * @param x value to count bits of

   231  * @return the number of bits set to one in x

   232  */

   233 static av_always_inline av_const int av_popcount64_c(uint64_t x)

   234 {

   235     return av_popcount(x) + av_popcount(x >> 32);

   236 }

   237 

   238 #define MKTAG(a,b,c,d) ((a) | ((b) << 8) | ((c) << 16) | ((unsigned)(d) << 24))

   239 #define MKBETAG(a,b,c,d) ((d) | ((c) << 8) | ((b) << 16) | ((unsigned)(a) << 24))

   240 

   241 /**

   242  * Convert a UTF-8 character (up to 4 bytes) to its 32-bit UCS-4 encoded form.

   243  *

   244  * @param val      Output value, must be an lvalue of type uint32_t.

   245  * @param GET_BYTE Expression reading one byte from the input.

   246  *                 Evaluated up to 7 times (4 for the currently

   247  *                 assigned Unicode range).  With a memory buffer

   248  *                 input, this could be *ptr++.

   249  * @param ERROR    Expression to be evaluated on invalid input,

   250  *                 typically a goto statement.

   251  */

   252 #define GET_UTF8(val, GET_BYTE, ERROR)\

   253     val= GET_BYTE;\

   254     {\

   255         int ones= 7 - av_log2(val ^ 255);\

   256         if(ones==1)\

   257             ERROR\

   258         val&= 127>>ones;\

   259         while(--ones > 0){\

   260             int tmp= GET_BYTE - 128;\

   261             if(tmp>>6)\

   262                 ERROR\

   263             val= (val<<6) + tmp;\

   264         }\

   265     }

   266 

   267 /**

   268  * Convert a UTF-16 character (2 or 4 bytes) to its 32-bit UCS-4 encoded form.

   269  *

   270  * @param val       Output value, must be an lvalue of type uint32_t.

   271  * @param GET_16BIT Expression returning two bytes of UTF-16 data converted

   272  *                  to native byte order.  Evaluated one or two times.

   273  * @param ERROR     Expression to be evaluated on invalid input,

   274  *                  typically a goto statement.

   275  */

   276 #define GET_UTF16(val, GET_16BIT, ERROR)\

   277     val = GET_16BIT;\

   278     {\

   279         unsigned int hi = val - 0xD800;\

   280         if (hi < 0x800) {\

   281             val = GET_16BIT - 0xDC00;\

   282             if (val > 0x3FFU || hi > 0x3FFU)\

   283                 ERROR\

   284             val += (hi<<10) + 0x10000;\

   285         }\

   286     }\

   287 

   288 /**

   289  * @def PUT_UTF8(val, tmp, PUT_BYTE)

   290  * Convert a 32-bit Unicode character to its UTF-8 encoded form (up to 4 bytes long).

   291  * @param val is an input-only argument and should be of type uint32_t. It holds

   292  * a UCS-4 encoded Unicode character that is to be converted to UTF-8. If

   293  * val is given as a function it is executed only once.

   294  * @param tmp is a temporary variable and should be of type uint8_t. It

   295  * represents an intermediate value during conversion that is to be

   296  * output by PUT_BYTE.

   297  * @param PUT_BYTE writes the converted UTF-8 bytes to any proper destination.

   298  * It could be a function or a statement, and uses tmp as the input byte.

   299  * For example, PUT_BYTE could be "*output++ = tmp;" PUT_BYTE will be

   300  * executed up to 4 times for values in the valid UTF-8 range and up to

   301  * 7 times in the general case, depending on the length of the converted

   302  * Unicode character.

   303  */

   304 #define PUT_UTF8(val, tmp, PUT_BYTE)\

   305     {\

   306         int bytes, shift;\

   307         uint32_t in = val;\

   308         if (in < 0x80) {\

   309             tmp = in;\

   310             PUT_BYTE\

   311         } else {\

   312             bytes = (av_log2(in) + 4) / 5;\

   313             shift = (bytes - 1) * 6;\

   314             tmp = (256 - (256 >> bytes)) | (in >> shift);\

   315             PUT_BYTE\

   316             while (shift >= 6) {\

   317                 shift -= 6;\

   318                 tmp = 0x80 | ((in >> shift) & 0x3f);\

   319                 PUT_BYTE\

   320             }\

   321         }\

   322     }

   323 

   324 /**

   325  * @def PUT_UTF16(val, tmp, PUT_16BIT)

   326  * Convert a 32-bit Unicode character to its UTF-16 encoded form (2 or 4 bytes).

   327  * @param val is an input-only argument and should be of type uint32_t. It holds

   328  * a UCS-4 encoded Unicode character that is to be converted to UTF-16. If

   329  * val is given as a function it is executed only once.

   330  * @param tmp is a temporary variable and should be of type uint16_t. It

   331  * represents an intermediate value during conversion that is to be

   332  * output by PUT_16BIT.

   333  * @param PUT_16BIT writes the converted UTF-16 data to any proper destination

   334  * in desired endianness. It could be a function or a statement, and uses tmp

   335  * as the input byte.  For example, PUT_BYTE could be "*output++ = tmp;"

   336  * PUT_BYTE will be executed 1 or 2 times depending on input character.

   337  */

   338 #define PUT_UTF16(val, tmp, PUT_16BIT)\

   339     {\

   340         uint32_t in = val;\

   341         if (in < 0x10000) {\

   342             tmp = in;\

   343             PUT_16BIT\

   344         } else {\

   345             tmp = 0xD800 | ((in - 0x10000) >> 10);\

   346             PUT_16BIT\

   347             tmp = 0xDC00 | ((in - 0x10000) & 0x3FF);\

   348             PUT_16BIT\

   349         }\

   350     }\

   351 

   352 

   353 

   354 #include "mem.h"

   355 

   356 #ifdef HAVE_AV_CONFIG_H

   357 #    include "internal.h"

   358 #endif /* HAVE_AV_CONFIG_H */

   359 

   360 #endif /* AVUTIL_COMMON_H */

   361 

   362 /*

   363  * The following definitions are outside the multiple inclusion guard

   364  * to ensure they are immediately available in intmath.h.

   365  */

   366 

   367 #ifndef av_ceil_log2

   368 #   define av_ceil_log2     av_ceil_log2_c

   369 #endif

   370 #ifndef av_clip

   371 #   define av_clip          av_clip_c

   372 #endif

   373 #ifndef av_clip_uint8

   374 #   define av_clip_uint8    av_clip_uint8_c

   375 #endif

   376 #ifndef av_clip_int8

   377 #   define av_clip_int8     av_clip_int8_c

   378 #endif

   379 #ifndef av_clip_uint16

   380 #   define av_clip_uint16   av_clip_uint16_c

   381 #endif

   382 #ifndef av_clip_int16

   383 #   define av_clip_int16    av_clip_int16_c

   384 #endif

   385 #ifndef av_clipl_int32

   386 #   define av_clipl_int32   av_clipl_int32_c

   387 #endif

   388 #ifndef av_clip_uintp2

   389 #   define av_clip_uintp2   av_clip_uintp2_c

   390 #endif

   391 #ifndef av_sat_add32

   392 #   define av_sat_add32     av_sat_add32_c

   393 #endif

   394 #ifndef av_sat_dadd32

   395 #   define av_sat_dadd32    av_sat_dadd32_c

   396 #endif

   397 #ifndef av_clipf

   398 #   define av_clipf         av_clipf_c

   399 #endif

   400 #ifndef av_popcount

   401 #   define av_popcount      av_popcount_c

   402 #endif

   403 #ifndef av_popcount64

   404 #   define av_popcount64    av_popcount64_c

   405 #endif