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/libavutil/common.h

http://github.com/FFmpeg/FFmpeg
C Header | 562 lines | 288 code | 50 blank | 224 comment | 56 complexity | 0cd5a728b56d5bb8485cf9f01fdd65a7 MD5 | raw file
  1/*
  2 * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
  3 *
  4 * This file is part of FFmpeg.
  5 *
  6 * FFmpeg 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 * FFmpeg 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 FFmpeg; 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#if defined(__cplusplus) && !defined(__STDC_CONSTANT_MACROS) && !defined(UINT64_C)
 30#error missing -D__STDC_CONSTANT_MACROS / #define __STDC_CONSTANT_MACROS
 31#endif
 32
 33#include <errno.h>
 34#include <inttypes.h>
 35#include <limits.h>
 36#include <math.h>
 37#include <stdint.h>
 38#include <stdio.h>
 39#include <stdlib.h>
 40#include <string.h>
 41
 42#include "attributes.h"
 43#include "macros.h"
 44#include "version.h"
 45#include "libavutil/avconfig.h"
 46
 47#if AV_HAVE_BIGENDIAN
 48#   define AV_NE(be, le) (be)
 49#else
 50#   define AV_NE(be, le) (le)
 51#endif
 52
 53//rounded division & shift
 54#define RSHIFT(a,b) ((a) > 0 ? ((a) + ((1<<(b))>>1))>>(b) : ((a) + ((1<<(b))>>1)-1)>>(b))
 55/* assume b>0 */
 56#define ROUNDED_DIV(a,b) (((a)>=0 ? (a) + ((b)>>1) : (a) - ((b)>>1))/(b))
 57/* Fast a/(1<<b) rounded toward +inf. Assume a>=0 and b>=0 */
 58#define AV_CEIL_RSHIFT(a,b) (!av_builtin_constant_p(b) ? -((-(a)) >> (b)) \
 59                                                       : ((a) + (1<<(b)) - 1) >> (b))
 60/* Backwards compat. */
 61#define FF_CEIL_RSHIFT AV_CEIL_RSHIFT
 62
 63#define FFUDIV(a,b) (((a)>0 ?(a):(a)-(b)+1) / (b))
 64#define FFUMOD(a,b) ((a)-(b)*FFUDIV(a,b))
 65
 66/**
 67 * Absolute value, Note, INT_MIN / INT64_MIN result in undefined behavior as they
 68 * are not representable as absolute values of their type. This is the same
 69 * as with *abs()
 70 * @see FFNABS()
 71 */
 72#define FFABS(a) ((a) >= 0 ? (a) : (-(a)))
 73#define FFSIGN(a) ((a) > 0 ? 1 : -1)
 74
 75/**
 76 * Negative Absolute value.
 77 * this works for all integers of all types.
 78 * As with many macros, this evaluates its argument twice, it thus must not have
 79 * a sideeffect, that is FFNABS(x++) has undefined behavior.
 80 */
 81#define FFNABS(a) ((a) <= 0 ? (a) : (-(a)))
 82
 83/**
 84 * Comparator.
 85 * For two numerical expressions x and y, gives 1 if x > y, -1 if x < y, and 0
 86 * if x == y. This is useful for instance in a qsort comparator callback.
 87 * Furthermore, compilers are able to optimize this to branchless code, and
 88 * there is no risk of overflow with signed types.
 89 * As with many macros, this evaluates its argument multiple times, it thus
 90 * must not have a side-effect.
 91 */
 92#define FFDIFFSIGN(x,y) (((x)>(y)) - ((x)<(y)))
 93
 94#define FFMAX(a,b) ((a) > (b) ? (a) : (b))
 95#define FFMAX3(a,b,c) FFMAX(FFMAX(a,b),c)
 96#define FFMIN(a,b) ((a) > (b) ? (b) : (a))
 97#define FFMIN3(a,b,c) FFMIN(FFMIN(a,b),c)
 98
 99#define FFSWAP(type,a,b) do{type SWAP_tmp= b; b= a; a= SWAP_tmp;}while(0)
100#define FF_ARRAY_ELEMS(a) (sizeof(a) / sizeof((a)[0]))
101
102/* misc math functions */
103
104#ifdef HAVE_AV_CONFIG_H
105#   include "config.h"
106#   include "intmath.h"
107#endif
108
109/* Pull in unguarded fallback defines at the end of this file. */
110#include "common.h"
111
112#ifndef av_log2
113av_const int av_log2(unsigned v);
114#endif
115
116#ifndef av_log2_16bit
117av_const int av_log2_16bit(unsigned v);
118#endif
119
120/**
121 * Clip a signed integer value into the amin-amax range.
122 * @param a value to clip
123 * @param amin minimum value of the clip range
124 * @param amax maximum value of the clip range
125 * @return clipped value
126 */
127static av_always_inline av_const int av_clip_c(int a, int amin, int amax)
128{
129#if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
130    if (amin > amax) abort();
131#endif
132    if      (a < amin) return amin;
133    else if (a > amax) return amax;
134    else               return a;
135}
136
137/**
138 * Clip a signed 64bit integer value into the amin-amax range.
139 * @param a value to clip
140 * @param amin minimum value of the clip range
141 * @param amax maximum value of the clip range
142 * @return clipped value
143 */
144static av_always_inline av_const int64_t av_clip64_c(int64_t a, int64_t amin, int64_t amax)
145{
146#if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
147    if (amin > amax) abort();
148#endif
149    if      (a < amin) return amin;
150    else if (a > amax) return amax;
151    else               return a;
152}
153
154/**
155 * Clip a signed integer value into the 0-255 range.
156 * @param a value to clip
157 * @return clipped value
158 */
159static av_always_inline av_const uint8_t av_clip_uint8_c(int a)
160{
161    if (a&(~0xFF)) return (~a)>>31;
162    else           return a;
163}
164
165/**
166 * Clip a signed integer value into the -128,127 range.
167 * @param a value to clip
168 * @return clipped value
169 */
170static av_always_inline av_const int8_t av_clip_int8_c(int a)
171{
172    if ((a+0x80U) & ~0xFF) return (a>>31) ^ 0x7F;
173    else                  return a;
174}
175
176/**
177 * Clip a signed integer value into the 0-65535 range.
178 * @param a value to clip
179 * @return clipped value
180 */
181static av_always_inline av_const uint16_t av_clip_uint16_c(int a)
182{
183    if (a&(~0xFFFF)) return (~a)>>31;
184    else             return a;
185}
186
187/**
188 * Clip a signed integer value into the -32768,32767 range.
189 * @param a value to clip
190 * @return clipped value
191 */
192static av_always_inline av_const int16_t av_clip_int16_c(int a)
193{
194    if ((a+0x8000U) & ~0xFFFF) return (a>>31) ^ 0x7FFF;
195    else                      return a;
196}
197
198/**
199 * Clip a signed 64-bit integer value into the -2147483648,2147483647 range.
200 * @param a value to clip
201 * @return clipped value
202 */
203static av_always_inline av_const int32_t av_clipl_int32_c(int64_t a)
204{
205    if ((a+0x80000000u) & ~UINT64_C(0xFFFFFFFF)) return (int32_t)((a>>63) ^ 0x7FFFFFFF);
206    else                                         return (int32_t)a;
207}
208
209/**
210 * Clip a signed integer into the -(2^p),(2^p-1) range.
211 * @param  a value to clip
212 * @param  p bit position to clip at
213 * @return clipped value
214 */
215static av_always_inline av_const int av_clip_intp2_c(int a, int p)
216{
217    if (((unsigned)a + (1 << p)) & ~((2 << p) - 1))
218        return (a >> 31) ^ ((1 << p) - 1);
219    else
220        return a;
221}
222
223/**
224 * Clip a signed integer to an unsigned power of two range.
225 * @param  a value to clip
226 * @param  p bit position to clip at
227 * @return clipped value
228 */
229static av_always_inline av_const unsigned av_clip_uintp2_c(int a, int p)
230{
231    if (a & ~((1<<p) - 1)) return (~a) >> 31 & ((1<<p) - 1);
232    else                   return  a;
233}
234
235/**
236 * Clear high bits from an unsigned integer starting with specific bit position
237 * @param  a value to clip
238 * @param  p bit position to clip at
239 * @return clipped value
240 */
241static av_always_inline av_const unsigned av_mod_uintp2_c(unsigned a, unsigned p)
242{
243    return a & ((1U << p) - 1);
244}
245
246/**
247 * Add two signed 32-bit values with saturation.
248 *
249 * @param  a one value
250 * @param  b another value
251 * @return sum with signed saturation
252 */
253static av_always_inline int av_sat_add32_c(int a, int b)
254{
255    return av_clipl_int32((int64_t)a + b);
256}
257
258/**
259 * Add a doubled value to another value with saturation at both stages.
260 *
261 * @param  a first value
262 * @param  b value doubled and added to a
263 * @return sum sat(a + sat(2*b)) with signed saturation
264 */
265static av_always_inline int av_sat_dadd32_c(int a, int b)
266{
267    return av_sat_add32(a, av_sat_add32(b, b));
268}
269
270/**
271 * Subtract two signed 32-bit values with saturation.
272 *
273 * @param  a one value
274 * @param  b another value
275 * @return difference with signed saturation
276 */
277static av_always_inline int av_sat_sub32_c(int a, int b)
278{
279    return av_clipl_int32((int64_t)a - b);
280}
281
282/**
283 * Subtract a doubled value from another value with saturation at both stages.
284 *
285 * @param  a first value
286 * @param  b value doubled and subtracted from a
287 * @return difference sat(a - sat(2*b)) with signed saturation
288 */
289static av_always_inline int av_sat_dsub32_c(int a, int b)
290{
291    return av_sat_sub32(a, av_sat_add32(b, b));
292}
293
294/**
295 * Clip a float value into the amin-amax range.
296 * @param a value to clip
297 * @param amin minimum value of the clip range
298 * @param amax maximum value of the clip range
299 * @return clipped value
300 */
301static av_always_inline av_const float av_clipf_c(float a, float amin, float amax)
302{
303#if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
304    if (amin > amax) abort();
305#endif
306    if      (a < amin) return amin;
307    else if (a > amax) return amax;
308    else               return a;
309}
310
311/**
312 * Clip a double value into the amin-amax range.
313 * @param a value to clip
314 * @param amin minimum value of the clip range
315 * @param amax maximum value of the clip range
316 * @return clipped value
317 */
318static av_always_inline av_const double av_clipd_c(double a, double amin, double amax)
319{
320#if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
321    if (amin > amax) abort();
322#endif
323    if      (a < amin) return amin;
324    else if (a > amax) return amax;
325    else               return a;
326}
327
328/** Compute ceil(log2(x)).
329 * @param x value used to compute ceil(log2(x))
330 * @return computed ceiling of log2(x)
331 */
332static av_always_inline av_const int av_ceil_log2_c(int x)
333{
334    return av_log2((x - 1) << 1);
335}
336
337/**
338 * Count number of bits set to one in x
339 * @param x value to count bits of
340 * @return the number of bits set to one in x
341 */
342static av_always_inline av_const int av_popcount_c(uint32_t x)
343{
344    x -= (x >> 1) & 0x55555555;
345    x = (x & 0x33333333) + ((x >> 2) & 0x33333333);
346    x = (x + (x >> 4)) & 0x0F0F0F0F;
347    x += x >> 8;
348    return (x + (x >> 16)) & 0x3F;
349}
350
351/**
352 * Count number of bits set to one in x
353 * @param x value to count bits of
354 * @return the number of bits set to one in x
355 */
356static av_always_inline av_const int av_popcount64_c(uint64_t x)
357{
358    return av_popcount((uint32_t)x) + av_popcount((uint32_t)(x >> 32));
359}
360
361static av_always_inline av_const int av_parity_c(uint32_t v)
362{
363    return av_popcount(v) & 1;
364}
365
366#define MKTAG(a,b,c,d) ((a) | ((b) << 8) | ((c) << 16) | ((unsigned)(d) << 24))
367#define MKBETAG(a,b,c,d) ((d) | ((c) << 8) | ((b) << 16) | ((unsigned)(a) << 24))
368
369/**
370 * Convert a UTF-8 character (up to 4 bytes) to its 32-bit UCS-4 encoded form.
371 *
372 * @param val      Output value, must be an lvalue of type uint32_t.
373 * @param GET_BYTE Expression reading one byte from the input.
374 *                 Evaluated up to 7 times (4 for the currently
375 *                 assigned Unicode range).  With a memory buffer
376 *                 input, this could be *ptr++, or if you want to make sure
377 *                 that *ptr stops at the end of a NULL terminated string then
378 *                 *ptr ? *ptr++ : 0
379 * @param ERROR    Expression to be evaluated on invalid input,
380 *                 typically a goto statement.
381 *
382 * @warning ERROR should not contain a loop control statement which
383 * could interact with the internal while loop, and should force an
384 * exit from the macro code (e.g. through a goto or a return) in order
385 * to prevent undefined results.
386 */
387#define GET_UTF8(val, GET_BYTE, ERROR)\
388    val= (GET_BYTE);\
389    {\
390        uint32_t top = (val & 128) >> 1;\
391        if ((val & 0xc0) == 0x80 || val >= 0xFE)\
392            {ERROR}\
393        while (val & top) {\
394            unsigned int tmp = (GET_BYTE) - 128;\
395            if(tmp>>6)\
396                {ERROR}\
397            val= (val<<6) + tmp;\
398            top <<= 5;\
399        }\
400        val &= (top << 1) - 1;\
401    }
402
403/**
404 * Convert a UTF-16 character (2 or 4 bytes) to its 32-bit UCS-4 encoded form.
405 *
406 * @param val       Output value, must be an lvalue of type uint32_t.
407 * @param GET_16BIT Expression returning two bytes of UTF-16 data converted
408 *                  to native byte order.  Evaluated one or two times.
409 * @param ERROR     Expression to be evaluated on invalid input,
410 *                  typically a goto statement.
411 */
412#define GET_UTF16(val, GET_16BIT, ERROR)\
413    val = (GET_16BIT);\
414    {\
415        unsigned int hi = val - 0xD800;\
416        if (hi < 0x800) {\
417            val = (GET_16BIT) - 0xDC00;\
418            if (val > 0x3FFU || hi > 0x3FFU)\
419                {ERROR}\
420            val += (hi<<10) + 0x10000;\
421        }\
422    }\
423
424/**
425 * @def PUT_UTF8(val, tmp, PUT_BYTE)
426 * Convert a 32-bit Unicode character to its UTF-8 encoded form (up to 4 bytes long).
427 * @param val is an input-only argument and should be of type uint32_t. It holds
428 * a UCS-4 encoded Unicode character that is to be converted to UTF-8. If
429 * val is given as a function it is executed only once.
430 * @param tmp is a temporary variable and should be of type uint8_t. It
431 * represents an intermediate value during conversion that is to be
432 * output by PUT_BYTE.
433 * @param PUT_BYTE writes the converted UTF-8 bytes to any proper destination.
434 * It could be a function or a statement, and uses tmp as the input byte.
435 * For example, PUT_BYTE could be "*output++ = tmp;" PUT_BYTE will be
436 * executed up to 4 times for values in the valid UTF-8 range and up to
437 * 7 times in the general case, depending on the length of the converted
438 * Unicode character.
439 */
440#define PUT_UTF8(val, tmp, PUT_BYTE)\
441    {\
442        int bytes, shift;\
443        uint32_t in = val;\
444        if (in < 0x80) {\
445            tmp = in;\
446            PUT_BYTE\
447        } else {\
448            bytes = (av_log2(in) + 4) / 5;\
449            shift = (bytes - 1) * 6;\
450            tmp = (256 - (256 >> bytes)) | (in >> shift);\
451            PUT_BYTE\
452            while (shift >= 6) {\
453                shift -= 6;\
454                tmp = 0x80 | ((in >> shift) & 0x3f);\
455                PUT_BYTE\
456            }\
457        }\
458    }
459
460/**
461 * @def PUT_UTF16(val, tmp, PUT_16BIT)
462 * Convert a 32-bit Unicode character to its UTF-16 encoded form (2 or 4 bytes).
463 * @param val is an input-only argument and should be of type uint32_t. It holds
464 * a UCS-4 encoded Unicode character that is to be converted to UTF-16. If
465 * val is given as a function it is executed only once.
466 * @param tmp is a temporary variable and should be of type uint16_t. It
467 * represents an intermediate value during conversion that is to be
468 * output by PUT_16BIT.
469 * @param PUT_16BIT writes the converted UTF-16 data to any proper destination
470 * in desired endianness. It could be a function or a statement, and uses tmp
471 * as the input byte.  For example, PUT_BYTE could be "*output++ = tmp;"
472 * PUT_BYTE will be executed 1 or 2 times depending on input character.
473 */
474#define PUT_UTF16(val, tmp, PUT_16BIT)\
475    {\
476        uint32_t in = val;\
477        if (in < 0x10000) {\
478            tmp = in;\
479            PUT_16BIT\
480        } else {\
481            tmp = 0xD800 | ((in - 0x10000) >> 10);\
482            PUT_16BIT\
483            tmp = 0xDC00 | ((in - 0x10000) & 0x3FF);\
484            PUT_16BIT\
485        }\
486    }\
487
488
489
490#include "mem.h"
491
492#ifdef HAVE_AV_CONFIG_H
493#    include "internal.h"
494#endif /* HAVE_AV_CONFIG_H */
495
496#endif /* AVUTIL_COMMON_H */
497
498/*
499 * The following definitions are outside the multiple inclusion guard
500 * to ensure they are immediately available in intmath.h.
501 */
502
503#ifndef av_ceil_log2
504#   define av_ceil_log2     av_ceil_log2_c
505#endif
506#ifndef av_clip
507#   define av_clip          av_clip_c
508#endif
509#ifndef av_clip64
510#   define av_clip64        av_clip64_c
511#endif
512#ifndef av_clip_uint8
513#   define av_clip_uint8    av_clip_uint8_c
514#endif
515#ifndef av_clip_int8
516#   define av_clip_int8     av_clip_int8_c
517#endif
518#ifndef av_clip_uint16
519#   define av_clip_uint16   av_clip_uint16_c
520#endif
521#ifndef av_clip_int16
522#   define av_clip_int16    av_clip_int16_c
523#endif
524#ifndef av_clipl_int32
525#   define av_clipl_int32   av_clipl_int32_c
526#endif
527#ifndef av_clip_intp2
528#   define av_clip_intp2    av_clip_intp2_c
529#endif
530#ifndef av_clip_uintp2
531#   define av_clip_uintp2   av_clip_uintp2_c
532#endif
533#ifndef av_mod_uintp2
534#   define av_mod_uintp2    av_mod_uintp2_c
535#endif
536#ifndef av_sat_add32
537#   define av_sat_add32     av_sat_add32_c
538#endif
539#ifndef av_sat_dadd32
540#   define av_sat_dadd32    av_sat_dadd32_c
541#endif
542#ifndef av_sat_sub32
543#   define av_sat_sub32     av_sat_sub32_c
544#endif
545#ifndef av_sat_dsub32
546#   define av_sat_dsub32    av_sat_dsub32_c
547#endif
548#ifndef av_clipf
549#   define av_clipf         av_clipf_c
550#endif
551#ifndef av_clipd
552#   define av_clipd         av_clipd_c
553#endif
554#ifndef av_popcount
555#   define av_popcount      av_popcount_c
556#endif
557#ifndef av_popcount64
558#   define av_popcount64    av_popcount64_c
559#endif
560#ifndef av_parity
561#   define av_parity        av_parity_c
562#endif