xref: /third_party/ffmpeg/libavutil/common.h (revision cabdff1a) 
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
45//rounded division & shift
46#define RSHIFT(a,b) ((a) > 0 ? ((a) + ((1<<(b))>>1))>>(b) : ((a) + ((1<<(b))>>1)-1)>>(b))
47/* assume b>0 */
48#define ROUNDED_DIV(a,b) (((a)>=0 ? (a) + ((b)>>1) : (a) - ((b)>>1))/(b))
49/* Fast a/(1<<b) rounded toward +inf. Assume a>=0 and b>=0 */
50#define AV_CEIL_RSHIFT(a,b) (!av_builtin_constant_p(b) ? -((-(a)) >> (b)) \
51                                                       : ((a) + (1<<(b)) - 1) >> (b))
52/* Backwards compat. */
53#define FF_CEIL_RSHIFT AV_CEIL_RSHIFT
54
55#define FFUDIV(a,b) (((a)>0 ?(a):(a)-(b)+1) / (b))
56#define FFUMOD(a,b) ((a)-(b)*FFUDIV(a,b))
57
58/**
59 * Absolute value, Note, INT_MIN / INT64_MIN result in undefined behavior as they
60 * are not representable as absolute values of their type. This is the same
61 * as with *abs()
62 * @see FFNABS()
63 */
64#define FFABS(a) ((a) >= 0 ? (a) : (-(a)))
65#define FFSIGN(a) ((a) > 0 ? 1 : -1)
66
67/**
68 * Negative Absolute value.
69 * this works for all integers of all types.
70 * As with many macros, this evaluates its argument twice, it thus must not have
71 * a sideeffect, that is FFNABS(x++) has undefined behavior.
72 */
73#define FFNABS(a) ((a) <= 0 ? (a) : (-(a)))
74
75/**
76 * Unsigned Absolute value.
77 * This takes the absolute value of a signed int and returns it as a unsigned.
78 * This also works with INT_MIN which would otherwise not be representable
79 * As with many macros, this evaluates its argument twice.
80 */
81#define FFABSU(a) ((a) <= 0 ? -(unsigned)(a) : (unsigned)(a))
82#define FFABS64U(a) ((a) <= 0 ? -(uint64_t)(a) : (uint64_t)(a))
83
84/* misc math functions */
85
86#ifdef HAVE_AV_CONFIG_H
87#   include "config.h"
88#   include "intmath.h"
89#endif
90
91#ifndef av_ceil_log2
92#   define av_ceil_log2     av_ceil_log2_c
93#endif
94#ifndef av_clip
95#   define av_clip          av_clip_c
96#endif
97#ifndef av_clip64
98#   define av_clip64        av_clip64_c
99#endif
100#ifndef av_clip_uint8
101#   define av_clip_uint8    av_clip_uint8_c
102#endif
103#ifndef av_clip_int8
104#   define av_clip_int8     av_clip_int8_c
105#endif
106#ifndef av_clip_uint16
107#   define av_clip_uint16   av_clip_uint16_c
108#endif
109#ifndef av_clip_int16
110#   define av_clip_int16    av_clip_int16_c
111#endif
112#ifndef av_clipl_int32
113#   define av_clipl_int32   av_clipl_int32_c
114#endif
115#ifndef av_clip_intp2
116#   define av_clip_intp2    av_clip_intp2_c
117#endif
118#ifndef av_clip_uintp2
119#   define av_clip_uintp2   av_clip_uintp2_c
120#endif
121#ifndef av_mod_uintp2
122#   define av_mod_uintp2    av_mod_uintp2_c
123#endif
124#ifndef av_sat_add32
125#   define av_sat_add32     av_sat_add32_c
126#endif
127#ifndef av_sat_dadd32
128#   define av_sat_dadd32    av_sat_dadd32_c
129#endif
130#ifndef av_sat_sub32
131#   define av_sat_sub32     av_sat_sub32_c
132#endif
133#ifndef av_sat_dsub32
134#   define av_sat_dsub32    av_sat_dsub32_c
135#endif
136#ifndef av_sat_add64
137#   define av_sat_add64     av_sat_add64_c
138#endif
139#ifndef av_sat_sub64
140#   define av_sat_sub64     av_sat_sub64_c
141#endif
142#ifndef av_clipf
143#   define av_clipf         av_clipf_c
144#endif
145#ifndef av_clipd
146#   define av_clipd         av_clipd_c
147#endif
148#ifndef av_popcount
149#   define av_popcount      av_popcount_c
150#endif
151#ifndef av_popcount64
152#   define av_popcount64    av_popcount64_c
153#endif
154#ifndef av_parity
155#   define av_parity        av_parity_c
156#endif
157
158#ifndef av_log2
159av_const int av_log2(unsigned v);
160#endif
161
162#ifndef av_log2_16bit
163av_const int av_log2_16bit(unsigned v);
164#endif
165
166/**
167 * Clip a signed integer value into the amin-amax range.
168 * @param a value to clip
169 * @param amin minimum value of the clip range
170 * @param amax maximum value of the clip range
171 * @return clipped value
172 */
173static av_always_inline av_const int av_clip_c(int a, int amin, int amax)
174{
175#if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
176    if (amin > amax) abort();
177#endif
178    if      (a < amin) return amin;
179    else if (a > amax) return amax;
180    else               return a;
181}
182
183/**
184 * Clip a signed 64bit integer value into the amin-amax range.
185 * @param a value to clip
186 * @param amin minimum value of the clip range
187 * @param amax maximum value of the clip range
188 * @return clipped value
189 */
190static av_always_inline av_const int64_t av_clip64_c(int64_t a, int64_t amin, int64_t amax)
191{
192#if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
193    if (amin > amax) abort();
194#endif
195    if      (a < amin) return amin;
196    else if (a > amax) return amax;
197    else               return a;
198}
199
200/**
201 * Clip a signed integer value into the 0-255 range.
202 * @param a value to clip
203 * @return clipped value
204 */
205static av_always_inline av_const uint8_t av_clip_uint8_c(int a)
206{
207    if (a&(~0xFF)) return (~a)>>31;
208    else           return a;
209}
210
211/**
212 * Clip a signed integer value into the -128,127 range.
213 * @param a value to clip
214 * @return clipped value
215 */
216static av_always_inline av_const int8_t av_clip_int8_c(int a)
217{
218    if ((a+0x80U) & ~0xFF) return (a>>31) ^ 0x7F;
219    else                  return a;
220}
221
222/**
223 * Clip a signed integer value into the 0-65535 range.
224 * @param a value to clip
225 * @return clipped value
226 */
227static av_always_inline av_const uint16_t av_clip_uint16_c(int a)
228{
229    if (a&(~0xFFFF)) return (~a)>>31;
230    else             return a;
231}
232
233/**
234 * Clip a signed integer value into the -32768,32767 range.
235 * @param a value to clip
236 * @return clipped value
237 */
238static av_always_inline av_const int16_t av_clip_int16_c(int a)
239{
240    if ((a+0x8000U) & ~0xFFFF) return (a>>31) ^ 0x7FFF;
241    else                      return a;
242}
243
244/**
245 * Clip a signed 64-bit integer value into the -2147483648,2147483647 range.
246 * @param a value to clip
247 * @return clipped value
248 */
249static av_always_inline av_const int32_t av_clipl_int32_c(int64_t a)
250{
251    if ((a+0x80000000u) & ~UINT64_C(0xFFFFFFFF)) return (int32_t)((a>>63) ^ 0x7FFFFFFF);
252    else                                         return (int32_t)a;
253}
254
255/**
256 * Clip a signed integer into the -(2^p),(2^p-1) range.
257 * @param  a value to clip
258 * @param  p bit position to clip at
259 * @return clipped value
260 */
261static av_always_inline av_const int av_clip_intp2_c(int a, int p)
262{
263    if (((unsigned)a + (1 << p)) & ~((2 << p) - 1))
264        return (a >> 31) ^ ((1 << p) - 1);
265    else
266        return a;
267}
268
269/**
270 * Clip a signed integer to an unsigned power of two range.
271 * @param  a value to clip
272 * @param  p bit position to clip at
273 * @return clipped value
274 */
275static av_always_inline av_const unsigned av_clip_uintp2_c(int a, int p)
276{
277    if (a & ~((1<<p) - 1)) return (~a) >> 31 & ((1<<p) - 1);
278    else                   return  a;
279}
280
281/**
282 * Clear high bits from an unsigned integer starting with specific bit position
283 * @param  a value to clip
284 * @param  p bit position to clip at
285 * @return clipped value
286 */
287static av_always_inline av_const unsigned av_mod_uintp2_c(unsigned a, unsigned p)
288{
289    return a & ((1U << p) - 1);
290}
291
292/**
293 * Add two signed 32-bit values with saturation.
294 *
295 * @param  a one value
296 * @param  b another value
297 * @return sum with signed saturation
298 */
299static av_always_inline int av_sat_add32_c(int a, int b)
300{
301    return av_clipl_int32((int64_t)a + b);
302}
303
304/**
305 * Add a doubled value to another value with saturation at both stages.
306 *
307 * @param  a first value
308 * @param  b value doubled and added to a
309 * @return sum sat(a + sat(2*b)) with signed saturation
310 */
311static av_always_inline int av_sat_dadd32_c(int a, int b)
312{
313    return av_sat_add32(a, av_sat_add32(b, b));
314}
315
316/**
317 * Subtract two signed 32-bit values with saturation.
318 *
319 * @param  a one value
320 * @param  b another value
321 * @return difference with signed saturation
322 */
323static av_always_inline int av_sat_sub32_c(int a, int b)
324{
325    return av_clipl_int32((int64_t)a - b);
326}
327
328/**
329 * Subtract a doubled value from another value with saturation at both stages.
330 *
331 * @param  a first value
332 * @param  b value doubled and subtracted from a
333 * @return difference sat(a - sat(2*b)) with signed saturation
334 */
335static av_always_inline int av_sat_dsub32_c(int a, int b)
336{
337    return av_sat_sub32(a, av_sat_add32(b, b));
338}
339
340/**
341 * Add two signed 64-bit values with saturation.
342 *
343 * @param  a one value
344 * @param  b another value
345 * @return sum with signed saturation
346 */
347static av_always_inline int64_t av_sat_add64_c(int64_t a, int64_t b) {
348#if (!defined(__INTEL_COMPILER) && AV_GCC_VERSION_AT_LEAST(5,1)) || AV_HAS_BUILTIN(__builtin_add_overflow)
349    int64_t tmp;
350    return !__builtin_add_overflow(a, b, &tmp) ? tmp : (tmp < 0 ? INT64_MAX : INT64_MIN);
351#else
352    int64_t s = a+(uint64_t)b;
353    if ((int64_t)(a^b | ~s^b) >= 0)
354        return INT64_MAX ^ (b >> 63);
355    return s;
356#endif
357}
358
359/**
360 * Subtract two signed 64-bit values with saturation.
361 *
362 * @param  a one value
363 * @param  b another value
364 * @return difference with signed saturation
365 */
366static av_always_inline int64_t av_sat_sub64_c(int64_t a, int64_t b) {
367#if (!defined(__INTEL_COMPILER) && AV_GCC_VERSION_AT_LEAST(5,1)) || AV_HAS_BUILTIN(__builtin_sub_overflow)
368    int64_t tmp;
369    return !__builtin_sub_overflow(a, b, &tmp) ? tmp : (tmp < 0 ? INT64_MAX : INT64_MIN);
370#else
371    if (b <= 0 && a >= INT64_MAX + b)
372        return INT64_MAX;
373    if (b >= 0 && a <= INT64_MIN + b)
374        return INT64_MIN;
375    return a - b;
376#endif
377}
378
379/**
380 * Clip a float value into the amin-amax range.
381 * If a is nan or -inf amin will be returned.
382 * If a is +inf amax will be returned.
383 * @param a value to clip
384 * @param amin minimum value of the clip range
385 * @param amax maximum value of the clip range
386 * @return clipped value
387 */
388static av_always_inline av_const float av_clipf_c(float a, float amin, float amax)
389{
390#if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
391    if (amin > amax) abort();
392#endif
393    return FFMIN(FFMAX(a, amin), amax);
394}
395
396/**
397 * Clip a double value into the amin-amax range.
398 * If a is nan or -inf amin will be returned.
399 * If a is +inf amax will be returned.
400 * @param a value to clip
401 * @param amin minimum value of the clip range
402 * @param amax maximum value of the clip range
403 * @return clipped value
404 */
405static av_always_inline av_const double av_clipd_c(double a, double amin, double amax)
406{
407#if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
408    if (amin > amax) abort();
409#endif
410    return FFMIN(FFMAX(a, amin), amax);
411}
412
413/** Compute ceil(log2(x)).
414 * @param x value used to compute ceil(log2(x))
415 * @return computed ceiling of log2(x)
416 */
417static av_always_inline av_const int av_ceil_log2_c(int x)
418{
419    return av_log2((x - 1U) << 1);
420}
421
422/**
423 * Count number of bits set to one in x
424 * @param x value to count bits of
425 * @return the number of bits set to one in x
426 */
427static av_always_inline av_const int av_popcount_c(uint32_t x)
428{
429    x -= (x >> 1) & 0x55555555;
430    x = (x & 0x33333333) + ((x >> 2) & 0x33333333);
431    x = (x + (x >> 4)) & 0x0F0F0F0F;
432    x += x >> 8;
433    return (x + (x >> 16)) & 0x3F;
434}
435
436/**
437 * Count number of bits set to one in x
438 * @param x value to count bits of
439 * @return the number of bits set to one in x
440 */
441static av_always_inline av_const int av_popcount64_c(uint64_t x)
442{
443    return av_popcount((uint32_t)x) + av_popcount((uint32_t)(x >> 32));
444}
445
446static av_always_inline av_const int av_parity_c(uint32_t v)
447{
448    return av_popcount(v) & 1;
449}
450
451/**
452 * Convert a UTF-8 character (up to 4 bytes) to its 32-bit UCS-4 encoded form.
453 *
454 * @param val      Output value, must be an lvalue of type uint32_t.
455 * @param GET_BYTE Expression reading one byte from the input.
456 *                 Evaluated up to 7 times (4 for the currently
457 *                 assigned Unicode range).  With a memory buffer
458 *                 input, this could be *ptr++, or if you want to make sure
459 *                 that *ptr stops at the end of a NULL terminated string then
460 *                 *ptr ? *ptr++ : 0
461 * @param ERROR    Expression to be evaluated on invalid input,
462 *                 typically a goto statement.
463 *
464 * @warning ERROR should not contain a loop control statement which
465 * could interact with the internal while loop, and should force an
466 * exit from the macro code (e.g. through a goto or a return) in order
467 * to prevent undefined results.
468 */
469#define GET_UTF8(val, GET_BYTE, ERROR)\
470    val= (GET_BYTE);\
471    {\
472        uint32_t top = (val & 128) >> 1;\
473        if ((val & 0xc0) == 0x80 || val >= 0xFE)\
474            {ERROR}\
475        while (val & top) {\
476            unsigned int tmp = (GET_BYTE) - 128;\
477            if(tmp>>6)\
478                {ERROR}\
479            val= (val<<6) + tmp;\
480            top <<= 5;\
481        }\
482        val &= (top << 1) - 1;\
483    }
484
485/**
486 * Convert a UTF-16 character (2 or 4 bytes) to its 32-bit UCS-4 encoded form.
487 *
488 * @param val       Output value, must be an lvalue of type uint32_t.
489 * @param GET_16BIT Expression returning two bytes of UTF-16 data converted
490 *                  to native byte order.  Evaluated one or two times.
491 * @param ERROR     Expression to be evaluated on invalid input,
492 *                  typically a goto statement.
493 */
494#define GET_UTF16(val, GET_16BIT, ERROR)\
495    val = (GET_16BIT);\
496    {\
497        unsigned int hi = val - 0xD800;\
498        if (hi < 0x800) {\
499            val = (GET_16BIT) - 0xDC00;\
500            if (val > 0x3FFU || hi > 0x3FFU)\
501                {ERROR}\
502            val += (hi<<10) + 0x10000;\
503        }\
504    }\
505
506/**
507 * @def PUT_UTF8(val, tmp, PUT_BYTE)
508 * Convert a 32-bit Unicode character to its UTF-8 encoded form (up to 4 bytes long).
509 * @param val is an input-only argument and should be of type uint32_t. It holds
510 * a UCS-4 encoded Unicode character that is to be converted to UTF-8. If
511 * val is given as a function it is executed only once.
512 * @param tmp is a temporary variable and should be of type uint8_t. It
513 * represents an intermediate value during conversion that is to be
514 * output by PUT_BYTE.
515 * @param PUT_BYTE writes the converted UTF-8 bytes to any proper destination.
516 * It could be a function or a statement, and uses tmp as the input byte.
517 * For example, PUT_BYTE could be "*output++ = tmp;" PUT_BYTE will be
518 * executed up to 4 times for values in the valid UTF-8 range and up to
519 * 7 times in the general case, depending on the length of the converted
520 * Unicode character.
521 */
522#define PUT_UTF8(val, tmp, PUT_BYTE)\
523    {\
524        int bytes, shift;\
525        uint32_t in = val;\
526        if (in < 0x80) {\
527            tmp = in;\
528            PUT_BYTE\
529        } else {\
530            bytes = (av_log2(in) + 4) / 5;\
531            shift = (bytes - 1) * 6;\
532            tmp = (256 - (256 >> bytes)) | (in >> shift);\
533            PUT_BYTE\
534            while (shift >= 6) {\
535                shift -= 6;\
536                tmp = 0x80 | ((in >> shift) & 0x3f);\
537                PUT_BYTE\
538            }\
539        }\
540    }
541
542/**
543 * @def PUT_UTF16(val, tmp, PUT_16BIT)
544 * Convert a 32-bit Unicode character to its UTF-16 encoded form (2 or 4 bytes).
545 * @param val is an input-only argument and should be of type uint32_t. It holds
546 * a UCS-4 encoded Unicode character that is to be converted to UTF-16. If
547 * val is given as a function it is executed only once.
548 * @param tmp is a temporary variable and should be of type uint16_t. It
549 * represents an intermediate value during conversion that is to be
550 * output by PUT_16BIT.
551 * @param PUT_16BIT writes the converted UTF-16 data to any proper destination
552 * in desired endianness. It could be a function or a statement, and uses tmp
553 * as the input byte.  For example, PUT_BYTE could be "*output++ = tmp;"
554 * PUT_BYTE will be executed 1 or 2 times depending on input character.
555 */
556#define PUT_UTF16(val, tmp, PUT_16BIT)\
557    {\
558        uint32_t in = val;\
559        if (in < 0x10000) {\
560            tmp = in;\
561            PUT_16BIT\
562        } else {\
563            tmp = 0xD800 | ((in - 0x10000) >> 10);\
564            PUT_16BIT\
565            tmp = 0xDC00 | ((in - 0x10000) & 0x3FF);\
566            PUT_16BIT\
567        }\
568    }\
569
570
571
572#include "mem.h"
573
574#ifdef HAVE_AV_CONFIG_H
575#    include "internal.h"
576#endif /* HAVE_AV_CONFIG_H */
577
578#endif /* AVUTIL_COMMON_H */
579