FFmpeg/libavutil/common.h
Andreas Rheinhardt bd50e715a9 avutil/common: Move everything inside inclusion guards
libavutil/common.h is a public header that provides generic math
functions whereas libavutil/intmath.h is a private header that contains
plattform-specific optimized versions of said math functions. common.h
includes intmath.h (when building the FFmpeg libraries) so that the
optimized versions are used for them.

This interdependency sometimes causes trouble: intmath.h once contained
an inlined ff_sqrt function that relied upon av_log2_16bit. In case there
was no optimized logarithm available on this plattform, intmath.h needed
to include common.h to get the generic implementation and this has been
done after the optimized versions (if any) have been provided so that
common.h used the optimized versions; it also needed to be done before
ff_sqrt. Yet when intmath.h was included from common.h and if an ordinary
inclusion guard was used by common.h, the #include "common.h" in intmath.h
was a no-op and therefore av_log2_16bit was still unknown at the end of
intmath.h (and also in ff_sqrt) if no optimized version was available.

Before a955b59658 this was solved by
duplicating the #ifndef av_log2_16bit check after the inclusion of
common.h in intmath.h; said commit instead moved these checks to the
end of common.h, outside the inclusion guards and made common.h include
itself to get these unguarded defines. This is still the current
state of affairs.

Yet this is unnecessary since 9734b8ba56
as said commit removed ff_sqrt as well as the #include "common.h" from
intmath.h. Therefore this commit moves everything inside the inclusion
guards and makes common.h not include itself.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
2021-02-11 09:07:10 +01:00

609 lines
18 KiB
C

/*
* copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
*
* This file is part of FFmpeg.
*
* FFmpeg 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.
*
* FFmpeg 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 FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* common internal and external API header
*/
#ifndef AVUTIL_COMMON_H
#define AVUTIL_COMMON_H
#if defined(__cplusplus) && !defined(__STDC_CONSTANT_MACROS) && !defined(UINT64_C)
#error missing -D__STDC_CONSTANT_MACROS / #define __STDC_CONSTANT_MACROS
#endif
#include <errno.h>
#include <inttypes.h>
#include <limits.h>
#include <math.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "attributes.h"
#include "macros.h"
#include "version.h"
#include "libavutil/avconfig.h"
#if AV_HAVE_BIGENDIAN
# define AV_NE(be, le) (be)
#else
# define AV_NE(be, le) (le)
#endif
//rounded division & shift
#define RSHIFT(a,b) ((a) > 0 ? ((a) + ((1<<(b))>>1))>>(b) : ((a) + ((1<<(b))>>1)-1)>>(b))
/* assume b>0 */
#define ROUNDED_DIV(a,b) (((a)>=0 ? (a) + ((b)>>1) : (a) - ((b)>>1))/(b))
/* Fast a/(1<<b) rounded toward +inf. Assume a>=0 and b>=0 */
#define AV_CEIL_RSHIFT(a,b) (!av_builtin_constant_p(b) ? -((-(a)) >> (b)) \
: ((a) + (1<<(b)) - 1) >> (b))
/* Backwards compat. */
#define FF_CEIL_RSHIFT AV_CEIL_RSHIFT
#define FFUDIV(a,b) (((a)>0 ?(a):(a)-(b)+1) / (b))
#define FFUMOD(a,b) ((a)-(b)*FFUDIV(a,b))
/**
* Absolute value, Note, INT_MIN / INT64_MIN result in undefined behavior as they
* are not representable as absolute values of their type. This is the same
* as with *abs()
* @see FFNABS()
*/
#define FFABS(a) ((a) >= 0 ? (a) : (-(a)))
#define FFSIGN(a) ((a) > 0 ? 1 : -1)
/**
* Negative Absolute value.
* this works for all integers of all types.
* As with many macros, this evaluates its argument twice, it thus must not have
* a sideeffect, that is FFNABS(x++) has undefined behavior.
*/
#define FFNABS(a) ((a) <= 0 ? (a) : (-(a)))
/**
* Unsigned Absolute value.
* This takes the absolute value of a signed int and returns it as a unsigned.
* This also works with INT_MIN which would otherwise not be representable
* As with many macros, this evaluates its argument twice.
*/
#define FFABSU(a) ((a) <= 0 ? -(unsigned)(a) : (unsigned)(a))
#define FFABS64U(a) ((a) <= 0 ? -(uint64_t)(a) : (uint64_t)(a))
/**
* Comparator.
* For two numerical expressions x and y, gives 1 if x > y, -1 if x < y, and 0
* if x == y. This is useful for instance in a qsort comparator callback.
* Furthermore, compilers are able to optimize this to branchless code, and
* there is no risk of overflow with signed types.
* As with many macros, this evaluates its argument multiple times, it thus
* must not have a side-effect.
*/
#define FFDIFFSIGN(x,y) (((x)>(y)) - ((x)<(y)))
#define FFMAX(a,b) ((a) > (b) ? (a) : (b))
#define FFMAX3(a,b,c) FFMAX(FFMAX(a,b),c)
#define FFMIN(a,b) ((a) > (b) ? (b) : (a))
#define FFMIN3(a,b,c) FFMIN(FFMIN(a,b),c)
#define FFSWAP(type,a,b) do{type SWAP_tmp= b; b= a; a= SWAP_tmp;}while(0)
#define FF_ARRAY_ELEMS(a) (sizeof(a) / sizeof((a)[0]))
/* misc math functions */
#ifdef HAVE_AV_CONFIG_H
# include "config.h"
# include "intmath.h"
#endif
#ifndef av_ceil_log2
# define av_ceil_log2 av_ceil_log2_c
#endif
#ifndef av_clip
# define av_clip av_clip_c
#endif
#ifndef av_clip64
# define av_clip64 av_clip64_c
#endif
#ifndef av_clip_uint8
# define av_clip_uint8 av_clip_uint8_c
#endif
#ifndef av_clip_int8
# define av_clip_int8 av_clip_int8_c
#endif
#ifndef av_clip_uint16
# define av_clip_uint16 av_clip_uint16_c
#endif
#ifndef av_clip_int16
# define av_clip_int16 av_clip_int16_c
#endif
#ifndef av_clipl_int32
# define av_clipl_int32 av_clipl_int32_c
#endif
#ifndef av_clip_intp2
# define av_clip_intp2 av_clip_intp2_c
#endif
#ifndef av_clip_uintp2
# define av_clip_uintp2 av_clip_uintp2_c
#endif
#ifndef av_mod_uintp2
# define av_mod_uintp2 av_mod_uintp2_c
#endif
#ifndef av_sat_add32
# define av_sat_add32 av_sat_add32_c
#endif
#ifndef av_sat_dadd32
# define av_sat_dadd32 av_sat_dadd32_c
#endif
#ifndef av_sat_sub32
# define av_sat_sub32 av_sat_sub32_c
#endif
#ifndef av_sat_dsub32
# define av_sat_dsub32 av_sat_dsub32_c
#endif
#ifndef av_sat_add64
# define av_sat_add64 av_sat_add64_c
#endif
#ifndef av_sat_sub64
# define av_sat_sub64 av_sat_sub64_c
#endif
#ifndef av_clipf
# define av_clipf av_clipf_c
#endif
#ifndef av_clipd
# define av_clipd av_clipd_c
#endif
#ifndef av_popcount
# define av_popcount av_popcount_c
#endif
#ifndef av_popcount64
# define av_popcount64 av_popcount64_c
#endif
#ifndef av_parity
# define av_parity av_parity_c
#endif
#ifndef av_log2
av_const int av_log2(unsigned v);
#endif
#ifndef av_log2_16bit
av_const int av_log2_16bit(unsigned v);
#endif
/**
* Clip a signed integer value into the amin-amax range.
* @param a value to clip
* @param amin minimum value of the clip range
* @param amax maximum value of the clip range
* @return clipped value
*/
static av_always_inline av_const int av_clip_c(int a, int amin, int amax)
{
#if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
if (amin > amax) abort();
#endif
if (a < amin) return amin;
else if (a > amax) return amax;
else return a;
}
/**
* Clip a signed 64bit integer value into the amin-amax range.
* @param a value to clip
* @param amin minimum value of the clip range
* @param amax maximum value of the clip range
* @return clipped value
*/
static av_always_inline av_const int64_t av_clip64_c(int64_t a, int64_t amin, int64_t amax)
{
#if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
if (amin > amax) abort();
#endif
if (a < amin) return amin;
else if (a > amax) return amax;
else return a;
}
/**
* Clip a signed integer value into the 0-255 range.
* @param a value to clip
* @return clipped value
*/
static av_always_inline av_const uint8_t av_clip_uint8_c(int a)
{
if (a&(~0xFF)) return (~a)>>31;
else return a;
}
/**
* Clip a signed integer value into the -128,127 range.
* @param a value to clip
* @return clipped value
*/
static av_always_inline av_const int8_t av_clip_int8_c(int a)
{
if ((a+0x80U) & ~0xFF) return (a>>31) ^ 0x7F;
else return a;
}
/**
* Clip a signed integer value into the 0-65535 range.
* @param a value to clip
* @return clipped value
*/
static av_always_inline av_const uint16_t av_clip_uint16_c(int a)
{
if (a&(~0xFFFF)) return (~a)>>31;
else return a;
}
/**
* Clip a signed integer value into the -32768,32767 range.
* @param a value to clip
* @return clipped value
*/
static av_always_inline av_const int16_t av_clip_int16_c(int a)
{
if ((a+0x8000U) & ~0xFFFF) return (a>>31) ^ 0x7FFF;
else return a;
}
/**
* Clip a signed 64-bit integer value into the -2147483648,2147483647 range.
* @param a value to clip
* @return clipped value
*/
static av_always_inline av_const int32_t av_clipl_int32_c(int64_t a)
{
if ((a+0x80000000u) & ~UINT64_C(0xFFFFFFFF)) return (int32_t)((a>>63) ^ 0x7FFFFFFF);
else return (int32_t)a;
}
/**
* Clip a signed integer into the -(2^p),(2^p-1) range.
* @param a value to clip
* @param p bit position to clip at
* @return clipped value
*/
static av_always_inline av_const int av_clip_intp2_c(int a, int p)
{
if (((unsigned)a + (1 << p)) & ~((2 << p) - 1))
return (a >> 31) ^ ((1 << p) - 1);
else
return a;
}
/**
* Clip a signed integer to an unsigned power of two range.
* @param a value to clip
* @param p bit position to clip at
* @return clipped value
*/
static av_always_inline av_const unsigned av_clip_uintp2_c(int a, int p)
{
if (a & ~((1<<p) - 1)) return (~a) >> 31 & ((1<<p) - 1);
else return a;
}
/**
* Clear high bits from an unsigned integer starting with specific bit position
* @param a value to clip
* @param p bit position to clip at
* @return clipped value
*/
static av_always_inline av_const unsigned av_mod_uintp2_c(unsigned a, unsigned p)
{
return a & ((1U << p) - 1);
}
/**
* Add two signed 32-bit values with saturation.
*
* @param a one value
* @param b another value
* @return sum with signed saturation
*/
static av_always_inline int av_sat_add32_c(int a, int b)
{
return av_clipl_int32((int64_t)a + b);
}
/**
* Add a doubled value to another value with saturation at both stages.
*
* @param a first value
* @param b value doubled and added to a
* @return sum sat(a + sat(2*b)) with signed saturation
*/
static av_always_inline int av_sat_dadd32_c(int a, int b)
{
return av_sat_add32(a, av_sat_add32(b, b));
}
/**
* Subtract two signed 32-bit values with saturation.
*
* @param a one value
* @param b another value
* @return difference with signed saturation
*/
static av_always_inline int av_sat_sub32_c(int a, int b)
{
return av_clipl_int32((int64_t)a - b);
}
/**
* Subtract a doubled value from another value with saturation at both stages.
*
* @param a first value
* @param b value doubled and subtracted from a
* @return difference sat(a - sat(2*b)) with signed saturation
*/
static av_always_inline int av_sat_dsub32_c(int a, int b)
{
return av_sat_sub32(a, av_sat_add32(b, b));
}
/**
* Add two signed 64-bit values with saturation.
*
* @param a one value
* @param b another value
* @return sum with signed saturation
*/
static av_always_inline int64_t av_sat_add64_c(int64_t a, int64_t b) {
#if (!defined(__INTEL_COMPILER) && AV_GCC_VERSION_AT_LEAST(5,1)) || AV_HAS_BUILTIN(__builtin_add_overflow)
int64_t tmp;
return !__builtin_add_overflow(a, b, &tmp) ? tmp : (tmp < 0 ? INT64_MAX : INT64_MIN);
#else
int64_t s = a+(uint64_t)b;
if ((int64_t)(a^b | ~s^b) >= 0)
return INT64_MAX ^ (b >> 63);
return s;
#endif
}
/**
* Subtract two signed 64-bit values with saturation.
*
* @param a one value
* @param b another value
* @return difference with signed saturation
*/
static av_always_inline int64_t av_sat_sub64_c(int64_t a, int64_t b) {
#if (!defined(__INTEL_COMPILER) && AV_GCC_VERSION_AT_LEAST(5,1)) || AV_HAS_BUILTIN(__builtin_sub_overflow)
int64_t tmp;
return !__builtin_sub_overflow(a, b, &tmp) ? tmp : (tmp < 0 ? INT64_MAX : INT64_MIN);
#else
if (b <= 0 && a >= INT64_MAX + b)
return INT64_MAX;
if (b >= 0 && a <= INT64_MIN + b)
return INT64_MIN;
return a - b;
#endif
}
/**
* Clip a float value into the amin-amax range.
* @param a value to clip
* @param amin minimum value of the clip range
* @param amax maximum value of the clip range
* @return clipped value
*/
static av_always_inline av_const float av_clipf_c(float a, float amin, float amax)
{
#if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
if (amin > amax) abort();
#endif
if (a < amin) return amin;
else if (a > amax) return amax;
else return a;
}
/**
* Clip a double value into the amin-amax range.
* @param a value to clip
* @param amin minimum value of the clip range
* @param amax maximum value of the clip range
* @return clipped value
*/
static av_always_inline av_const double av_clipd_c(double a, double amin, double amax)
{
#if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
if (amin > amax) abort();
#endif
if (a < amin) return amin;
else if (a > amax) return amax;
else return a;
}
/** Compute ceil(log2(x)).
* @param x value used to compute ceil(log2(x))
* @return computed ceiling of log2(x)
*/
static av_always_inline av_const int av_ceil_log2_c(int x)
{
return av_log2((x - 1U) << 1);
}
/**
* Count number of bits set to one in x
* @param x value to count bits of
* @return the number of bits set to one in x
*/
static av_always_inline av_const int av_popcount_c(uint32_t x)
{
x -= (x >> 1) & 0x55555555;
x = (x & 0x33333333) + ((x >> 2) & 0x33333333);
x = (x + (x >> 4)) & 0x0F0F0F0F;
x += x >> 8;
return (x + (x >> 16)) & 0x3F;
}
/**
* Count number of bits set to one in x
* @param x value to count bits of
* @return the number of bits set to one in x
*/
static av_always_inline av_const int av_popcount64_c(uint64_t x)
{
return av_popcount((uint32_t)x) + av_popcount((uint32_t)(x >> 32));
}
static av_always_inline av_const int av_parity_c(uint32_t v)
{
return av_popcount(v) & 1;
}
#define MKTAG(a,b,c,d) ((a) | ((b) << 8) | ((c) << 16) | ((unsigned)(d) << 24))
#define MKBETAG(a,b,c,d) ((d) | ((c) << 8) | ((b) << 16) | ((unsigned)(a) << 24))
/**
* Convert a UTF-8 character (up to 4 bytes) to its 32-bit UCS-4 encoded form.
*
* @param val Output value, must be an lvalue of type uint32_t.
* @param GET_BYTE Expression reading one byte from the input.
* Evaluated up to 7 times (4 for the currently
* assigned Unicode range). With a memory buffer
* input, this could be *ptr++, or if you want to make sure
* that *ptr stops at the end of a NULL terminated string then
* *ptr ? *ptr++ : 0
* @param ERROR Expression to be evaluated on invalid input,
* typically a goto statement.
*
* @warning ERROR should not contain a loop control statement which
* could interact with the internal while loop, and should force an
* exit from the macro code (e.g. through a goto or a return) in order
* to prevent undefined results.
*/
#define GET_UTF8(val, GET_BYTE, ERROR)\
val= (GET_BYTE);\
{\
uint32_t top = (val & 128) >> 1;\
if ((val & 0xc0) == 0x80 || val >= 0xFE)\
{ERROR}\
while (val & top) {\
unsigned int tmp = (GET_BYTE) - 128;\
if(tmp>>6)\
{ERROR}\
val= (val<<6) + tmp;\
top <<= 5;\
}\
val &= (top << 1) - 1;\
}
/**
* Convert a UTF-16 character (2 or 4 bytes) to its 32-bit UCS-4 encoded form.
*
* @param val Output value, must be an lvalue of type uint32_t.
* @param GET_16BIT Expression returning two bytes of UTF-16 data converted
* to native byte order. Evaluated one or two times.
* @param ERROR Expression to be evaluated on invalid input,
* typically a goto statement.
*/
#define GET_UTF16(val, GET_16BIT, ERROR)\
val = (GET_16BIT);\
{\
unsigned int hi = val - 0xD800;\
if (hi < 0x800) {\
val = (GET_16BIT) - 0xDC00;\
if (val > 0x3FFU || hi > 0x3FFU)\
{ERROR}\
val += (hi<<10) + 0x10000;\
}\
}\
/**
* @def PUT_UTF8(val, tmp, PUT_BYTE)
* Convert a 32-bit Unicode character to its UTF-8 encoded form (up to 4 bytes long).
* @param val is an input-only argument and should be of type uint32_t. It holds
* a UCS-4 encoded Unicode character that is to be converted to UTF-8. If
* val is given as a function it is executed only once.
* @param tmp is a temporary variable and should be of type uint8_t. It
* represents an intermediate value during conversion that is to be
* output by PUT_BYTE.
* @param PUT_BYTE writes the converted UTF-8 bytes to any proper destination.
* It could be a function or a statement, and uses tmp as the input byte.
* For example, PUT_BYTE could be "*output++ = tmp;" PUT_BYTE will be
* executed up to 4 times for values in the valid UTF-8 range and up to
* 7 times in the general case, depending on the length of the converted
* Unicode character.
*/
#define PUT_UTF8(val, tmp, PUT_BYTE)\
{\
int bytes, shift;\
uint32_t in = val;\
if (in < 0x80) {\
tmp = in;\
PUT_BYTE\
} else {\
bytes = (av_log2(in) + 4) / 5;\
shift = (bytes - 1) * 6;\
tmp = (256 - (256 >> bytes)) | (in >> shift);\
PUT_BYTE\
while (shift >= 6) {\
shift -= 6;\
tmp = 0x80 | ((in >> shift) & 0x3f);\
PUT_BYTE\
}\
}\
}
/**
* @def PUT_UTF16(val, tmp, PUT_16BIT)
* Convert a 32-bit Unicode character to its UTF-16 encoded form (2 or 4 bytes).
* @param val is an input-only argument and should be of type uint32_t. It holds
* a UCS-4 encoded Unicode character that is to be converted to UTF-16. If
* val is given as a function it is executed only once.
* @param tmp is a temporary variable and should be of type uint16_t. It
* represents an intermediate value during conversion that is to be
* output by PUT_16BIT.
* @param PUT_16BIT writes the converted UTF-16 data to any proper destination
* in desired endianness. It could be a function or a statement, and uses tmp
* as the input byte. For example, PUT_BYTE could be "*output++ = tmp;"
* PUT_BYTE will be executed 1 or 2 times depending on input character.
*/
#define PUT_UTF16(val, tmp, PUT_16BIT)\
{\
uint32_t in = val;\
if (in < 0x10000) {\
tmp = in;\
PUT_16BIT\
} else {\
tmp = 0xD800 | ((in - 0x10000) >> 10);\
PUT_16BIT\
tmp = 0xDC00 | ((in - 0x10000) & 0x3FF);\
PUT_16BIT\
}\
}\
#include "mem.h"
#ifdef HAVE_AV_CONFIG_H
# include "internal.h"
#endif /* HAVE_AV_CONFIG_H */
#endif /* AVUTIL_COMMON_H */