FFmpeg 5.1.6
Macros | Functions
common.h File Reference

common internal and external API header More...

#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 "mem.h"

Go to the source code of this file.

Macros

#define RSHIFT(a, b)   ((a) > 0 ? ((a) + ((1<<(b))>>1))>>(b) : ((a) + ((1<<(b))>>1)-1)>>(b))
 
#define ROUNDED_DIV(a, b)   (((a)>=0 ? (a) + ((b)>>1) : (a) - ((b)>>1))/(b))
 
#define AV_CEIL_RSHIFT(a, b)
 
#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))
 
#define FFABS(a)   ((a) >= 0 ? (a) : (-(a)))
 Absolute value, Note, INT_MIN / INT64_MIN result in undefined behavior as they are not representable as absolute values of their type. More...
 
#define FFSIGN(a)   ((a) > 0 ? 1 : -1)
 
#define FFNABS(a)   ((a) <= 0 ? (a) : (-(a)))
 Negative Absolute value. More...
 
#define FFABSU(a)   ((a) <= 0 ? -(unsigned)(a) : (unsigned)(a))
 Unsigned Absolute value. More...
 
#define FFABS64U(a)   ((a) <= 0 ? -(uint64_t)(a) : (uint64_t)(a))
 
#define av_ceil_log2   av_ceil_log2_c
 
#define av_clip   av_clip_c
 
#define av_clip64   av_clip64_c
 
#define av_clip_uint8   av_clip_uint8_c
 
#define av_clip_int8   av_clip_int8_c
 
#define av_clip_uint16   av_clip_uint16_c
 
#define av_clip_int16   av_clip_int16_c
 
#define av_clipl_int32   av_clipl_int32_c
 
#define av_clip_intp2   av_clip_intp2_c
 
#define av_clip_uintp2   av_clip_uintp2_c
 
#define av_mod_uintp2   av_mod_uintp2_c
 
#define av_sat_add32   av_sat_add32_c
 
#define av_sat_dadd32   av_sat_dadd32_c
 
#define av_sat_sub32   av_sat_sub32_c
 
#define av_sat_dsub32   av_sat_dsub32_c
 
#define av_sat_add64   av_sat_add64_c
 
#define av_sat_sub64   av_sat_sub64_c
 
#define av_clipf   av_clipf_c
 
#define av_clipd   av_clipd_c
 
#define av_popcount   av_popcount_c
 
#define av_popcount64   av_popcount64_c
 
#define av_parity   av_parity_c
 
#define GET_UTF8(val, GET_BYTE, ERROR)
 Convert a UTF-8 character (up to 4 bytes) to its 32-bit UCS-4 encoded form. More...
 
#define GET_UTF16(val, GET_16BIT, ERROR)
 Convert a UTF-16 character (2 or 4 bytes) to its 32-bit UCS-4 encoded form. More...
 
#define PUT_UTF8(val, tmp, PUT_BYTE)
 Convert a 32-bit Unicode character to its UTF-8 encoded form (up to 4 bytes long). More...
 
#define PUT_UTF16(val, tmp, PUT_16BIT)
 Convert a 32-bit Unicode character to its UTF-16 encoded form (2 or 4 bytes). More...
 

Functions

av_const int av_log2 (unsigned v)
 
av_const int av_log2_16bit (unsigned v)
 
static av_always_inline av_const int av_clip_c (int a, int amin, int amax)
 Clip a signed integer value into the amin-amax range. More...
 
static av_always_inline av_const int64_t av_clip64_c (int64_t a, int64_t amin, int64_t amax)
 Clip a signed 64bit integer value into the amin-amax range. More...
 
static av_always_inline av_const uint8_t av_clip_uint8_c (int a)
 Clip a signed integer value into the 0-255 range. More...
 
static av_always_inline av_const int8_t av_clip_int8_c (int a)
 Clip a signed integer value into the -128,127 range. More...
 
static av_always_inline av_const uint16_t av_clip_uint16_c (int a)
 Clip a signed integer value into the 0-65535 range. More...
 
static av_always_inline av_const int16_t av_clip_int16_c (int a)
 Clip a signed integer value into the -32768,32767 range. More...
 
static av_always_inline av_const int32_t av_clipl_int32_c (int64_t a)
 Clip a signed 64-bit integer value into the -2147483648,2147483647 range. More...
 
static av_always_inline av_const int av_clip_intp2_c (int a, int p)
 Clip a signed integer into the -(2^p),(2^p-1) range. More...
 
static av_always_inline av_const unsigned av_clip_uintp2_c (int a, int p)
 Clip a signed integer to an unsigned power of two range. More...
 
static av_always_inline av_const unsigned av_mod_uintp2_c (unsigned a, unsigned p)
 Clear high bits from an unsigned integer starting with specific bit position. More...
 
static av_always_inline int av_sat_add32_c (int a, int b)
 Add two signed 32-bit values with saturation. More...
 
static av_always_inline int av_sat_dadd32_c (int a, int b)
 Add a doubled value to another value with saturation at both stages. More...
 
static av_always_inline int av_sat_sub32_c (int a, int b)
 Subtract two signed 32-bit values with saturation. More...
 
static av_always_inline int av_sat_dsub32_c (int a, int b)
 Subtract a doubled value from another value with saturation at both stages. More...
 
static av_always_inline int64_t av_sat_add64_c (int64_t a, int64_t b)
 Add two signed 64-bit values with saturation. More...
 
static av_always_inline int64_t av_sat_sub64_c (int64_t a, int64_t b)
 Subtract two signed 64-bit values with saturation. More...
 
static av_always_inline av_const float av_clipf_c (float a, float amin, float amax)
 Clip a float value into the amin-amax range. More...
 
static av_always_inline av_const double av_clipd_c (double a, double amin, double amax)
 Clip a double value into the amin-amax range. More...
 
static av_always_inline av_const int av_ceil_log2_c (int x)
 Compute ceil(log2(x)). More...
 
static av_always_inline av_const int av_popcount_c (uint32_t x)
 Count number of bits set to one in x. More...
 
static av_always_inline av_const int av_popcount64_c (uint64_t x)
 Count number of bits set to one in x. More...
 
static av_always_inline av_const int av_parity_c (uint32_t v)
 

Detailed Description

common internal and external API header

Definition in file common.h.

Macro Definition Documentation

◆ RSHIFT

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

Definition at line 46 of file common.h.

◆ ROUNDED_DIV

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

Definition at line 48 of file common.h.

◆ AV_CEIL_RSHIFT

#define AV_CEIL_RSHIFT (   a,
 
)
Value:
(!av_builtin_constant_p(b) ? -((-(a)) >> (b)) \
: ((a) + (1<<(b)) - 1) >> (b))
#define av_builtin_constant_p
Definition: attributes.h:160

Definition at line 50 of file common.h.

◆ FF_CEIL_RSHIFT

#define FF_CEIL_RSHIFT   AV_CEIL_RSHIFT

Definition at line 53 of file common.h.

◆ FFUDIV

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

Definition at line 55 of file common.h.

◆ FFUMOD

#define FFUMOD (   a,
 
)    ((a)-(b)*FFUDIV(a,b))

Definition at line 56 of file common.h.

◆ FFABS

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

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 also
FFNABS()

Definition at line 64 of file common.h.

◆ FFSIGN

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

Definition at line 65 of file common.h.

◆ FFNABS

#define FFNABS (   a)    ((a) <= 0 ? (a) : (-(a)))

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.

Definition at line 73 of file common.h.

◆ FFABSU

#define FFABSU (   a)    ((a) <= 0 ? -(unsigned)(a) : (unsigned)(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.

Definition at line 81 of file common.h.

◆ FFABS64U

#define FFABS64U (   a)    ((a) <= 0 ? -(uint64_t)(a) : (uint64_t)(a))

Definition at line 82 of file common.h.

◆ av_ceil_log2

#define av_ceil_log2   av_ceil_log2_c

Definition at line 92 of file common.h.

◆ av_clip

#define av_clip   av_clip_c

Definition at line 95 of file common.h.

◆ av_clip64

#define av_clip64   av_clip64_c

Definition at line 98 of file common.h.

◆ av_clip_uint8

#define av_clip_uint8   av_clip_uint8_c

Definition at line 101 of file common.h.

◆ av_clip_int8

#define av_clip_int8   av_clip_int8_c

Definition at line 104 of file common.h.

◆ av_clip_uint16

#define av_clip_uint16   av_clip_uint16_c

Definition at line 107 of file common.h.

◆ av_clip_int16

#define av_clip_int16   av_clip_int16_c

Definition at line 110 of file common.h.

◆ av_clipl_int32

#define av_clipl_int32   av_clipl_int32_c

Definition at line 113 of file common.h.

◆ av_clip_intp2

#define av_clip_intp2   av_clip_intp2_c

Definition at line 116 of file common.h.

◆ av_clip_uintp2

#define av_clip_uintp2   av_clip_uintp2_c

Definition at line 119 of file common.h.

◆ av_mod_uintp2

#define av_mod_uintp2   av_mod_uintp2_c

Definition at line 122 of file common.h.

◆ av_sat_add32

#define av_sat_add32   av_sat_add32_c

Definition at line 125 of file common.h.

◆ av_sat_dadd32

#define av_sat_dadd32   av_sat_dadd32_c

Definition at line 128 of file common.h.

◆ av_sat_sub32

#define av_sat_sub32   av_sat_sub32_c

Definition at line 131 of file common.h.

◆ av_sat_dsub32

#define av_sat_dsub32   av_sat_dsub32_c

Definition at line 134 of file common.h.

◆ av_sat_add64

#define av_sat_add64   av_sat_add64_c

Definition at line 137 of file common.h.

◆ av_sat_sub64

#define av_sat_sub64   av_sat_sub64_c

Definition at line 140 of file common.h.

◆ av_clipf

#define av_clipf   av_clipf_c

Definition at line 143 of file common.h.

◆ av_clipd

#define av_clipd   av_clipd_c

Definition at line 146 of file common.h.

◆ av_popcount

#define av_popcount   av_popcount_c

Definition at line 149 of file common.h.

◆ av_popcount64

#define av_popcount64   av_popcount64_c

Definition at line 152 of file common.h.

◆ av_parity

#define av_parity   av_parity_c

Definition at line 155 of file common.h.

◆ GET_UTF8

#define GET_UTF8 (   val,
  GET_BYTE,
  ERROR 
)
Value:
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-8 character (up to 4 bytes) to its 32-bit UCS-4 encoded form.

Parameters
valOutput value, must be an lvalue of type uint32_t.
GET_BYTEExpression 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
ERRORExpression 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.

Definition at line 469 of file common.h.

◆ GET_UTF16

#define GET_UTF16 (   val,
  GET_16BIT,
  ERROR 
)
Value:
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;\
}\
}\

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

Parameters
valOutput value, must be an lvalue of type uint32_t.
GET_16BITExpression returning two bytes of UTF-16 data converted to native byte order. Evaluated one or two times.
ERRORExpression to be evaluated on invalid input, typically a goto statement.

Definition at line 494 of file common.h.

◆ PUT_UTF8

#define PUT_UTF8 (   val,
  tmp,
  PUT_BYTE 
)
Value:
{\
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\
}\
}\
}
av_const int av_log2(unsigned v)

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

Parameters
valis 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.
tmpis 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.
PUT_BYTEwrites 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.

Definition at line 522 of file common.h.

◆ PUT_UTF16

#define PUT_UTF16 (   val,
  tmp,
  PUT_16BIT 
)
Value:
{\
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\
}\
}\

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

Parameters
valis 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.
tmpis 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.
PUT_16BITwrites 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.

Definition at line 556 of file common.h.

Function Documentation

◆ av_log2()

av_const int av_log2 ( unsigned  v)

Referenced by av_ceil_log2_c().

◆ av_log2_16bit()

av_const int av_log2_16bit ( unsigned  v)

◆ av_clip_c()

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

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

Parameters
avalue to clip
aminminimum value of the clip range
amaxmaximum value of the clip range
Returns
clipped value

Definition at line 173 of file common.h.

◆ av_clip64_c()

static av_always_inline av_const int64_t av_clip64_c ( int64_t  a,
int64_t  amin,
int64_t  amax 
)
static

Clip a signed 64bit integer value into the amin-amax range.

Parameters
avalue to clip
aminminimum value of the clip range
amaxmaximum value of the clip range
Returns
clipped value

Definition at line 190 of file common.h.

◆ av_clip_uint8_c()

static av_always_inline av_const uint8_t av_clip_uint8_c ( int  a)
static

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

Parameters
avalue to clip
Returns
clipped value

Definition at line 205 of file common.h.

◆ av_clip_int8_c()

static av_always_inline av_const int8_t av_clip_int8_c ( int  a)
static

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

Parameters
avalue to clip
Returns
clipped value

Definition at line 216 of file common.h.

◆ av_clip_uint16_c()

static av_always_inline av_const uint16_t av_clip_uint16_c ( int  a)
static

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

Parameters
avalue to clip
Returns
clipped value

Definition at line 227 of file common.h.

◆ av_clip_int16_c()

static av_always_inline av_const int16_t av_clip_int16_c ( int  a)
static

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

Parameters
avalue to clip
Returns
clipped value

Definition at line 238 of file common.h.

◆ av_clipl_int32_c()

static av_always_inline av_const int32_t av_clipl_int32_c ( int64_t  a)
static

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

Parameters
avalue to clip
Returns
clipped value

Definition at line 249 of file common.h.

◆ av_clip_intp2_c()

static av_always_inline av_const int av_clip_intp2_c ( int  a,
int  p 
)
static

Clip a signed integer into the -(2^p),(2^p-1) range.

Parameters
avalue to clip
pbit position to clip at
Returns
clipped value

Definition at line 261 of file common.h.

◆ av_clip_uintp2_c()

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

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

Parameters
avalue to clip
pbit position to clip at
Returns
clipped value

Definition at line 275 of file common.h.

◆ av_mod_uintp2_c()

static av_always_inline av_const unsigned av_mod_uintp2_c ( unsigned  a,
unsigned  p 
)
static

Clear high bits from an unsigned integer starting with specific bit position.

Parameters
avalue to clip
pbit position to clip at
Returns
clipped value

Definition at line 287 of file common.h.

◆ av_sat_add32_c()

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

Add two signed 32-bit values with saturation.

Parameters
aone value
banother value
Returns
sum with signed saturation

Definition at line 299 of file common.h.

◆ av_sat_dadd32_c()

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

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

Parameters
afirst value
bvalue doubled and added to a
Returns
sum sat(a + sat(2*b)) with signed saturation

Definition at line 311 of file common.h.

◆ av_sat_sub32_c()

static av_always_inline int av_sat_sub32_c ( int  a,
int  b 
)
static

Subtract two signed 32-bit values with saturation.

Parameters
aone value
banother value
Returns
difference with signed saturation

Definition at line 323 of file common.h.

◆ av_sat_dsub32_c()

static av_always_inline int av_sat_dsub32_c ( int  a,
int  b 
)
static

Subtract a doubled value from another value with saturation at both stages.

Parameters
afirst value
bvalue doubled and subtracted from a
Returns
difference sat(a - sat(2*b)) with signed saturation

Definition at line 335 of file common.h.

◆ av_sat_add64_c()

static av_always_inline int64_t av_sat_add64_c ( int64_t  a,
int64_t  b 
)
static

Add two signed 64-bit values with saturation.

Parameters
aone value
banother value
Returns
sum with signed saturation

Definition at line 347 of file common.h.

◆ av_sat_sub64_c()

static av_always_inline int64_t av_sat_sub64_c ( int64_t  a,
int64_t  b 
)
static

Subtract two signed 64-bit values with saturation.

Parameters
aone value
banother value
Returns
difference with signed saturation

Definition at line 366 of file common.h.

◆ av_clipf_c()

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

Clip a float value into the amin-amax range.

If a is nan or -inf amin will be returned. If a is +inf amax will be returned.

Parameters
avalue to clip
aminminimum value of the clip range
amaxmaximum value of the clip range
Returns
clipped value

Definition at line 388 of file common.h.

◆ av_clipd_c()

static av_always_inline av_const double av_clipd_c ( double  a,
double  amin,
double  amax 
)
static

Clip a double value into the amin-amax range.

If a is nan or -inf amin will be returned. If a is +inf amax will be returned.

Parameters
avalue to clip
aminminimum value of the clip range
amaxmaximum value of the clip range
Returns
clipped value

Definition at line 405 of file common.h.

◆ av_ceil_log2_c()

static av_always_inline av_const int av_ceil_log2_c ( int  x)
static

Compute ceil(log2(x)).

Parameters
xvalue used to compute ceil(log2(x))
Returns
computed ceiling of log2(x)

Definition at line 417 of file common.h.

◆ av_popcount_c()

static av_always_inline av_const int av_popcount_c ( uint32_t  x)
static

Count number of bits set to one in x.

Parameters
xvalue to count bits of
Returns
the number of bits set to one in x

Definition at line 427 of file common.h.

◆ av_popcount64_c()

static av_always_inline av_const int av_popcount64_c ( uint64_t  x)
static

Count number of bits set to one in x.

Parameters
xvalue to count bits of
Returns
the number of bits set to one in x

Definition at line 441 of file common.h.

◆ av_parity_c()

static av_always_inline av_const int av_parity_c ( uint32_t  v)
static

Definition at line 446 of file common.h.