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 "version.h"
#include "libavutil/avconfig.h"
#include "common.h"
#include "mem.h"

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

#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	FFDIFFSIGN(x, y) (((x)>(y)) - ((x)<(y)))
	Comparator. More...

#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]))

#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))

#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 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

◆ AV_NE

#define AV_NE	(	be,
		le
	)	(le)

Examples:: demuxing_decoding.c, and resampling_audio.c.

Definition at line 50 of file common.h.

Referenced by get_format_from_sample_fmt().

◆ RSHIFT

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

Definition at line 54 of file common.h.

◆ ROUNDED_DIV

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

Definition at line 56 of file common.h.

◆ AV_CEIL_RSHIFT

#define AV_CEIL_RSHIFT	(	a,
		b
	)

Value:

(!av_builtin_constant_p(b) ? -((-(a)) >> (b)) \

: ((a) + (1<<(b)) - 1) >> (b))

av_builtin_constant_p

#define av_builtin_constant_p

Definition: attributes.h:154

Definition at line 58 of file common.h.

◆ FF_CEIL_RSHIFT

#define FF_CEIL_RSHIFT AV_CEIL_RSHIFT

Definition at line 61 of file common.h.

◆ FFUDIV

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

Definition at line 63 of file common.h.

◆ FFUMOD

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

Definition at line 64 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 72 of file common.h.

◆ FFSIGN

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

Definition at line 73 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 81 of file common.h.

◆ FFDIFFSIGN

#define FFDIFFSIGN	(	x,
		y
	)	(((x)>(y)) - ((x)<(y)))

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.

Definition at line 92 of file common.h.

◆ FFMAX

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

Definition at line 94 of file common.h.

◆ FFMAX3

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

Definition at line 95 of file common.h.

◆ FFMIN

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

Examples:: avio_reading.c, demuxing_decoding.c, and transcode_aac.c.

Definition at line 96 of file common.h.

Referenced by decode_packet(), load_encode_and_write(), and read_packet().

◆ FFMIN3

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

Definition at line 97 of file common.h.

◆ FFSWAP

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

Definition at line 99 of file common.h.

◆ FF_ARRAY_ELEMS

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

Examples:: demuxing_decoding.c, and resampling_audio.c.

Definition at line 100 of file common.h.

Referenced by get_format_from_sample_fmt().

◆ MKTAG

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

Definition at line 366 of file common.h.

◆ MKBETAG

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

Definition at line 367 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) {\
            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

val	Output value, must be an lvalue of type uint32_t.
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++.
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.

Definition at line 385 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

val	Output value, must be an lvalue of type uint32_t.
GET_16BIT	Expression returning two bytes of UTF-16 data converted to native byte order. Evaluated one or two times.
ERROR	Expression to be evaluated on invalid input, typically a goto statement.

Definition at line 410 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\
            }\
        }\
    }

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

Parameters

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.
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.
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.

Definition at line 438 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

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.
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.
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.

Definition at line 472 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

a	value to clip
amin	minimum value of the clip range
amax	maximum value of the clip range

Returns: clipped value

Definition at line 127 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

a	value to clip
amin	minimum value of the clip range
amax	maximum value of the clip range

Returns: clipped value

Definition at line 144 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

a	value to clip

Returns: clipped value

Definition at line 159 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

a	value to clip

Returns: clipped value

Definition at line 170 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

a	value to clip

Returns: clipped value

Definition at line 181 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

a	value to clip

Returns: clipped value

Definition at line 192 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

a	value to clip

Returns: clipped value

Definition at line 203 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

a	value to clip
p	bit position to clip at

Returns: clipped value

Definition at line 215 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

a	value to clip
p	bit position to clip at

Returns: clipped value

Definition at line 229 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

a	value to clip
p	bit position to clip at

Returns: clipped value

Definition at line 241 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

a	one value
b	another value

Returns: sum with signed saturation

Definition at line 253 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

a	first value
b	value doubled and added to a

Returns: sum sat(a + sat(2*b)) with signed saturation

Definition at line 265 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

a	one value
b	another value

Returns: difference with signed saturation

Definition at line 277 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

a	first value
b	value doubled and subtracted from a

Returns: difference sat(a - sat(2*b)) with signed saturation

Definition at line 289 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.

Parameters

a	value to clip
amin	minimum value of the clip range
amax	maximum value of the clip range

Returns: clipped value

Definition at line 301 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.

Parameters

a	value to clip
amin	minimum value of the clip range
amax	maximum value of the clip range

Returns: clipped value

Definition at line 318 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

x	value used to compute ceil(log2(x))

Returns: computed ceiling of log2(x)

Definition at line 332 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

x	value to count bits of

Returns: the number of bits set to one in x

Definition at line 342 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

x	value to count bits of

Returns: the number of bits set to one in x

Definition at line 356 of file common.h.

◆ av_parity_c()

static av_always_inline av_const int av_parity_c ( uint32_t v )

static

Definition at line 361 of file common.h.

Macros

Functions

Detailed Description

Macro Definition Documentation

◆ AV_NE

◆ RSHIFT

◆ ROUNDED_DIV

◆ AV_CEIL_RSHIFT

◆ FF_CEIL_RSHIFT

◆ FFUDIV

◆ FFUMOD

◆ FFABS

◆ FFSIGN

◆ FFNABS

◆ FFDIFFSIGN

◆ FFMAX

◆ FFMAX3

◆ FFMIN

◆ FFMIN3

◆ FFSWAP

◆ FF_ARRAY_ELEMS

◆ MKTAG

◆ MKBETAG

◆ GET_UTF8

◆ GET_UTF16

◆ PUT_UTF8

◆ PUT_UTF16

Function Documentation

◆ av_log2()

◆ av_log2_16bit()

◆ av_clip_c()

◆ av_clip64_c()

◆ av_clip_uint8_c()

◆ av_clip_int8_c()

◆ av_clip_uint16_c()

◆ av_clip_int16_c()

◆ av_clipl_int32_c()

◆ av_clip_intp2_c()

◆ av_clip_uintp2_c()

◆ av_mod_uintp2_c()

◆ av_sat_add32_c()

◆ av_sat_dadd32_c()

◆ av_sat_sub32_c()

◆ av_sat_dsub32_c()

◆ av_clipf_c()

◆ av_clipd_c()

◆ av_ceil_log2_c()

◆ av_popcount_c()

◆ av_popcount64_c()

◆ av_parity_c()