macros.h File Reference

#include "libavutil/avconfig.h"

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Macros
#define	AV_NE(be, le)   (le)
#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	AV_STRINGIFY(s)   AV_TOSTRING(s)
#define	AV_TOSTRING(s)   #s
#define	AV_GLUE(a, b)   a ## b
#define	AV_JOIN(a, b)   AV_GLUE(a, b)
#define	AV_PRAGMA(s)   _Pragma(#s)
#define	FFALIGN(x, a)   (((x)+(a)-1)&~((a)-1))

Detailed Description

Utility Preprocessor macros

Definition in file macros.h.

Macro Definition Documentation

AV_NE

#define AV_NE	(		be,
			le
	)		(le)

Examples

decode_audio.c, demuxing_decoding.c, and resampling_audio.c.

Definition at line 33 of file macros.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 45 of file macros.h.

FFMAX

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

Definition at line 47 of file macros.h.

FFMAX3

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

Definition at line 48 of file macros.h.

FFMIN

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

Examples

avio_reading.c, and transcode_aac.c.

Definition at line 49 of file macros.h.

FFMIN3

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

Definition at line 50 of file macros.h.

FFSWAP

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

Definition at line 52 of file macros.h.

FF_ARRAY_ELEMS

#define FF_ARRAY_ELEMS

(

a

)

(sizeof(a) / sizeof((a)[0]))

Definition at line 53 of file macros.h.

MKTAG

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

Definition at line 55 of file macros.h.

MKBETAG

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

Definition at line 56 of file macros.h.

AV_PRAGMA

#define AV_PRAGMA

(

s

)

_Pragma(#s)

Definition at line 76 of file macros.h.

FFALIGN

#define FFALIGN	(		x,
			a
	)		(((x)+(a)-1)&~((a)-1))

Definition at line 78 of file macros.h.