FFmpeg  2.7.1
Macros | Functions | Variables
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 "version.h"
#include "libavutil/avconfig.h"
#include "common.h"
#include "mem.h"

Go to the source code of this file.

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 FF_CEIL_RSHIFT(a, b)
 
#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)))
 
#define FFSIGN(a)   ((a) > 0 ? 1 : -1)
 
#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 FFALIGN(x, a)   (((x)+(a)-1)&~((a)-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))
 
#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 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...
 

Variables

attribute_deprecated const uint8_t av_reverse [256]
 Reverse the order of the bits of an 8-bits unsigned integer. More...
 

Detailed Description

common internal and external API header

Definition in file common.h.

Macro Definition Documentation

#define AV_NE (   be,
  le 
)    (le)
Examples:
demuxing_decoding.c, and resampling_audio.c.

Definition at line 49 of file common.h.

Referenced by get_format_from_sample_fmt().

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

Definition at line 53 of file common.h.

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

Definition at line 55 of file common.h.

#define FF_CEIL_RSHIFT (   a,
 
)
Value:
(!av_builtin_constant_p(b) ? -((-(a)) >> (b)) \
: ((a) + (1<<(b)) - 1) >> (b))
#define av_builtin_constant_p
Definition: attributes.h:147

Definition at line 57 of file common.h.

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

Definition at line 59 of file common.h.

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

Definition at line 60 of file common.h.

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

Definition at line 61 of file common.h.

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

Definition at line 62 of file common.h.

#define FFMAX (   a,
 
)    ((a) > (b) ? (a) : (b))
Examples:
decoding_encoding.c.

Definition at line 64 of file common.h.

Referenced by select_sample_rate().

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

Definition at line 65 of file common.h.

#define FFMIN (   a,
 
)    ((a) > (b) ? (b) : (a))
Examples:
avio_reading.c, demuxing_decoding.c, and transcode_aac.c.

Definition at line 66 of file common.h.

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

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

Definition at line 67 of file common.h.

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

Definition at line 69 of file common.h.

#define FF_ARRAY_ELEMS (   a)    (sizeof(a) / sizeof((a)[0]))
Examples:
demuxing_decoding.c, and resampling_audio.c.

Definition at line 70 of file common.h.

Referenced by get_format_from_sample_fmt().

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

Definition at line 71 of file common.h.

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

Definition at line 315 of file common.h.

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

Definition at line 316 of file common.h.

#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
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++.
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 334 of file common.h.

#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 359 of file common.h.

#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 387 of file common.h.

#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 421 of file common.h.

Function Documentation

av_const int av_log2 ( unsigned  v)

Referenced by av_ceil_log2_c().

av_const int av_log2_16bit ( unsigned  v)
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 105 of file common.h.

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 122 of file common.h.

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 137 of file common.h.

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 148 of file common.h.

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 159 of file common.h.

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 170 of file common.h.

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 181 of file common.h.

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 193 of file common.h.

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 207 of file common.h.

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 219 of file common.h.

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 231 of file common.h.

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 with signed saturation

Definition at line 243 of file common.h.

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

Definition at line 255 of file common.h.

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

Definition at line 272 of file common.h.

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 286 of file common.h.

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 296 of file common.h.

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 310 of file common.h.

Variable Documentation

attribute_deprecated const uint8_t av_reverse[256]

Reverse the order of the bits of an 8-bits unsigned integer.