libavutil/common.h File Reference

common internal and external API header More...

#include <ctype.h>
#include <errno.h>
#include <inttypes.h>
#include <limits.h>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "attributes.h"
#include "libavutil/avconfig.h"
#include "config.h"
#include "intmath.h"
#include "common.h"
#include "mem.h"
#include "internal.h"

Go to the source code of this file.

Defines

#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 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.
#define GET_UTF16(val, GET_16BIT, ERROR)
 Convert a UTF-16 character (2 or 4 bytes) to its 32-bit UCS-4 encoded form.
#define PUT_UTF8(val, tmp, PUT_BYTE)
 Convert a 32-bit Unicode character to its UTF-8 encoded form (up to 4 bytes long).
#define PUT_UTF16(val, tmp, PUT_16BIT)
 Convert a 32-bit Unicode character to its UTF-16 encoded form (2 or 4 bytes).

Functions

static av_always_inline
av_const int 
av_log2_c (unsigned int v)
static av_always_inline
av_const int 
av_log2_16bit_c (unsigned int 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.
static av_always_inline
av_const uint8_t 
av_clip_uint8_c (int a)
 Clip a signed integer value into the 0-255 range.
static av_always_inline
av_const int8_t 
av_clip_int8_c (int a)
 Clip a signed integer value into the -128,127 range.
static av_always_inline
av_const uint16_t 
av_clip_uint16_c (int a)
 Clip a signed integer value into the 0-65535 range.
static av_always_inline
av_const int16_t 
av_clip_int16_c (int a)
 Clip a signed integer value into the -32768,32767 range.
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.
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.
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.
static av_always_inline
av_const int 
av_ceil_log2_c (int x)
 Compute ceil(log2(x)).
static av_always_inline
av_const int 
av_popcount_c (uint32_t x)
 Count number of bits set to one in x.
static av_always_inline
av_const int 
av_popcount64_c (uint64_t x)
 Count number of bits set to one in x.

Variables

const uint8_t ff_log2_tab [256]
const uint8_t av_reverse [256]

Detailed Description

common internal and external API header

Definition in file common.h.


Define Documentation

#define AV_NE (   be,
  le 
)    (le)

Definition at line 43 of file common.h.

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

Definition at line 61 of file common.h.

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

Definition at line 52 of file common.h.

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

Definition at line 62 of file common.h.

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

Definition at line 55 of file common.h.

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

Definition at line 56 of file common.h.

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

Definition at line 57 of file common.h.

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

Definition at line 58 of file common.h.

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

Definition at line 53 of file common.h.

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

Definition at line 60 of file common.h.

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

Definition at line 50 of file common.h.

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

Definition at line 51 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 271 of file common.h.

#define GET_UTF8 (   val,
  GET_BYTE,
  ERROR 
)
Value:
val= GET_BYTE;\
    {\
        int ones= 7 - av_log2(val ^ 255);\
        if(ones==1)\
            ERROR\
        val&= 127>>ones;\
        while(--ones > 0){\
            int tmp= GET_BYTE - 128;\
            if(tmp>>6)\
                ERROR\
            val= (val<<6) + tmp;\
        }\
    }

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.

Definition at line 247 of file common.h.

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

Definition at line 234 of file common.h.

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

Definition at line 233 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 333 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\
            }\
        }\
    }

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 299 of file common.h.

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

Definition at line 49 of file common.h.

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

Definition at line 47 of file common.h.


Function Documentation

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 204 of file common.h.

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 112 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 157 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 135 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 146 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 124 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 180 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 193 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 168 of file common.h.

static av_always_inline av_const int av_log2_16bit_c ( unsigned int  v) [static]

Definition at line 85 of file common.h.

static av_always_inline av_const int av_log2_c ( unsigned int  v) [static]

Definition at line 69 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 228 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 214 of file common.h.


Variable Documentation

const uint8_t av_reverse[256]

Definition at line 54 of file mathematics.c.

const uint8_t ff_log2_tab[256]

Definition at line 43 of file mathematics.c.