Miam-Player  0.8.0
A nice music player
common.h File Reference
#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"

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 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)))
 
#define FFSIGN(a)   ((a) > 0 ? 1 : -1)
 
#define FFNABS(a)   ((a) <= 0 ? (a) : (-(a)))
 
#define FFDIFFSIGN(x, y)   (((x)>(y)) - ((x)<(y)))
 
#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)
 
#define GET_UTF16(val, GET_16BIT, ERROR)
 
#define PUT_UTF8(val, tmp, PUT_BYTE)
 
#define PUT_UTF16(val, tmp, PUT_16BIT)
 

Functions

av_const int av_log2 (unsigned v)
 
av_const int av_log2_16bit (unsigned v)
 

Detailed Description

common internal and external API header

Macro Definition Documentation

#define AV_CEIL_RSHIFT (   a,
 
)
Value:
(!av_builtin_constant_p(b) ? -((-(a)) >> (b)) \
: ((a) + (1<<(b)) - 1) >> (b))
#define av_builtin_constant_p(x)
Definition: attributes.h:158
#define AV_NE (   be,
  le 
)    (le)
#define FF_ARRAY_ELEMS (   a)    (sizeof(a) / sizeof((a)[0]))
#define FF_CEIL_RSHIFT   AV_CEIL_RSHIFT
#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()
#define FFDIFFSIGN (   x,
 
)    (((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.

#define FFMAX (   a,
 
)    ((a) > (b) ? (a) : (b))
#define FFMAX3 (   a,
  b,
 
)    FFMAX(FFMAX(a,b),c)
#define FFMIN (   a,
 
)    ((a) > (b) ? (b) : (a))
#define FFMIN3 (   a,
  b,
 
)    FFMIN(FFMIN(a,b),c)
#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.

#define FFSIGN (   a)    ((a) > 0 ? 1 : -1)
#define FFSWAP (   type,
  a,
 
)    do{type SWAP_tmp= b; b= a; a= SWAP_tmp;}while(0)
#define FFUDIV (   a,
 
)    (((a)>0 ?(a):(a)-(b)+1) / (b))
#define FFUMOD (   a,
 
)    ((a)-(b)*FFUDIV(a,b))
#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.
#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.
#define MKBETAG (   a,
  b,
  c,
 
)    ((d) | ((c) << 8) | ((b) << 16) | ((unsigned)(a) << 24))
#define MKTAG (   a,
  b,
  c,
 
)    ((a) | ((b) << 8) | ((c) << 16) | ((unsigned)(d) << 24))
#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.
#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.
#define ROUNDED_DIV (   a,
 
)    (((a)>0 ? (a) + ((b)>>1) : (a) - ((b)>>1))/(b))
#define RSHIFT (   a,
 
)    ((a) > 0 ? ((a) + ((1<<(b))>>1))>>(b) : ((a) + ((1<<(b))>>1)-1)>>(b))

Function Documentation

av_const int av_log2 ( unsigned  v)
av_const int av_log2_16bit ( unsigned  v)