libavcodec/cabac.c File Reference

Context Adaptive Binary Arithmetic Coder. More...

#include <string.h>
#include "libavutil/common.h"
#include "get_bits.h"
#include "cabac.h"
#include "cabac_functions.h"

Go to the source code of this file.

Functions
void	ff_init_cabac_encoder (CABACContext *c, uint8_t *buf, int buf_size)
void	ff_init_cabac_decoder (CABACContext *c, const uint8_t *buf, int buf_size)
void	ff_init_cabac_states (CABACContext *c)
Variables
uint8_t	ff_h264_cabac_tables [512+4 *2 *64+4 *64+63]
static const uint8_t	lps_range [64][4]
static uint8_t	h264_lps_state [2 *64]
static uint8_t	h264_mps_state [2 *64]
static const uint8_t	mps_state [64]
static const uint8_t	lps_state [64]
static const uint8_t	last_coeff_flag_offset_8x8 [63]

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Detailed Description

Context Adaptive Binary Arithmetic Coder.

Definition in file cabac.c.

---

Function Documentation

void ff_init_cabac_decoder	(	CABACContext *	c,
		const uint8_t *	buf,
		int	buf_size
	)

Parameters:

buf_size

size of buf in bits

Definition at line 125 of file cabac.c.

Referenced by decode_slice(), and ff_h264_decode_mb_cabac().

void ff_init_cabac_encoder	(	CABACContext *	c,
		uint8_t *	buf,
		int	buf_size
	)

Parameters:

buf_size

size of buf in bits

Definition at line 112 of file cabac.c.

void ff_init_cabac_states

(

CABACContext *

c

)

Definition at line 140 of file cabac.c.

Referenced by decode_slice().

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Variable Documentation

uint8_t ff_h264_cabac_tables[512+4 *2 *64+4 *64+63]

Initial value:

 {
 9,8,7,7,6,6,6,6,5,5,5,5,5,5,5,5,
 4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,
 3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
 3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
}

Definition at line 34 of file cabac.c.

uint8_t h264_lps_state[2 *64] [static]

Definition at line 76 of file cabac.c.

Referenced by ff_init_cabac_states().

uint8_t h264_mps_state[2 *64] [static]

Definition at line 77 of file cabac.c.

Referenced by ff_init_cabac_states().

const uint8_t last_coeff_flag_offset_8x8[63] [static]

Initial value:

 {
 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4,
 5, 5, 5, 5, 6, 6, 6, 6, 7, 7, 7, 7, 8, 8, 8
}

Definition at line 101 of file cabac.c.

Referenced by ff_init_cabac_states().

const uint8_t lps_range[64][4] [static]

Initial value:

 {
{128,176,208,240}, {128,167,197,227}, {128,158,187,216}, {123,150,178,205},
{116,142,169,195}, {111,135,160,185}, {105,128,152,175}, {100,122,144,166},
{ 95,116,137,158}, { 90,110,130,150}, { 85,104,123,142}, { 81, 99,117,135},
{ 77, 94,111,128}, { 73, 89,105,122}, { 69, 85,100,116}, { 66, 80, 95,110},
{ 62, 76, 90,104}, { 59, 72, 86, 99}, { 56, 69, 81, 94}, { 53, 65, 77, 89},
{ 51, 62, 73, 85}, { 48, 59, 69, 80}, { 46, 56, 66, 76}, { 43, 53, 63, 72},
{ 41, 50, 59, 69}, { 39, 48, 56, 65}, { 37, 45, 54, 62}, { 35, 43, 51, 59},
{ 33, 41, 48, 56}, { 32, 39, 46, 53}, { 30, 37, 43, 50}, { 29, 35, 41, 48},
{ 27, 33, 39, 45}, { 26, 31, 37, 43}, { 24, 30, 35, 41}, { 23, 28, 33, 39},
{ 22, 27, 32, 37}, { 21, 26, 30, 35}, { 20, 24, 29, 33}, { 19, 23, 27, 31},
{ 18, 22, 26, 30}, { 17, 21, 25, 28}, { 16, 20, 23, 27}, { 15, 19, 22, 25},
{ 14, 18, 21, 24}, { 14, 17, 20, 23}, { 13, 16, 19, 22}, { 12, 15, 18, 21},
{ 12, 14, 17, 20}, { 11, 14, 16, 19}, { 11, 13, 15, 18}, { 10, 12, 15, 17},
{ 10, 12, 14, 16}, {  9, 11, 13, 15}, {  9, 11, 12, 14}, {  8, 10, 12, 14},
{  8,  9, 11, 13}, {  7,  9, 11, 12}, {  7,  9, 10, 12}, {  7,  8, 10, 11},
{  6,  8,  9, 11}, {  6,  7,  9, 10}, {  6,  7,  8,  9}, {  2,  2,  2,  2},
}

Definition at line 57 of file cabac.c.

Referenced by ff_init_cabac_states().

const uint8_t lps_state[64] [static]

Initial value:

 {
  0, 0, 1, 2, 2, 4, 4, 5,
  6, 7, 8, 9, 9,11,11,12,
 13,13,15,15,16,16,18,18,
 19,19,21,21,22,22,23,24,
 24,25,26,26,27,27,28,29,
 29,30,30,30,31,32,32,33,
 33,33,34,34,35,35,35,36,
 36,36,37,37,37,38,38,63,
}

Definition at line 90 of file cabac.c.

Referenced by ff_init_cabac_states().

const uint8_t mps_state[64] [static]

Initial value:

 {
  1, 2, 3, 4, 5, 6, 7, 8,
  9,10,11,12,13,14,15,16,
 17,18,19,20,21,22,23,24,
 25,26,27,28,29,30,31,32,
 33,34,35,36,37,38,39,40,
 41,42,43,44,45,46,47,48,
 49,50,51,52,53,54,55,56,
 57,58,59,60,61,62,62,63,
}

Definition at line 79 of file cabac.c.

Referenced by ff_init_cabac_states().