+++ /dev/null
-/*
- * H.26L/H.264/AVC/JVT/14496-10/... encoder/decoder
- * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- *
- */
-
-/**
- * @file cabac.h
- * Context Adaptive Binary Arithmetic Coder.
- */
-
-
-#undef NDEBUG
-#include <assert.h>
-
-typedef struct CABACContext{
- int low;
- int range;
- int outstanding_count;
-#ifdef STRICT_LIMITS
- int symCount;
-#endif
- uint8_t lps_range[2*64][4]; ///< rangeTabLPS
- uint8_t lps_state[2*64]; ///< transIdxLPS
- uint8_t mps_state[2*64]; ///< transIdxMPS
- uint8_t *bytestream_start;
- uint8_t *bytestream;
- int bits_left; ///<
- PutBitContext pb;
-}CABACContext;
-
-extern const uint8_t ff_h264_lps_range[64][4];
-extern const uint8_t ff_h264_mps_state[64];
-extern const uint8_t ff_h264_lps_state[64];
-
-void ff_init_cabac_encoder(CABACContext *c, uint8_t *buf, int buf_size);
-void ff_init_cabac_decoder(CABACContext *c, uint8_t *buf, int buf_size);
-void ff_init_cabac_states(CABACContext *c, uint8_t const (*lps_range)[4],
- uint8_t const *mps_state, uint8_t const *lps_state, int state_count);
-
-
-static inline void put_cabac_bit(CABACContext *c, int b){
- put_bits(&c->pb, 1, b);
- for(;c->outstanding_count; c->outstanding_count--){
- put_bits(&c->pb, 1, 1-b);
- }
-}
-
-static inline void renorm_cabac_encoder(CABACContext *c){
- while(c->range < 0x100){
- //FIXME optimize
- if(c->low<0x100){
- put_cabac_bit(c, 0);
- }else if(c->low<0x200){
- c->outstanding_count++;
- c->low -= 0x100;
- }else{
- put_cabac_bit(c, 1);
- c->low -= 0x200;
- }
-
- c->range+= c->range;
- c->low += c->low;
- }
-}
-
-static inline void put_cabac(CABACContext *c, uint8_t * const state, int bit){
- int RangeLPS= c->lps_range[*state][((c->range)>>6)&3];
-
- if(bit == ((*state)&1)){
- c->range -= RangeLPS;
- *state= c->mps_state[*state];
- }else{
- c->low += c->range - RangeLPS;
- c->range = RangeLPS;
- *state= c->lps_state[*state];
- }
-
- renorm_cabac_encoder(c);
-
-#ifdef STRICT_LIMITS
- c->symCount++;
-#endif
-}
-
-static inline void put_cabac_static(CABACContext *c, int RangeLPS, int bit){
- assert(c->range > RangeLPS);
-
- if(!bit){
- c->range -= RangeLPS;
- }else{
- c->low += c->range - RangeLPS;
- c->range = RangeLPS;
- }
-
- renorm_cabac_encoder(c);
-
-#ifdef STRICT_LIMITS
- c->symCount++;
-#endif
-}
-
-/**
- * @param bit 0 -> write zero bit, !=0 write one bit
- */
-static inline void put_cabac_bypass(CABACContext *c, int bit){
- c->low += c->low;
-
- if(bit){
- c->low += c->range;
- }
-//FIXME optimize
- if(c->low<0x200){
- put_cabac_bit(c, 0);
- }else if(c->low<0x400){
- c->outstanding_count++;
- c->low -= 0x200;
- }else{
- put_cabac_bit(c, 1);
- c->low -= 0x400;
- }
-
-#ifdef STRICT_LIMITS
- c->symCount++;
-#endif
-}
-
-/**
- *
- * @return the number of bytes written
- */
-static inline int put_cabac_terminate(CABACContext *c, int bit){
- c->range -= 2;
-
- if(!bit){
- renorm_cabac_encoder(c);
- }else{
- c->low += c->range;
- c->range= 2;
-
- renorm_cabac_encoder(c);
-
- assert(c->low <= 0x1FF);
- put_cabac_bit(c, c->low>>9);
- put_bits(&c->pb, 2, ((c->low>>7)&3)|1);
-
- flush_put_bits(&c->pb); //FIXME FIXME FIXME XXX wrong
- }
-
-#ifdef STRICT_LIMITS
- c->symCount++;
-#endif
-
- return (get_bit_count(&c->pb)+7)>>3;
-}
-
-/**
- * put (truncated) unary binarization.
- */
-static inline void put_cabac_u(CABACContext *c, uint8_t * state, int v, int max, int max_index, int truncated){
- int i;
-
- assert(v <= max);
-
-#if 1
- for(i=0; i<v; i++){
- put_cabac(c, state, 1);
- if(i < max_index) state++;
- }
- if(truncated==0 || v<max)
- put_cabac(c, state, 0);
-#else
- if(v <= max_index){
- for(i=0; i<v; i++){
- put_cabac(c, state+i, 1);
- }
- if(truncated==0 || v<max)
- put_cabac(c, state+i, 0);
- }else{
- for(i=0; i<=max_index; i++){
- put_cabac(c, state+i, 1);
- }
- for(; i<v; i++){
- put_cabac(c, state+max_index, 1);
- }
- if(truncated==0 || v<max)
- put_cabac(c, state+max_index, 0);
- }
-#endif
-}
-
-/**
- * put unary exp golomb k-th order binarization.
- */
-static inline void put_cabac_ueg(CABACContext *c, uint8_t * state, int v, int max, int is_signed, int k, int max_index){
- int i;
-
- if(v==0)
- put_cabac(c, state, 0);
- else{
- const int sign= v < 0;
-
- if(is_signed) v= ABS(v);
-
- if(v<max){
- for(i=0; i<v; i++){
- put_cabac(c, state, 1);
- if(i < max_index) state++;
- }
-
- put_cabac(c, state, 0);
- }else{
- int m= 1<<k;
-
- for(i=0; i<max; i++){
- put_cabac(c, state, 1);
- if(i < max_index) state++;
- }
-
- v -= max;
- while(v >= m){ //FIXME optimize
- put_cabac_bypass(c, 1);
- v-= m;
- m+= m;
- }
- put_cabac_bypass(c, 0);
- while(m>>=1){
- put_cabac_bypass(c, v&m);
- }
- }
-
- if(is_signed)
- put_cabac_bypass(c, sign);
- }
-}
-
-static inline void renorm_cabac_decoder(CABACContext *c){
- while(c->range < 0x10000){
- c->range+= c->range;
- c->low+= c->low;
- if(--c->bits_left == 0){
- c->low+= *c->bytestream++;
- c->bits_left= 8;
- }
- }
-}
-
-static inline int get_cabac(CABACContext *c, uint8_t * const state){
- int RangeLPS= c->lps_range[*state][((c->range)>>14)&3]<<8;
- int bit;
-
- c->range -= RangeLPS;
- if(c->low < c->range){
- bit= (*state)&1;
- *state= c->mps_state[*state];
- }else{
- bit= ((*state)&1)^1;
- c->low -= c->range;
- c->range = RangeLPS;
- *state= c->lps_state[*state];
- }
- renorm_cabac_decoder(c);
-
- return bit;
-}
-
-static inline int get_cabac_static(CABACContext *c, int RangeLPS){
- int bit;
-
- c->range -= RangeLPS;
- if(c->low < c->range){
- bit= 0;
- }else{
- bit= 1;
- c->low -= c->range;
- c->range = RangeLPS;
- }
- renorm_cabac_decoder(c);
-
- return bit;
-}
-
-static inline int get_cabac_bypass(CABACContext *c){
- c->low += c->low;
-
- if(--c->bits_left == 0){
- c->low+= *c->bytestream++;
- c->bits_left= 8;
- }
-
- if(c->low < c->range){
- return 0;
- }else{
- c->low -= c->range;
- return 1;
- }
-}
-
-/**
- *
- * @return the number of bytes read or 0 if no end
- */
-static inline int get_cabac_terminate(CABACContext *c){
- c->range -= 2<<8;
- if(c->low < c->range){
- renorm_cabac_decoder(c);
- return 0;
- }else{
- return c->bytestream - c->bytestream_start;
- }
-}
-
-/**
- * get (truncated) unnary binarization.
- */
-static inline int get_cabac_u(CABACContext *c, uint8_t * state, int max, int max_index, int truncated){
- int i;
-
- for(i=0; i<max; i++){
- if(get_cabac(c, state)==0)
- return i;
-
- if(i< max_index) state++;
- }
-
- return truncated ? max : -1;
-}
-
-/**
- * get unary exp golomb k-th order binarization.
- */
-static inline int get_cabac_ueg(CABACContext *c, uint8_t * state, int max, int is_signed, int k, int max_index){
- int i, v;
- int m= 1<<k;
-
- if(get_cabac(c, state)==0)
- return 0;
-
- if(0 < max_index) state++;
-
- for(i=1; i<max; i++){
- if(get_cabac(c, state)==0){
- if(is_signed && get_cabac_bypass(c)){
- return -i;
- }else
- return i;
- }
-
- if(i < max_index) state++;
- }
-
- while(get_cabac_bypass(c)){
- i+= m;
- m+= m;
- }
-
- v=0;
- while(m>>=1){
- v+= v + get_cabac_bypass(c);
- }
- i += v;
-
- if(is_signed && get_cabac_bypass(c)){
- return -i;
- }else
- return i;
-}
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