* 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
+ * This file is part of Libav.
+ *
+ * Libav 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.
+ * version 2.1 of the License, or (at your option) any later version.
*
- * This library is distributed in the hope that it will be useful,
+ * Libav 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
+ * License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- *
*/
/**
- * @file cabac.h
+ * @file
* Context Adaptive Binary Arithmetic Coder.
*/
+#ifndef AVCODEC_CABAC_H
+#define AVCODEC_CABAC_H
+
+#include <stdint.h>
-//#undef NDEBUG
-#include <assert.h>
+#include "put_bits.h"
-#define CABAC_BITS 8
+extern uint8_t ff_h264_cabac_tables[512 + 4*2*64 + 4*64 + 63];
+#define H264_NORM_SHIFT_OFFSET 0
+#define H264_LPS_RANGE_OFFSET 512
+#define H264_MLPS_STATE_OFFSET 1024
+#define H264_LAST_COEFF_FLAG_OFFSET_8x8_OFFSET 1280
+
+#define CABAC_BITS 16
#define CABAC_MASK ((1<<CABAC_BITS)-1)
typedef struct CABACContext{
int low;
int range;
- int outstanding_count;
-#ifdef STRICT_LIMITS
- int symCount;
-#endif
- uint8_t lps_range[2*65][4]; ///< rangeTabLPS
- uint8_t lps_state[2*64]; ///< transIdxLPS
- uint8_t mps_state[2*64]; ///< transIdxMPS
const uint8_t *bytestream_start;
const uint8_t *bytestream;
const uint8_t *bytestream_end;
- 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];
-extern const uint8_t ff_h264_norm_shift[256];
-
-
-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, 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 void put_cabac(CABACContext *c, uint8_t * const state, int bit){
- int RangeLPS= c->lps_range[*state][c->range>>6];
-
- 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 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 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 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 (put_bits_count(&c->pb)+7)>>3;
-}
-
-/**
- * put (truncated) unary binarization.
- */
-static 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 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 void refill(CABACContext *c){
- if(c->bytestream <= c->bytestream_end)
-#if CABAC_BITS == 16
- c->low+= (c->bytestream[0]<<9) + (c->bytestream[1]<<1);
-#else
- c->low+= c->bytestream[0]<<1;
-#endif
- c->low -= CABAC_MASK;
- c->bytestream+= CABAC_BITS/8;
-}
-
-#if 0 /* all use commented */
-static void refill2(CABACContext *c){
- int i, x;
-
- x= c->low ^ (c->low-1);
- i= 8 - ff_h264_norm_shift[x>>(CABAC_BITS+1)];
-
- x= -CABAC_MASK;
-
- if(c->bytestream < c->bytestream_end)
-#if CABAC_BITS == 16
- x+= (c->bytestream[0]<<9) + (c->bytestream[1]<<1);
-#else
- x+= c->bytestream[0]<<1;
-#endif
-
- c->low += x<<i;
- c->bytestream+= CABAC_BITS/8;
-}
-#endif
-
-static inline void renorm_cabac_decoder(CABACContext *c){
- while(c->range < (0x200 << CABAC_BITS)){
- c->range+= c->range;
- c->low+= c->low;
- if(!(c->low & CABAC_MASK))
- refill(c);
- }
-}
-
-static inline void renorm_cabac_decoder_once(CABACContext *c){
-#ifdef ARCH_X86
- int temp;
-#if 0
- //P3:683
- asm(
- "lea -0x20000(%0), %2 \n\t"
- "shr $31, %2 \n\t" //FIXME 31->63 for x86-64
- "shl %%cl, %0 \n\t"
- "shl %%cl, %1 \n\t"
- : "+r"(c->range), "+r"(c->low), "+c"(temp)
- );
-#elif 0
- //P3:680
- asm(
- "cmp $0x20000, %0 \n\t"
- "setb %%cl \n\t" //FIXME 31->63 for x86-64
- "shl %%cl, %0 \n\t"
- "shl %%cl, %1 \n\t"
- : "+r"(c->range), "+r"(c->low), "+c"(temp)
- );
-#elif 1
- int temp2;
- //P3:665
- asm(
- "lea -0x20000(%0), %%eax \n\t"
- "cdq \n\t"
- "mov %0, %%eax \n\t"
- "and %%edx, %0 \n\t"
- "and %1, %%edx \n\t"
- "add %%eax, %0 \n\t"
- "add %%edx, %1 \n\t"
- : "+r"(c->range), "+r"(c->low), "+a"(temp), "+d"(temp2)
- );
-#elif 0
- int temp2;
- //P3:673
- asm(
- "cmp $0x20000, %0 \n\t"
- "sbb %%edx, %%edx \n\t"
- "mov %0, %%eax \n\t"
- "and %%edx, %0 \n\t"
- "and %1, %%edx \n\t"
- "add %%eax, %0 \n\t"
- "add %%edx, %1 \n\t"
- : "+r"(c->range), "+r"(c->low), "+a"(temp), "+d"(temp2)
- );
-#else
- int temp2;
- //P3:677
- asm(
- "cmp $0x20000, %0 \n\t"
- "lea (%0, %0), %%eax \n\t"
- "lea (%1, %1), %%edx \n\t"
- "cmovb %%eax, %0 \n\t"
- "cmovb %%edx, %1 \n\t"
- : "+r"(c->range), "+r"(c->low), "+a"(temp), "+d"(temp2)
- );
-#endif
-#else
- //P3:675
- int shift= (uint32_t)(c->range - (0x200 << CABAC_BITS))>>31;
- c->range<<= shift;
- c->low <<= shift;
-#endif
- if(!(c->low & CABAC_MASK))
- refill(c);
-}
-
-static int get_cabac(CABACContext *c, uint8_t * const state){
- //FIXME gcc generates duplicate load/stores for c->low and c->range
-START_TIMER
- int s = *state;
- int RangeLPS= c->lps_range[s][c->range>>(CABAC_BITS+7)]<<(CABAC_BITS+1);
- int bit, lps_mask attribute_unused;
-
- c->range -= RangeLPS;
-#if 1
- if(c->low < c->range){
- bit= s&1;
- *state= c->mps_state[s];
- renorm_cabac_decoder_once(c);
- }else{
-// int shift= ff_h264_norm_shift[RangeLPS>>17];
- bit= (s&1)^1;
- c->low -= c->range;
- *state= c->lps_state[s];
- c->range = RangeLPS;
- renorm_cabac_decoder(c);
-/* c->range = RangeLPS<<shift;
- c->low <<= shift;
- if(!(c->low & 0xFFFF)){
- refill2(c);
- }*/
- }
-#else
- lps_mask= (c->range - c->low)>>31;
-
- c->low -= c->range & lps_mask;
- c->range += (RangeLPS - c->range) & lps_mask;
-
- bit= (s^lps_mask)&1;
- *state= c->mps_state[s - (128&lps_mask)];
-
- lps_mask= ff_h264_norm_shift[c->range>>(CABAC_BITS+2)];
- c->range<<= lps_mask;
- c->low <<= lps_mask;
- if(!(c->low & CABAC_MASK))
- refill2(c);
-#endif
-STOP_TIMER("get_cabac")
- return bit;
-}
-
-static int get_cabac_bypass(CABACContext *c){
- c->low += c->low;
-
- if(!(c->low & CABAC_MASK))
- refill(c);
-
- 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 int get_cabac_terminate(CABACContext *c){
- c->range -= 4<<CABAC_BITS;
- if(c->low < c->range){
- renorm_cabac_decoder_once(c);
- return 0;
- }else{
- return c->bytestream - c->bytestream_start;
- }
-}
-
-/**
- * get (truncated) unnary binarization.
- */
-static 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 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;
+void ff_init_cabac_states(void);
- if(is_signed && get_cabac_bypass(c)){
- return -i;
- }else
- return i;
-}
+#endif /* AVCODEC_CABAC_H */
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