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-rw-r--r--libavcodec/cabac.c164
1 files changed, 159 insertions, 5 deletions
diff --git a/libavcodec/cabac.c b/libavcodec/cabac.c
index 6ba9303dc1..187b7dc445 100644
--- a/libavcodec/cabac.c
+++ b/libavcodec/cabac.c
@@ -2,20 +2,20 @@
* H.26L/H.264/AVC/JVT/14496-10/... encoder/decoder
* Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
*
- * This file is part of Libav.
+ * This file is part of FFmpeg.
*
- * Libav is free software; you can redistribute it and/or
+ * FFmpeg 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 2.1 of the License, or (at your option) any later version.
*
- * Libav is distributed in the hope that it will be useful,
+ * FFmpeg 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 Libav; if not, write to the Free Software
+ * License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
@@ -73,7 +73,8 @@ static const uint8_t lps_range[64][4]= {
{ 6, 8, 9, 11}, { 6, 7, 9, 10}, { 6, 7, 8, 9}, { 2, 2, 2, 2},
};
-static uint8_t h264_mps_state[2 * 64];
+static uint8_t h264_lps_state[2*64];
+static uint8_t h264_mps_state[2*64];
static const uint8_t mps_state[64]= {
1, 2, 3, 4, 5, 6, 7, 8,
@@ -152,10 +153,14 @@ void ff_init_cabac_states(void)
h264_mps_state[2 * i + 1] = 2 * mps_state[i] + 1;
if( i ){
+ h264_lps_state[2*i+0]=
ff_h264_mlps_state[128-2*i-1]= 2*lps_state[i]+0;
+ h264_lps_state[2*i+1]=
ff_h264_mlps_state[128-2*i-2]= 2*lps_state[i]+1;
}else{
+ h264_lps_state[2*i+0]=
ff_h264_mlps_state[128-2*i-1]= 1;
+ h264_lps_state[2*i+1]=
ff_h264_mlps_state[128-2*i-2]= 0;
}
}
@@ -163,3 +168,152 @@ void ff_init_cabac_states(void)
ff_h264_last_coeff_flag_offset_8x8[i] = last_coeff_flag_offset_8x8[i];
}
}
+
+#ifdef TEST
+#define SIZE 10240
+
+#include "libavutil/lfg.h"
+#include "avcodec.h"
+#include "cabac.h"
+
+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= ff_h264_lps_range[2*(c->range&0xC0) + *state];
+
+ if(bit == ((*state)&1)){
+ c->range -= RangeLPS;
+ *state = h264_mps_state[*state];
+ }else{
+ c->low += c->range - RangeLPS;
+ c->range = RangeLPS;
+ *state= h264_lps_state[*state];
+ }
+
+ renorm_cabac_encoder(c);
+}
+
+/**
+ * @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;
+ }
+}
+
+/**
+ *
+ * @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);
+
+ av_assert0(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
+ }
+
+ return (put_bits_count(&c->pb)+7)>>3;
+}
+
+int main(void){
+ CABACContext c;
+ uint8_t b[9*SIZE];
+ uint8_t r[9*SIZE];
+ int i;
+ uint8_t state[10]= {0};
+ AVLFG prng;
+
+ av_lfg_init(&prng, 1);
+ ff_init_cabac_encoder(&c, b, SIZE);
+ ff_init_cabac_states();
+
+ for(i=0; i<SIZE; i++){
+ if(2*i<SIZE) r[i] = av_lfg_get(&prng) % 7;
+ else r[i] = (i>>8)&1;
+ }
+
+ for(i=0; i<SIZE; i++){
+START_TIMER
+ put_cabac_bypass(&c, r[i]&1);
+STOP_TIMER("put_cabac_bypass")
+ }
+
+ for(i=0; i<SIZE; i++){
+START_TIMER
+ put_cabac(&c, state, r[i]&1);
+STOP_TIMER("put_cabac")
+ }
+
+ put_cabac_terminate(&c, 1);
+
+ ff_init_cabac_decoder(&c, b, SIZE);
+
+ memset(state, 0, sizeof(state));
+
+ for(i=0; i<SIZE; i++){
+START_TIMER
+ if( (r[i]&1) != get_cabac_bypass(&c) )
+ av_log(NULL, AV_LOG_ERROR, "CABAC bypass failure at %d\n", i);
+STOP_TIMER("get_cabac_bypass")
+ }
+
+ for(i=0; i<SIZE; i++){
+START_TIMER
+ if( (r[i]&1) != get_cabac(&c, state) )
+ av_log(NULL, AV_LOG_ERROR, "CABAC failure at %d\n", i);
+STOP_TIMER("get_cabac")
+ }
+ if(!get_cabac_terminate(&c))
+ av_log(NULL, AV_LOG_ERROR, "where's the Terminator?\n");
+
+ return 0;
+}
+
+#endif /* TEST */