Fixed-point LSP and LPC decoding routines for ACELP-based codecs

[ffmpeg] / libavcodec / cabac.c

diff --git a/libavcodec/cabac.c b/libavcodec/cabac.c
index 8dd00a3cd9cb1965492c84265b612fbeedfacf93..fc17bb6ac4c578d41dc5dcb5474fd193b4d7880d 100644 (file)
--- a/libavcodec/cabac.c
+++ b/libavcodec/cabac.c
@@ -17,7 +17,6 @@
  * You should have received a copy of the GNU Lesser General Public
  * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- *
  */
 
 /**
@@ -31,7 +30,7 @@
 #include "bitstream.h"
 #include "cabac.h"
 
-const uint8_t ff_h264_lps_range[64][4]= {
+static const uint8_t lps_range[64][4]= {
 {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},
@@ -50,7 +49,12 @@ const uint8_t ff_h264_lps_range[64][4]= {
 {  6,  8,  9, 11}, {  6,  7,  9, 10}, {  6,  7,  8,  9}, {  2,  2,  2,  2},
 };
 
-const uint8_t ff_h264_mps_state[64]= {
+uint8_t ff_h264_mlps_state[4*64];
+uint8_t ff_h264_lps_range[4*2*64];
+uint8_t ff_h264_lps_state[2*64];
+uint8_t ff_h264_mps_state[2*64];
+
+static const uint8_t mps_state[64]= {
   1, 2, 3, 4, 5, 6, 7, 8,
   9,10,11,12,13,14,15,16,
  17,18,19,20,21,22,23,24,
@@ -61,7 +65,7 @@ const uint8_t ff_h264_mps_state[64]= {
  57,58,59,60,61,62,62,63,
 };
 
-const uint8_t ff_h264_lps_state[64]= {
+static const uint8_t lps_state[64]= {
   0, 0, 1, 2, 2, 4, 4, 5,
   6, 7, 8, 9, 9,11,11,12,
  13,13,15,15,16,16,18,18,
@@ -71,25 +75,40 @@ const uint8_t ff_h264_lps_state[64]= {
  33,33,34,34,35,35,35,36,
  36,36,37,37,37,38,38,63,
 };
-
-const uint8_t ff_h264_norm_shift[256]= {
- 8,7,6,6,5,5,5,5,4,4,4,4,4,4,4,4,
- 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,
+#if 0
+const uint8_t ff_h264_norm_shift_old[128]= {
+ 7,6,5,5,4,4,4,4,3,3,3,3,3,3,3,3,
  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,
- 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,
 };
+#endif
+const uint8_t ff_h264_norm_shift[512]= {
+ 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,
+};
 
 /**
  *
@@ -124,38 +143,49 @@ void ff_init_cabac_decoder(CABACContext *c, const uint8_t *buf, int buf_size){
     c->low =  (*c->bytestream++)<<10;
 #endif
     c->low+= ((*c->bytestream++)<<2) + 2;
-    c->range= 0x1FE<<(CABAC_BITS + 1);
+    c->range= 0x1FE;
 }
 
-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){
+void ff_init_cabac_states(CABACContext *c){
     int i, j;
 
-    for(i=0; i<state_count; i++){
+    for(i=0; i<64; i++){
         for(j=0; j<4; j++){ //FIXME check if this is worth the 1 shift we save
-            c->lps_range[2*i+2][j+4]=
-            c->lps_range[2*i+3][j+4]= lps_range[i][j];
+            ff_h264_lps_range[j*2*64+2*i+0]=
+            ff_h264_lps_range[j*2*64+2*i+1]= lps_range[i][j];
         }
 
-        c->mps_state[2*i+2]= 2*mps_state[i]+2;
-        c->mps_state[2*i+3]= 2*mps_state[i]+3;
+        ff_h264_mlps_state[128+2*i+0]=
+        ff_h264_mps_state[2*i+0]= 2*mps_state[i]+0;
+        ff_h264_mlps_state[128+2*i+1]=
+        ff_h264_mps_state[2*i+1]= 2*mps_state[i]+1;
 
         if( i ){
-            c->lps_state[2*i+2]= 2*lps_state[i]+2;
-            c->lps_state[2*i+3]= 2*lps_state[i]+3;
+#ifdef BRANCHLESS_CABAC_DECODER
+            ff_h264_mlps_state[128-2*i-1]= 2*lps_state[i]+0;
+            ff_h264_mlps_state[128-2*i-2]= 2*lps_state[i]+1;
+        }else{
+            ff_h264_mlps_state[128-2*i-1]= 1;
+            ff_h264_mlps_state[128-2*i-2]= 0;
+#else
+            ff_h264_lps_state[2*i+0]= 2*lps_state[i]+0;
+            ff_h264_lps_state[2*i+1]= 2*lps_state[i]+1;
         }else{
-            c->lps_state[2*i+2]= 3;
-            c->lps_state[2*i+3]= 2;
+            ff_h264_lps_state[2*i+0]= 1;
+            ff_h264_lps_state[2*i+1]= 0;
+#endif
         }
     }
 }
 
-#if 0 //selftest
+#ifdef TEST
+#undef random
 #define SIZE 10240
 
 #include "avcodec.h"
+#include "cabac.h"
 
-int main(){
+int main(void){
     CABACContext c;
     uint8_t b[9*SIZE];
     uint8_t r[9*SIZE];
@@ -163,7 +193,7 @@ int main(){
     uint8_t state[10]= {0};
 
     ff_init_cabac_encoder(&c, b, SIZE);
-    ff_init_cabac_states(&c, ff_h264_lps_range, ff_h264_mps_state, ff_h264_lps_state, 64);
+    ff_init_cabac_states(&c);
 
     for(i=0; i<SIZE; i++){
         r[i]= random()%7;
@@ -233,4 +263,4 @@ STOP_TIMER("get_cabac_ueg")
     return 0;
 }
 
-#endif
+#endif /* TEST */