qscale has a range of 0..51 we thus do not need a 256 entry table and neither need

to and it with 0xFF.

Originally committed as revision 14336 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/h264.c

@@ -1584,7 +1584,7 @@ static void chroma_dc_dct_c(DCTELEM *block){
  * gets the chroma qp.
  */
 static inline int get_chroma_qp(H264Context *h, int t, int qscale){
-    return h->pps.chroma_qp_table[t][qscale & 0xff];
+    return h->pps.chroma_qp_table[t][qscale];
 }
 
 //FIXME need to check that this does not overflow signed 32 bit for low qp, I am not sure, it's very close
@@ -7337,8 +7337,8 @@ static void
 build_qp_table(PPS *pps, int t, int index)
 {
     int i;
-    for(i = 0; i < 255; i++)
+    for(i = 0; i < 52; i++)
-        pps->chroma_qp_table[t][i & 0xff] = chroma_qp[av_clip(i + index, 0, 51)];
+        pps->chroma_qp_table[t][i] = chroma_qp[av_clip(i + index, 0, 51)];
 }
 
 static inline int decode_picture_parameter_set(H264Context *h, int bit_length){

libavcodec/h264.h

@@ -138,7 +138,7 @@ typedef struct PPS{
     int transform_8x8_mode;     ///< transform_8x8_mode_flag
     uint8_t scaling_matrix4[6][16];
     uint8_t scaling_matrix8[2][64];
-    uint8_t chroma_qp_table[2][256];  ///< pre-scaled (with chroma_qp_index_offset) version of qp_table
+    uint8_t chroma_qp_table[2][64];  ///< pre-scaled (with chroma_qp_index_offset) version of qp_table
     int chroma_qp_diff;
 }PPS;