INTRA PCM macroblocks support patch by (Loic )lll+ffmpeg m4x org)

This patch adds the support for INTRA PCM macroblocks in CAVLC and CABAC
mode, the deblocking needed a small modification and so did the
intra4x4_pred_mode prediction.

With this patch, the 5 streams of the conformance suite containing INTRA
PCM macroblocks now decode entirely, 4 are completely corrects, 1 is
incorrect since the first B slice because of deblocking in B slice not
yet implemented.

The code is not optimized for speed, it is not necessary IPCM
macroblocks are rare, but it could be optimized for code size, if
someone want to do this, feel free.

Originally committed as revision 3941 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/h264.c

@@ -482,10 +482,10 @@ static inline void fill_caches(H264Context *h, int mb_type, int for_deblock){
                 h->intra4x4_pred_mode_cache[7+8*0]= h->intra4x4_pred_mode[top_xy][3];
             }else{
                 int pred;
-                if(IS_INTRA16x16(top_type) || (IS_INTER(top_type) && !h->pps.constrained_intra_pred))
-                    pred= 2;
-                else{
+                if(!top_type || (IS_INTER(top_type) && h->pps.constrained_intra_pred))
                     pred= -1;
+                else{
+                    pred= 2;
                 }
                 h->intra4x4_pred_mode_cache[4+8*0]=
                 h->intra4x4_pred_mode_cache[5+8*0]=
@@ -498,10 +498,10 @@ static inline void fill_caches(H264Context *h, int mb_type, int for_deblock){
                     h->intra4x4_pred_mode_cache[3+8*2 + 2*8*i]= h->intra4x4_pred_mode[left_xy[i]][left_block[1+2*i]];
                 }else{
                     int pred;
-                    if(IS_INTRA16x16(left_type[i]) || (IS_INTER(left_type[i]) && !h->pps.constrained_intra_pred))
-                        pred= 2;
-                    else{
+                    if(!left_type[i] || (IS_INTER(left_type[i]) && h->pps.constrained_intra_pred))
                         pred= -1;
+                    else{
+                        pred= 2;
                     }
                     h->intra4x4_pred_mode_cache[3+8*1 + 2*8*i]=
                     h->intra4x4_pred_mode_cache[3+8*2 + 2*8*i]= pred;
@@ -2739,6 +2739,34 @@ static void hl_decode_mb(H264Context *h){
 //        dct_offset = s->linesize * 16;
     }
 
+    if (IS_INTRA_PCM(mb_type)) {
+        unsigned int x, y;
+
+        // The pixels are stored in h->mb array in the same order as levels,
+        // copy them in output in the correct order.
+        for(i=0; i<16; i++) {
+            for (y=0; y<4; y++) {
+                for (x=0; x<4; x++) {
+                    *(dest_y + h->block_offset[i] + y*linesize + x) = h->mb[i*16+y*4+x];
+                }
+            }
+        }
+        for(i=16; i<16+4; i++) {
+            for (y=0; y<4; y++) {
+                for (x=0; x<4; x++) {
+                    *(dest_cb + h->block_offset[i] + y*uvlinesize + x) = h->mb[i*16+y*4+x];
+                }
+            }
+        }
+        for(i=20; i<20+4; i++) {
+            for (y=0; y<4; y++) {
+                for (x=0; x<4; x++) {
+                    *(dest_cr + h->block_offset[i] + y*uvlinesize + x) = h->mb[i*16+y*4+x];
+                }
+            }
+        }
+        goto deblock;
+    }
     if(IS_INTRA(mb_type)){
         if(h->deblocking_filter)
             xchg_mb_border(h, dest_y, dest_cb, dest_cr, linesize, uvlinesize, 1);
@@ -2845,6 +2873,7 @@ static void hl_decode_mb(H264Context *h){
             }
         }
     }
+deblock:
     if(h->deblocking_filter) {
         backup_mb_border(h, dest_y, dest_cb, dest_cr, linesize, uvlinesize);
         fill_caches(h, mb_type, 1); //FIXME dont fill stuff which isnt used by filter_mb
@@ -3984,38 +4013,39 @@ decode_intra_mb:
     h->slice_table[ mb_xy ]= h->slice_num;
     
     if(IS_INTRA_PCM(mb_type)){
-        const uint8_t *ptr;
-        int x, y;
+        unsigned int x, y;
         
         // we assume these blocks are very rare so we dont optimize it
         align_get_bits(&s->gb);
         
-        ptr= s->gb.buffer + get_bits_count(&s->gb);
-    
+        // The pixels are stored in the same order as levels in h->mb array.
         for(y=0; y<16; y++){
-            const int index= 4*(y&3) + 64*(y>>2);
+            const int index= 4*(y&3) + 32*((y>>2)&1) + 128*(y>>3);
             for(x=0; x<16; x++){
-                h->mb[index + (x&3) + 16*(x>>2)]= *(ptr++);
+                tprintf("LUMA ICPM LEVEL (%3d)\n", show_bits(&s->gb, 8));
+                h->mb[index + (x&3) + 16*((x>>2)&1) + 64*(x>>3)]= get_bits(&s->gb, 8);
             }
         }
         for(y=0; y<8; y++){
             const int index= 256 + 4*(y&3) + 32*(y>>2);
             for(x=0; x<8; x++){
-                h->mb[index + (x&3) + 16*(x>>2)]= *(ptr++);
+                tprintf("CHROMA U ICPM LEVEL (%3d)\n", show_bits(&s->gb, 8));
+                h->mb[index + (x&3) + 16*(x>>2)]= get_bits(&s->gb, 8);
             }
         }
         for(y=0; y<8; y++){
             const int index= 256 + 64 + 4*(y&3) + 32*(y>>2);
             for(x=0; x<8; x++){
-                h->mb[index + (x&3) + 16*(x>>2)]= *(ptr++);
+                tprintf("CHROMA V ICPM LEVEL (%3d)\n", show_bits(&s->gb, 8));
+                h->mb[index + (x&3) + 16*(x>>2)]= get_bits(&s->gb, 8);
             }
         }
     
-        skip_bits(&s->gb, 384); //FIXME check /fix the bitstream readers
-        
-        //FIXME deblock filter, non_zero_count_cache init ...
+        // In deblocking, the quantiser is 0
+        s->current_picture.qscale_table[mb_xy]= 0;
+        h->chroma_qp = get_chroma_qp(h, 0);
+        // All coeffs are presents
         memset(h->non_zero_count[mb_xy], 16, 16);
-        s->current_picture.qscale_table[mb_xy]= s->qscale;
         
         return 0;
     }
@@ -4919,13 +4949,49 @@ decode_intra_mb:
     h->slice_table[ mb_xy ]= h->slice_num;
 
     if(IS_INTRA_PCM(mb_type)) {
-        /* TODO */
-        assert(0);
-        h->cbp_table[mb_xy] = 0xf +4*2; //FIXME ?!
-        h->cbp_table[mb_xy] |= 0x1C0;
+        const uint8_t *ptr;
+        unsigned int x, y;
+        
+        // We assume these blocks are very rare so we dont optimize it.
+        // FIXME The two following lines get the bitstream position in the cabac
+        // decode, I think it should be done by a function in cabac.h (or cabac.c).
+        ptr= h->cabac.bytestream;
+        if (h->cabac.low&0x1) ptr-=CABAC_BITS/8;
+
+        // The pixels are stored in the same order as levels in h->mb array.
+        for(y=0; y<16; y++){
+            const int index= 4*(y&3) + 32*((y>>2)&1) + 128*(y>>3);
+            for(x=0; x<16; x++){
+                tprintf("LUMA ICPM LEVEL (%3d)\n", *ptr);
+                h->mb[index + (x&3) + 16*((x>>2)&1) + 64*(x>>3)]= *ptr++;
+            }
+        }
+        for(y=0; y<8; y++){
+            const int index= 256 + 4*(y&3) + 32*(y>>2);
+            for(x=0; x<8; x++){
+                tprintf("CHROMA U ICPM LEVEL (%3d)\n", *ptr);
+                h->mb[index + (x&3) + 16*(x>>2)]= *ptr++;
+            }
+        }
+        for(y=0; y<8; y++){
+            const int index= 256 + 64 + 4*(y&3) + 32*(y>>2);
+            for(x=0; x<8; x++){
+                tprintf("CHROMA V ICPM LEVEL (%3d)\n", *ptr);
+                h->mb[index + (x&3) + 16*(x>>2)]= *ptr++;
+            }
+        }
+
+        ff_init_cabac_decoder(&h->cabac, ptr, h->cabac.bytestream_end - ptr);
+
+        // All blocks are presents
+        h->cbp_table[mb_xy] = 0x1ef;
         h->chroma_pred_mode_table[mb_xy] = 0;
-        s->current_picture.qscale_table[mb_xy]= s->qscale;
-        return -1;
+        // In deblocking, the quantiser is 0
+        s->current_picture.qscale_table[mb_xy]= 0;
+        h->chroma_qp = get_chroma_qp(h, 0);
+        // All coeffs are presents
+        memset(h->non_zero_count[mb_xy], 16, 16);
+        return 0;
     }
 
     fill_caches(h, mb_type, 0);
@@ -5605,7 +5671,9 @@ static void filter_mb( H264Context *h, int mb_x, int mb_y, uint8_t *img_y, uint8
             }
 
             /* Filter edge */
-            qp = ( s->qscale + s->current_picture.qscale_table[mbn_xy] + 1 ) >> 1;
+            // Do not use s->qscale as luma quantiser because it has not the same
+            // value in IPCM macroblocks.
+            qp = ( s->current_picture.qscale_table[mb_xy] + s->current_picture.qscale_table[mbn_xy] + 1 ) >> 1;
             //tprintf("filter mb:%d/%d dir:%d edge:%d, QPy:%d, QPc:%d, QPcn:%d\n", mb_x, mb_y, dir, edge, qp, h->chroma_qp, s->current_picture.qscale_table[mbn_xy]);
             if( dir == 0 ) {
                 filter_mb_edgev( h, &img_y[4*edge], linesize, bS, qp );