h264: Fix frame sync / random access handling.

It seems I have misunderstood the spec when I implemented this
originally.
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/h264.c

@@ -3906,13 +3906,13 @@ static int decode_nal_units(H264Context *h, const uint8_t *buf, int buf_size){
                     (hx->nal_unit_type == NAL_IDR_SLICE);
 
             if (h->recovery_frame == h->frame_num) {
-                h->sync |= 1;
+                s->current_picture_ptr->sync |= 1;
                 h->recovery_frame = -1;
             }
 
             h->sync |= !!s->current_picture_ptr->f.key_frame;
             h->sync |= 3*!!(s->flags2 & CODEC_FLAG2_SHOW_ALL);
-            s->current_picture_ptr->sync = h->sync;
+            s->current_picture_ptr->sync |= h->sync;
 
             if (h->current_slice == 1) {
                 if(!(s->flags2 & CODEC_FLAG2_CHUNKS)) {
@@ -4129,13 +4129,11 @@ not_extra:
         field_end(h, 0);
 
         *data_size = 0; /* Wait for second field. */
-        if (h->next_output_pic && h->next_output_pic->sync) {
-            if(h->sync>1 || h->next_output_pic->f.pict_type != AV_PICTURE_TYPE_B){
+        if (h->next_output_pic && (h->next_output_pic->sync || h->sync>1)) {
                 *data_size = sizeof(AVFrame);
                 *pict = *(AVFrame*)h->next_output_pic;
         }
     }
-    }
 
     assert(pict->data[0] || !*data_size);
     ff_print_debug_info(s, pict);

libavcodec/h264_refs.c

@@ -654,8 +654,7 @@ int ff_h264_execute_ref_pic_marking(H264Context *h, MMCO *mmco, int mmco_count){
     print_long_term(h);
 
     if(err >= 0 && h->long_ref_count==0 && h->short_ref_count<=2 && h->pps.ref_count[0]<=1 + (s->picture_structure != PICT_FRAME) && s->current_picture_ptr->f.pict_type == AV_PICTURE_TYPE_I){
-        h->sync |= 1;
-        s->current_picture_ptr->sync |= h->sync;
+        s->current_picture_ptr->sync |= 1;
     }
 
     return (h->s.avctx->err_recognition & AV_EF_EXPLODE) ? err : 0;