dxva2_hevc: properly signal the num_delta_pocs from the SPS RPS

ucNumDeltaPocsOfRefRpsIdx needs to contain the flat value from the SPS RPS,
and not the final computed value from the slice header RPS, as this calculation
is done internally by the driver again.

Sample-Id: http://trailers.divx.com/hevc/Sintel_4k_27qp_24fps_1aud_9subs.mkvi

libavcodec/dxva2_hevc.c

@@ -92,7 +92,7 @@ static void fill_picture_parameters(const AVCodecContext *avctx, AVDXVAContext *
     pp->init_qp_minus26                          = pps->pic_init_qp_minus26;
 
     if (h->sh.short_term_ref_pic_set_sps_flag == 0 && h->sh.short_term_rps) {
-        pp->ucNumDeltaPocsOfRefRpsIdx            = h->sh.short_term_rps->num_delta_pocs;
+        pp->ucNumDeltaPocsOfRefRpsIdx            = h->sh.short_term_rps->rps_idx_num_delta_pocs;
         pp->wNumBitsForShortTermRPSInSlice       = h->sh.short_term_ref_pic_set_size;
     }
 

libavcodec/hevc.h

@@ -276,6 +276,7 @@ enum ScanType {
 typedef struct ShortTermRPS {
     unsigned int num_negative_pics;
     int num_delta_pocs;
+    int rps_idx_num_delta_pocs;
     int32_t delta_poc[32];
     uint8_t used[32];
 } ShortTermRPS;

libavcodec/hevc_ps.c

@@ -136,6 +136,7 @@ int ff_hevc_decode_short_term_rps(GetBitContext *gb, AVCodecContext *avctx,
                 return AVERROR_INVALIDDATA;
             }
             rps_ridx = &sps->st_rps[sps->nb_st_rps - delta_idx];
+            rps->rps_idx_num_delta_pocs = rps_ridx->num_delta_pocs;
         } else
             rps_ridx = &sps->st_rps[rps - sps->st_rps - 1];