func: static int dxva2_retrieve_data(AVCodecContext *s, AVFrame *frame)
  
  {
  
      InputStream        *ist = s->opaque;
  
      DXVA2Context       *ctx = ist->hwaccel_ctx;
  
      int                ret;
  
  
  
      ret = av_hwframe_transfer_data(ctx->tmp_frame, frame, 0);
  
      if (ret < 0)
  
          return ret;
  
  
  
      ret = av_frame_copy_props(ctx->tmp_frame, frame);
  
      if (ret < 0) {
  
          av_frame_unref(ctx->tmp_frame);
  
          return ret;
  
      }
  
  
  
      av_frame_unref(frame);
  
      av_frame_move_ref(frame, ctx->tmp_frame);
  
  
  
      return 0;
  
  }
  