func: static int dxva2_get_buffer(AVCodecContext *s, AVFrame *frame, int flags)
  
  {
  
      InputStream  *ist = s->opaque;
  
      DXVA2Context *ctx = ist->hwaccel_ctx;
  
  
  
      return av_hwframe_get_buffer(ctx->hw_frames_ctx, frame, 0);
  
  }
  