[FFmpeg-devel] [PATCH v2 6/6] lavc/qsvdec: Add VP9 decoder support

[Li, Zhong]

> > @@ -90,6 +90,17 @@ static av_cold int qsv_decode_init(AVCodecContext
> > *avctx)
> >      }
> >  #endif
> >
> > +#if CONFIG_VP9_QSV_DECODER
> > +    if (avctx->codec_id == AV_CODEC_ID_VP9) {
> > +        static const char *uid_vp9dec_hw =
> > "a922394d8d87452f878c51f2fc9b4131";
> 
> Should not be actually needed (and I hope it will work:)). VP9 hw plugin is
> actually a tiny compatibility stub which redirects everything to the mediasdk
> library.  Considering that you just add VP9 decoding support you don't need
> to care about compatibility (I hope). Hence, you can try to just initialize VP9
> decoder directly from the mediasdk library as you are doing for AVC decoder.

Good point. But my question is that will it broken for the case "the latest ffmpeg + an old version MSDK"?
Thus means:
1. Start from the version for MSDK support VP9 decoding, hw plugin is not needed. 
2. Or we don't care the compatibility "the latest ffmpeg + an old version MSDK", user should update MSDK.

If it is case 1, I am quite happy to remove vp9 hw plugin code. If it is case2, I would say I can't agree. 
How do you think?