[FFmpeg-devel] [PATCH] qsv: get FrameInfo.Shift by desc->comp[0].shift

[Fu, Linjie]

> -----Original Message-----
> From: Li, Zhong <zhong.li at intel.com>
> Sent: Thursday, September 12, 2019 21:23
> To: FFmpeg development discussions and patches <ffmpeg-
> devel at ffmpeg.org>
> Cc: Fu, Linjie <linjie.fu at intel.com>
> Subject: RE: [FFmpeg-devel] [PATCH] qsv: get FrameInfo.Shift by desc-
> >comp[0].shift
> 
> > From: ffmpeg-devel <ffmpeg-devel-bounces at ffmpeg.org> On Behalf Of
> Linjie Fu
> > Sent: Wednesday, September 11, 2019 12:09 AM
> > To: ffmpeg-devel at ffmpeg.org
> > Cc: Fu, Linjie <linjie.fu at intel.com>
> > Subject: [FFmpeg-devel] [PATCH] qsv: get FrameInfo.Shift by desc-
> >comp[0].shift
> >
> > Since Y410 is a pixel format with depth > 8 but shift = 0, get Shift info by
> depth is
> > not quite accurate.
> >
> > Signed-off-by: Linjie Fu <linjie.fu at intel.com>
> > ---
> >  libavcodec/qsvenc.c       | 4 ++--
> >  libavutil/hwcontext_qsv.c | 2 +-
> >  2 files changed, 3 insertions(+), 3 deletions(-)
> >
> > diff --git a/libavcodec/qsvenc.c b/libavcodec/qsvenc.c index
> 9bf8574..912f2a8
> > 100644
> > --- a/libavcodec/qsvenc.c
> > +++ b/libavcodec/qsvenc.c
> > @@ -437,7 +437,7 @@ static int init_video_param_jpeg(AVCodecContext
> > *avctx, QSVEncContext *q)
> >      q->param.mfx.FrameInfo.ChromaFormat   =
> MFX_CHROMAFORMAT_YUV420;
> >      q->param.mfx.FrameInfo.BitDepthLuma   = desc->comp[0].depth;
> >      q->param.mfx.FrameInfo.BitDepthChroma = desc->comp[0].depth;
> > -    q->param.mfx.FrameInfo.Shift          = desc->comp[0].depth > 8;
> > +    q->param.mfx.FrameInfo.Shift          = desc->comp[0].shift > 0;
> 
> Is it safe enough?
> As MSDK docs: "Not all codecs and SDK implementations support this value.
> Use Query function to check if this feature is supported."

Checked the MSDK doc:
https://github.com/Intel-Media-SDK/MediaSDK/blob/master/doc/mediasdk-man.md#mfxFrameInfo

It shows that not only Shift, but also BitDepthLuma and BitDepthChroma are warned with:
"Not all codecs and SDK implementations support this value. Use Query function to check if this feature is supported."

Hence I think we could fix this in a separate patch to make the usage of FrameInfo.Shift/BitDepthLuma/BitDepthChroma
Safer if necessary.

Thanks,
- linjie