[FFmpeg-devel] [PATCH] vdpau: do not use buggy HEVC support by default

[wm4]

On Sat, 1 Jul 2017 07:10:47 -0700
Philip Langdale <philipl at overt.org> wrote:

> On Sat,  1 Jul 2017 11:40:38 +0200
> wm4 <nfxjfg at googlemail.com> wrote:
> 
> > NVIDIA broke its own API when using VDPAU decoding. If you retrieve
> > the decoded YUV data, or if you map the surfaces with GL interop, the
> > result are interlacing artifacts. The only way to get non-broken data
> > is by using the vdpau video mixer to convert it to RGB. There is no
> > way to block the non-working operations in a reasonable way (a
> > VdpVideoSurface has to support all operations).
> > 
> > NVIDIA refuses to fix this issue (it "fixed" it by making it work with
> > the video mixer, but the rest is still broken). There is no sign of
> > that changing.
> > 
> > Do not use HEVC by default with the generic hwaccle API. Detect
> > whether it's the NVIDIA native implementation, and exit with an
> > error. (The same thing work with the MESA implementation.)
> > 
> > As an escape hatch and to allow applications to use the decoder if
> > they really want to (perhaps because they make sure to explicitly use
> > the video mixer), reuse AV_HWACCEL_FLAG_ALLOW_PROFILE_MISMATCH to
> > disable this check.
> > 
> > Once NVIDIA fixes the bug, working driver versions could be detected,
> > and it could be allowed again.
> > ---
> >  libavcodec/vdpau.c | 19 +++++++++++++++++++
> >  1 file changed, 19 insertions(+)
> > 
> > diff --git a/libavcodec/vdpau.c b/libavcodec/vdpau.c
> > index 9c7804a287..42ebddbeee 100644
> > --- a/libavcodec/vdpau.c
> > +++ b/libavcodec/vdpau.c
> > @@ -127,6 +127,8 @@ int ff_vdpau_common_init(AVCodecContext *avctx,
> > VdpDecoderProfile profile, VdpVideoSurfaceQueryCapabilities
> > *surface_query_caps; VdpDecoderQueryCapabilities *decoder_query_caps;
> >      VdpDecoderCreate *create;
> > +    VdpGetInformationString *info;
> > +    const char *info_string;
> >      void *func;
> >      VdpStatus status;
> >      VdpBool supported;
> > @@ -209,6 +211,23 @@ int ff_vdpau_common_init(AVCodecContext *avctx,
> > VdpDecoderProfile profile, return AVERROR(ENOTSUP);
> >  
> >      status = vdctx->get_proc_address(vdctx->device,
> > +
> > VDP_FUNC_ID_GET_INFORMATION_STRING,
> > +                                     &func);
> > +    if (status != VDP_STATUS_OK)
> > +        return vdpau_error(status);
> > +    else
> > +        info = func;
> > +
> > +    status = info(&info_string);
> > +    if (status != VDP_STATUS_OK)
> > +        return vdpau_error(status);
> > +    if (avctx->codec_id == AV_CODEC_ID_HEVC && strncmp(info_string,
> > "NVIDIA ", 7) == 0 &&
> > +        !(avctx->hwaccel_flags &
> > AV_HWACCEL_FLAG_ALLOW_PROFILE_MISMATCH)) {
> > +        av_log(avctx, AV_LOG_VERBOSE, "HEVC with NVIDIA VDPAU
> > drivers is buggy, skipping.\n");
> > +        return AVERROR(ENOTSUP);
> > +    }
> > +
> > +    status = vdctx->get_proc_address(vdctx->device,
> >                                       VDP_FUNC_ID_VIDEO_SURFACE_QUERY_CAPABILITIES,
> >                                       &func);
> >      if (status != VDP_STATUS_OK)  
> 
> Go for it.

And pushed.