[FFmpeg-devel] [PATCH] lavc/vaapi_encode_h265: fix max_transform_hierarchy_depth_inter/intra

[Linjie Fu]

On Thu, Sep 3, 2020 at 1:32 PM Xiang, Haihao <haihao.xiang at intel.com> wrote:
>
> On Mon, 2020-04-13 at 13:06 +0000, Fu, Linjie wrote:
> > > From: ffmpeg-devel <ffmpeg-devel-bounces at ffmpeg.org> On Behalf Of
> > > Mark Thompson
> > > Sent: Monday, April 13, 2020 20:20
> > > To: ffmpeg-devel at ffmpeg.org
> > > Subject: Re: [FFmpeg-devel] [PATCH] lavc/vaapi_encode_h265: fix
> > > max_transform_hierarchy_depth_inter/intra
> > >
> > > On 13/04/2020 05:32, Linjie Fu wrote:
> > > > Set the max_transform_hierarchy_depth_inter/intra to 2 by default
> > > > based on the Programmer's Reference Manuals (PRM) in [1].
> > > >
> > > > Intel Encoder only supports 2 levels of quad-tree. That is:
> > > >     - max_transform_hierarchy_depth_inter/intra <= 2.
> > > >
> > > > [1] <https://01.org/sites/default/files/documentation/intel-gfx-prm-osrc-
> > >
> > > kbl-vol10-hevc.pdf>
> > > >
> > > > Signed-off-by: Linjie Fu <linjie.fu at intel.com>
> > > > ---
> > > > Fixed value for intel platform, makes more sense on TGL+ platform.
> > > > (If conflict with other driver capability, we may add query support
> > > >  later)
> > > >  libavcodec/vaapi_encode_h265.c | 5 +++--
> > > >  1 file changed, 3 insertions(+), 2 deletions(-)
> > > >
> > > > diff --git a/libavcodec/vaapi_encode_h265.c
> > >
> > > b/libavcodec/vaapi_encode_h265.c
> > > > index cd48545..d6cb82a 100644
> > > > --- a/libavcodec/vaapi_encode_h265.c
> > > > +++ b/libavcodec/vaapi_encode_h265.c
> > > > @@ -445,8 +445,9 @@ static int
> > >
> > > vaapi_encode_h265_init_sequence_params(AVCodecContext *avctx)
> > > >      sps->log2_min_luma_transform_block_size_minus2   = 0;
> > > >      sps->log2_diff_max_min_luma_transform_block_size = 3;
> > > >      // Full transform hierarchy allowed (2-5).
> > > > -    sps->max_transform_hierarchy_depth_inter = 3;
> > > > -    sps->max_transform_hierarchy_depth_intra = 3;
> > > > +    // Default to 2 based on Programmer's Reference Manuals of Intel
> > >
> > > graphics
> > > > +    sps->max_transform_hierarchy_depth_inter = 2;
> > > > +    sps->max_transform_hierarchy_depth_intra = 2;
> > > >      // AMP works.
> > > >      sps->amp_enabled_flag = 1;
> > > >      // SAO and temporal MVP do not work.
> > > >
> > >
> > > I don't much like the idea of changing this based on a value in a Kaby Lake
> > > document given that the current value hasn't had any problems on Kaby Lake.
> > > Can you explain the benefits of changing this?
> >
> > It fixes the encoding issue for HEVC on gen12+ platform.
> > We didn't notice this either, until it triggers gpu hang for encoding on Tiger
> > Lake (gen12).
> >
> > > Can you confirm that it continues to work on all the other currently-working
> > > platforms?
> > >
> >
> > Yes, we set up CI and runs full-round tests for conformance and catch
> > regression on different
> > platforms(CFL/CML/ICL/KBL/SKL).
> >
> > Identical fix has been merged in gstreamer-vaapi, no regression is detected on
> > other platforms.
> >
> https://gitlab.freedesktop.org/gstreamer/gstreamer-vaapi/-/merge_requests/282/diffs?commit_id=17d82e14e78af901f1cd7f2344e173ad6ae6a8a6
>
> Hi Mark,
>
> Till now we didn't see regression with Linjie's patch, do you have any other
> concern on Linjie's patch?
>
Also ping for this, since TGL has been announced recently.

- Linjie