Re: [FFmpeg-devel] [PATCH v3 2/2] lavc/vaapi_encode_h265: Set general_*_constriaint flags with profile

["Wang, Fei W" <fei.w.wang-at-intel.com@ffmpeg.org>]

On Wed, 2024-03-20 at 16:44 +0800, Fei Wang wrote:
> On Mon, 2024-03-18 at 21:22 +0000, Mark Thompson wrote:
> > On 18/03/2024 04:21, fei.w.wang-at-intel.com@ffmpeg.org wrote:
> > > From: Fei Wang <fei.w.wang@intel.com>
> > > 
> > > According to Table A.2 in spec.
> > > 
> > > Signed-off-by: Fei Wang <fei.w.wang@intel.com>
> > > ---
> > >   libavcodec/vaapi_encode_h265.c | 176 +++++++++++++++++++++++---
> > > --
> > > -----
> > >   1 file changed, 123 insertions(+), 53 deletions(-)
> > > 
> > > diff --git a/libavcodec/vaapi_encode_h265.c
> > > b/libavcodec/vaapi_encode_h265.c
> > > index 43755e2188..5ed317ce11 100644
> > > --- a/libavcodec/vaapi_encode_h265.c
> > > +++ b/libavcodec/vaapi_encode_h265.c
> > > @@ -258,6 +258,124 @@ fail:
> > >       return err;
> > >   }
> > >   
> > > +static int vaapi_encode_h265_init_ptl(AVCodecContext *avctx)
> > > +{
> > > +    VAAPIEncodeContext      *ctx = avctx->priv_data;
> > > +    VAAPIEncodeH265Context *priv = avctx->priv_data;
> > > +    H265RawVPS              *vps = &priv->raw_vps;
> > > +    H265RawProfileTierLevel *ptl = &vps->profile_tier_level;
> > > +
> > > +    ptl->general_profile_space = 0;
> > > +    ptl->general_profile_idc   = avctx->profile;
> > > +    ptl->general_tier_flag     = priv->tier;
> > > +
> > > +    ptl->general_profile_compatibility_flag[ptl-
> > > > general_profile_idc] = 1;
> > > +
> > > +    if (ptl->general_profile_compatibility_flag[1])
> > > +        ptl->general_profile_compatibility_flag[2] = 1;
> > > +    if (ptl->general_profile_compatibility_flag[3]) {
> > > +        ptl->general_profile_compatibility_flag[1] = 1;
> > > +        ptl->general_profile_compatibility_flag[2] = 1;
> > > +    }
> > > +
> > > +    ptl->general_progressive_source_flag    = 1;
> > > +    ptl->general_interlaced_source_flag     = 0;
> > > +    ptl->general_non_packed_constraint_flag = 1;
> > > +    ptl->general_frame_only_constraint_flag = 1;
> > > +
> > > +    if (avctx->profile >= 4) {
> > > +        ptl->general_intra_constraint_flag            = ctx-
> > > > gop_size == 1;
> > > +        ptl->general_one_picture_only_constraint_flag = 0;
> > > +        ptl->general_lower_bit_rate_constraint_flag   = 1;
> > > +        ptl->general_max_14bit_constraint_flag        = 0;
> > > +
> > > +        switch (ctx->va_profile) {
> > > +#if VA_CHECK_VERSION(1, 2, 0)
> > > +        case VAProfileHEVCMain12:
> > > +            // Main 12
> > > +            ptl->general_max_12bit_constraint_flag      = 1;
> > > +            ptl->general_max_10bit_constraint_flag      = 0;
> > > +            ptl->general_max_8bit_constraint_flag       = 0;
> > > +            ptl->general_max_422chroma_constraint_flag  = 1;
> > > +            ptl->general_max_420chroma_constraint_flag  = 1;
> > > +            ptl->general_max_monochrome_constraint_flag = 0;
> > > +            break;
> > > +        case VAProfileHEVCMain422_10:
> > > +            // Main 4:2:2 10
> > > +            ptl->general_max_12bit_constraint_flag      = 1;
> > > +            ptl->general_max_10bit_constraint_flag      = 1;
> > > +            ptl->general_max_8bit_constraint_flag       = 0;
> > > +            ptl->general_max_422chroma_constraint_flag  = 1;
> > > +            ptl->general_max_420chroma_constraint_flag  = 0;
> > > +            ptl->general_max_monochrome_constraint_flag = 0;
> > > +            break;
> > > +        case VAProfileHEVCMain422_12:
> > > +            // Main 4:2:2 12
> > > +            ptl->general_max_12bit_constraint_flag      = 1;
> > > +            ptl->general_max_10bit_constraint_flag      = 0;
> > > +            ptl->general_max_8bit_constraint_flag       = 0;
> > > +            ptl->general_max_422chroma_constraint_flag  = 1;
> > > +            ptl->general_max_420chroma_constraint_flag  = 0;
> > > +            ptl->general_max_monochrome_constraint_flag = 0;
> > > +            break;
> > > +        case VAProfileHEVCMain444:
> > > +            // Main 4:4:4
> > > +            ptl->general_max_12bit_constraint_flag      = 1;
> > > +            ptl->general_max_10bit_constraint_flag      = 1;
> > > +            ptl->general_max_8bit_constraint_flag       = 1;
> > > +            ptl->general_max_422chroma_constraint_flag  = 0;
> > > +            ptl->general_max_420chroma_constraint_flag  = 0;
> > > +            ptl->general_max_monochrome_constraint_flag = 0;
> > > +            break;
> > > +        case VAProfileHEVCMain444_10:
> > > +            // Main 4:4:4 10
> > > +            ptl->general_max_12bit_constraint_flag      = 1;
> > > +            ptl->general_max_10bit_constraint_flag      = 1;
> > > +            ptl->general_max_8bit_constraint_flag       = 0;
> > > +            ptl->general_max_422chroma_constraint_flag  = 0;
> > > +            ptl->general_max_420chroma_constraint_flag  = 0;
> > > +            ptl->general_max_monochrome_constraint_flag = 0;
> > > +            break;
> > > +        case VAProfileHEVCMain444_12:
> > > +            // Main 4:4:4 12
> > > +            ptl->general_max_12bit_constraint_flag      = 1;
> > > +            ptl->general_max_10bit_constraint_flag      = 0;
> > > +            ptl->general_max_8bit_constraint_flag       = 0;
> > > +            ptl->general_max_422chroma_constraint_flag  = 0;
> > > +            ptl->general_max_420chroma_constraint_flag  = 0;
> > > +            ptl->general_max_monochrome_constraint_flag = 0;
> > > +            break;
> > > +#endif
> > > +        default:
> > > +            av_log(avctx, AV_LOG_ERROR, "Unknown profile to init
> > > PTL.\n");
> > > +            return AVERROR(EINVAL);
> > > +        }
> > > +    }
> > 
> > Why is this an improvement over the current code which sets the
> > constraint flags based on the actual content of the stream?
> > 
> > Note the requirement in A.3.5 for decoder support:
> > 
> > general_profile_idc is equal to 4 or
> > general_profile_compatibility_flag[ 4 ] is equal to 1 for the
> > bitstream, and
> > the value of each constraint flag listed in Table A.2 is greater
> > than
> > or equal to the value(s) specified in the row
> > of Table A.2 for the format range extensions profile for which the
> > decoder conformance is evaluated.
> > 
> > which says that decoders must be able to support streams which set
> > additional constraint flags beyond those which are specified for a
> > particular profile (in particular, an 8-bit 4:2:2 stream must be
> > decodable by any decoder supporting either "Main 4:2:2 10" or "Main
> > 4:4:4", so ideally it shouldn't be marked to require one of those
> > in
> > particular).
> 
> That's a capability request for decoder. For encoder side, I'd prefer
> to use the most typical values. The constraint flags in Table A.2/3/5
> are strictly checked to get rext profile in ff_h265_get_profile(),
> and
> seems the constraint flags is the only way to distinguish profiles in
> rext(all the rext profiles shares same general_profile_idc or
> general_profile_compatibility_flag[ 4 ]).

Hi Mark,

Any other comments on this patchset?

Thanks
Fei

> 
> Thanks
> Fei
> 
> > Thanks,
> > 
> > - Mark
> > _______________________________________________
> > ffmpeg-devel mailing list
> > ffmpeg-devel@ffmpeg.org
> > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> > 
> > To unsubscribe, visit link above, or email
> > ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-devel

To unsubscribe, visit link above, or email
ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".