[FFmpeg-devel] [PATCH] lavc/vaapi_encode_h265: add support for low-power encoding

[Xiang, Haihao]

> > On 06/02/18 08:17, Haihao Xiang wrote:
> > > Although VAEntrypointEncSliceLP was added in old version of VAAPI, we
> > > never implemented it for VAAPI H265 encoder before. so it is reasonable
> > > to require VAAPI 1.0
> > > 
> > > Signed-off-by: Haihao Xiang <haihao.xiang at intel.com>
> > > ---
> > >  libavcodec/vaapi_encode_h265.c | 18 +++++++++++++++++-
> > >  1 file changed, 17 insertions(+), 1 deletion(-)
> > > 
> > > diff --git a/libavcodec/vaapi_encode_h265.c
> > > b/libavcodec/vaapi_encode_h265.c
> > > index f3b4f6c7e26..efe1148127f 100644
> > > --- a/libavcodec/vaapi_encode_h265.c
> > > +++ b/libavcodec/vaapi_encode_h265.c
> > > @@ -65,6 +65,7 @@ typedef struct VAAPIEncodeH265Options {
> > >      int aud;
> > >      int profile;
> > >      int level;
> > > +    int low_power;
> > >  } VAAPIEncodeH265Options;
> > >  
> > >  
> > > @@ -914,7 +915,18 @@ static av_cold int
> > > vaapi_encode_h265_init(AVCodecContext *avctx)
> > >                 avctx->profile);
> > >          return AVERROR(EINVAL);
> > >      }
> > > -    ctx->va_entrypoint = VAEntrypointEncSlice;
> > > +
> > > +    if (opt->low_power) {
> > > +#if VA_CHECK_VERSION(1, 0, 0)
> > > +        ctx->va_entrypoint = VAEntrypointEncSliceLP;
> > > +#else
> > > +        av_log(avctx, AV_LOG_ERROR, "Low-power encoding is not "
> > > +               "supported with this VAAPI version.\n");
> > > +        return AVERROR(EINVAL);
> > > +#endif
> > > +    } else {
> > > +        ctx->va_entrypoint = VAEntrypointEncSlice;
> > > +    }
> > >  
> > >      if (avctx->bit_rate > 0) {
> > >          if (avctx->rc_max_rate == avctx->bit_rate)
> > > @@ -986,6 +998,10 @@ static const AVOption vaapi_encode_h265_options[] = {
> > >      { LEVEL("6.2", 186) },
> > >  #undef LEVEL
> > >  
> > > +    { "low_power", "Use low-power encoding mode (experimental: only
> > > supported "
> > 
> > Do you want to copy this comment?
> > 
> 
> Actually I want to delete the comments in (), but the limitation for HEVC low
> power encoding still exist. It would be better to add some VAAPI attributes to
> query the capability/limitation etc.
> 
> 
> > > +      "on some platforms, does not support all features)",
> > > +      OFFSET(low_power), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, FLAGS },
> > > +
> > >      { NULL },
> > >  };
> > >  
> > > 
> > 
> > How can I test this (and the following patch)?  It doesn't appear to exist
> > on
> > any current platform/driver.
> > 
> 
> Cannon Lake support HEVC low power encoding, do you have this
> platform?  https:/
> /github.com/intel/media-driver/ should support this feature but it isn't ready
> in https://github.com/intel/intel-vaapi-driver. 
> 
> > I don't like how this code is being copied around, but I guess it would work
> > for now.  I'll look into doing something more sensible here.
> > 
> 
> I also dislike duplicated code. I wanted to add some common options for VAAPI
> encoder in FFmpeg, such as QP. However low power encoding is not available for
> some codecs, such as VP8, so I copied&pasted the code here. 
> 
> Another thing is a driver may not support both VAEntrypointEncSliceLP and
> VAEntrypointEncSlice, so I want to change the value range of low_power to -1,
> 0,
> 1. -1 means auto mode, FFmpeg-vaapi will select the first applicable
> entrypoint,
> what is your comment for this proposal?

Hi Mark,

Do you have any comment to the above proposal? https://github.com/xhaihao/media-
driver only supports VAEntrypointEncSliceLP for vp9 on Cannonlake. With the
above proposal, the end user doesn't need to know which entrypoint is supported
by the underly driver. 

Thank
Haihao