[FFmpeg-devel] [PATCH 1/5] lavc : yami : add libyami decoder/encoder

Chao Liu yijinliu at gmail.com
Tue Aug 16 10:37:13 EEST 2016


On Mon, Aug 15, 2016 at 7:44 PM, Jun Zhao <mypopydev at gmail.com> wrote:

>
>
> On 2016/8/16 10:14, Chao Liu wrote:
> > On Mon, Aug 15, 2016 at 6:00 PM, Jun Zhao <mypopydev at gmail.com> wrote:
> >
> >>
> >>
> >> On 2016/8/16 1:48, Jean-Baptiste Kempf wrote:
> >>> On 15 Aug, Hendrik Leppkes wrote :
> >>>>> On Mon, Aug 15, 2016 at 10:22 AM, Jun Zhao <mypopydev at gmail.com>
> >> wrote:
> >>>>>>> add libyami decoder/encoder/vpp in ffmpeg, about build step,
> >>>>>>> please refer to the link: https://github.com/01org/
> >> ffmpeg_libyami/wiki/Build
> >>>>>>>
> >>>>>
> >>>>> We've had patches for yami before, and they were not applied because
> >>>>> many developers did not agree with adding more wrappers for the same
> >>>>> hardware decoders which we already support.
> >>>>> Please refer to the discussion in this thread:
> >>>>> https://ffmpeg.org/pipermail/ffmpeg-devel/2015-January/167388.html
> >>>>>
> >>>>> The concerns and reasons brought up there should not really have
> >> changed.
> >>> I still object very strongly against yami.
> >>>
> >>> It is a library that does not bring much that we could not do
> ourselves,
> >>> it duplicates a lot of our code, it is the wrong level of abstraction
> >>> for libavcodec, it is using a bad license and there is no guarantee of
> >>> maintainership in the future.
> >>
> >> I know the worry after read the above thread.For Intel GPU HW accelerate
> >> decode/encode,
> >> now have 3 options in ffmpeg:
> >>
> >> 1. ffmpeg and QSV (Media SDK)
> >> 2. ffmpeg vaapi hw accelerate decoder/native vaapi encoder
> >> 3. ffmpeg and libyami
> >>
> > Sorry for this little diversion: what are the differences between QSV and
> > vaapi?
> > My understanding is that QSV has better performance, while vaapi supports
> > more decoders / encoders. Is that correct?
> > It would be nice if there are some data showing the speed of these HW
> > accelerated decoders / encoders.
>
> QSV has better performance is right, but libyami have more
> decoders/encoders than
> vaapi hw accel decoder/encoder. :)
>
> According our profile, the speed of QSV/Libyami/vaapi-hw accel decoder and
> native
> vaapi encoder are: QSV > ffmpeg and libyami > vaapi-hw accel decoder and
> native
> vaapi encoder
>
> >
> >>
> >> And I know the guys prefer option 2 than 3, but I have a little
> question,
> >> what's the
> >> difference about ffmpeg/libyami and the other external codec library(e,g
> >> openh264,
> >> videotoolbox...)?
> >>
> > Is 2 available in ffmpeg today or is it sth. planned?
> >
>
> Option 2 is available today :), I think the wiki page (
> https://wiki.libav.org/Hardware/vaapi)
> is good refer to for option 2, if you want to try. :)

Thanks. But that's for libav. These decoders and encoders are not available
for ffmpeg.

>


> >>
> >> As I know Intel have 3 full time Libyami developers, so no guarantee
> maybe
> >> is wrong.:)
> >>
> >> Tks.
> >> _______________________________________________
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> >> ffmpeg-devel at ffmpeg.org
> >> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> >>
> > _______________________________________________
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> > ffmpeg-devel at ffmpeg.org
> > http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> >
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