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

[Chao Liu]

On Mon, Aug 15, 2016 at 10:22 PM, Jun Zhao <mypopydev at gmail.com> wrote:

>
>
> On 2016/8/16 11:07, Timothy Gu wrote:
> > Hi
> >
> > 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:
> >>> 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. :)
> >>
> >
> > I am not sure where you got this information.
> >
> > On Intel platforms they all use the same chip. Because VAAPI supports
> more
> > than just Intel platforms, VAAPI supports all codecs libyami and QSV
> > support, if not more.
> >
> > QSV works on both Windows and Linux, although it is a pain to set up a
> > Linux QSV environment (you have to have the right distro, right kernel,
> > etc.).
> >
> >
>
> I means ffmpeg_VAAPI hw accel decoder/native VAAPI encoder, not the VAAPI
> as
> interface.
>
> >>
> >> 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
> >>
> >
> > You didn't mention _how_ you profiled things, and for HW encoding
> different
> > ways of profiling can cause wildly different results. If for example you
> > are not doing zero-copy VAAPI operations, you are inherently giving the
> > other two methods an edge.
> >
>
> I used the ffmpeg_QSV/ffmpeg_libyami/ffmpeg_vaapi to do zero-copy mode
> transcode with default setting as profile case.
>
Perhaps you could share your test environment settings and the results, so
others could repro and confirm what you said, which could make this patch
more appealing.
IIUC, there is no hardware accelerated encoder for VP8 in ffmpeg yet.
That's another value of this patch..

>
> > Timothy
> > _______________________________________________
> > ffmpeg-devel mailing list
> > ffmpeg-devel at ffmpeg.org
> > http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> >
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel at ffmpeg.org
> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>