[FFmpeg-user] vpxenc-vp9 row-mt

[Szucsik György]

On 21 October 2017 at 17:47, Moritz Barsnick <barsnick at gmx.net> wrote:

> On Sat, Oct 21, 2017 at 16:15:04 +0200, Szucsik György wrote:
> > Hello,
> >
> > I understand that row-mt has been implemented into ffmpeg with this
> patch:
> > https://patchwork.ffmpeg.org/patch/2745/
> >
> > However, I build ffmpeg and it doesn't show up in the options, not even
> in
> > -h full. If I'm not mistaken (by looking at libvpxenc.c), this has to be
> > enabled during compile time. How can this be done without modifying the
> > source code? Did I just stumble upon a bug?
>
> This feature depends on an implementation in libvpx, which was
> introduced there in February, but hasn't been included in a release of
> theirs yet:
> ​​
> https://github.com/webmproject/libvpx/commit/
> 5881601488ef4278d7ca2b06e2ad4d44b3063620
>
> The named ffmpeg patch checks for availability/advertisement of this
> feature when building.
>

This is rather odd, since vpxenc has had this feature already for some
time. Looks like there is a miscommunication here, unfortunately.


>
> > Also, there seems to be a mix of row-mt and row_mt in the source which
> is a
> > bit confusing. Please advise.


> What do you mean? Feel free to quote a line (refer to a proper version
> of the file though).
>

​I was referring to this line (please note my C skills are very basic)
https://github.com/FFmpeg/FFmpeg/blob/master/libavcodec/libvpxenc.c#L1159

The option that needs to be passed is row-mt but the variable that's
responsible for controlling this behavior is called row_mt. A bit of
inconsistency but if it works, it works.​