[Matroska-devel] FFV1/MKV IETF Session followup

Sebastian G. <bastik> bastik.public.mailinglist at gmx.de
Sat Jul 25 09:30:21 CEST 2015

25.07.2015, 00:08 Ralph Giles:
> On 24/07/15 06:36 AM, Sebastian G. <bastik> wrote:
>> How does one play a Matroska file with Firefox? It supports WebM
>> which is a subset of Matroska, but I am unable to play a Matroska
>> file that contains an h.264 encoded video, which is supported by
>> Firefox as well.
> Firefox only supports the vp8, vp9, vorbis, and opus codecs in the
> WebM variant of Matroska. To play h.264 you have to use the mp4 containe
> r.

I was aware that the combination of h.264 and MP4 work in Firefox, but
not with Matroska.

Mozilla still could support Matroska files containing h.264 streams
without diluting WebM.

> In Nightly and Developer Edition builds you can remux Matroska to mp4
> in javascript and play it through the MediaSource Extensions API.
> Hopefully that will be available in release builds in a few months.
> This API is available in Chrome, Safari, and Microsoft Edge as well.

To me it sounds like a workaround. At least when there is support for a
subset of a container format.

> As you say, WebM is a subset of Matroska. There's value in having a
> separately-labelled container with only free-to-implement codecs. I'd
> much rather people put Opus alongside h.264 in mp4 than in WebM.

I appreciate the value of the WebM Project. One is that you know what to
expect what is inside the container.

I would not favor h.264 streams within WebM as it goes against their
goals, I guess, but to have support for Matroska with Opus and h.264,
because it is supported anyway.

Best Regards,
Sebastian G. (bastik)

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