No compatible streams are currently available: Firefox + Matroska .mkv

[demonGeek 8]

I have just replaced a Plex server with Emby (4.6.7.0, Ubuntu x64), and I'm seeing "No compatible streams are currently available." when trying to play certain videos with transcoding disabled.

1. The same videos worked with Plex also without transcoding.
2. The error occurs only on Firefox (v99). Chromium browsers work correctly.
3. The error occurs on both Windows and Linux clients.
4. The error occurs on h.264 MKV files using Matroska format encoded using V_MPEG4/ISO/AVC.
5. The error does NOT occur on MP4 files using MPEG-4 encoded using avc1.

I would have guessed that Firefox was the problem except that these same videos played on Firefox when using Plex. The OpenH264 Video Codec is installed and enabled on Firefox.

I'd appreciate any troubleshooting ideas.

Edited May 6, 2022 by demonGeek

[Luke 42078]

Hi there, Firefox doesn't support mkv so you need to at least allow the option for conversion without transcoding.

[demonGeek 8]

Understood. Thanks for your help.

[Luke 42078]

I think in the case of Plex they don't even allow you to turn off this type of conversion so that might be what led to that impression when comparing us to them.

[demonGeek 8]

Yes, that's possible however I noticed that enabling just conversion on Emby still adds files to the transcoding cache which would, over time, gradually fill up the disk. I did not see this behaviour in Plex - with transcoding turned off, disk usage remained basically the same. Of course Plex may have been cleaning up temporary files periodically...

[Luke 42078]

26 minutes ago, demonGeek said:

Yes, that's possible however I noticed that enabling just conversion on Emby still adds files to the transcoding cache which would, over time, gradually fill up the disk. I did not see this behaviour in Plex - with transcoding turned off, disk usage remained basically the same. Of course Plex may have been cleaning up temporary files periodically...

The upcoming 4.7 server release will have better cleanup of these files. Thanks.