Support WebM file format without renaming to MKV

[patters]

WebM is the only non-patent-encumbered video format to rival H.264/H.265, and it's becoming more prevalent (originally VP8/Vorbis, now tends to be VP9/Opus audio in a Matroska container with specific options set). This request is linked to issue 1073 since currently Serviio lacks Opus audio support also. Though for example Samsung UHD TVs support VP9, they need the Opus audio to be transcoded - something Serviio cannot currently achieve (you end up with a transcoded video with no audio track).

Sample media with VP8 here. Sample media with VP9 here which is part of the FlowPlayer's example content.

[Petr Nejedly]

so this request is to do what? - match .webm files

Do we need to setup some transcoding?

[patters]

Yes matching .webm files even if FFmpeg doesn't really regard them as being any different to MKV. I guess some device profiles could be edited where the devices can play WebM natively. The Xbox One S seems to play them fine for instance, when using VLC as a DLNA client (after renaming to MKV, as is currently necessary to get Serviio to add them to the library). VLC is assigned the generic profile by Serviio.

I suspect it may be best to add the support first, then the user community can perhaps improve the device profiles later once people can experiment with example media on their devices (as per how the H.265 transcoding settings were added gradually).

[Petr Nejedly]

.webm files are now looked at. no profile change has been made