Subject: vlc: convert mp4 to webm: This muxer is not provided directly by VLC: It could be missing

From: local10 <[email-masked]>
Date: Wed, 14 Aug 2024 16:18:39 +0200 (CEST)

Package: vlc
Version: 3.0.21-0+deb12u1

VLC fails to properly convert mp4 to webm, instead it creates a webm file that show a black screen instead of the proper video. Upon researching it further, the VLC shows the "This muxer is not provided directly by VLC: It could be missing" message in the Encapsulation tab.

Steps to reproduce:

1. Select Media > convert/save from the menu.
2. Click 'add' button and select the file you want to convert
3. Click 'Convert/Save' button
4. In the 'profile' dropdown select 'Video - VP80 + Vorbis (Webm)'
5. Click on the button next to the drop down ("edit selected profile" - looks like a spanner icon)
6. Encapsulation tab should be set as Webm. The Encapsulation tab is indeed set to webm but it also contains the "This muxer is not provided directly by VLC: It could be missing" message/warning (see the enclosed pic).

See https://stackoverflow.com/questions/9582463/how-can-i-convert-from-mp4-to-webm/28629749#28629749 for more details.

However, running
    name="my.vide.file.to.convert"; ffmpeg -i "$name".mp4 -acodec libvorbis -aq 5 -ac 2 -threads 2 "$name".webm
converts the mp4 file to webm properly.

Operating System: Debian GNU/Linux 12
KDE Plasma Version: 5.27.5  KDE Frameworks Version: 5.103.0  Qt Version: 5.15.8
Kernel Version: 6.1.0-23-amd64 (64-bit)
Graphics Platform: X11

Regards,