Currently when running Chromium through the Kiosk image, it is not possible to play .aac audio due to codec limitations explained here: Audio/Video - The Chromium Projects (Chrome only)
Simple way to test it (on any machine) is to just install Chromium and run an .aac sample from: Audio Samples — Audio Development Framework documentation
Instead of using the built-in player, the browser simply downloads the file.
It seems this is an intentional behaviour of typical Chromium build, as it won’t use the codecs available on the system - for example installing ffmpeg and the related gstreamer packages allow you to play the .aac through ffplay, but it has no effect on Chromium
This is generally solved either by installing a distro-provided prebuilt “extras” package (chromium-ffmpeg-extra, chromium-ffmpeg-codecs) that has the built .so libraries needed, or doing your own Chromium build with extra flags to include proprietary codec support.
To make the first approach more complicated, these packages have been moving towards snaps lately.
So the typical Ubuntu package now involves simply docs about the transition: chromium-codecs-ffmpeg_80.0.3987.163-0ubuntu1_amd64.deb 20.04 LTS Download (pkgs.org)
Additionally, simply moving the .so lib to the install directory is tricky because of the versioning as well as the fact that the Chrome package itself seems to differ (slightly) based on distro.
Debian – File list of package chromium/bullseye/arm64
Ubuntu – File list of package chromium-browser/bionic/arm64
I noticed that the Chromium install in the image came from the Toradex feed:
APT-Sources: Index of /debian/snapshots/20210610T044134Z testing/main arm64 Packages
Indicating an internal build. I was wondering if it would be possible for Toradex to perhaps build and distribute an alternate version with extra codecs?