1930182 - MediaSource.isTypeSupported('audio/mp4; codecs="mp3"') not working anymore

Status: UNCONFIRMED

(Core :: Audio/Video: GMP, defect)

Description

[Leonard Drs]

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:133.0) Gecko/20100101 Firefox/133.0

Steps to reproduce:

Ran MediaSource.isTypeSupported('audio/mp4; codecs="mp3"') on the console.

Actual results:

With WebCodecs flag on, returns false, with WebCodecs flag off, returns true

Expected results:

I guess it should return true in both case.

Comment 1

[Leonard Drs]

Erratum, even disabling WebCodecs didn't made isTypeSupported return true.
It does returns true on a Firefox/132.0.1 though

Comment 2

[BugBot [:suhaib / :marco/ :calixte]]

The Bugbug bot thinks this bug should belong to the 'Core::Audio/Video: Web Codecs' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Comment 3

[az [:az]]

I tried this on nightly running Linux and was unable to repro - I had MediaSource.isTypeSupported('audio/mp4; codecs="mp3"') return true both with and without dom.media.webcodecs.enabled. :chunmin, would you have any thoughts here?

Comment 4

[Andrew Osmond [:aosmond] (he/him)]

The logic to determine what MediaSource.isTypeSupported returns for audio/mp4 is fairly straightforward:
https://searchfox.org/mozilla-central/rev/f2df1ff64cb876e10c72ce7eed1fc9eac3f877bb/dom/media/mediasource/MediaSource.cpp#160-184

There shouldn't be any WebCodecs dependency and I would have expected the default prefs in 132 and 133 to allow this to work. Can you supply your about:support and/or the values for media.mediasource.mp4.enabled and privacy.resistFingerprinting in your working/broken Firefox profiles? Thanks!

Comment 5

[C.M.Chang[:chunmin]]

As Andrew said, MediaSource.isTypeSupported has no dependency on webcodecs.

Comment 6

[Leonard Drs]

Attachment: OK

Hi,

Yeah indeed the webcodec thing was a false alarm. I couldn't edit my message about it but tried to erratum.
`privacy.resistFingerprinting` is set to false and `media.mediasource.mp4.enabled` is set to true.

For `about:support`:

```

Comment 7

[Leonard Drs]

Sorry for the double message, sending the attachment also sent the previous message.

It would look like it's a me issue.
What I'm seeing so far:
When starting Firefox, the first call to MediaSource.isTypeSupported('audio/mp4; codecs="mp3"') returns true but any of next ones return false.
After looking at about:support I can see that somehow my computer don't support H264 Software decoding. It was working a week ago but I guess one of my updates broke it and I feared it was Firefox, hence this issue.
I'm sorry for the all fuss, I don't know how to fix what happened so far but when I do I'll eventually communicate here in case someone else come across this issue

Comment 8

[Andrew Osmond [:aosmond] (he/him)]

I see H264 decoding isn't supported from your profile, but you do have the OpenH264 2.3.2 plugin downloaded (Firefox does this automatically), so it should work:

1. Is media.gmp.decoder.enabled set to true under about:config?
2. Does it say OpenH264 is installed under about:addons and then Plugins? What happens if you press the gear icon on that page and select "Check For Updates"?
3. If you go to about:support, find "Profile Directory" and open a terminal. Run ls -la <PROFILE_DIR>/gmp-gmpopenh264/2.3.2 and paste the results (just want to know the file sizes). I am expecting 1592408 for libgmpopenh264.so, 116 for gmpopenh264.info.

Comment 9

[Leonard Drs]

1. media.gmp.decoder.enabled is already set to true in about:config
2. There is a OpenH264 installed (OpenH264 Video Codec provided by Cisco Systems, Inc.) v2.3.2 last updated on June 23, 2023, no updates available.
3. libgmpopenh264.so is indeed 1592408, gmpopenh264.info is 116

Comment 10

[Leonard Drs]

Checked for both default-release and dev-edition, they both pose the same issue.
Could it be an issue with the audio backend - pulse? The issue arose when I did an system update.