Open Bug 1376217 Opened 4 years ago Updated 6 months ago

No sound in mp4 with aac


(Core :: Audio/Video: Playback, defect, P3)

52 Branch





(Reporter: moz, Unassigned)




(1 file)

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Firefox/52.0
Build ID: 20170614102148

Steps to reproduce:

Open a HTML5 web page with <video> tag and MP4 as <source> like
Open an MP4 directly like

Actual results:

Video is displayed correctly but there is no sound.

Future testing proves that MP4 files with MP3 sound track plays both with video and sound.
With others containers - OGG and WEBM – there are no problems with sound or video

Expected results:

MP4 files with AAC audio streams files should be played with sound.
Component: Untriaged → Audio/Video: Playback
Product: Firefox → Core
no repro:

fennec 54.0 locale te
fennec 55.0b3 locale en-us
fennec 56.0a1 build: 20170615100256 locale te
Confirmed the problem persists in Firefox 54.0.
In the player the sound volume button seams disabled (see screenshot) – clicking on it does nothing.
Using Mageia 5, with gstreamer both 0.10 and 1.0 installed
What version of ffmpeg/libav are you using?
I have the following packages installed:

I didn't have ffmpeg installed.
Installing ffmpeg-2.4.13-1.mga5.x86_64 did not change the situation, but found this build is configured with –disable-decoder=aac and "ffmpeg -decoders | grep -i aac" shows nothing.
Running "ffplay big_buck_bunny.mp4" shows video without sound and reports "No codec could be found with id 86018"

So, the problem seems to be that Firefox selects to play MP4/AAC even when AAC decoder is not available.
Depends on: 1379047
Flags: needinfo?(jyavenard)
Priority: -- → P3
(In reply to Y.B. from comment #5)
> So, the problem seems to be that Firefox selects to play MP4/AAC even when
> AAC decoder is not available.

The issue is that we still play the video even if we don't have a valid audio track.
we ignore invalid tracks and only error if we have no available tracks.

this behaviour was added in bug 1267637 (P2)
Flags: needinfo?(jyavenard)
Until next ESR version comes out I have solved the problem for my particular case by recompiling FFmpeg with enabled AAC codec and replacing the ones coming with the Linux distribution. The binaries may be tested from (Note: this FFmpeg build may be used for testing purposes only, and may be found "illegal" in some jurisdictions).
ESR won’t help here, as the issue is with ffmpeg options.

With firefox: 78.4.0esr (64 bity)
following link don't play audio
some info from mediainfo: mp4a-67-2, variable, audio stream (2) after video stream (1).
ffplay and vlc plays AAC sound with no problem. Chromium plays it too.
Google search show that it is common problem on older videos.

firefox: 78.4.0esr (64 bity) plays AAC with no problem in mentioned above:

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