1244453 - AAC audio - only noise on mixcloud (and possibly other) multimedia sites

Status: RESOLVED FIXED

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

Description

[Gustavo Homem]

User Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:43.0) Gecko/20100101 Firefox/43.0
Build ID: 20160106234230

Steps to reproduce:

Went to mixcloud (eg, https://www.mixcloud.com/inesinlectra/in_lectra____get-up-its-summer___july-2013-mix-set/ ) and pressed play.


Actual results:

Playback started, very loud white noise was played instead of music.


Expected results:

Music should have played.

Comment 1

[Gustavo Homem]

Attachment: Stream is detected on the page info dialog, if we play it from there only noise can be heard too.

Comment 2

[Gustavo Homem]

The sound file can be downloaded with

wget https://stream13.mixcloud.com/c/m4a/64/9/6/a/0/0cd8-ade8-4356-9180-a385bafd71ff.m4a

and player fine with mplayer locally.

File info from Mplayer:

==========================================================================
Opening audio decoder: [ffmpeg] FFmpeg/libavcodec audio decoders
libavcodec version 53.35.0 (external)
Mismatching header version 53.32.2
AUDIO: 44100 Hz, 2 ch, s16le, 70.3 kbit/4.98% (ratio: 8782->176400)
Selected audio codec: [ffaac] afm: ffmpeg (FFmpeg AAC (MPEG-2/MPEG-4 Audio))
==========================================================================


File info from VLC:

MPEG4 AAC Audio, Stereo, 44100 hz, AAC Extension SBR

Comment 3

[Loic]

WFM with FF44 on Win 7, but maybe issue with Linux version.

Comment 4

[Gustavo Homem]

This is reproducible on the Fraunhoffer AAC test page:

HE-AAC Channel ID - FAIL (noise only)
AAC-LC Channel ID - WORKS
HE-AAC Channel ID - With H.264 Video - FAIL
LFE and SBR Test - FAIL (noisy) 
LFE and SBR Test - With H.264 Video - FAIL (partially works but too noisy)

I downloaded the HE-AAC Channel ID sound file at it plays fine with ffplay and mplayer.

Comment 5

[Gustavo Homem]

Here is the link:

https://www2.iis.fraunhofer.de/AAC/multichannel.html

Further info:

The HE-AAC Channel ID sound file also plays fine with gst123 which uses gstreamer. What is Firefox using has a backend to play AAC files? Or is is decoded internally?

Comment 6

[Gustavo Homem]

Attachment: Facebook video that exposes the same problem.

Comment 7

[Gustavo Homem]

This also affects Facebook (see attachment). 

This pref setting fixes the problem for Facebook (sound plays OK afterwards...):

media.fragmented-mp4.gmp.enabled = true

but prevents Instagram videos from playing and prevents Mixcloud sounds (which otherwise play only noise) from playing (there is a "progress" indicator shown forever and the playback doesn't start).

Related report:

https://bugs.launchpad.net/ubuntu/+source/ubuntu-docs/+bug/1528268

Comment 8

[Gustavo Homem]

I just realized a Firefox update was available. After upgrading from 43 to 44 Facebook, Mixcloud and the Fraunhofer test page are working without any problems. 

The problem has been present for a couple releases (can't recall when it started but only now I had time to properly research and report) but seems fixed now.

Comment 9

[Anthony Jones (:ajones, :kentuckyfriedtakahe, :k17e)]

Jean-Yves fixed this in 44.