567491 - Short audio-only WebM files cannot be played

Status: RESOLVED FIXED

(Core :: Audio/Video, defect)

Description

[bugzilla]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.3a4webm) Gecko/20100518 MozillaDeveloperPreview/3.7a4webm
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.3a4webm) Gecko/20100518 MozillaDeveloperPreview/3.7a4webm

Longer audio-only WebM files seem to work just fine. Same with short Ogg/Vorbis files. I took one of my Ogg/Vorbis files and put its audio stream into a WebM file and it stopped working.

Reproducible: Always

Steps to Reproduce:
1. Open http://kaioa.com/k/ct/firefox/blam.ogg
2. Open http://kaioa.com/k/ct/firefox/blam.webm
Actual Results:  
First one plays (as it should), second one is silent. Same result if the Video or Audio element is used.

Expected Results:  
It should be possible to play very short WebM/Vorbis files. It's essential for games (Canvas/WebGL).

Duration: 0:00.783 (34510 samples)
Sample Rate: 44100 Hz
Channels: 1
Bitrate: 88 kbps
Codec: Vorbis
Encoding: lossy
Tool: Xiph.Org libVorbis I 20070622

The Ogg/Vorbis file was created with OggdropXpd. The MKA was created with MKVtoolnix and then finally cleaned up with mkclean (4: 'webm' v2).

Comment 1

[bugzilla]

Here is an even shorter sample which also fails in Opera:

http://kaioa.com/k/ct/firefox/pickup.webm | 0:00.099 (4381 samples)

Comment 2

[Matthew Gregan [:kinetik]]

Both of these files are triggering a livelock in the decoder for me.

Comment 3

[Matthew Gregan [:kinetik]]

Livelock is caused by the callback period being 0 for audio-only files.  I've mentioned it here: https://bugzilla.mozilla.org/show_bug.cgi?id=566245#c16

With that fixed, both of the files play fine for me.

Comment 4

[Matthew Gregan [:kinetik]]

This bug is fixed in the WebM decoder that just landed on mozilla-central, so marking this as resolved.