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No Audio w/ mp4a
Posted: 08 Oct 2009 17:59
by cjoshuav
I downloaded some MPEG-4 videos from the Prelinger archive (the highest rez ones), and am not getting audio. The video looks great, cheesey haircuts aside.
The audio codec is mp4a.
Operating system: Vista 64-bit, all current updates
Any suggestions?
Re: No Audio w/ m4a
Posted: 08 Oct 2009 18:37
by jeroensky
M4a is a extension. it means: Advanced audio coding audio only with no drm in a mp4 container.
So i guess you mean the AAC (Advanced Audio Coding) codec /mp4a in vlc.
I have no problems with playing my *.m4a files (aac/16bit/2.0 & 5.1/48KHz) on vista 64bit (uptodate, without the crap) & vlc 1.0.2 32bit
Re: No Audio w/ mp4a
Posted: 08 Oct 2009 22:42
by cjoshuav
Here's the full info:
Stream 1
Type: Audio
Codec: mp4a
Lang: English
Channels: Stereo
Sample Rate: 44100 Hz
AAC extension: SBR
Re: No Audio w/ mp4a
Posted: 09 Oct 2009 12:06
by VLC_help
Can you share us a sample file?
Re: No Audio w/ mp4a
Posted: 10 Oct 2009 01:36
by cjoshuav
Re: No Audio w/ mp4a
Posted: 10 Oct 2009 17:46
by VLC_help
You also get
faad warning: Unexpected channel configuration change
faad warning: Unexpected channel configuration change
messages to message log (Tools -> Messages... set Verbosity to 2) when you play the file?
Re: No Audio w/ mp4a
Posted: 10 Oct 2009 18:21
by Lotesdelere
Yep I got these messages as well but I wonder why since it's a stereo audio track.
MPlayer is playing it but with a lot of repeatitions as if it was jumping back every 5 seconds or so. It's playing fine in MPC-HC with the internal built-in decoder though and also in WMP using CoreAAC.
To demux and remux the file with MP4Box didn't help so I guess there is something unusual in this audio track.
Re: No Audio w/ mp4a
Posted: 11 Oct 2009 09:30
by cybmole
i had a lot of trouble recently with a similar issue - look for thread "no audio in m4a" for fixes & explanations, or search for m4b - I think mine is the only thread with that in title
Re: No Audio w/ mp4a
Posted: 11 Oct 2009 12:54
by VLC_help
Then it must be bug in FAAD decoder.
Re: No Audio w/ mp4a
Posted: 12 Oct 2009 17:01
by cybmole
Then it must be bug in FAAD decoder.
in my case - everything worked when FAAD was forced into use. I had to untick option to use system codecs & remove quicktime from preferred list.
Re: No Audio w/ mp4a
Posted: 06 May 2013 09:54
by TheSa|nt
I am resurecting this only because it's the first thing that comes up on Google...so best to have an up-to-date strategy.
For those having issues with AAC audio (or "MP4a" audio streams within videos)...
Go to Tools -> Preferences -> (show all) -> Audio/Codex -> Scroll down to "Preferred decoders list" and make sure "quicktime" isn't listed. If so...get rid of it. That's one of the biggest problems with VLC and AAC (or MP4a).