Audio output problems with MPEG-4 AAC.

[mixray]

Hi all!

I compiled the 0.7.1 under RedHat 9 on EPIA-M with live support and run the rtsp stream. I can see, but cann't hear anything. The vlc wrote :

main decoder error: no suitable decoder module for fourcc `mp4a'.

VLC probably does not support this sound or video format.

Does anybody know what to do?

Thank you for answers.

[hans-jürgen]

Does anybody know what to do?

You have to compile VLC with FAAD2 support (open source AAC decoder). You can get the source code e.g. from http://www.audiocoding.com/download.php or check out the latest version from the SourceForge CVS. At the moment there are some changes happening due to Parametric Stereo support, so you should rather use the release version 2.0.

[mixray]

The problem, that the audio doesn't work with FAAD2 support. I compiled it with faad, gotten through the vlc source page with proper flag in configure, but it doesn't work. And I don't know what to do.

[Gibalou]

"no suitable decoder module for fourcc `mp4a'" means you didn't compile the faad plugin.

Check by running: vlc -l|grep faad
It should display: faad AAC audio decoder (using libfaad2)

[mixray]

Yes. You are right.
It didn't show the libfaad, only AAC demuxer.
So I need to recompile it.
Do I need to recompile the ffmpeg with libfaad support or only vlc?

Thank you for your answers.

[Gibalou]

AAC decoding support in ffmpeg is buggy so you really need to compile the libfaad plugin for VLC.
Get libfaad, compile and install it then ./configure vlc with --enable-faad.

[mixray]

I did that you have said me.
And know there is no message, about no suitable decoder module for fourcc `mp4a,
but there is no sound agan.
Though, than I made vlc -l | grep faad, it showed me that faad2 is loaded.

May be there some setting inside the vlc that iI need to chage?

[hans-jürgen]

And know there is no message, about no suitable decoder module for fourcc `mp4a, but there is no sound agan.

In your first posting you mentioned that you "run the RTSP stream", so which RTSP stream do you mean (link)? Maybe that stream has no audio, and is it a MP4 file or a live stream based on SDP?

[mixray]

It's for sure has audio, because than I run it on mplayer there is sound there, but there is the sync problem, and I want check it on vlc. It is MP4 stream.

When I run vlc in verbose mode it wrote in the output:
faad decoder warning: Unexpected channel configuration change.

[hans-jürgen]

It's for sure has audio, because than I run it on mplayer there is sound there, but there is the sync problem, and I want check it on vlc. It is MP4 stream.

How did you create that MP4 file (which video and audio codec, which muxer)? Did you hint the video and audio tracks and optimize the MP4 file with your muxer?

[mixray]

It is not file. It's RTSP stream from server in the another location. So I did create it. Really it is one of the TV chanels, that the provider streams here. View->Stream and Media info shows that there are mp4v and mp4a codecs with some bitrates. I know according to the mplayer that it is the MPEG-4 AAC audio codec.

Sorry, I can't answer you question about audio and video tracks. I'm a newbie in the field and don't catch what are you taking about.

Thank you for your answers.

[mixray]

Sorry for annoing, but I cann't solve this problem. And I saw topic, about same problem under Windows. Name of topic : no audio from 0.7.1 with mp4 - but older VLC was fine !

Anybody can help me????