No sound

[flibberty]

I have posted about this problem before, but nobody suggested a solution. Perhaps I did not describe it clearly, so I'll try again. I'm not an expert in VLC.

I used Elgato converter to convert some VHS tapes to H.264.
The resulting files are:
MPEG-4
Dimensions 640x480
Codecs H.264, AAC
Audio Channels: 2

These files run fine on Quicktime Player. However, when I try to run them with VLC, there is no sound at all. As VLC is the application on my school's computers, I really need these files to run properly on VLC.
One strange thing that I've noticed is that although there are two audio channels, the 'Audio Channels...' menu item is greyed out.
I am running the latest Lion system, and up to date VLC. I deleted all vlc prefs, but that had no effect.
I would really appreciate it if somebody could tell me how to fix this.
Thanks

[flibberty]

OK, I've found out a few things.
First, I've gone through the fifty or so mp4 (H264) files that I have made from VHS tapes in the past few months (about 50). There are ten where VLC does not play any sound (although they are fine on QT). There doesn't seem to be any difference between the good files and the bad files. In some cases, both good file and problem file are from the same VHS: just parts one and two.
Secondly, I discovered that if I make a segment of a problem file (with QT7Pro), then that VLC will play that segment with no problem. In fact, if I make a huge segment, with everything except the first few seconds of the video, then VLC will play the sound fine. However, if the segment includes the beginning of the video, then VLC will not play the sound at all. So, below is a link to a five second segment of the start of one of these files. VLC will not play the sound, although the sound is certainly there, and comes out fine with QT.
I really would appreciate it if someone would take a look, and tell me if they can spot why I am having these problems. I expect there is a simple answer, but I know little about these things. (to get the file, I think you have to right-click on Download linked file).

http://dl.dropbox.com/u/1000972/Tim%27s ... 0sound.mov

[nkoriyama]

It's well-known problem of faad (aac decoder).
The decoder often fails when audio channel are changing. For example Stereo -> Mono -> Stereo.

This issue has not been fixed.
http://trac.videolan.org/vlc/ticket/3714

[flibberty]

Thanks.
I think perhaps that whether or not a file audio plays properly depends on whether I start recording after I start the video stream, or vice versa. I shall check that out.

[nkoriyama]

There is a patch for this issue, and this issue is not only on Mac, but all platforms.
Applying the patch to my own build (Mac/Windows), I can play the video file "Tim's No sound.mov" that you uploaded. Of course, I can play it properly with sound.

I'll look again the patch and will send it to the VLC-dev.
If it is applied, the issue will be fixed for the future release.

[nkoriyama]

My patch was applied.
You can play "No sound" video with sounds after VLC-1.2.

If you want to play now, you can try nightly build:
http://nightlies.videolan.org/