[Solved] libmad in Avidemux 2.6.4 in F19

[giampaolo44]

Hi,

I know this will look like a terrible nooby question  , and I have browsed in the forum for a while but... I installed Avidemux from F19 repos (rawhide enabled), and it seems not to come with the libmad libraries, although they are installed on my system (libmad-0.15.1b-16.fc19), since in the Audio menu there's no trace of the Build VBR Time Map command.
Does it need to be compiled with them, rather than just have them installed?
Would I need to reinstall Avidemux and compile it? Currently I have 2.6.4-5.fc19

Thanks!

[mean]

VBR time map is done automatically with 2.6
mad is bundled with avidemux, you should not need to install anything except if fedora disabled avidemux mad

[giampaolo44]

Thanks mean 

Ok, so now I am in the middle of nowhere with what I was trying to sort out in the first place: I downloaded a video from youtube in mp4 HQ (1020p I believe), which plays very well. 

I tried to extract the audio in mp3: Avidemux did it, but the file is unreadable with any player (Gnome player says "stopped" as soon as the file starts).

Looking at the audio file with Audacity, it looks like it were 5 seconds long, and playing it does give the impression it has a bunch of compressed data in it. In fact it still is a 3.5Mb files, not a full mp3 but at least half of it.

My first thought, based on browsing around for answers, was that it was in VBR and was not mapped properly. Could it be something else?

Thanks a lot.

[mean]

I guess it is AAC
And AAC without a container does not work

[giampaolo44]

Thanks for your answers.

Today I tried again and it worked.

Since I had a few more files to look at, it happened to me again also with a different one.  I came to the conclusion that in very rare cases the "Save audio" process seems to fail, giving those kind of files as a result. I could tell from two signals: first, it took too little to save the audio stream, and secondly the audio stream was shorter than it should have been (in my case roughly half).
Re-running the extraction did the job.

Cheers