hi people

i would like to know how to extract the audio track from a media file (AVI, WMV, MPG ...) ?

What are you guys recommanding ?

MPG: TMPGEnc -> File -> MPEG Tools -> Demultiplexer | Load your mpg -> doubleclick on the audio and save it
AVI: VirtualDub ->File -> Open File | File -> Save WAV...

WMV: That´s more complicated. Without reencoding there is one way:
You need VirtualDub 1.3c or any other version with patched asf-support. First change the FourCC from WMV1 / WMV2 or whatever to, lets say "DIVX" (you can do that in a hex-editor). Now you can open it with VirtualDub. Do not seek in the Video (it will probably crash because of wrong FourCC), just click on File -> Save WAV like with the avi. You need change the FourCC back that your WMV is playable again.

thanks for those infos

moutaye, I have not tried WMV, but I have extracted, quite easily, audio tracks from the other formats using the "Extract Audio from Video" feature in CEP v2. CEP extracts the audio from video as quickly as it opens any file. You can then save it to any format you choose, providing you have the necessay plugins. If you don't have CEP v2, you can follow S_O's advice or use Total Recorder which is quite slow in comparison.

Later.

It won't work, I'm affraid, otherwise MS lawyers would wear Syntrillium out on courts.
You can try to demux with GraphEdit or VDubMod (via AviSynth).

Yes, I believe that, but that's not the point of my reply which is that CEP v2 rips all the other formats fine. The only reason that I did not try to rip the audio from a WMV files is that I stay away from all MS formats. However, all the others (avi, mpg, mpeg, etc) work perfectly, and, as I said, they are ripped Fast.

Oh, ak, one last thing. Please forgive my ignorance, but I'm not into video, so, could you tell me what demux is. I assume, though, that from your reply it has something to do with ripping audio from video.

Afaik demuxing refers to seperating the audio and video streams, muxing refers to mixing/interleaving (?) the audio and video together.

dTb, thank you. Now, if I ever do get into video, I'll know what demuxing is. One last word, what a strange term. I'm into etymology, so now I'm going to have to find out where and how the term came about.

To mux or demux, that is the question. (Sheesh, Shakespeare is probably spinning in his grave )

Later.

The origin of 'mux' comes from electronics, where 'mux' is short for multiplex, which is essentially just converting parallel data into serial data. (I might have that backwards, though.) Audio and video are parallel data, files are serial.

Did I say demux? Actually extracting audio to wav was meant.
Demuxing (extracting wma track) should be possible with WMEncoder, I think.

I also have no wmv's to play with, so it's only theoretical.

I think you may be confusing this with modem, modulator/demodulator. That is the technique of turning bits parallel into bits serial and back again. Multiplexing is concerned with the interleaving/de-interleaving of multiple streams, originally concerned with data coms. Similar idea, though.

I found this through Google here: http://www.trinary.cc/Tutorial/Mux/Mux.htm

Multiplexers

A multiplexer is a circuit that takes 3 inputs and allows one to be selected for output. It is a critical circuit and is used extensively throughout computer systems. To create a 3 to 1 MUX, we will take advantage of the Identity: 2 ¯ [this mark is supposed to be a little down arrow] A = A. The scheme is to use the identity to enable the proper selection. Then the 3 inputs will be MAXed together to recombine them. In order for the MAX to work correctly, disabled lines will need to output 0.


Demultiplexers

A Demultiplexer is just the opposite of a multiplexer. It takes 1 input and creates 3 outputs. Internally, its construction is similar to the multiplexer except the outputs are not combined at the end with a MAX operation. Instead, each one remains separate. As shown in Figure 3, it is designed to pass a 0 on all outputs except the one selected which passes the true value of the input. It can be designed to pass a 2 except the selected output also. This would be referred to as "active low logic" and tends to be more useful than "active high logic".

Later