Is there a command line way to demux an AC3 from an avi file?

[Mentalmummy]

I am trying to demux AC3 audio from avi files using the command line in Windows Xp but cannot seem to find out a way to do it. I have AviDemux but can`t find in the help file or elsewhere how to extract the AC3 audio.

I have Avisynth and AVS2wav and tried, as I do with other avi files, to do it using these but when it gets AC3 audio it always seems to bug out on me although I do have an AC3 filter, so would like to simply demultiplex the audio from the video if possible.

I`m sure there must be a way to do this, can anyone point me in the right direction please?

[Prodater64]

I am trying to demux AC3 audio from avi files using the command line in Windows Xp ...


One idea would be to extract with BeSweet command line (i don't know if a transcode is involved if your target has same properties than your source).

BeSweet.exe -core( -input "e:\DVD Authoring Working Folder\001 Projects\005\MainMenu.avi" -output "e:\DVD Authoring Working Folder\001 Projects\005\MainMenu.ac3" ) -ssrc( --rate 48000 ) -ac3enc( -b 384 -6ch )

Another option would be VirtualDubMod, but you will need to search what is the correct command line.
In both cases i don't know how to deal with the problem when avis have more than one audio track.

[Matthew]

I use VirtualDubMod plus the following vcf:
echo VirtualDub.Open("C:/test.avi",0,0);
echo VirtualDub.RemoveInputStreams();
echo VirtualDub.stream[0].SetSource(0x73647561,0);
echo VirtualDub.stream[0].Demux("C:/bah.ac3");

[f@chance]

For me the easiest is to use AVI2SVCD / DVD2SVCD. Just open the AVI file for conversion. Then start conversion and it extracts the audio as soon as the log says extraction finished, close the audio transcoding commandline windows and cancel the MPEG encoding and you have the extracted Audio, wether AC3, MPA or MP3 it extracts it all.

[Mentalmummy]

I like the virtualdub idea but it just tells me that the file is not recognised as an avi and also a vcf error so will keep trying.

I cant use the AVI program idea as it needs to be unattended command line so I think the Besweet idea looks the best for me.

Thanks :)

[Pookie]

http://www.thozie.de/avimaster/AVIMaster.zip


avimaster -rs0 filename.avi output.ac3

[KpeX]

mplayer file.avi -vo null -dumpaudio -dumpfile audio.ac3

There are numerous mplayer compiles for windows floating around, check the search for links.

[mean]

since you have avidemux

avidemux2 --load youravi.avi --save-raw-audio target --quit

should do

[Mentalmummy]

Thankyou for the help.

The avimux line didn`t work, I seperated some of the options with spaces but still would load the file but not demux or anything so I tried avimaster but the ac3 produced shows in different programs like VirtualDubMod as not being a legitimate audio file, also when finished you have to press Enter and I need it to be automated.

I`m not sure about BeSweet as I used to use that but for extracting other audio and found it was often a few seconds out of sync for some reason so I will go and try to find mplayer for Windows now but also try BeSweet, I do appreciate all this assistance :)

[Mentalmummy]

The Besweet option results in "error 58: unknown input file format" regarding the avi although according to virtualdubmod it is an ac3 avi.

I will figure this out. Thanks again :)

[Mentalmummy]

Mplayer works, the extracted ac3 is a few milliseconds longer for some reason but seems okay otherwise :)