Extracting without conversion

jasper-isis · Post by **jasper-isis** » Sun Jan 19, 2003 10:26 pm

I want to extract the audio from a DivX movie and attach it to another video file, with minimum loss of sound quality. I know that VirtualDub can make a .WAV file from the .AVI, but will I lose quality in the process? It's probably yes, since the file will be recompressed back into .MP3 eventually.

So does anyone know how I can extract the audio without making a conversion to .WAV? Don't forget I'll still have to re-attach the audio to another file. Thanks!

klinky · Post by **klinky** » Sun Jan 19, 2003 11:44 pm

If you plan to edit it in Premiere, then you'll probably want to just save it as a Uncompressed WAVE file. You would need to set Vdub to Full Processing mode under the Audio menu and change compression to "Uncompressed". If you leave it on Direct Stream Copy, then it will just chunk out a file in whatever format the original audio stream was encoded in.

~klinky

jasper-isis · Post by **jasper-isis** » Mon Jan 20, 2003 12:08 am

Thanks for the reply; however, I don't plan to edit it in premiere. I only want to extract the audio file from one DivX AVI and stick it on another. This will probably be done using only VirtualDub.

Am I sounding vague? Okay, I'll come clean - but don't hate me for it! Please!

I have two versions of a fansub. One has really crappy-looking picture, and the other one has beautiful visual quality but no sound nor any subtitles. I only want to take audio from the crappy-picture version and attach it to the no-audio version and add subtitles and the same time.

So yeah... is converting the MP3 to uncompressed WAV the only way to go about that?

The movie wont be used for AMV-making. It is solely for my own enjoyment of an anime that hasn't yet been released on DVD. (That sounded cheesy, but you get my point.

)

klinky · Post by **klinky** » Mon Jan 20, 2003 1:28 am

So long as they're the same length. I am not sure what will happen if you try and mux a audo stream that is shorter/longer from your video stream.

You could just leave it on Direct Stream Copy, goto Save Wav... . Load the good video file up, goto Audio, Select WAV file, select the "wav" file you just made. Set video to Direct Stream Copy. Then save the file out.

However, why doesn't your fansub have sound? You're sure it's not some sorta codec issue. I don't know of any group out there that distros audio-less fansubs. That kinda defeats teh purpose.

~klinky

jasper-isis · Post by **jasper-isis** » Mon Jan 20, 2003 2:04 am

I have no idea what audio codec it's supposed to be. After running the file through GSpot, I got this:

ac3 (0x2000) "Dolby Laboratories, Inc"

I did a search on Google, but only found that some other people were having the same problem as me - and we all got the file from the same place (ShareReactor). Strange...

Anyway, I chose Direct Stream Copy in VirtualDub and saved as WAV. It made a WAV file about 183 mb big (compare to the almost 700 mb source file) but it doesn't seem to be playable on any programs...

I would have used Full Processing Mode, but VirtualDub complained about audio compression not being compatible with source format, which is weird since I didn't choose any audio compression.

klinky · Post by **klinky** » Mon Jan 20, 2003 2:30 am

It's a AC3 audio stream

You need a AC3 audio decoder:

http://www.doom9.org/index.html?/software.htm

Look under Filters.

~klinky

jasper-isis · Post by **jasper-isis** » Mon Jan 20, 2003 12:14 pm

Oh.

Heh... thanks.