Converting ac3 to mp3 in an xvid avi.

[kilivipin]

I recently backed up Visitor Q using AutoGk. It all went fine, but I used the 2 channel ac3 instead of mp3, which is what I normally use. Now, my problem is, my pc is too slow to play it back, the ac3 decoding is killing my pii 333mhz with 80mb ram. I could re encode the entire thing, but it would take anywhere from 24 to 30 hours to back it up again. So is there any way that I canuse Direct stream copy or something like that in virtual dub to change the audio from ac3 to mp3? Is it possible to demux the audio from the avi, convert it to mp3 and reinsert it, but by using direct stream copy on the video, so it doesn't take 30 hours?

[moivre]

It's easyer with VirtualDubMod. LOad the movie in it, and if you have lame acm or radium mp3 1.263 codec on the system simply transcode it (go to streams, stream list, right click on the audio stream, full processing mode, compression, and choose lame mp3 or fraunhofer mp3). I'm not sure that the latest vdubmod can do that, use some older version.
Hope this help, moivre

[Boulder]

Originally posted by kilivipin
I recently backed up Visitor Q using AutoGk. It all went fine, but I used the 2 channel ac3 instead of mp3, which is what I normally use. Now, my problem is, my pc is too slow to play it back, the ac3 decoding is killing my pii 333mhz with 80mb ram. I could re encode the entire thing, but it would take anywhere from 24 to 30 hours to back it up again. So is there any way that I canuse Direct stream copy or something like that in virtual dub to change the audio from ac3 to mp3? Is it possible to demux the audio from the avi, convert it to mp3 and reinsert it, but by using direct stream copy on the video, so it doesn't take 30 hours?

Demux the AC3 track with VDub/VDubMod, in Streams->Stream List, choose track and select Demux. Encode the AC3 track to MP3 with BeSweet, use BeSweet GUI for some help. Then open the clip in VDub again, disable the AC3 track and add the MP3 track. Make sure you have Direct stream copy selected for video and then save the clip (with a different name). You should now have a video clip with the MP3 audio.

[kilivipin]

Originally posted by moivre
It's easyer with VirtualDubMod. LOad the movie in it, and if you have lame acm or radium mp3 1.263 codec on the system simply transcode it (go to streams, stream list, right click on the audio stream, full processing mode, compression, and choose lame mp3 or fraunhofer mp3). I'm not sure that the latest vdubmod can do that, use some older version.
Hope this help, moivre
Worked great! Thanks.

Boulder: I'll try yours out tomight as well. Thanks for all of your help.

[Boulder]

A little tip for better quality: use ABR in LAME if you use BeSweet GUI;)

[kilivipin]

Originally posted by Boulder
Demux the AC3 track with VDub/VDubMod, in Streams->Stream List, choose track and select Demux. Encode the AC3 track to MP3 with BeSweet, use BeSweet GUI for some help. Then open the clip in VDub again, disable the AC3 track and add the MP3 track. Make sure you have Direct stream copy selected for video and then save the clip (with a different name). You should now have a video clip with the MP3 audio.
I tried your method as well and it worked grand, but I have one question. How is it that VirtualDubMod transcoded the files twice as fast as Besweet? Is Besweet better quality?

[Boulder]

BeSweet should give you better quality as it uses LAME. The ACM has given certain problems to some people. You can download the latest lame_enc.dll (take v3.96.1 stable!) from http://www.rarewares.org , place it in the BeSweet folder. Also download the libmmd.dll and place in in your Windows\System32 folder. The latest version should be quite a lot faster than the one that's supplied with BeSweet.

Also the ACM codec doesn't support VBR encoding (which might be one reason why it's faster), but VBR will give you better quality than CBR for the same bitrate.