Troubles with AVI + AC3, extracting, converting, ugh, please just read...

[takearushfan]

Hi again,
I have an AVI which contains AC3 audio. My goal is to extract the AC3 from the AVI and use BeSweet (?), AC3Machine (?) - (you tell me) to end up with the 6 mono wav channels.
Is this even possible?
Thanks,
Justin

[guns1inger]

Load the avi into virtualdubmod. Click on Streams->Strea List. Highlight the audio track and click on Demux. Save the ac3 file to a new location.

I don't use besweet, so you will have to work out the next step on your own.

[takearushfan]

Huh (in a pleased way),
You did it again. Much appreciated
Thanks,
Justin

[takearushfan]

Interesting (to me anyway),
These AVIs that are supposedly 5.1 are apparently 5.0. Has anyone else noticed this? ... assuming anyone else has checked out the 6 AC3 channels in an AVI :P

[guns1inger]

A lot of commercial discs are mastered with little or nothing in the LFE. If you don't have a decoding amp and you are getting the downmixed stereo then you don't miss it because the LFE isn't included inthe downmix. If you do have a decoding amp, most have a threshhold set low enough that the LFE stays busy even without a dedicated channel in the mix.

[manono]

Hi-

These AVIs that are supposedly 5.1 are apparently 5.0.

Although there is such a thing as DD 5.0, most really are DD 5.1. If you play the DVD in PowerDVD and turn on the OSD, it'll tell you what kind of audio it has. If you open the AC3 in HeadAC3he, it'll tell you. I think GSpot will as well, by opening either the AVI or the AC3 track. As guns1inger says, there often just isn't much going on in the LFEs.

If you're decoding to 6 Mono WAV files, and then playing the LFE, you can often go long stretches before hearing anything. You can open it in a WAV editor, find where the waveform is actually doing something, play it at that part, and hear it.

[takearushfan]

Hm,
Well I looked at the waveform in Audition and it's completely flat. Though, I guess I could've boosted it to see if there's anything there. I just figure that if there's no trace of anything without boosting it, it's most likely entirely empty *shrug*
- Justin

[fLYtRap]

I'm just curious, what is the point of doing 6ch mono

[takearushfan]

I'm not sure what you're asking. What do you mean by "the point of doing"?

[fLYtRap]

If you have 6 channels audio in mono signal you can't enjoy sourround sound, which is what is the purpose of haveing 6 channels audio.

[guns1inger]

It is difficult to edit AC3 and retain all the channel. The solution is to extract he 6 mono channels, edit them, then re-encode back to 5.1 AC3