Increase volume WITHOUT re-encoding??

[thegeeman]

I have an avi file with 6ch audio; intend to demux with VirtualdubMod and convert video to DVD etc etc etc; then re-mux.

My question is:- Is it possible to output the audio from VirtualdubMod with an increased volume level but WITHOUT re-encoding it? The reason i ask is that i came across this link ( https://www.videohelp.com/forum/archive/t271802.html ) and a comment from Guns1inger but i cannot seem to get it to work. I open up VDubMod-go to Options, then Preferences and scroll to Audio tab and i see the audio volume there but i can't seem to configure after that.

I've looked on this site but can't find a guide; all seem to suggest that i must re-encode after.

Any thoughts/suggestions????

[jtoolman2000]

I'm no audio expert but I think once you make a change to the audio in any way, it will have to reencode it. It's the same as making a minute chage to a video clip. It has to re do it to incorporate the changes.

[thegeeman]

Granted Guns1ingers comment says 'without re-encoding the video'!!! But the question still stands re. not having to re-encode the audio?

[manono]

It depends. How are you playing the AVI? On the computer? And the audio is AC3? If so, it could be something as simple as going into the AC3 Filter Configuration and changing the Preset to LOUD.

[celtic_druid]

Well if your 6 channel audio happens to be aac then the answer is yes. If it is AC3 or DTS, then no.

Not sure if it is just technically not possible to do with AC3 or just that no one has written "AC3gain" yet.

[thegeeman]

Manono:- If i was playing them on PC then i could sort that. No, this is before i mux files back together and for the volume to be increased when i fianlly burn to disc. Thanks for the reply though.

Celtic_Druid:- These are not aac; they are 6ch AC3; so will have to save as different file, boost volume and re-encode back to 6ch with Vegas. I know how to do it, i just didn't know whether it was possible to save a lot of work by potentially skipping this step. I do appreciate you replying. It is very much appreciated.

Thanks alot guys.

[manono]

Hi-

That was the point I was trying to make, although I may not have been very clear about it. The audio level on the PC may be different from that on your standalone, depending on how you have your AC3 Filter configured. I assume your AVI is encoded from a commercial DVD. And I'm assuming that the AC3 inside it is also direct from that same DVD, untouched. If so, it's already been normalized correctly. The volume should already be good, although it may not sound that way on the PC. Sometimes you get such things as loud music with soft dialog, but that's a different issue. So, my suggestion is to go ahead and author using that same AC3 audio track, and then burn the DVD to disc (DVD-RW for testing, maybe), and play it in your standalone. In about 99% of the cases, it'll sound just fine.

[guns1inger]

The only software I have heard of that can do this is mp3gain, which, as the anme suggest, only works on mp3 files. It actually alters the volume of the file without re-encoding the audio. I don't know of anything that can do this for other formats.

That said, if this si the original DVD audio then it is probably set at the correct levels, however because of the wide dynamic range of AC3 audio, the quiet sections sound very quiet by comparison to the mid and loud sections. This si by design, and altering this can undo the effort that has gone into the sound design to begin with. Unless you need to turn your volume up to 120% just to hear the explosions, I'd leave it be.