Newbie :: AVI audio editing . . . how?

[pretzeltop]

If I have an AVI file (XVID or DIVX), is there a way to edit the audio?

Yes, I'm somewhat of a video editing newbie, so if I ask about something impossible, just tell me. No offense.


Or is there something else I can do to bleep out offensive words (overlay bleep sound)?

Is there any kind of software that you know about for this kind of task?

Do I have to separate the audio, edit it, and then re-join the audio to the video?


Any suggestions? Ideas? Experiences?


Thanks.

[manono]

Do I have to separate the audio, edit it, and then re-join the audio to the video?

Yes. Demux the audio, at the same time converting it to WAV audio. Use some kind of a WAV editor like Audigy to do whatever you want to the audio. Reencode it to whatever it was before (AC3, MP3, whatever), before then muxing it back into the video.

You're not asking the impossible; in fact it's pretty easy to accomplish, if you know what you're doing. If you don't, then there are some things to learn along the way.

[pretzeltop]

Thank you manono!

Looks like I'll have to Google "demux" and find out what kind of tool would be the best to do it with.

Thanks for the swift reply! You rock!

[manono]

Sorry, when I said Audigy, I meant to say Audacity. It's a very good and free WAV editor that will allow you to silence the parts your sensitive ears don't want to hear. .

For XviD AVIs, you can use VDub(Mod) among other programs to demux (separate the audio from the video). There are guides for its use both here and at Doom9.

[pretzeltop]

Thanks again manono.

The audio editing part is the easiest part for me, so don't worry about mixing up those names.

This afternoon, I've tried to get things to work with AVIDemux, but I would be happy to find something a tad more simple to demux and remux.

As I said, I'm a newbie in this department. Thanks for the VDub hint. I shall check this out now and see if that'll work better for me.

Thanks again for all your help!

[manono]

I use VDubMod for demuxing, although other programs can also do it easily. Open the AVI and go Streams->Stream List->Right-click the audio, and set as 'Full Processing Mode'. Then hit 'Save WAV' and give it a name.

That gives you a PCM WAV file ready for editing. Edit it however you like, but don't change the length or you'll have synch issues later on. When done, reconvert to whatever you want or whatever it was originally, AC3 audio or MP3, most likely.

Open the AVI, set Video to Direct Stream Copy, go Streams->Streams List, 'Disable' the current audio, 'Add' your newly edited and converted audio. Back to the main screen and File->Save As, give it a new name, wait a few seconds (or minutes, depending on the length of the video), and you're done.

[pretzeltop]

Thanks again manono!

You have helped me to get going with the whole process, and I greatly appreciate that.

So now that I have the audio "fixed" the way I want it, what's the best way to join it with the video again? Is there a tool that works better than others? For example, I tried to make this work with Avidemux, but I'm not sure that the way I did that was correct — or the most efficient way.

In Avidemux, I opened the AVI file again, went to Audio > Main Track > Audio source and selected "External MP3" to select the edited MP3 file. After that, I did Save > Save Video, and I think it worked. Somehow.


My biggest problem, right now, is that the original audio was a little bit out of sync with the video. There is probably a name for that. What's the proper thing to do to adjust the audio with the video? Is that what you call MUXing? What values have to be adjusted by how much?

I guess, I could look at the AVI settings with GSpot and find out all kinds of things, but I just don't know what I need to look for and how to calculate the offset (or whatever it's properly called).


At any rate, thanks for getting me this far. Your help is greatly appreciated.

[manono]

So now that I have the audio "fixed" the way I want it, what's the best way to join it with the video again?

I explained in my last paragraph above how to add the edited audio back in. As for it being out-of-synch, assuming the amount is constant (off by the same amount all the way through), when you add back the audio, right-click it and go into interleaving. By adjusting the audio skew you adjust the delay. 1000ms=1 second and setting a negative delay causes the audio to play earlier, a positive one, later.

[pretzeltop]

Thanks manono.

Sorry to have asked the same thing that you've already answered. My bad.

Let me try this. You have been extremely helpful, and I just wanted to say THANKS!