Commentary track

[AlanHK]

I've found a podcast commentary track I'd like to add to a video and burn to DVD.

I can just drop the commentary as a separate audio track in the authoring app, but it would be nice to have the original soundtrack in the background.

Professional DVDs seem to do this by fading the movie sound when the commentators are talking; this is a bit labour intensive for me. Is there an automated way to do that (with free software)?

Otherwise I thought I could put the commentary track in the left channel, the movie sound (reduced to mono) in the right, so I could adjust the levels while listening. (I still have the original stereo in the first track when I just want the movie.)

Any comments?

[guns1inger]

I don't know of an automated way to do this, and personally I would hate to have the two soundtracks in seperate channels. While you may be able to adjust themseperately on your PC, it can be a real pain on a TV or amp.

It shouldn't be that hard or take too long to mix down the two to get the effct you want. Especially if you have an audio app that displays the sound waves. I would mix something like this down in Vegas, and could get a first pass mix in around 15 minutes, then refine for as long as necessary (or I felt like it). If there is a lot of talking, then first pass is to set the soundtrack volume low enought across the entire track for all the dialongue to be heard. This becomes the base level, and the rest is a matter of raising the volume when the dialogue drops off.

[AlanHK]

Well, not having Vegas, I'm using Audacity.

I did make a mix track after all.
I copied the original soundtrack, then used the Envelope tool to manually select and reduce loud parts. But this is pretty labour intensive.
I looked at the filters available, and found Compressor, which does that based on a curve. I set Threshold -29; ratio 10:1. Then I ran Amplify effect at -5.5 dB on the whole track. Mixed this with the commentary and it seems pretty clear.

Took longer than my original idea of separate channels, but now having the methodology worked out, it's pretty easy, so I thought I'd post the details for posterity.

[guns1inger]

Thanks for the follow up. So many disappear without letting us know if it worked, and if so, how.

[Greensold]

Came across these posts on a Google search and the question went unanswered...

I found out that the Audacity plugin "Auto Duck" does exactly what we need here: http://audacityteam.org/manual/index.php?title=Auto_Duck

Posted for future searchers.

[AlanHK]

"Auto Duck" does exactly what we need here.

I tried it and it does work.
However, it is incredibly slow. It took well over an hour to process a 45 minutes audio project with two tracks.
Using Compressor took only about 3 minutes. So I reverted to Compressor.

[triefy]

Now I'm curious.

I have an audio file that I would like to convert into an DVD audio track to play along with the movie. I want re-burn the DVD with the new audio track as an option along with the other audio tracks on the original DVD. What is the process you used after syncing up the audio to get it on the DVD?

[guns1inger]

It depends on how complicated you want it to be. Converting the file to AC3 - the most playable format - can be done with Aften, Besweet or FFMpegGUI. Putting this into an existing DVD can be complicated, but is doable.

[sambat]

I used 'MixAudio' and Avisynth to do this with an AVI file.
Enter the percentage that you wish to allow each stream (25:75, 10:90)
It's fast and works good.


http://avisynth.org/MixAudio

[AlanHK]

I have an audio file that I would like to convert into an DVD audio track to play along with the movie. I want re-burn the DVD with the new audio track as an option along with the other audio tracks on the original DVD. What is the process you used after syncing up the audio to get it on the DVD?

Just about any authoring application will let you supply several audio tracks.

See https://www.videohelp.com/tools/sections/authoring-dvd

I mostly use GuiForDVDAuthor.

Your audio has to be DVD compliant: best format is probably AC3, at 48000 sampling rate.
I use 128k bitrate, audiophiles would go for higher.
You can use ffmpegGUI, BeSweet, AftenGUI to make this.

[triefy]

Well, now I have encoded everything and I have the .m2v and .ac3 files. Re-Authored the DVD and I try to burn it to .iso (or just try to burn it) and it has problems.

One thing is the layer break. The original file was around 8GB's and this one a little over 8GB. However, I used DVD Shrink to make sure it fits. Can anyone tell me how to split sectors up in PGCEdit??

I really need some help on this, I catch on quick but after working 5 days on this project I think my brain is fried.

HELP!