Best steps to final AC3 audio on home videos

[sbueffel]

I am currently taking my home videos (DV) and transferring them to avi. Then I do scene edits\transitions in VideoStudio 6 or Showbiz 1.1. I export that to MPEG2. I used to then author the DVD in MovieFactory with menus, music, etc. But that leaves the audio in PCM. I would like to have the audio as AC3. So I imported the MPEG2 into DVDIt and author a video there, with the final output in AC3. This, of course, causes the audio to be demuxed, transcoded,and remuxed into the VOBs. Is this the most expedient\efficient route to accomplish what I want?

I don't know if there are any quality issues when demux the audio from the video and put it back in, etc. Also, I didn't know if I should extract the audio from the AVIs first thing, do everything with the video as an elementary stream and then import the audio into DVDIt as the last thing. But then I was concerned about sync issues. Or maybe author the disc with PCM, use IFOEdit to demux the audio, use BeSweet to transcode and then IFOEdit to remux.

As you can see my mind is brainstorm mode, and I thought it best to seek answers from those who probably know best. Your help is appreciated.

Scott

[DJRumpy]

I always split my audio out, and I never have sync problems. You didn't specify if you were changing the length of your avi's. If this is the case, you'll have to leave them together during those stages to keep them in- sync (pardon the expression).

If you choose to move your audio directly to AC3, I believe you can use the latest BeSweet to work with 5.1 AC3. SpruceUp as a DVD authoring tool also natively supports it.

If your using DVDIt, it always demuxes your files anyway, so if your source is muxed, your just adding extra time.

[sbueffel]

Very rarely do I edit the length of the video. It would be to cut out the beginning or end of the capture that blended a different video. My editing in ShowBiz is for scene transitions and titles (I only use VideoStudio to capture and for scene detection; it is WAY better than ShowBiz's scene detection).

I use SpruceUp or Maestro for authoring commerical DVDs but I use MovieFactory for home videos because it is easy to make nice and simple menus that look good. I don't want to have to change the digital output of my player to PCM just to support my home videos so that's why I want AC3.

I don't mind leaving the audio muxed; I just didn't know if I was affecting quality of the audio and\or video by going through all the steps I do, only to have DVDIt demux it to do the final transcoding to AC3.

Thanks, DJ.

[DJRumpy]

I've never noticed any loss of quality from decompressing and re-compressing audio, assuming you never compress to a lower bitrate.

[Nolonemo]

I think as long as the audio you're bringing into DVDIt is PCM, no problem. If you are converting MPEG 1 layer 2 to AC3 you could have some quality loss.

[sbueffel]

I believe the audio is remaining PCM when I compress to MPEG from ShowBiz and author in MovieFactory, only because I have to change the audio output options on my player to make the sound work. How can I find out for sure? Will opening the IFO file in IFOEdit show similar information for PCM or MP2 like it does when encoded with AC3? Thanks.

[DJRumpy]

I would assume it does. I've never had a DVD that uses PCM, but the fact that IFOEdit notes an AC3 source leads me to believe it would also note a PCM source.

[Nolonemo]

My home theater receiver briefly displays the type of audio stream when you fire up a dvd in the settop player (ie, PCM for pcm, MPEG for mpeg 1 layer 2, 2/0 for DD 2/0, etc.)

[sbueffel]

I haven't had a chance to pop in the only DVD I have made so far from a home video. I will do that tonight and report back.