AC3 audio delays

[ziggy1971]

Hello all,

I seem to be having some problems getting the AC3 5.1 audio in sync with my MPEG-2 video during the DVD authoring process.

I downloaded part of a television series in .mkv format that I want to put on DVD. I managed to extract the AC3 audio and encode the video to MPEG-2 format, however, there seems to be a a/v sync problem.

I've been using DVD-lab Pro for DVD authoring, it does offer an audio delay option, but if you don't know exactly what that delay is, you're SOL. No real-time audio/video (I think it's time to find better DVD authoring software, any suggestions?)

Anyway, I would like to know if and how I could fix this. I would rather not have to re-encode the AC3 audio (it's about 5 seconds out of sync), but if I do, how do I trim the audio? Do I have to separate the channels? If so, how do I demux the AC3 to separate streams?

Any suggestions/advice is greatly appreciated,
Thanx for now,
Cheers,
ziggy1971 8)

[AlanHK]

DelayCut can add time (delay) or cut AC3.

[ziggy1971]

Hi AlanHK,

Thanx for the link, I'll give it a try and see if it can fix the problem.

Cheers,
ziggy1971 8)

[guns1inger]

Load the elementary streams (video and audio) into Media Player Classic and use the + and - keys on the number pad to adjust the delay until you sort out what it is. You can then use DelayCut or DLP to adjust for it.

[ziggy1971]

Hi guns1inger,

How do you load elementary streams (video and audio) into Media Player Classic?

Cheers,
ziggy1971 8)

[guns1inger]

File -> Open File

Load the video into the Open field, and the audio stream in the Dub field.

[ziggy1971]

Hi guns1inger,

Now why wouldn't the makers of Media Player Classic just have labelled the fields "video" & "audio" instead of "Open" and "Dub"? It would've made things so much easier and I wouldn't feel like a complete idiot for asking such a trivial question.

Oh well, thanx for the info though.

Cheers,
ziggy1971 8)

[guns1inger]

Dub is an audio term, but you are right that it isn't the clearest label

[AlanHK]

How do you load elementary streams (video and audio) into Media Player Classic?

Normally, if the files are in the same folder with the same name, MPC loads them automatically.
Eg: if you open movie.m2v and you have movie.ac3 in the same folder, the audio will also be loaded without you having to select it. Somtimes this can be annoying, but usually it's what you want.

[Mrsash]

Do you use Klite codec pack? I have this issue on 2 Pc's I installed this on. Tmpg dvd Author 3.x, goldwave have issues in keeping Ac3 in sync when I convert AVI to Mpeg 2. When my PC's play these files it works perfect. Only when I convert it do I have these issues...

[guns1inger]

The only good codec pack is one you never install

[Mrsash]

The only good codec pack is one you never install

I prob would agree but what do you use? I was advised to install ffdshow only but setting it up makes my skin crawl. Is there a guide how to configure it.

[guns1inger]

Mostly the defaults are fine. The only time you might need to screw with it is for the vfw side if you are a Vdub user.