MPEG Mediator: Audio Sync Problems

Yoda · #1 08-07-2002, 11:46 AM

kwag,
still can't get the audio to sync with the video even using this method. i must be doing something wrong with bbmpeg or headac3he but i followed all the examples you have put in the various post. it seems the audio lines up to be longer than the video when muxed and the mpg file is played back for comparisons. under bbmpeg "program stream settings" you have "vcd" selected and "vbr" checked and "forced mux rate" set to 0.
is there any thing i may have missed there.

-yoda

Yoda · #2 08-07-2002, 12:09 PM

also, when i check file properties in mpeg mediator is tells me the film is 29.97 and fitcd tells me 23.97. which setting should i use in tmpgenc, 29.97 or 23.97?

Yoda · #3 08-07-2002, 12:29 PM

kwag,
what is your setting in fitcd for multiplexing?

kwag · #4 08-07-2002, 12:53 PM

Quote:

Originally Posted by Yoda

also, when i check file properties in mpeg mediator is tells me the film is 29.97 and fitcd tells me 23.97. which setting should i use in tmpgenc, 29.97 or 23.97?

The properties tells you that the file is 29.97, but FitCD is telling you that it's 23.976 because Mediator is doing IVTC. That means that the original was shot FILM.
So you would encode at 23.976. Just like FitCD says.

-kwag

kwag · #5 08-07-2002, 12:57 PM

Quote:

Originally Posted by Yoda

kwag,
what is your setting in fitcd for multiplexing?

Doesn't matter what you set, because the value is not used for the .avs generated script.

-kwag

mediator · #6 08-08-2002, 02:52 AM

To clear this up a bit: The Framerate in the 'Properties' window is the display framerate as coded in the MPEG-stream not necessarily the rate of the coded frames in the stream. So even if the source is FILM (23.97 or 24 Hz) the properties may display 29.97 or 30 Hz due to telecining.

-mediator

Yoda · #7 08-08-2002, 12:30 PM

Kwag,
I still cannot sync audio and video. When you use Mediator do you save the wav file while encoding with Tmpgenc? That's the only thing I haven't tried yet. If you save seperately then how does bbMpeg know what the correct sync frames are?

-Yoda

kwag · #8 08-08-2002, 01:08 PM

Quote:

Originally Posted by Yoda

Kwag,
I still cannot sync audio and video. When you use Mediator do you save the wav file while encoding with Tmpgenc? That's the only thing I haven't tried yet. If you save seperately then how does bbMpeg know what the correct sync frames are?

-Yoda

Hi Yoda,
I first encode the video stream only, then after that, I save the WAV from Mediator.
Then I open this WAV with headac3he and encode it to mp2. Last step is mux both streams with bbmpeg. Has not failed yet!

-kwag

Yoda · #9 08-08-2002, 01:33 PM

That's exactly how I do it. I even tried the procedure on a different machine loaded from scratch and I still have sync problems. This is really bugging me

The only way I've ever been able to encode the movie correctly is if I used Tmpgenc on the video and audio. If it's not Mediator then it has to be Avisynth to Tmpgenc. What version of Avisynth are you using?

-Yoda

kwag · #10 08-08-2002, 02:07 PM

AviSynth Beta 1.06.
I just installed version 2 today, but haven't tested it yet.

-kwag

Yoda · #11 08-09-2002, 01:07 PM

I give up, can't make it work. I'll wait and see if anyone else has this problem and how they fixed it otherwise back to the old tried and true DVA2AVI>Tmpgenc method.

rendalunit · #12 08-10-2002, 10:25 PM

hey Yoda,

I just ran into an audio sync problem too- I ripped an older movie called "our man Flint" and saved the audio to wav with Mediator and encoded it with Headac3he using surround 2 and the audio was completely out of sync when viewed with WinDVD.

So then I demuxed the audio with DVD2AVI and encoded it with Headac3he using plain ol' surround and it's in perfect sync. Now I have no idea what the problem was but I'm guessing that it was the surround vs surround 2 in Headac3he- btw- what's the difference between the two Kwag?

thx,
ren

kwag · #13 08-10-2002, 10:33 PM

Quote:

Originally Posted by rendalunit

hey Yoda,

I just ran into an audio sync problem too- I ripped an older movie called "our man Flint" and saved the audio to wav with Mediator and encoded it with Headac3he using surround 2 and the audio was completely out of sync when viewed with WinDVD.

So then I demuxed the audio with DVD2AVI and encoded it with Headac3he using plain ol' surround and it's in perfect sync. Now I have no idea what the problem was but I'm guessing that it was the surround vs surround 2 in Headac3he- btw- what's the difference between the two Kwag?

thx,
ren

Hi ren,

Quoting doom9's guide:

"Dolby Surround 2 coding. This special mode codes the output in a way that Dolby Pro Logic II decoders can separate the rear channels, while remaining completely compatible to regular Dolby Pro Logic decoders."

Here's the link: http://www.doom9.org/mp2-hac3.htm

-kwag

rendalunit · #14 08-10-2002, 11:11 PM

hey Kwag, thanks for the explanation and the link.

disregard my last post because the audio is still out of sync by a mile

I'm not sure what happened here- I'm going to start over with this one.

rendalunit · #15 08-11-2002, 12:37 AM

well my audio sync issues are related to WinDVD! I burned the movie and it plays great- perfect sync. Also it is synced up when I preview with WMP. I don't know why it's messed up in WinDVD

kwag · #16 08-11-2002, 12:55 AM

Quote:

Originally Posted by rendalunit

well my audio sync issues are related to WinDVD! I burned the movie and it plays great- perfect sync. Also it is synced up when I preview with WMP. I don't know why it's messed up in WinDVD

It happens to me too ren

I always now preview in WMP, because the same audio/video sync issues in WinDVD.
Isn't it an (IN)perfect world!

-kwag

Yoda · #17 08-19-2002, 02:04 PM

Do me a favor kwag. Before you burn your latest encode, find out where the end of the 1st vob file is in the film. Then run the completed mpg in windvd and tell me if the audio goes out of sync at the beginning of the 2nd vob. I've had some time to play and noticed I'm synced until the first vob then the audio lags a bit, and a bit more for each vob.
Maybe this will be a starting point to tracking the audio/video sync problem I have.

-Yoda

kwag · #18 08-19-2002, 02:56 PM

Quote:

Originally Posted by Yoda

Do me a favor kwag. Before you burn your latest encode, find out where the end of the 1st vob file is in the film. Then run the completed mpg in windvd and tell me if the audio goes out of sync at the beginning of the 2nd vob. I've had some time to play and noticed I'm synced until the first vob then the audio lags a bit, and a bit more for each vob.
Maybe this will be a starting point to tracking the audio/video sync problem I have.

-Yoda

Hi yoda,
The audio goes out of sync at just about any point in WinDVD. Beginning, end, everywhere. It's random. So it is a problem with MPEG-1 VBR in WinDVD.

-kwag