Determining "audio delay" by watching ...

[aLu]

... is not that easy, especially with foreign language audio tracks when you can't read peoples lips.
Maybe this is trivial, but am I the only one who has problems of getting the right sync? Here's my standard method:

* Get the video via Flask
[* Demux and audio track via DVD2AVI to get the delay value in the filename - maybe this can be found in the IFO? where? Because the value's mostly false, I leave out this step]
* Extract the *wav via GraphEdit
* Flip the two together in VirtualDub and determine sync by trial-and-error. Find a scene with sound effects and adjust sync (deviation below 40 ms isn't recognizeable, in theory).

How can I properly determine the offset value the DVD uses?

[dani82]

here's a frame that freezes for about 1/3 of a second of the 1st second, that would be the main reason why its' out-of-sync (i think that's a bug); or it could just be me?

you wouldn't see it if the screen was blank.

[SirThomasLipton]

Hi there.

I've got a little pb :/

The delay indicated in the ac3 file name is not correct! How can I find the correct delay without reading on actors' lips?

Thx.

[Manao]

If you want a 'visual' method to find delay, don't read on the lips, but search a scene where there is a door that slams or something like that ( a short sound ). Load the movie with Nandub, playback the movie around the scene with the short sound, and play a little with the interleaving -> audio delay setting until you fing the right one.

Hope this works, I never tryed, but theorically, it should work.

[SirThomasLipton]

Okay I know I can do it by a visual method but is there some software which can do that (calculate the right delay)?

[Manao]

Sorry, I didn't take enough time to read your post :rolleyes:

For your question, I don't know, I thought DVD2AVI was never wrong. Is your DVD sync when playbacks with a DVD player ?

[SirThomasLipton]

The DVD is okay, I watched it yesterday evening :/

When I ripped it, I had the choice between 2 French AC3 tracks! Maybe I chose the wrong one... but I don't have the DVD anymore so I can't rip it again :/

The delay actually indicated is 10240ms but the sound tack is still too late :/

[SirThomasLipton]

Okay I found the right delay thanks to a door ;)

But strange, it was 8500ms instead of 10240ms!

[aLu]

@dani82
Does this have anything to do with what I asked? ;-[


Here's my solution :)

There is no automatic solution.
Start with 80/120/160 ms, that's the most common (might be 360, too). Work yourself up in increments of 40 ms, that's the shortest deviation humans normally notice (and correspondent with the PAL framerate).
Carefully align the audio to lip movements. When they seem to be simultaneous, add another 40 ms, because usually the mouth moves before anything comes out. The result should be correct, i.e. natural. Let the movie ly around for some days and watch it again. Trust your feelings to make final adjustments.

That's rather easy for o-tone movies, synchronized ones are a little harder.

But hey, you DVD freaks - there HAS to be some way for the DVD to know how to sync the audio ---?

[Swede]

I haven't had a 'Out-of-sync'-audio for more than two years now. That's about the same time I stopped using Flask...
Maybe it's better now but I would strongly advice you to use *anything* else.

[dani82]

aLu

you said you had a problem getting the audio and video sync, if you did find out how much the dvd was delay by and adjusted; i told you that one of flask bugs was that it frozen for about 1/3 of a second (do you understand), while thr video freezes the audio will go on, making the video and audio to be out of sync.

i just add about 2 second in front of the audio, and keep moving the mark in time until the audio is sync with the video; it's better than wasting your time adding little by little.

[aLu]

@dani82
Okay, I see. But the point is - I don't get my audio via Flask or DVD2AVI, but as a seperate WAV-track trough Graphedit, because that gives better quality (IMO Flask audio sounds a little muffled). So it HAS to be synced afterwards.

I've had delays from 40-360 ms (mostly 160), and a Flask freeze-frame for 200ms can't be causing that(can't be the case with me really - that's a little too long).
Anyone who can really handle IFOEDIT, where is the audio delay value stored in the IFO?