Progessive/Interlaced = sound off.. help!

[X-treme]

I'm trying to back up my movie, and when viewing the specs with dvd2avi, the frame type is constantly juggling back and forth from progressive to interlacted. It's wild how fast it switches. The video type remains above 95%, but beings slowly at 90% (intially) and creeps up to 95%.

So, after using GK to convert the dvd to xvid, and then syncing the mp3/ac3 sound file to the movie, there is a slight delay. Why is that?

Out of all my backups, I never ran into this problem before. The audio states that there is a 0 second time delay, so I have no idea what the problem is.

Any suggestions?

[racer-x]

More than likely it the result of going from Interlaced @ 29.97 fps to Progressive @ 23.97 fps. When you encoded the video, you encoded it at a constant framerate, thus getting the audio out of sync.

The same thing happend to me when I rencoded Return of the king. The first 30 sec were 30i, it then jumped to 24p and remained there till the end. When I rencoded it @ 24p it delayed the audio about 16 frames. I had to cut the first 16 frame off of the begining (it was just a black screen anyway) to get the audio synced up correctly.

You could bypass all this by backing up with DVDShrink and forget about it.

By the way.............one post is enough.

[Baldrick]

please don't cross post.

[X-treme]

Thanks for the response.

So having the ENTIRE movie interlaced/progressive, am I screwed?
I've never used dvdshrink to make xvids before?

I'm not sure what else to say except, what should I do now?

[X-treme]

I also just check another movie of mine, and for the first few frames it's interlaced, then stays constant in progressive mode for the entire film.
How do I section out those 'bad' (interlaced) frames?

Thanks!

[racer-x]

Sorry, I thought you were backing up to DVD.

This may become a new trend for the movie industry to make it harder to rencode their movies.

[racer-x]

I guess in your case it may be easier to adjust the audio. You could convert the ac3 to wave and edit it. Either cut some off the begining or add some silence. Or you could use some tools that will let you change the audio delay of the ac3 to a + or a - value. I've never used such tool, but I know the're out there.

[X-treme]

I think the audio tool is the only way to go in this situation. What a pain in the rear.

I also just checked DVD2AVI and when I 'force film', i notice a flicker every 5-10seconds, whereas if set to 'none', the flicker comes only once every 20 seconds.

Thanks for the info! Now it's time to look for audio tools

[X-treme]

Racer X, how do you remove certain frames? Which tool do you use for that?

Thanks!

[flaninacupboard]

hmm, being in PAL land i've never seen/heard of this before.

are the 30i/24p sections in different VOBs? didn't think a single mpeg stream could have different framerates...

[racer-x]

X-treme wrote:

Racer X, how do you remove certain frames? Which tool do you use for that?

Thanks!

You can use an Mpeg editor like Womble or MianConcept Mpeg Pro that works with Premeire Pro to edit the Mpeg, but it will need to be rencoded. I actually did a quick and dirty cut with DVDShrink. Like I said, the part I cut was just a black screen at the beging. DVDShrink actually did a perfect job, but it is tough to be precise with it.

flaninacupboard wrote:

are the 30i/24p sections in different VOBs? didn't think a single mpeg stream could have different framerates...

In The Return Of The King it was in the same Vob. I was quite surprised too when I played it in WMP Clasic and it started as 29.97 fps then about 30 sec latter jumped to 23.97 fps. I still can't figure out how they did it.

My audio was actually a little ahead of the video after I encoded it @ 24p. After I trimed about 16 frames off the begining, it was in perfect sync all the way to the end (3 hr movie).

[X-treme]

WOW! I am finally finished syncing the entire film. All I can say is, what a PAIN IN THE A**!

Here's what I had to do (there must be an easier way). First I took the film (.avi) and realized that for the first 10minutes there were FBI warnings/preview to the movie, which needed to be removed. That was the problem. I tried searching through all the archives on the site, but found nothing that would help me out, except picking up a few pointers here and there. So, I opened virtualdub, opened the video and audio file (had to convert ac3 to wav), and the fun began! Using VD I delayed the audio by -28000ms. Also, I had to remove a few hundred frames, which were the excess part of the movie from the beginning (thanks to whom gave me the audio- interleaving tip in a previous thread!). After 4 hours of editing/previewing the same 5minutes of the movie to watch for perfect sync, I finally acheived success! I can't say my audio delay is perfect, because i'm already up to -28000ms, but after viewing the video everything looks perfect to the naked eye.

What a process.

I sure hope there is another way around that next time.
I'll have to look into Womble (even though I did download it, and installed it, I don't believe it could do what I wanted).

Thanks for all your help. I sure hope I don't have to do this many times!

[flaninacupboard]

flaninacupboard wrote:

are the 30i/24p sections in different VOBs? didn't think a single mpeg stream could have different framerates...

In The Return Of The King it was in the same Vob. I was quite surprised too when I played it in WMP Clasic and it started as 29.97 fps then about 30 sec latter jumped to 23.97 fps. I still can't figure out how they did it.

My audio was actually a little ahead of the video after I encoded it @ 24p. After I trimed about 16 frames off the begining, it was in perfect sync all the way to the end (3 hr movie).

Perhaps it's done with multi angle? i mean as long as the I frames come at the same timecode can an alternate angle have different properties?