Sync problems, related to FPS? An on going struggle

[slowpoke115]

Hi I've got a PAL encoded video with VBR (yuk), first thing I did was extracted the audio to wave with vdub and then turned it into CBR and remuxed the video, it was perfectly in sync. I imported it into DIKO and attempted to turn the PAL video into an NTSC video (FPS was 23.97 and I wanted it DVD compatable at 29FPS, I don't remember the exact numbers).

This usually works fine for me but the audio was amazingly out of sync so initially I put a delay into DVD lab pro but it still goes out of sync within the first 5 minutes. I thought the audio might not have had the same FPS conversion that the video did so I changed that with BeSweet which makes the pitch sound crap and yes it's still out of sync!

I'm completely out of ideas now, I'd use tmpgenc but it takes ages and I usually end up with files over 2 gig which is not ideal for my three film DVD, I'd also usually stick with PAL but the other films are all NTSC.

Any ideas, please help, I'm desperate my computers been encoding and decoding for 3 days almost none stop now

[slowpoke115]

OK, I've checked my CBR avi and it's out of sync... Sorry, I should of watched the video a bit longer. I have no idea why it's out of sync though, I've never had any sync issues before. My original source is DEFINITLY not out of sync, triple checked that one!

[guns1inger]

PAL isn't 23.976 fps, it's 25. So if you srouce is 23.976 it is already NTSC. Encode it as 23.976, apply 2:3 pulldow and author.

Are you sure you have PAL source ?

[slowpoke115]

Oh, yeah must be NTSC already.

My source has no bad frames, I've tried demuxing with vdubmp3 freeze, got a wave file - I muxed this with the original source and the outputted file is out of sync, is that even possible?! This has really confused me, I've changed nothing except my VBR audio to wave, does that usually cause delays or anything?

I should probably start a new thread or something as my problems changed a tad.

[guns1inger]

I wouldn't start a new thread. Your key problem is the same - audio sync.

I would try one of the following

1. ConvertXtoDVD, or it's freeware predecessor, DivxtoDVD. It usually handles VBR MP3 OK.

2. Open the avi in vdubmod. When you get the VBR warning, answer yes to re-write the header. Go to streams->Stream List. Full Processing mode. Set compression to Uncompressed PCM and save Wav. Try using this in place of the VBR audio.

3. As for 2, but use ffmpeggui to encode as AC3. Encode the video seperately in tmpgenc, then author with DVD Lab Pro.

[slowpoke115]

Thanks a lot! I tried converting a few minutes of it with win avi video converter and it seemed in sync so I'm trying tmpgenc as I think win avi vid converter looks crap. Sadly it's going to cost me 5 hours, all because freenc and just about every version of virtualdub can't seem to do the job properly. I tried your second suggestion so if this fails I'll try the first and third.

Thanks for your help

[slowpoke115]

I tried tmpgenc built into DIKO and it gave me a 1.2gig wav file and 60meg video despite taking 6 hours to encode. ConverxtoDVD puts a watermark in the bottom unless I buy it and also there are no options to output a specific resolution (720 x 480). I'd try opening the file in tmpgenc without DIKO taking over everything but it's going to take another 6 hours and I have no idea whether or not it will work until the whole operation is finished.

The problem with the audio is as soon as it's extracted from the video it's different regardless of what programs I use, I've tried demuxing the audio with virtual dub mp3 freeze and virtualdub mod, as soon as I do that the audio is VERY out of sync with the video and it seems almost randomly out of sync with some parts +200ms out of sync and others -40, changing the outputted file format will not help as the old rule of computing dictates 'garbage in garbage out', the file I'm putting in is crap and even if the output was DTS or something amazing it would still be out of sync.

I think I'll have to bite the bullet and use win avi video converter to do a really crap looking job and then demux it all, if I had more faith in tmpgenc I'd use that. I can't believe one video can cause such a huge problem, the xvid I started with looks flawless.

Not happy

[guns1inger]

DivxtoDVD is the free version of ConverttoDVD. You can find it in the tools section. It does not watermark the video. It only does full D1, but you can choose NTSC (720 x 480) or PAL (720 x 576). Format also defines framerate, so choose the right one. That said, if you leave it on auto it will choose the correct one for you if you have standard framerates in the source.

I have had only one VBR MP# audio track that no matter what I did, would not sync. Obviously the variable part of VBR was very variable . . . . . . It reacted in much the same way you described - the sync varied in both directions. Even ConvertXtoDVD couldn't convert it, so in the end I gave up.

[slowpoke115]

I used convertXtoDVD, worked a treat and the pictures really nice and of course the audio is in sync! Initially DVDlab moaned at the audio being AC3 and all my other audio being MPA so I had to reencode it, but it worked!! Very pleased with the finished result, thanks for your help, I shall use converxtoDVD next time I get vbr vids.


Thanks once again

[guns1inger]

You don't have to re-encode, just put that title in it's own titleset. One of the restrictions when authoring is that assets in a given titleset must have the same video and audio attributes (format, resolution etc), however didferent titlesets can have different formats.

Just something for the future. My preference if for AC3 anyway, so all my audio assets are encoded as either 2.0 or 5.1 AC3.