video and sound captured magix sent out of sync

mark-perry wrote on 6/22/2020, 4:02 AM

example 1 - i used an external capture video for my own PAL VHS tape, the second clip was during the capture.

it guess was caused by the in-between signal during the 2 tapings.

example 2 - another one i'm trying to work on this is a NTSC widescreen DVD-R, originally from an Australia PAL off-air 4 x 3 (1981) (this is not my creation) which i wanted to try to re-author as the original PAL & 4 x 3 taping. i dubbed it in from the DVD but as you can see Magix has sent this one out of sync

maybe this was caused by the tape disturbances during the original capture in the picture and Magix didn't like those and chopped them out, but i dubbed this in using the internal DVD as i thought it was caused by my external DVD at first.

This is been created in PAL 25 fps 4x3 720-576, maybe I could change to NTSC and author it as PAL, so this is a see how it goes test.

Below is the first capture from the DVD I left this long so you can see the faults in the original capture and from the off-air taping which would be a generation from the original source tape.

go to 7:27 which is where the commercial is but the audio is at the end of the clip

any theories, are there any settings i should change

Comments

AAProds wrote on 6/22/2020, 6:50 PM

@mark-perry

That's a pretty wild scene change in the first video and the ABC News audio in the second part isn't playing at a stable speed either. I'm not surprised the audio is out of sync.

For clip 1, I suggest you cut it into two clips on the timeline.

There are two scenarios with audio sync issues: a linear out-of-sync, which can be corrected by simply moving the whole audio object left or right (ie earlier or later); use the Audio Video Offset feature for that (right click on the audio track, choose Audio Video Offset and experiment with the frame advance and retard).

The second is a bit trickier, where it's in-sync at the start but drifts off as the movie progresses. Use the Object Stretch mouse mode for that. Get the audio in sync at the start, then ungroup the video and audio, then in Object Stretch mouse mode, drag the end of the audio to lengthen or shorten the audio object. Provided the drift is consistent, you should be able to get the audio in sync at the end as well, meaning the whole video will be in sync.

mark-perry wrote on 6/23/2020, 12:50 AM

the first one i did the audio in WAV in Audacity of the whole junction added it to the timeline, split the video in two (picture/audio), aligned the imported audio then kept playing the video until i got all the (best) frames of the transition. it worked out fine but it wasn't finished being 2 hours and that threw the chapters out of wack but then again i hadn't saved a MAGIX file of then made an ISO of that.

i also noticed it captured the audio but it waited till the picture was tracked up and consequently throwing both out of sync.

the second was started two days ago. all i did was import the DVD and and straight away created an ISO with no chapters in the format i wanted as an assessment (81 minutes so plenty of room on a physical DVD) and that's where i spotted the wild drift.

i also noticed when the Warm Up Begins the camera before the first chicane it chopped out a few frames and replaced them with previous frames, so obviously when the program doesn't like a bad frame it replaces it with a previous frame so you're left with having to try capturing that frame.

i really think this selecting of bad frames chucking them out with the result of throwing both elements out of sync should be ripped out of the Magix program.

mark-perry wrote on 6/23/2020, 1:23 AM

here's that gap fixed with only 3 or 4 stubborn frames it wouldn't grab

AAProds wrote on 6/23/2020, 6:21 AM

@mark-perry Mark, re the first, I think you're being a bit harsh criticising MEP not capturing that VHS properly. That tape recording looks seriously corrupted and probably needs to be run through a TBC (Time-Based Corrector) between the VCR and the capture device to have any hope of keeping the audio in sync.

Re the second, I don't understand what you're doing with the DVD. How did you "import" it? DVDs are simply a group of VOB files, themselves variants of MPEG. If you "drag" the DVD onto the timeline, MEP will prompt you to save it to the hard disk (DVDs cannot be edited straight from the DVD itself) and then put the whole movie onto the timeline. You can then check it's in sync there, before you re-burn it. If the original DVD was in-sync, it will be in-sync on the timeline. It cannot be any other way.

The other thing I don't understand is "straight away created an ISO with no chapters in the format i wanted as an assessment". DVD ISOs can only be in one format: VOB (ie MPEG).

i also noticed when the Warm Up Begins the camera before the first chicane it chopped out a few frames and replaced them with previous frames, so obviously when the program doesn't like a bad frame it replaces it with a previous frame so you're left with having to try capturing that frame.

i really think this selecting of bad frames chucking them out with the result of throwing both elements out of sync should be ripped out of the Magix program.

I've done a lot of capturing over the years and have not seen any evidence of this. If it is happening, it is only happening because the source is so bad. How could you then possibly "capture that frame" if MEP can't do it? Unless you go basic using, say, Virtual Dub...

johnebaker wrote on 6/23/2020, 7:57 AM

@mark-perry, @AAProds

Hi MArk, Alwyn

. . . . . If the original DVD was in-sync, it will be in-sync on the timeline. It cannot be any other way. . . . .

Except when copy protection screws up the frame table which forces the audio out of sync.

MEP has the ablility to recreate the frame table - select all the video clips and right click, Create (new) frame table .

This should correct any mpg audio sync issues.

HTH

John EB

mark-perry wrote on 6/23/2020, 8:31 AM

Copy DVD, yes was prompted to copy movie or whole disc and then the format warnings. I just created an ISO for the VOBs (rather than a physical disc) and tested the VOBs on my media player as a first check then assess what I'd need to do.

The first video, bedtimes calling I talk about that tomorrow but i will say I'm aware of the quality of the sources so I'm not expecting miracles.