DVD to MP4 conversion - sometimes video speed spontaneously increases 1.33x and sound goes away.

[compunoob]

Trying to use VLC > Media > Convert/Save to back up a few dvds.
Complete newbie here, but I've looked around and haven't seen anything like this my problem as well as:
* tried 6 movies total
- 2 are fine
- 2 are fine for >1hr then vid speeds up by 1.33x and audio goes dead
- 1 has audio all the way, but vid is 1.33x fast from start
- 1 is ~1.04x fast vid for ~7 min, then vid speeds up to 1.33x fast, then at 19:40 the horribly unsync'd audio cuts out.
Tried
* 2 different computers (1 is Windows 10, one is Windows 11) -> super similar results on one of the dvd that stays fine for 1+ hour, then goes screwy
Tried some advice from https://forum.videolan.org/viewtopic.php?f=2&t=156428
#1 couldn't find especially nVidia on my Windows 10 computer, but given 2 computers, this wouldn't seem like a good candidate
#2 tried vlc versions 3.0.18 & 3.0.20 -> super similar results
#8 - Try Preferences -> Input/Codec -> HW accelerated decoding to "None"
-> I set Hardware-accelerated decoding to "Disable" -> much bigger file but same results
#9 - On Windows, try Preferences -> Video -> Output to something different (dx11 or d3d)
-> I set Hardware-accelerated decoding to "Direct3D11 Video Output" AND Hardware-accelerated decoding to "Direct3D11 Video Acceleration" -> same results

This (VLC conversion) seemed like such a great idea. VLC plays the disks just fine so the input-to-screen-output seems to work, "all ya need to do" is take the screen-output and turn it into MP4 output file. How did this go so terribly wrong ... and only sometimes?

Thanks in advance

[Lotesdelere]

There are other reports about conversion issues.
https://forum.videolan.org/viewtopic.php?f=14&t=163663

Try with a nightly build:
https://nightlies.videolan.org

[compunoob]

????
First let me say that the people behind VLC have down a pretty amazing job at developing it. And from what I can tell, Lotesdelere is one of the main people at least from what I can tell from this forum. So thank you. That said, I'm confused by your response.
Your 1st link is to something regarding:
Batch converting MTS to MP4 and preserving audio
Besides the word converting, I don't see much in common. It is not even converting dvd to mp4 and doesn't seem to have the spontaneous video speed change that I am having (that seems to me to be the underlying issue with the audio going away)
The link you suggest to him ( iancruick ) has to do with conversion, but seems to have more to do with cutting and doesn't seem to share much with my issue.
So I'm not sure where you were headed with your suggestion, but I'm not seeing any connection or help.
You also suggest for iancruick to check out nightly build @
https://nightlies.videolan.org
I tried to check that out but ran into a user IQ underflow error. Any hints on how to install one of these?

Thanks again.

[Lotesdelere]

For 64-bit Windows :
https://artifacts.videolan.org/vlc/nightly-win64/

Use the most recent one.

[compunoob]

Thanks, but yes. I made it that far, but I downloaded the .exe (from 4/14) that I was hoping was an installation file and it didn't seem to work on its own.
So it is as simple as also downloading the .msi file and having it present in the same folder as the .exe? Or is it a more involved process. Sorry for being a ... computer noob.

[Lotesdelere]

The EXE file is the regular installer and it's working fine for me. But yes, you can also use the MSI installer.

[compunoob]

Thanks and yep, the exe worked "fine", it was just that I got this "error" (more like warning) when I tried it

But after hitting "more info" and pushing thru I tried converting, but didn't get very far at all. After setting up and starting the conversion, I got this error

Not sure what the heck JIT is in order to enable it, but do you think enabling the "Display the output" option would help at all? Like I said in OP - vlc plays the dvd just fine. Something gets messed up in the video-to-mp4 process.
Is there anything else I can do to provide debugging info either
A) for this nightly version that actually bombs or
B) for the original version that "thinks" it is operating successfully

On a separate note ... nevermind. This was about my images not posting, but it was my fault and now fixed

[Rémi Denis-Courmont]

That crash is a bug in a dependent library (I guess dvdnav?).