Captured video is skewed

[VeryNaughtyBoy42]

I'm trying to capture video from an external capture device (Canopus ADVC-100). VLC sees it fine but can't seem to display the video straight, instead it's splitting it into angled bands. Picture attached. Any ideas? I've reset all the VLC settings but it made no difference. Other apps (Quicktime, iMovie) can read video from the device fine, it's just VLC that struggles.

While I can record with Quicktime it cuts out after 15 minutes. iMovie will record but not at the correct resolution (native PAL).

[unidan]

Can you do a capture that you can upload and share the file? It would give every elements to reproduce and fix the issue.

[VeryNaughtyBoy42]

Well as I've just discovered, the capture doesn't appear to actually capture anything!

Here's a screen recording ... http://lpbaker.com/images/screencap.mov

As you can see, the preview is broken, but so is the timer. It jumps around all over the place.

After this I switched to Quicktime 10.5 and did a movie recording from the same device, and it worked fine. Here's the video if it helps ... http://lpbaker.com/images/qtcap.mov

Happy to provide any other info I can if you tell me where to find it

[unidan]

Ok, this looks like a bug in the avcapture module, I'll check on my end, thanks for reporting this!

[VeryNaughtyBoy42]

Ex-programmer here. If I can do anything to help, let me know. I'm comfortable with scouring log files, noting debug info, using trial modules, etc. Anything but coding! Thanks I'd really like to get a decent capture from the many VHS tapes I have before they disintegrate.

[unidan]

Great, I'll provide more details then.

What is used here is this module: https://code.videolan.org/videolan/vlc/ ... vcapture.m

It's likely that this part is invalid: https://code.videolan.org/videolan/vlc/ ... m#L506-517

In particular, i_visible_width/height might be different from i_width/height, in which case the picture pitch will be invalid and a skew like you have will appear.

Otherwise, it's also possible that the copy itself is not correct : https://code.videolan.org/videolan/vlc/ ... ure.m#L230

In both cases, it will depends on the initial format from the capture, I'm not exactly sure if I can reproduce without this, but you might be able to check it from the log, run /Application/VLC.app/macos/VLC -vv directly (not sure of the exact path) to grab those!

[InTheWings]

Otherwise, it's also possible that the copy itself is not correct : https://code.videolan.org/videolan/vlc/ ... ure.m#L230

one liner is correct if stride is correct for non-planar formats

[InTheWings]

To help you, we need messages, to completely understand what your problems is.

From windows command line or linux or macos terminal, launch vlc with options -vv and --logfile=file

• Windows example: vlc.exe -vv --logfile=c:\vlclog.txt
• Linux example: vlc -vv --logfile=vlclog.txt, or vlc -vv 2>&1 > logfile.txt

Then paste the full resulting log here between [​code]and[​/code] (or use Pastebin.com if it's too long)

Also don't forget to name your Operating System and provide the VLC media player version.

[VeryNaughtyBoy42]

I'll post more info in the coming days - this is a bit of a week for me. Stay tuned!

[VeryNaughtyBoy42]

OK, this is done.

VLC 3.0.17.3 Vetinari (Intel 64bit) on Mac OSX Monterey 12.5.1 (21G83)

Here's the screen capture of what I did from start to finish: https://www.lpbaker.com/images/vlccap2.mov

And here's the log file: https://www.lpbaker.com/images/vlclog.txt

[VeryNaughtyBoy42]

Just following up on this -- any more information required from me?