[BUG] Tagstudio crashes when clicking on a video that has no frames

[Thesacraft]

When clicking on a video that has no frames Tagstudio crashes.
Thats the video that crashes it:

https://drive.google.com/file/d/1PMB1wWUr9k8cWOzRGa2jpH14kCOIZJiF/view?usp=sharing
(i uploaded it to drive because i think you can't dowload it when its uploaded to github)

[Thesacraft]

Also there is no Error that is outputed to the console. And the thumbnail preview is also missing with the loading texture being there instead, which also prevents you from closing tagstudio completly(thumbnail threads aren't ended correctly).

[Loran425]

Looks like cv2 defaults to not throwing exceptions.
For discovery this can be changed by calling video.setExceptionMode(True)

This appears to be related to trying to read the file with 0 frames as video.read() will lag for 5+ seconds on my machine so I'm guessing something else errors out trying to wait for that. I'll toss together a quick PR that will just raise an error if the frame_count is 0 or -1 (returned on invalid files)

[CyanVoxel]

Looks like cv2 defaults to not throwing exceptions. For discovery this can be changed by calling video.setExceptionMode(True)

This appears to be related to trying to read the file with 0 frames as video.read() will lag for 5+ seconds on my machine so I'm guessing something else errors out trying to wait for that. I'll toss together a quick PR that will just raise an error if the frame_count is 0 or -1 (returned on invalid files)

You know what, I was running into a similar issue with cv2/ffmpeg errors on the thumbnails branch and ended up creating an is_readable_video method for testing if a codec is valid before wasting time erroring out trying to render the thumbnail. It uses ffmpeg.probe to read the video metadata before attempting to send it off to cv2 to read, and I bet we could just put in an extra condition to check for the number of frames and consider that "unreadable".

[Loran425]

You know what, I was running into a similar issue with cv2/ffmpeg errors on the thumbnails branch and ended up creating an is_readable_video method for testing if a codec is valid before wasting time erroring out trying to render the thumbnail. It uses ffmpeg.probe to read the video metadata before attempting to send it off to cv2 to read, and I bet we could just put in an extra condition to check for the number of frames and consider that "unreadable".

That would also work as long as that is_readable_video function is called in both the thumb renderer and the preview panel.

[CyanVoxel]

That would also work as long as that is_readable_video function is called in both the thumb renderer and the preview panel.

It should be called in both. For now though I'm happy with your solution #275 and'll get that pulled soon