Fast Seek versus A-B Repeat

[Spike1]

If, in Settings > Extra Settings > Video, "Always use fast seek" is selected, then an A-B repeat region is defined, most of the time the jump back to the start of the region results in an infinite loop lasting under half a second. My guess is that Fast Seek (sub-legend: "Seek is faster but may be less precise") is indeed so imprecise as to land you before the repeat region, triggering another seek. Disabling Fast Seek always solves it, though seek is then...slow. Tested on 3.6.0 Beta 1 nightly 2024-03-01 on several Samsung tablets.

[Aza]

We should indeed disable fast seek in AB repeat mode. Your issue is now tracked here: https://code.videolan.org/videolan/vlc- ... ssues/3056

Doe it happen with some specific samples? If so, could you please share one?

[Spike1]

I am using local .mp4 files and have not found one on which the bug does not occur.

AB repeat should not use slow seek, because it's so slow on Samsung Android 8 tablets that it wrecks the loop effect. Instead, if my guess in the first post is correct, AB should have a special case to disable seek in the case that it has just performed a seek.

[Spike1]

The bug is still present on the Nightly of 2024-10-01.

If my theory about the bug is correct, VLC has code that jumps to the start of an A-B repeat region anytime it is OUTSIDE the region. But fast seek to A jumps before A and then walks to A, triggering another jump, ad infinitum. It would solve the bug to change the A-B repeat code to only jump if it is BEYOND (AFTER) the region.

[Aza]

Did you try with a recent nightly? Does it solve the issue?

[Spike1]

2024-10-01 is pretty recent. If you're saying work has been done on this in the last 6 days, I'll download again.

[Aza]

My bad, I misread your previous post. I'll reopen the issue and we'll take a look.