"AV sync issue" Question / Frame dropping?

[samtoy]

Hi all,

I'm converting some movies from BD folders created by tsMuxeR (Blu-ray output).

With most of these movies I get the following info (timings differ):

AV synchronization issues were found in file 'H://t00_some movie_(2011).mkv' (title #1)
AV sync issue in stream 1 at 0:00:00.010 with duration of 10.666ms : 1 early frame(s) dropped at start
AV sync issue in stream 2 at 0:00:00.031 with duration of 32ms : 1 early frame(s) dropped at start

Do I need to worry? Can this "frame dropping" result in a visual or audible glitch in the movie?

Edit: And does this mean that tsMuxeR is/was messing with the AV sync of the movie in general?

Thanks for any info,
S.

[setarip_old]

Just try one and find out ;>}

[samtoy]

Yes, but maybe my player (Popcorn Hour A-200) does not show any glitches but another player will.

I was hoping for a more technical explaination of that behaviour. Maybe the frame dropping at the start is totally normal and nothing to worry about.

[crowfax]

The reason, so far as I can tell, is that on some branching discs, frames are repeated when it movies between each m2ts file. So if MakeMKV didn't drop frames eventually you'd lose sync.

Blu-ray players must have a similar mechanism built into them.

[samtoy]

I just found out that such a MKV movie (with dropped frames) has a delay info added to MediaInfo's analysis:

Audio #1
..
Delay relative to video : 32ms
..

The same movie done directly from the BD does not have that line.

I guess that proves that the tsMuxeR step produces a 32ms sync problem...

[joe42]

I think MakeMKV only got the option "Show AV synchronization messages" in 1.7.0. I've been using all the versions for a while, and I have only seen the messages appear recently. They do appear sometimes when I am ripping directly from a blu-ray disc.