Are AV synchronization issues a problem?

[jriddle]

Hi,

I made a mkv file from the "Once Upon a Time... in Hollywood" blu-ray disc using MAkemkv 1.14.7 and received the following message when the program completed.

AV synchronization issues were found in file 'Once Upon a Time... in Hollywood-FPL_MainFeature_t01.mkv' (title #2)

I was curious concerning this message as I've never seen it before so I made another mkv file using Makemkv version 1.14.5 and never received the message. I loaded Makemkv version 1.14.5 on another Windows PC and it also had no message so I updated that PC with version 1.14.7 and once again received the same AV Sync message.

Why does this message show up using the newer version? and is the mkv file ok using the newer version software?

Thanks,
John

[Kirthew]

I tried to encode last night and using the latest download, my audio would not load. Playing on GOMplayer it had the wrong Codec. Other English audio track was for sight-impaired.

Don’t know how to get a proper download of it now.

[craignan]

I'm getting the same issues with the last 4 movies that I've ripped using 1.4.7. Downgraded to 1.4.5 and the AV message went away.

[jayper]

Seeing this message for the first time on 1.4.7 as well.

Edit:
I was curious so I tried out some variations after cleaning the disc:

- I just tried the same disc in another drive (libredrive) and got the same message: "AV synchronization issues were found in file..."
- I processed a decrypted folder back-up with another piece of software and their debug log did not cite any errors when creating a MKV file. This doesn't mean anything per se, but again, I was curious.

[jriddle]

We see AV Synchronization messages using version 1.14.7 where we didn’t see these messages in earlier software revisions. I checked the preferences settings and the box is unchecked to show AV Synchronization messages.

Can one of the experts shed some light on why these messages are showing up now and what do they mean?

Woodstock?

[Woodstock]

Actually, I've been in a lull from ripping since 1.14.7 came out; I got caught up on the backlog before Thanksgiving, and the December shipments from rightstufanime.com aren't due until just before Christmas...

For the most part, the AV sync messages haven't been a factor for me, but some people are having issues with Atmos when MakeMKV tries to do the fix-up.

[jayper]

I've seen these issues come in with UHD rips as well in the last few days, and in all cases none of the rips have included an Atmos track. They've been DTS-HD, and the Blu-Rays I have tested have all been DTS. I'll be sure to test some Dolby back-ups today.

What I find a bit peculiar is that when searching through the forums, most references to this error are accompanied with specific time codes and further explanation of the AV Sync issue. For example:

004007:0010 AV synchronization issues were found in file 'G:/Media/4K Movies/Hacksaw Ridge/Hacksaw_Ridge_t07.mkv' (title #8)
004008:0010 AV sync issue in stream 1 at 0:00:00 with duration of 0.666ms : encountered overlapping frame, audio skew is +0.666ms
004008:0010 AV sync issue in stream 2 at 0:00:00 with duration of 0.666ms : encountered overlapping frame, audio skew is +0.666ms

For me there have not been any additional information presented. I just get hit with something like:

AV synchronization issues were found in file 'Once Upon a Time... in Hollywood_t00.mkv' (title #1)

I also have the "Show AV Synchronization Messages" setting disabled and I am still getting these messages showing in the logs... Which doesn't seem right. Again, this is the first time I have ever seen the message and it makes me wonder if something has changed.

[jayper]

I tried a standard blu-ray, with TrueHD audio and got the same result:

Operation successfully completed
Saving 1 titles into directory P:/MakeMKV Output
AV synchronization issues were found in file 'Quick and the Dead, The (1995)_t00.mkv' (title #1)
Forced subtitles track #4 turned out to be empty and was removed from output file
Forced subtitles track #6 turned out to be empty and was removed from output file
1 titles saved

[Baby_Groot]

I am also getting the "AV synchronization issues were found in …" (where … specifies the movie title that was ripped) dialog message in v1.14.7 with every Blu-ray movie I rip (so far around 50 or so). There are no timestamps or other accompanying information along with the AV sync message and it always states the mkv rip has "completed successfully". The mkvs seem to play perfectly but seeing that AV sync message every time a rip has completed is a little unnerving. Is this message just a meaningless glitch with latest versions of makemkv or are the resulting rips actually affected in some way? Can someone please help out with this? Earlier versions did not produce this message.

[jayper]

I am also getting the "AV synchronization issues were found in …" (where … specifies the movie title that was ripped) dialog message in v1.14.7 with every Blu-ray movie I rip (so far around 50 or so). There are no timestamps or other accompanying information along with the AV sync message and it always states the mkv rip has "completed successfully". The mkvs seem to play perfectly but seeing that AV sync message every time a rip has completed is a little unnerving. Is this message just a meaningless glitch with latest versions of makemkv or are the resulting rips actually affected in some way? Can someone please help out with this? Earlier versions did not produce this message.

While I am sorry to see this is impacting you, I am glad to know that this is not unique to my setup or drives. As you stated, I am seeing this for ANY type of disc I use (BR, UHD), with different drives, and when ripping from a folder back-up or straight from the disc. The message is shown 100% of the time.

Hoping this gains a little traction and we can get some insight on what is going on. If it's nothing, I would just like to know it can be ignored. I've begun to hold off on backing up my backlog of movies, as I don't want to discover I need to re-rip after the next version release. Happy to help test or provide more information if needed.

[skipc]

I first noticed this with v1.14.6. After some investigation and comparison of mkv rips of the same disc with both 1.14.5 and 1.14.7, I've determined that .7 is inserted an single "AV synchronization" warning for every MKV saved out regardless of whether there are any errors or not. When a stream truly does have AV sync issues, there are two of these messages: the first is the legitimate av sync issue warning and will be accompanied by details of the AV sync problems found (if av sync logging is enabled in advanced preferences); the second is the extra warning that occurs for every MKV file written.

One difference I've noticed between the double-messages which occur when there are really av sync issues is that the legitimate warning contains the full output path to the mkv file whereas the bogus warning contains only the filename with no path.

So when I see this warning without a full path and no accompanying av sync details, I ignore it.

[mike admin]

I've determined that .7 is inserted an single "AV synchronization" warning for every MKV saved out regardless of whether there are any errors or not.

This is a naming issue. The 1.14.7 inserts this before printing "the subtitle track XXX turned to be empty and was removed", so you know what file this message is about. Now it is obviously confusing...

[jayper]

This is great news!

Thank you skipc for weighing in and sharing that information and thank you to Mike for adding that clarification. Good to know there's no material impact to the resulting file.

[Baby_Groot]

Excellent news! Very glad to hear the AV sync message is of no concern.

Thanks everyone.

[caseyn]

Is there anything to be done if I'm getting errors with av sync details? I had been getting the error with no details but last night I got av sync error details for the 1st time with John Wick 3.

AV synchronization issues were found in file '//vault/Movies/John Wick Chapter 3 - Parabellum (2019)/John Wick 3- Parabellum_t197.mkv' (title #198)
AV sync issue in stream 1 at 0:23:51.179 with duration of 0.375ms : encountered overlapping frame, audio skew is +1.083ms
AV sync issue in stream 1 at 0:23:51.180 with duration of 0.833ms : 1 frame(s) dropped to reduce audio skew to +0.25ms
AV sync issue in stream 1 at 0:24:13.035 with duration of 0.833ms : 1 frame(s) dropped to reduce audio skew to +0.083ms
AV sync issue in stream 1 at 0:44:35.131 with duration of 0.833ms : 1 frame(s) dropped to reduce audio skew to +0.041ms
AV sync issue in stream 1 at 1:02:27.660 with duration of 0.625ms : encountered overlapping frame, audio skew is +1.083ms
AV sync issue in stream 1 at 1:02:27.661 with duration of 0.833ms : 1 frame(s) dropped to reduce audio skew to +0.25ms
AV sync issue in stream 1 at 1:04:25.404 with duration of 0.833ms : 1 frame(s) dropped to reduce audio skew to +0.125ms
AV sync issue in stream 1 at 1:23:27.461 with duration of 0.833ms : 1 frame(s) dropped to reduce audio skew to +0.041ms
AV synchronization issues were found in file 'John Wick 3- Parabellum_t197.mkv' (title #198)

Looking at the durations it's probably not noticeable, but just wondering if there is a way to get a copy without sync issues.