Sound delay when exporting H264

[Hermelinde]

Hi!

I must admit that this is probably not the canonical use of this great suite, but I have been sometimes using DoM to burn in subtitles and export stereo H264 from various video or DCP sources for outdoor screenings (billingual subtitles are mandatory, but rarely provided by distributors for video screenings, especially for not-that-recents films...). Like I said, not canonical and a little bit shameful but still soooo much quicker and more convenient than an editing software ! Lazy me loves <3

With this last update (2.16.16), the stereo mix button is greyed when selecting H264 exports, any reasons why ?

But my real issue here is that I have a +/- 2 seconds sound delay when I export from an mkv source. This is a mkv with two 5.1 audio versions. I selected the original version's channels. I tried to export to stereo and to 5.1 but same problem. I tried exporting with the sound delay changed on the audio menu, but it did not fixed it.
(No sound delay on the original mkv file, of course... and never encountered the issue before this last update...)

Any ideas ?

Thanks !

[Carsten]

2 seconds is fundamental. When you just create a new project and add the same content (to make sure no previous settings stick unnoticed) - and now just play it back in preview - do you hear the same delay?

[carl]

The stereo mix button is a bug - thanks for pointing it out! It should be fixed in the next release (2.16.17).

[Hermelinde]

Hi ! Thanks for the replies !

@Carsten : Yes, I created new projects to make sure (3 times), previews seemed perfectly synced everytime ! But the final export were still delayed. I am currently trying to export from an older version of DoM (2.16.10), I will keep you posted once it is finished.

@Carl : Great, thanks !

[Hermelinde]

Update : Still out of sync with a new project created on the older version

I guess there is something I have not tried yet : to do it all over again, but not from an external drive. Do you think this could be the issue ?

And if it persists, I will try to obtain a different file from the distributor.

[carl]

Is it feasible to send me one of the files?

[Carsten]

Until then:

Could you please try to create a DCP from that content? Then load it into DCP-o-matic player and check sync.

If sync is okay in DCP-o-matic player for the DCP - create a new project, load the DCP into it, and try an export.


There were issues at some time with some specific MKVs which used strange timestamps. That should have been solved, and it wouldn't explain why the source seems to be in sync in preview, but not in export. But sometimes things are just weird.

- Carsten

[IoannisSyrogiannis]

What I would suggest, is to use MKVToolNix (GUI) to export the video with only the audio you want to use.
Then, make the DCP.
I had issues in the past that I couldn't resolve otherwise with mkv files with more than one audio streams.

[Hermelinde]

Hi ! Thanks for the replies.

@Carsten I am not super comfortable with sending the video, it is a rather big studio feature. But I can maybe record a "sneak peak" ?
Anyways, I followed your advice, exported a DCP and this is pretty hilarious because there is also a 2 seconds delay, but the other way around : the sound is 2 secs early !

@Ioannis : thank you for the advice ! I will try that.

[Hermelinde]

Hi again !

@Ioannis thank you so much, fixed it ! Very cool app, this MkvTool thingy !