Video Out of Sync (mov at 29.46 fps)

Anything and everything to do with DCP-o-matic.
Post Reply
slavadog
Posts: 4
Joined: Tue Oct 19, 2021 10:19 pm

Video Out of Sync (mov at 29.46 fps)

Post by slavadog »

I have a video that I need to play at our theater this weekend. The video (from movie inspector on my Mac) is at 29.46 fps, in .mov format. I am trying to convert it to DCP at 30 fps. When I do, obviously, the audio and video are out of sync. Is there a setting I can use in DCP-o-matic to get these to sync up?

Thanks!!
carl
Site Admin
Posts: 2338
Joined: Thu Nov 14, 2013 2:53 pm

Re: Video Out of Sync (mov at 29.46 fps)

Post by carl »

It should just work without you doing anything special. If you can post the metadata.xml file from inside the project folder (or email to carl@dcpomatic.com) we can take a look.
Carsten
Posts: 2648
Joined: Tue Apr 15, 2014 9:11 pm
Location: Germany

Re: Video Out of Sync (mov at 29.46 fps)

Post by Carsten »

Many DCI projection systems are able to play 30fps, but not all. The sync issue is automatically solved by DCP-o-matic, as Carl already wrote.
slavadog
Posts: 4
Joined: Tue Oct 19, 2021 10:19 pm

Re: Video Out of Sync (mov at 29.46 fps)

Post by slavadog »

Thanks! I'm seeing it as out of sync when I play the DCP within the DCP-o-matic UI. Haven't tried it on the projector yet, as I figured if it was out of sync here, it would be out of sync there.
slavadog
Posts: 4
Joined: Tue Oct 19, 2021 10:19 pm

Re: Video Out of Sync (mov at 29.46 fps)

Post by slavadog »

Carl - just sent an email with the xml file to you.
Carsten
Posts: 2648
Joined: Tue Apr 15, 2014 9:11 pm
Location: Germany

Re: Video Out of Sync (mov at 29.46 fps)

Post by Carsten »

When you open Timeline view, you should easily see wether video and audio have the same length. At least on a full length feature, a framerate misinterpretation between audio and video can be immediately detected there. You can't strictly judge from the playout in DCP-o-matic or DCP-o-matic player.

Typically, when your source is an interleaved video+audio file (e.g. Quicktime with audio, MKV with audio, etc.), DCP-o-matic will automatically adjust the audio sample rate to match the video frame rate shift. Only if you use separate audio files you need to adjust their frame rate reference to match that of the video.

DCP-o-matic will indicate the audio sample rate adjustment below the source properties window.


- Carsten
slavadog
Posts: 4
Joined: Tue Oct 19, 2021 10:19 pm

Re: Video Out of Sync (mov at 29.46 fps)

Post by slavadog »

Thanks for the help everyone. I went to the theater yesterday and downloaded the video on the projector and it worked perfectly. Not sure why, but when I play the video inside DCP-o-matic, it still appears to be out of sync. Looks like all is good, though. Thanks!!
Post Reply