DCP-o-matic

Is it better to have separate audio stems when building a DCP? I get sync issues with lips not matching but it seems to be random. Could it be beause of the audio is within my file rather than having it separate? Or, is it the quality of some of the audio on the different files? Also, what file type is the best to build with? I like to export as ProRes 4444 with my sound imbedded. Any suggestions that might help me improve my sync issues?

Thanks,

In general, you should not have sync issues, no matter wether you use interleaved or separate audio. However, it is usually safer to use video+audio interleaved, simply because 'less things can go wrong' when creating/maintaining the sync reference while exporting.

I understand that often separate audio files are recommended, but I don't think it's useful in general. Some of the larger mastering facilities want separate audio reels with 2-pop leader, but that is just a standard workflow for them. Often, these facilities use image sequences for video, and there is no file format for frame sequences + audio, so, they are booked on separate files for video and audio.


Prores + audio is okay and has no quality limitations.

As Carsten says, any sync problems (that are not present in the original file) are a bug and if it's possible to report them (with the problematic file) that's the ideal situation - then I can try to fix them.

I understand it's not always easy to provide source files, of course.

Thank you both for your input.

Carl, I am happy to share the files you would need. Can I just send you a download link? Would you be looking for the whole project folder or do you just want to look at the ProRes source file? I am happy to share with you online so you can download.

Hi, that would be amazing, just the prores source file (or even part of it, so long as it reproduces the bad sync).