Cutting the Drama Out of Blu-ray Production
Up until the last project I've stuck to 24p encodes, I matched the SRT times to the original Prores times and everything went smoothly and stayed in sync.
This time the customer wanted a 23.976p encode so I matched the SRT file to the ProRes both running at 23.976 and multiplexed it and fine at the start but drifts more and more as you progressed into the feature......
I re-timed the SRT file with a 23.98 timebase to the 23.976 Prores times and imported then multiplex......better but still too early near the end.
Out of desperation I changed the time-code setting in the DOST text file to 24000 and low and behold it was the closest I could get it...but not frame accurate like a 24p - 24p project or even a 29.97-29.97 project.
This can not be right.... and why isn't there a 23.976 setting on the time-code tab as 23.98 is not short hand for 23.976.
Depending on the subtitling software you're using, it is perfectly normal and necessary to set the DOSt file to 24000.
That's the way to do it and it'll sync as it should. If you want the long explanation why that is - here is a good read.
Except I am having the exact same problem - ever since upgrading to Version 3
We do mainly subtitled films - and in the past with 23.98 assets I change the head of the Dost file from 23976 to 24000 and it fits... but not this time
I have tried every variation - Film set to 23.98 and DOST at 23976
Film at 23.98 and DOST at 24000
Film at 24.00 and DOST at 24000
Film at 24.00 and DOST at 23976
And nothing work...
So I feel your pain Matt. Not sure what to suggest. If I come up with a solution I will let you know.
Always worked in 2.6 (with the tweak to the head of the file)
We've done several dozens of 23.98 discs since version 3.0, also on different workstations, and never had an issue when setting the dost to 24000.
So there has to be an issue with either your subtitle stream or the source. Without knowing where each of these assets is coming from it is difficult to suggest a remedy.
Yes, if your source is 23.986, encode as such, set the Do property for the asset to the same value. Prep the subtitles in 23.976, export as such and then simply set the header to 24000.
Thanks for all the replies, I'm glad it wasn't just me.
When I have a spare moment to play I'm going to create a 90min video file (23.976) with BITC then a SRT file with a title every 30 seconds and see which combination of settings gives you the least amount of drift.
1) 23.976 video stream SRT prepped to 23.976 DOST header to 24000
2) 23.976 video stream SRT prepped to 23.98 DOST header to 24000
It might be a week or two before I get time to try it.
23.976 and 23.98 are the same thing. Some applications just use a different short hand. There are no two different standards there.
So, whatever you subtitling application gives you there, use it. Don't modify it by hand because if you do this will screw things up.