My office neighbours have done sound post on a feature film, and were asked to make a 23.976  5.1 audio deliverable for a commercial Blu-Ray release. We are talking European releases here.

Which brought up the question, does Blu-Ray support 23.976p but not 24.00p? And if so, how come? Would seem odd to leave that out, since most European features are produced in 24.00fps, and it would be of course much easier if one did not have to convert the 24.00fps audio to 23.976.
 

 I looked into this a little bit an it seems that Blu Ray can support both 23.976 and 24 - I have always wondered why DVD did not have a single standard on it anyway with 23.976 or 24 as the play out can be managed by the player...

There would need to be a sample rate conversion if the frame rate changes for digital output though. I will keep digging.

Michael

On the L2, someone suggested it might be because BR players still have downconverted SD outputs, and if you feed those 23.98p, you can get to 30i, and if you feed them 25p, you can get to 25i, but if you feed them 24p, you can't easily get to neither PAL nor NTSC.

 Same issues in post which is why I suggested it would need to do a sample rate conversion for the audio as playback for frame rate change is farily straightfroward for picture. Also, PAL 24 for SD is not that great with the +1 field every 12 frames is quite annpying for movements and pans.

Michael

Then again, if we keep everything backwards compatible all the time, we'll only be creating more and more confusion...