Mixing 50i and 60i on Blu-ray?

NickHope wrote on 3/16/2008, 12:11 AM
My stock archive is all SD PAL DV or 1080-50i HDV. Most of my customers so far are from PAL markets.

But I'm about to do a stint in a place where most of the customers are from the US, so I'm thinking of shooting 1080-60i HDV. I'll be making them widescreen SD NTSC DVDs, at least to start with.

In the future when I want to do further projects with this footage, will it be possible to mix my 1080-50i footage with my 1080-60i footage on the same Blu-ray disc? How would this work? Separate files for each on the same disc? Could such separate files run seamlessly together (for example bull sharks in 50i followed by tiger sharks in 60i)?

Or is this like a SD DVD whereby the player reads it as either PAL or NTSC and that's that?

Comments

NickHope wrote on 4/8/2008, 5:22 AM
Apologies for the bump.

Before I go hunting for a Blu-Ray forum, anyone know if I can mix 50i and 60i on the same Blu-Ray disc?
farss wrote on 4/8/2008, 6:33 AM
I know zilch about BD however in theory I believe you can't mix PAL and NTSC on the one SD DVD but some time ago others here reported it does work. I suspect there's some truth in that as our DVD player outputs it's menus in NTSC.

However why would you want to mix them, why no convert all footage to say 50i and put it on one disk and then convert it all to 60i and put it on a different disk. That WILL work, 100% for sure.

Bob.
NickHope wrote on 4/8/2008, 6:44 AM
Well I could do that Bob but I'm trying to avoid the quality loss entailed in resampling the frame rate. I suppose 60i > 50i wouldn't be as bad as 50i > 60i, and at least it's the same number of lines so neither would be as bad as a PAL/NTSC standard definition conversion.
farss wrote on 4/8/2008, 6:53 AM
Could you stand the speed variation?
By that I mean speed up/down without resampling. Audio would be a problem, pitch shifting 20% could produce nasties.
Have you tried doing a conversion in Vegas, like you said with no scaling it could come out very well. Almost all stock libraries are 30p and they look very good resampled to 25p or 50i just in Vegas.

Bob.
NickHope wrote on 4/8/2008, 7:23 AM
Most of my stuff is underwater and I ditch the audio anyway so that's not a problem. A lot of underwater stuff could most certainly be slowed down from 60i to 50i. Slow mo is very common for underwater productions and a 17% slowdown is not much. Also stuff with little movement could go probably go from 50i to 60i.

But it would be nice if the Blu-Ray players just smoothly handle changes in framerate.

On thing I have always wondered. Are HDV 50i and 60i the same bitrate? In other words are there more bytes per frame in 50i? Or do you get a 20% higher video bitrate for 60i?