Apple ProRes 4444 XQ Support

[Dan Outhwaite]

I have attempted to add a cue with a 4444 XQ codec file, QLab tells me it is not supported.

Is there any chance this may be supported in the near future or has it not been implemented deliberately?

Thanks

[Sam Kusnetz]

It's not deliberately blocked, but since XQ was only introduced recently
I'm going to guess that adding support for it requires some kind of
change on our end that we just haven't had a reason to make.

I'll bring it to the attention of Chris and Sean, or they may jump in
themselves. But I wanted to get you a reply as soon as possible.

I should say, even if QLab already did support XQ, I do not recommend
using it. It's got a target data rate around 500Mbit/sec which is really
very high, and I would not expect very impressive realtime performance.
ProRes 4444 is already 300 Mbit/sec.

Cheerio
Sam
--
Sam Kusnetz | Figure 53 Field Operative
s...@figure53.com

[Sean Dougall]

Since QLab 3 is built on AVFoundation (rather than QuickTime, which is on its way out the door after almost a quarter century), it can only use codecs that AVFoundation knows how to support. Since there isn't currently a way to use extensions to add support for more codecs, adding new codecs to QLab would mean mostly bypassing AVFoundation and implementing many more low-level details ourselves, so it’s not something we’d undertake lightly. Which is not to say that that’ll never happen, but if it ever does happen, it’ll most likely be to add support for something like HAP.

4444 XQ is not likely to get that treatment, for all the reasons Sam mentioned. Its major stated benefit is that it preserves detail in high dynamic range content—but few existing projectors, if any, can even come close to the dynamic range of more traditional codecs, so XQ won’t realize those gains in playback. Also, all the ProRes codecs are proprietary, and implementing them ourselves would require licensing them from Apple.

—

Sean Dougall

se...@figure53.com

[Dan Outhwaite]

Thank you both!