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  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

QT proxies -- why not use Rocket and RMD?

Chris Kenny

Chris Kenny

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I'm obviously not aware of all the technical constraints, but given that it's Red's code that decompresses/debayers frames to hand off to QuickTime, it seems like it should be possible to enable Rocket acceleration for QT proxies, and therefore effectively get Rocket performance in any app working with them. That could potentially be a big deal.

Also, is there any fundamental technical reason why Red's QT component couldn't take RMD look files into account when decoding clips?

Right now, QT proxies are nearly useless to us; the addition of these two features would make them extremely useful.
 
A QT codec doesn't know what file the frames are coming from so the codec can't find the RMD. Rocket needs multiple frames an Quicktime can't do this either.
 
Deanan said:
A QT codec doesn't know what file the frames are coming from so the codec can't find the RMD. Rocket needs multiple frames an Quicktime can't do this either.
Click to expand...

Interesting

Does this have an implication on Rocket in Color?
 
Deanan said:
A QT codec doesn't know what file the frames are coming from so the codec can't find the RMD. Rocket needs multiple frames an Quicktime can't do this either.
Click to expand...

Are those the only technical limitations?
 
Gunleik Groven said:
You start to intrigue me seriously, in a good way! -:)

Are you implying that you have an ide on how to get around those limitations?
Click to expand...

QuickTime supports "frame reordering" for codecs that require multiple frames (independent decode/display times) to output a single frame. For example, H.264. In principle, if RED Rocket needs multiple frames, QuickTime 7 and later can accommodate this.

I'm not sure why RED Rocket needs to know the filename -- perhaps to get the additional frames? Maybe to get the RMD file? If I knew why, I could propose a solution.

UPDATE: Here's the link to the relevant API in QuickTime (for QT Sample Table atoms): http://developer.apple.com/mac/library/documentation/QuickTime/QTFF/QTFFChap2/qtff2.html#//apple_ref/doc/uid/TP40000939-CH204-33307
 
If I should pick a totally uneducated guess on why the Rocket needs multiple frames, it would be that it is set to buffer a minimum number of frames before playback is allowed, to accomodate smooth playback.

But this is a total wild goose chase from a non-programmer in the most true sense of the word, based basically on how the rocket plays back...
 
Is there an API for using RED Rocket? How are Adobe, Avid and others accessing RED Rocket now?
 
Deanan said:
A QT codec doesn't know what file the frames are coming from so the codec can't find the RMD. Rocket needs multiple frames an Quicktime can't do this either.
Click to expand...

Okay, I see what you're wanting here (didn't read closely enough the first time).

You could use the QT Sample Tables API to associate an "RMD" sample with each RedCode frame. (You only need one sample for all frames.)

It might even be able to make the RMD file external, in which case it might be possible to update it without modifying the QT proxy itself.

CineForm has a little helper app so you can change the metadata for the actively playing clip called SetActiveMetadata. You can read more about CineForm's ActiveMetadata stuff here: http://estore.cineform.com/products/TechNotes/ActiveMetadata.htm

UPDATE: video about ActiveMetadata here http://www.youtube.com/watch?v=LYw4S2YBvvI
 
Hmm. I'll fill out another one and send it in. Thanks for checking!
 
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