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Announcing jit.BC.QTKit , OSX-only QTKit-based replacement

Oct 18 2011 | 5:56 am

jit.BC.QTKit is designed to render videos as smoothly as possible, as it renders from QTKit and copies it to an internal using FBO copy. It sends out bangs (like a metro) when new frames are available, which you could use to trigger a (this isn’t always appropriate, but sometimes it helps!) It also sends bangs when a video ends, and several notifications on a successful video load.

This is a beta version, completed in just a few days, so I’d love to hear about your issues/suggestions/etc.
Infact, nobody besides me and my computer has tested this, so it may be 100% broken for you! Feedback would be great.
Special thanks to Anton Marini, Rob Ramirez, James George for helping make this possible!

to try it out, visit:
click downloads, click ‘download as zip’
The src is in development and may have stray comments that don’t make any sense/debug code/etc, but feel free to poke around.

copy jit.BC.QTKit.mxo to somewhere that Max will find it, and launch jit.BC.QTKit.maxhelp
email me at for suggestions/issues/fixes/etc

TODO: Find a way to tell a to use the texture ID of a CVOpenGLTextureRef so i don’t have to do an FBO copy to the, if anyone has suggestions on how to do this

Oct 18 2011 | 6:56 am

Very exciting! Haven’t tried it out yet, but it sounds like a great option for OSX Jitter users.

Oct 18 2011 | 7:09 am

Yes! Thanks for sharing, Brian!

Nice to see you at the expo…

Btw, making the copy from FBO should be fine. We don’t have a way to simply build a texture from an existing texture ID, and neither does QT have the ability to render to an externally created texture ID. I don’t think the gpu copy will be much of an issue however.


Oct 18 2011 | 9:31 am

Hello Brian,

Thank you very much for this.
Since years we can not manage projects with max, where we have to play
HD videos at its normal rate without stuttering.

One thing, which attract my attention at the jit.BC.QTKit external is,
that it does not loop smooth.
I think i would be great to add a loop attribute.


Oct 18 2011 | 9:55 am

Great work!!
But I do have an issue with speed, if I change the speed it reverts back to normal speed when the clip starts over.


Oct 18 2011 | 12:42 pm

Lee: I had removed loop mode because QTKit wasn’t triggering videoEnded notifications reliably if I had loop mode internally set to LOOP, something I needed for a particular installation. I will add it in later today.

Mattias: That is also something I added for a particular installation, but can make it more general purpose and remove that ‘feature’

JKC: good to meet you too! good to know about the FBO thing.

Thanks for the feedback!

Oct 18 2011 | 1:48 pm

Lee/Mattias: fixed those two issues, i think. try the latest commit and see the updated .maxhelp, and let me know if you have any more issues.

Oct 18 2011 | 3:36 pm

Thanks for this Brian, looks great!

Oct 22 2011 | 6:04 am

fixed a bug that was preventing multiple instances from loading simultaneously properly. was using a static global for something that should’ve been an instance variable. oops.

Nov 03 2011 | 5:19 pm

I committed a new version today that has UYVY matrix output with simultaneous texture output- It is slightly less efficient than just outputting a texture alone, but sometimes you want a pixel buffer too. In the future I will make the texture/jitter matrix/both as a selectable attribute.

I fixed some major bugs with regards to texture output (needed to be automatic 0 on the internal texture so that I wasn’t trying to bind a texture faster than it was writing to it), and feel pretty good about this version’s playback performance. Infact, I will be using it for a live performance in a week from now- the real test!

1) Rename some of the methods to be more in-line with
2) Fix the getters/setters to be more ‘Max-like’
3) colormode as an attribute
4) Texture/Pixels/Both as attribute

Nov 04 2011 | 11:56 am

hello brian,

thank you for updating this great object !
it would be great, if you could add a smooth loop function to the TODO list.

it here is a smal hickup if you play the movie in a loop.


Nov 04 2011 | 2:50 pm

lee: i fixed that 2 weeks ago right after you mentioned it, i think? try downloading the new version and setting "loopstate 1"

Nov 04 2011 | 3:31 pm

hello brian,

i have downloaded he last version.
there is still a hickup with "loopstate 1" , if the movie jumps from the end to
the begining.

you can check this easy, if you play the movie with the standard object. it stutters while playing, but the loop is smooth …


Nov 04 2011 | 4:08 pm

i don’t experience this. with loopstate 1, videoEnded presumably never gets triggered, and it is just looping internally using QTKit’s looping attribute.

‘loopstate 1’ basically sets this: [_movie setAttribute:[NSNumber numberWithBool:loops]
and the movie just does its thing and loops without involvement from Max, so if there is any stuttering, I imagine it would be QTKit vs. GWorld based.

If you could create an example patch to compare the two objects it’d be much appreciated!
What kind of system are you on? i did notice when i was using an external audio interface that used CoreAudio I had issues with QTKit.

Nov 07 2011 | 1:50 pm

hello brian,

here is a smal example, which demonstrate the problem.
the red video stutter, if the bar inside the movie is in the middle position.
the other movie is played with the standard object.
my system is:
MAX 5.1.9
Mac OSX 10.6.8.
Intel Core i7
2,2 GHz


Nov 07 2011 | 4:42 pm

thank you for the example, Lee- I now see what you are referring to. I am not sure of the cause of the issue- but I again suspect it relates to internal QTKit vs. GWorld differences. I’m not sure if it persists with different codecs / resolutions. I will try a few things and see if i can improve it at all.

Nov 07 2011 | 10:38 pm

Hello Brian,

sounds very exciting…but I can’t get it to work:

I get this error in both Max5 and Max6 (MBpro OSX 10.5.8) when loading the external:

jit.BC.QTKit: unable to load object bundle executable
2011-11-07 23:30:05.723 MaxMSP[1749:20b] Error loading /Applications/Max5/Cycling '74/jitter-externals/jit.BC.QTKit.mxo/Contents/MacOS/jit.BC.QTKit: dlopen(/Applications/Max5/Cycling '74/jitter-externals/jit.BC.QTKit.mxo/Contents/MacOS/jit.BC.QTKit, 262)
: no suitable image found. Did find:
/Applications/Max5/Cycling '74/jitter-externals/jit.BC.QTKit.mxo/Contents/MacOS/jit.BC.QTKit: unknown required load command 0x80000022

Says something to anybody?


Nov 07 2011 | 11:10 pm

Vincent: it probably has some OSX 10.6-required dependencies.

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