I am creating a playback engine to sync video display across 10 projectors using Jitter and networked mac minis. The work is going well (it syncs!) but I am seeing occassional judder in quicktime.

The judder is non-regular. Sometimes it goes away for 10 seconds, and then judders 2-3 times, while other times the judder happens randomly about every 3-4 seconds. No repeatability.

I am using vade's patches (thanks vade!) discussed here:

https://cycling74.com/forums/index.php?t=msg&goto=122482&rid=0&S=55830045e2d6458e089d3a6b88064409

In my case I am using the "direct" mode where Jitter hands playback duties directly to QuickTime. To that end this is really a quicktime/performance issue rather than a jitter issue. I see the same judder in quicktime player.

I am playing back XGA (1024x768) movies of motion graphics.

Test systems are a MBP 2.4, Mac Mini 1.83, Fast PC with GF9600 vid card. Leopard and Win XP. Quicktime 7.5 Same issue on all three systems.

I Have tried Jitter 1.63 and Max 5 runtime, as well as QuickTime player. No major differences.

Animation 75-100% (LOTS of judder, obviously)

... keyframing and hinting don't make a difference

I don't understand how all of these fast machines will judder on movies with low (1900 kb/s) data rates.

You can download the sameple movie I am testing with here:

http://electroland.net/transfer/Public/jitter/1.mov

My patch is included below, but again this is more about QT than Jitter.

I am creating a playback engine to sync video display across 10 projectors using Jitter and networked mac minis.  The work is going well (it syncs!) but I am seeing occassional judder in quicktime.  

The judder is non-regular.  Sometimes it goes away for 10 seconds, and then judders 2-3 times, while other times the judder happens randomly about every 3-4 seconds.  No repeatability.

I am using vade's patches (thanks vade!) discussed here:
https://cycling74.com/forums/index.php?t=msg&goto=122482&rid=0&S=55830045e2d6458e089d3a6b88064409

In my case I am using the "direct" mode where Jitter hands playback duties directly to QuickTime.  To that end this is really a quicktime/performance issue rather than a jitter issue.  I see the same judder in quicktime player.

Test systems are a MBP 2.4, Mac Mini 1.83, Fast PC with GF9600 vid card. Leopard and Win XP.  Quicktime 7.5  Same issue on all three systems.

I Have tried Jitter 1.63 and Max 5 runtime, as well as QuickTime player.  No major differences.

Codecs tested:
  Sorenson 3, 75-100%
  h.264 70-100%
  MPEG4 70-100%
  Photo JPEG 75-100% (more judder)
  Animation 75-100% (LOTS of judder, obviously)
  ... keyframing and hinting don't make a difference

You can download the sameple movie I am testing with here:
http://electroland.net/transfer/Public/jitter/1.mov

quicktime-judder-explorations

For myself, I got the best results using Apple Intermediate Codec, but I have no idea how this codec works in the PC world... I think it worth a try.

About the patch, I would consider trying the jit.gl objects and also a qmetro instead of a metro (see example below), just to see if it makes a difference. It kinda improved the fluidity of the playback when I tried it with your movie on my machine (MacBook Pro 2.16, Core Duo, 2 gigs of ram).

For myself, I got the best results using Apple Intermediate Codec, but I have no idea how this codec works in the PC world... I think it worth a try.
About the patch, I would consider trying the jit.gl objects and also a qmetro instead of a metro (see example below), just to see if it makes a difference. It kinda improved the fluidity of the playback when I tried it with your movie on my machine (MacBook Pro 2.16, Core Duo, 2 gigs of ram).
Good luck,

Thanks for these insights. I tried the method you recommended but I am seeing the same small judders on my test machines. I believe that passing the video directly to QuickTime *should* give me the best performance but so far that's not the case.

I gave Apple Intermediate a try but I think the data rate is giving my machine problems.

Thanks for these insights.  I tried the method you recommended but I am seeing the same small judders on my test machines.  I believe that passing the video directly to QuickTime *should* give me the best performance but so far that's not the case.

QuickTime Judder Explorations