QT movie suddenly becomes jittery in logic pro! Is this a bug? Please Help

Question

OK, this is very odd behavior, I must have changed some song setting here.
My Quick time movie jumps frames and doesn't play smoothly on one song but if i open it in another session it plays fine.
I first thought it was a CPU or hardrive problem but after removing all the audio and plugins from the problematic session the QT movie still behaves in the same odd way.
What did I change that its behaving this way?
Thanks,
Shil

Answer 1

Julian Scott wrote:
I have had repeated problems with Quicktimes in Logic. A common occurance is opening a movie to work with and to start with it works fine. Then after say an hour of working the frames start jumping and soon the movie is only playing 2 or 3 frames per second (rather than 25). Rebooting the computer is the only solution. The problem occurs with all sorts of movie data rates, codecs and sizes.
It has become such a problem that I've had to resort by running the video from a second computer using midi to synchronise.
Julian
I have had repeated problems with Quicktimes in Logic. A common occurance is opening a movie to work with and to start with it works fine. Then after say an hour of working the frames start jumping and soon the movie is only playing 2 or 3 frames per second (rather than 25). Rebooting the computer is the only solution. The problem occurs with all sorts of movie data rates, codecs and sizes.
i am pretty sure i know what this problem is....it is a RAM issue. what is happening is that as you run out of RAM, the OS 'pages out' memory to the virtual memory on your system drive. if your drive is full or a lot of memory is being used as virtual memory. this is why you are getting good performance at first, it starts falling over as your system drive is being driven hard, and rebooting helps refreshing the process.
the solution would be to:
• ensure you have plenty of RAM
• ensure that you have at least (as bare minimum) over 30% of your system drive free (actually the minimum should be around 50%)
• you have virtual memory switched on for samples inside logic
• you only run logic if it is using a lot of memory for stuff.
• reduce your track count if you don't need it.
• reduce your undo history in logic. it absolutely chews up RAM.