Jitter Sampler

Florent Ghys's icon

Hello,

I am working on a video sampler in Jitter and I am not sure whether I am doing something wrong or what I want to do is too demanding for my computer, which is a brand new MacBook Pro Intel Core i7 2.3GHz with 8Go DDR3.

The idea is to be able to play several short non-looped videos (here 6) with great accuracy from the computer's keyboard, a midi controller, or a live.step
I decided to separate the audio from the video since I am not convinced about the ability of spigot~ to read from the hard drive with a great accuracy. So, inside a ploy~ object I have a jit.qt.movie and a sfplay~ running at the same time. Each instance is muted when not used.
Outside of poly~ in the main patcher, there is a single output for the audio, 6 jit.pwindow to display each of the instances and a simple patcher to route keyboard keys to videos.
When I play more than four videos at the same time the videos totally go wild. They are not fluid at all, slow down, it is ugly and sad.
I tried to uncheck overdrive in the DSP Status, I tried the message [loadram 1] to the jit.qt.movie.
I tried to use a playbar instead of a qmetro. I tried to used metro instead of qmetro and I tried them with different rates. I tried with lighter videos.
I tried without a poly~, in bpatchers...

I really need a hand here!!
Thanks a lot,

Max Patch
Copy patch and select New From Clipboard in Max.

polytestvideo :

Max Patch
Copy patch and select New From Clipboard in Max.

Main Patcher :

dream's icon

In the main patcher, you have a typo in the "target 0, loadram $1" message box. That will mean your computer is trying to read off the HDD, which will bottleneck your system.

I haven't tested this fix, but it should improve matters dramatically. The behaviour you are reporting seems consistent with that problem.

Florent Ghys's icon

Oh thanks, but even when correcting it and trying loadram 0 or 1 it doesn't solve my problem...
Thanks anyway

Florent Ghys's icon

So would it mean Jitter // my computer can't handle 6 jit.pwindow and 6 jit.qt.movie at the same time ?

Any idea ?

Should I go for another software like vvvv or modul8 ?
or should I wait 10 years ?

Rob Ramirez's icon

search the forum for "jitter optimizations" or something similar.

the following article should come up, which is still relevant even after 5 years:
http://abstrakt.vade.info/?p=147

the following tutorial goes even further in explaining optimized video playback systems:
https://cycling74.com/tutorials/the-video-processing-system-part-1/

this video will be of interest as well:
https://cycling74.com/tutorials/work-your-framerates/

Florent Ghys's icon

Thanks a lot Robert, I am looking at these right now.

Florent Ghys's icon

Robert, I love you!!
These links are very helpful.
Actually a simple qlim after my multiple metro objects, as well as unchecking the onscreen option of the jit.pwindow did the job. I am very happy.
Hope this could help other Jitter newbies like me.