performance of a simple patch


    Dec 11 2006 | 10:23 pm
    Hello,
    I've got a quite simple Jitter patch which has some performance issues.
    It has a jit.qt.movie object connected directly to a jit.window. It is a "VJ style" patch which just has to trigger some Quicktime clips and display them on an external screen.
    The source material are 25 fps 720 x 576 Apple Animation clips using thousands of colours. This format gives us better performance than PhotoJPEG coded files.
    The computer is not too fast: an iBook G4 876 Mhz 768 MB ram running a MacOS 10.4 and the latest MaxMSP and Jitter. Content is run from an external firewire disc, probably a 5400 rpm model.
    The external display is a TV, run in 720 x 756 PAL display mode.
    This setup has trouble keeping a more or less steady 24/25 fps frame rate. It has notable, seemingly random dips in performace.
    Of course the system spec is not too great but one single stream of video shouldn't be that taxing?
    I'm looking for some ways to improve performance or the confirmation that the current performance is normal for this setup. An example is included underneath, displaying on the main display instead of a 2nd screen.
    Regards, Jorg

    • Dec 11 2006 | 10:32 pm
      How does this perform on your system? Have you tried using loadram and preroll on jit.qt.movie?
      wes
    • Dec 11 2006 | 10:44 pm
      Thanks for your reply.
      I'm not on the G4 system at the moment (will have acces again on wednesday) but on a 3.2 Ghz Athlon WinXP system this patch gives around 7 fps with a file which gives 24-25 fps with the patch I posted.
      Will look into loadram and preroll, I have not been using these.
      regards, Jorg
    • Dec 11 2006 | 11:00 pm
    • Dec 12 2006 | 1:00 am
      On 12/11/06, Jorg wrote: > > Thanks for your reply. > > I'm not on the G4 system at the moment (will have acces again on wednesday) but on a 3.2 Ghz Athlon WinXP system this patch gives around 7 fps with a file which gives 24-25 fps with the patch I posted. >
      That's pretty ridiculous and doesn't sound right to me at all. I was able to do 720x480 on my powerbook 1.6G and got 33fps no problem. Do you have demons in your computer?
      wes
    • Dec 13 2006 | 12:08 am
      Quote: wesley.hoke@gmail.com wrote on Tue, 12 December 2006 02:00
      > That's pretty ridiculous and doesn't sound right to me at all. I was > able to do 720x480 on my powerbook 1.6G and got 33fps no problem. Do > you have demons in your computer?
      It runs on Windows XP but there are no other specific demons that I'm aware of.
      However, I just ran your modified patch again and noticed that the Max window gives a huge load of openGL errors (texture wrap mode, texture mode, compare mode, all giving invalid enumerations). So that explains it probably. (The original patch doesn't use any OpenGL functionality). I will give your patch a try on the G4 tomorrow.
      regards, Jorg
    • Dec 15 2006 | 10:51 am
      Had some time on the G4 again and the "window" message instead of a patch cord gave a big boost in performance. It gives 24-25 fps now with hardly any dips below that and no big dips at all.
      Did not get around to testing the OpenGL method yet, but will do.
      regards, Jorg