Performance issues and Syphon - Isadora>QLab

  • Hi video folks,

    I'm currently Syphoning a single-stage Isadora output to QLab3 to make use of QLab's geometry controls and edge-blending. After many days of solid performance my Isadora patch is now topping out around 15 fps. 
    When I kill Syphon (by stopping the capture cue in QLab or removing the global Stage-to-Syphon actor in Isadora), performance returns to a passable ~28fps.
    Removing movie files from Isadora's media bin helps a bit (everything is Photo JPEG), and turning off camera capture (2 channels of 720/60 at half res) helps a lot. But Syphoning to QLab causes the biggest drop by far.
    Anyone encounter something like this? Could there be an issue with Isadora and Syphon or is it likely I'm overlooking something else?

  • Tell me this: what is your cycle count with Syphon on, and what is it with Syphon off; you can find this number in the Status Window (Windows > Show Status.)

    Furthermore, please try the attached app (Simple Client) which comes with the Syphon SDK. Does it cause the same performance drop?
    Best Wishes,

  • Hi Mark,

    Playing one movie file in one scene, toggling the Syphon actor on/off with Simple Client open resulted in a drop from 130 cycles / 29 fps to mostly around 70 cycles, 28 fps, but covering a range from 43 up to 100 cycles. With QLab running a Syphon-input cue instead of using Simple Client, the performance drop was similar, with cycles between 70-80, and fps around 27.
    These framerates are all in the range of OK, but the real trouble seems to kick in when I am jumping between scenes. Returning to the same scene as above, for example, sometimes causes a drop to as low as 20 cycles/ 10 fps with QLab/Syphon running, which jumps to 40 / 17 fps with QLab/Syphon off. Isadora's performance does not usually recover from this until I reopen the program. Which leads me to suspect there is a separate issue here with the way my movies are being loaded. Activity Monitor shows Disk Read speads peaking in the 7.8 MB/s range, but sometimes over 11 MB/s. This particular file is 1280x512, photoJPEG, 22mb/s, 24 fps. My other media tends to be 30 fps but the same compression/resolution otherwise.
    I feel like the more I dig the wider I need to cast this troubleshooting net. Suggestions?
    Many thanks,
    IsadoraCore 1.3.1f06
    Mac Pro early 2009
    2 x 2.26 quad core
    OS X 10.8.5
    NVIDIA GeForce GT 120 512 MB
    ATI Radeon HD 5770
    32GB RAM
    SSD media and boot disks

  • Dear Keith,

    When you say "jumping between scenes" -- are you simply cutting (fade time = 0.0) or are you crossfading? When crossfading, two scenes are running thus you twice the bandwidth requirements.
    I'm not at home right now, which prevents me from testing this setup on my similarly configured Mac Pro. I'll can try to duplicate the scenario once I'm back next week. (Please bump me with PM or email to ensure I do it... I'm covering a lot of bases right now.)
    Best Wishes,

  • P.S. Do you have the Core Video upgrade? If so, try switch to the CI Movie Player and CI Projector and see if that helps.

  • Thanks, Mark.

    Yes, I have the Core Video upgrade, and the scene I mentioned above is with a CI movie player and CI projector. I had tried the same scene with non-CI actors a while ago and got similar results.
    By "jumping" I mean clicking into other scenes directly, not necessarily using Jump actors. I'm familiar with the crossfading slow-down but that's not what I'm encountering. Most scenes start black and then turn on a movie or projector, so transitions are low-impact.
    I'll ping you a reminder a little later and see if you have a few minutes free.