Livecamera with 1.5minutes delay over one hour

  • ....i have a splitscreen of 4 izzy-projector on one HD-Projection: 2 x livecams, 1 x 1,5 minute delayed livecam (from one of the two livecams via component - blackmagic intensity pro) and 1 x file.
    the Splitscreen has to stay round aboute 1 hour - that means the data of the delayed camera has to be buffer for one hour - i`am right? - yesterday during the rehearsel - after half an hour the delayed cam-stream went to black - i had to restart the scene...if the delay-data are stored in the ram -could i go up with the ram from 16gb to 32gb and would be able to delay 1 hour of a live stream??? - any idea how to solve the problem???

    thanx Bodo

  • Record and play back one hour chunks instead I am pretty sure Isadora is still only 32 bit so you cannot access this much ram.

  • Dear Bodo,

    Fred is right. Isadora can only access 2GB.

    Here is the formula for the amount of RAM you need if you are using the Video Delay

    horz_resolution x vert_resolution x 4 x FPS x 60 x minutes

    where 4 is four bytes per pixel, and 60 is the number of seconds in a minute.

    So, for instance, with HD video, you would need

    1920 x 1080 x 4 x 25 * 60 * 1.5 = 18.66 Gigabytes -- that's more than Isadora can do.
    If you set the mode to YUV, then the "4" becomes a "2", and it is 9.3 GB. Still too much. But for SD Video with YUV it should be possible
    640 x 480 x 2 x 25 * 60 * 1.5 = 1.38 Gigabytes.
    I hope that helps.
    Best Wishes,

  • Dear Mark and Fred,

    thanx for the informations...yesterday i went down with the resolution input settings (of the component-hdtv camera) to quarter -and it worked well! - but to get more resolution the capturing idea would be interesting but for my understanding - capturing is not possible i think - because the delayed video has to run constantly over one hour beside (on the Splitscreen) the non delayed-stream - and i think a captured video only appear in the media window (ready to play) if you press -stop capture to disk (in my case after 1,5minutes)  _ this means i have only 1,5 minutes delayed video -isn`it ???

    ciao Bodo

  • Dear Bodo,

    The only other thing I can think of is to do this:
    1) Start Recording Movie 1
    2) After X minutes, stop recording movie 1, start playing movie 1, start recording movie 2
    3) After X minutes, stop recording movie 2, start playing movie 2, start recording movie 1
    4) Repeat steps 1 and 2 over and over
    There will be a glitch though... this is for sure. But you could then go on forever.
    Best Wishes,

  • Dear Mark,

    thanx for the tip but as i had anyway -for each of the 4 Windows of the Spliscreen- anly the quater Resolution of the full HD Projektor so it was ok with the quater input resolution for the Livecamera -which was delayed - and i have to say it worked like a charm!!!

    best Bodo