Talking about the "evaluation scheme of QC": Thats where often the miracle is generated! QC is starting to evaluate the render pipeline from output to input. It starts at the rendering patches (like Billboard, Sprite), looking backwards what input values are needed, where do they come from and did they change since last render cycle? This recursion goes on until it eventually reaches the Movie Importer patch giving it some CPU time to do its QuickTime stuff. But if QC don't need the image output (because of some Multiplexer patches, Sample and Hold patches, or other patches that break the image path) the Movie Importer patch don't get called at all, thus can't load more movie data, struggling when used out of a sudden again, and so on. Sometimes I work around this "performance optimization" with a small Billboard-patch rendering offscreen which is directly connected to the image output of the Movie Importer patch to keep the Movie Importer patch alive.
best, Achim Breidenbach Boinx Software Ltd. On 24.06.2013, at 19:51, George Toledo wrote: > Maybe take a browse again through all of the docs at the adc, and also the > plugin programming guide. If you keep in mind the evaluation scheme of QC, > and then think about the cocoa/OpenGL/whatever code that's being executed > inside of the patches, it can become more intuitive. > > On Jun 24, 2013, at 1:34 PM, Michael Diehr <m...@xochi.com> wrote: > >>> On Jun 23, 2013, at 5:24 PM, George Toledo <gtole...@gmail.com> wrote: >>> >>> There's really no black art to it, and it's predictable and does what it >>> does for reasonable reasons. Read up on patch types and execution modes at >>> the adc. >> >> My experiences over the past 5 years working with high-performance movie >> playback in QC has been anything but predictable - I've found lots of weird >> bugs, glitches and undocumented features that often leave me confused. >> >> Don't get me wrong, QC is an amazing product and the price can't be beat, >> but I often find myself having to resort to rather esoteric explanations >> when trying to explain *why* QC behaves the way it doe to my non-programmer >> colleague who is making QC compositions. The fact that she can do this at >> all even though she's not a programmer is rather nice :-) >> >> >>> You may want to note if the output port of the movie player is still >>> showing a moving image after sample and hold is set to false. I tend to >>> think it will. You're probably going to want to make sure you bypass that >>> part of the chain by multiplexing or shoving a blank file path in. >> >> That's not what we are seeing : in our tests, it seems as if a movie player >> patch is smart enough to not keep updating as long as you aren't using the >> Image downstream, but I'll keep that trick in mind of setting the path to "" >> if needed. >> >> Other than this mailing list, is there a central FAQ or Wiki where these >> hits & tips are collected? >> >> >> _______________________________________________ Do not post admin requests to the list. They will be ignored. Quartzcomposer-dev mailing list (Quartzcomposer-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/quartzcomposer-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
