necesary math to translate sfplay time into quicktime time

Sep 28, 2008 at 7:29pm

necesary math to translate sfplay time into quicktime time

sorry i couldn

Sep 29, 2008 at 2:13am

Hi autogusto,

First get the timescale of the movie you’re working with (gettimescale message). Say your movie has a QT timescale of 600. That means that 600 QT time values == 1000 msecs. So 1200 QT time values would be 2 seconds, 1800 QT values would be 3 seconds, etc.


Sep 29, 2008 at 5:57am

here’s relevant parts from a patch that syncs to groove~ object. the update interval of the number~ object sets your framerate.

– Pasted Max Patch, click to expand. –
Sep 30, 2008 at 4:21am

thank you guys for the reply

i have seen this patches using groove although i’m stuck in the interval=framerate relation i can’t really see how it works
although i need to use sfplay because the files are too large to be loaded into ram, and since i’m stuck i haven’t come with a reliable way to control quicktime frames or time through sfplay

any help will be appreciated


Sep 30, 2008 at 8:00am

Sep 30, 2008 at 3:59pm

sfplay~ has an optional position signal output.
enable that output and use that in place of the groove~ output.

sfplay’s is millisec position, so you have to divide by 1000.0 and multiply by the timescale (usually 600), to get get the proper quicktime “time” (not “frame”) attribute value based on millisecond time.

Oct 1, 2008 at 7:54am


dekam has posted a nice patch in this thread:

hope that helps,


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