[PD] need a workaround for detecting movement in Mac OS

Matteo Sisti Sette matteosistisette at gmail.com
Tue Apr 5 18:09:43 CEST 2011


Thank you a lot guys!

Thanks to your suggestions, this seems to be the solution (see attached 
patch). I have to try it on Mac though, to see if it really fixes the 
issue (hard to predict since the issue itself is pretty strange), but I 
expect it to.

I didn't expect the spigoting-the-gemhead-trick to work: I thought that 
having pix_movement receive the gemlist only some of the times a frame 
was rendered would cause strange interactions.

The pix_texture-right-inlet-trick even allows me to monitor the movement 
signal which is great.



On 04/05/2011 05:03 PM, cyrille henry wrote:
> depending on the aplication, it can help to separate the tracking and
> the rendering on 2 diferents process (2 diferent pd).
> (most computer have multiple processor now)
>
> to slow a gemhead, you can stop it (sending it 0) and then send it bangs
> with a metronome.
> if you don't use it for rendering it should work...
>
> c
>
>
> Le 05/04/2011 16:47, Matteo Sisti Sette a écrit :
>> On 04/05/2011 04:33 PM, chris clepper wrote:
>>> I used pix_movement and blob for basic motion detection for years. I
>>> gated the video signal so it would only output every half second or
>>> second
>>
>> How do you gate the video signal? That may be exactly the workaround I
>> need
>>
>>
>>> Try setting the GEM framerate to the
>>> advertised frame rate of your device and see if that helps.
>>
>> Yes it does help, it fixes the problem completely. But that is not an
>> option if i need to produce graphical output at a higher framerate.
>> It's ok to detect the movement at a rate equal to or lower than the
>> camera frame rate, but i can't lower the whole gem framerate because
>> that will affect video output.
>>
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>

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