[Pdmtl] [PD] Gem: firewire OSX problems

james tittle tigital at mac.com
Wed Mar 22 23:22:57 EST 2006

On Mar 22, 2006, at 6:53 PM, Alexandre Quessy wrote:
> I am using a firewire mini-DV camera with Gem on Hans' Pd-extended
> 0.39-2 on Mac OS X Tiger. This camera is usually 720x480 pixels. There
> are 2 problems I am facing right now :

...if you are just using the gem that comes in pd-extended, I suggest  
replacing it with the most recent one found on my website: http:// 

> 1) [pix_video] is having a hard time trying to connect with the  
> camera.
> I get the silent green screen. Are there options I should check  
> out ? Is
> Pd-Extended-0.38-4's Gem more stable on Tiger ?

...green screen means yuv processing; since you are trying to use  
[pix_mask], the help patch says it require RGBA, so i'd send the  
following messages to [pix_video]:
[colorspace RGBA<
[dimen 720 480<

...if this doesn't work, send [dialog< to the object, and make sure  
the correct device is selected, and that video is working there (also  
play with various scopes for fun)...

> 2) I am trying to apply a [pix_mask] to this video stream from  
> QuickTime
> loops. I always get an error telling me that there is a size mismatch.
> They are all 720x480 quicktime files of about 50 Mb max. Maybe another
> codec would work better ? Motion jpeg ? (as read on the pd-list) AVI ?
> MPEG4 ?

...[pix_mask] would require a codec with an alpha channel, also your  
footage would need an alpha channel that is somehow meaningful (ie.  
not all 1 or 0)...AVI's just a container for a movie, like .mov...

> Thanks ! (this is kind of 48 hours before the show...)

...doesn't matter, as long as it works for the show ;-)


More information about the Pdmtl mailing list