[PD] [GEM-dev] [GEM]

IOhannes m zmoelnig zmoelnig at iem.at
Wed Apr 15 09:39:02 CEST 2009

Loic Kessous wrote:
> Hi,
> I just want to report this but I don't know if it's related to gem-dev 
> or usual pd-gem, so sorry for cross-posting.
> I am using pix_movement and pix_movement2 on os X and MSW vista and 
> apparently with pix_movement the display is not correct on MSW, It 
> doesn't show the video processed but the original one. On os X it's 
> working correctly. For pix_movement2 it's working on the 2 plateforms.

this is as expected.
when you are using [pix_movement] with an RGBA image-stream (which is 
the default on w32), it will store the difference images in the 
alpha-channel. if you send [pix_movement] a greyscale image (which has 
no alpha channel) it will output the processed data in the grey-channel 
as well.
[pix_movement2] seems to internally convert the image to greyscale and 
work on the grey channel directly.

you could:
- convert the pix-stream to greyscale using [pix_grey] (before 
- turn on alpha-blending with the [alpha] object to let the 
alpha-channel have an effect.

i know that this is somewhat inconsisten (for legacy reasons).
storing the processed data in the alpha-channel sounded like a good idea 
back then. it doesn't sound that right now.
it will stay like this for legacy reasons.
(but thinking of it: it might be a good idea to turn the functionality 
of [pix_movement] into [pix_movement1] (consistent with [pix_movement2]) 
and make [pix_movement] an abstraction using the new object and 
mimicking the old behaviour.

-------------- next part --------------
A non-text attachment was scrubbed...
Name: smime.p7s
Type: application/x-pkcs7-signature
Size: 3636 bytes
Desc: S/MIME Cryptographic Signature
URL: <http://lists.puredata.info/pipermail/pd-list/attachments/20090415/50420f8d/attachment.bin>

More information about the Pd-list mailing list