[PD] GEM : GLSL Mixer - working 2 channel video mixer example

[vade]

I just tried my powerbook 1.67 with OS X 10.4.9 and PD 0.4.03 nightly  
12/24 (same as before), no crashing, solid 60fps with 2 QT movies  
playing.

:)

On Dec 25, 2007, at 1:04 PM, Max Neupert wrote:

> very interesting, but also a good example on how to lock the computer
> completely with gem - at least my old powerbook. i had to hard reset
> because complete unresponsiveness. with [frame 10( it runs nicely
> though. see my last post on how to avoid the lock-up.
>
> max
>
> Am 24.12.2007 um 21:35 schrieb vade:
>
>> Yes, very efficient, and also give you LOTS of flexibility . the
>> regular GL_BLEND_MODES do not offer that many variations (not many  
>> are
>> useful for video). Want to make a GPU powered chroma key - shader.
>> Want to make feedback but have FSAA on, probably shader :)
>> etc etc. Want to make 4 way mixer? shader! See where I am going
>> here? :)
>>
>>
>> On Dec 24, 2007, at 3:29 PM, Hans-Christoph Steiner wrote:
>>
>>>
>>> Nice, works for me.  Is the idea that shaders are a efficient way of
>>> mixing video?
>>>
>>> .hc
>>>
>>> On Dec 24, 2007, at 12:04 PM, vade wrote:
>>>
>>>> Hello
>>>>
>>>> Here is a 2 channel mixer using overlay blend mode with GLSL. This
>>>> works, is decently fast and gives me the expected result.
>>>>
>>>> If you want more blend modes, feel free to grab them from http://
>>>> 001.vade.info
>>>> (or elsewhere, most are trivial to figure out)- the glsl shaders
>>>> for the mixers use the same subroutine layout in the glsl, so it is
>>>> trivial to swap. I did not include them out of sheer laziness.
>>>>
>>>> Caveats with PD 0.4.03 Extended nightly from Dec 24th (Mac OS X
>>>> 10.5.1, QT 7.3, Intel):
>>>>
>>>> - had to edit the GLSL program to fix multitexture coordinate
>>>> issue. Only can use the texture dims from the zeroths texture unit.
>>>> - could not get sampler2DRect working at all - only had a single
>>>> texel mapped it seemed.
>>>> - had weird issue where I would sometimes have to close the gemwin
>>>> (0, destroy) and then re create it to see the textures assigned to
>>>> texture units.
>>>> 	this happened most often after closing and re-opening the patch.
>>>>
>>>> Please see the included question(s) within the PD patch concerning
>>>> using framebuffer to grab the output of the rendered shader and
>>>> send it to yet another shader. Ive included an exposure shader in
>>>> an attempt to make a chain of GLSL effects. I however could not get
>>>> gemframebuffer to output any usable texture after using  
>>>> glslprogram.
>>>>
>>>> Thanks, hope this is helpful to those out there
>>>>
>>>> FUDDLE DUDDLE !@#!@#!@#()*!@#(*@#
>
>
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