matrix composition in uyvy

    Guilherme Martins
    Aug 12 2012 | 11:21 pm
    I am working on a composition that mixes a masked movie and a background movie into the same matrix, I absolutely need that the final end to be merged on a matrix.. for the sake of performance I would like to change the colormode to uyvy but I am still a bit noob working with shaders and GPU, any help will be much appreciated
    don't forget to download the attached .png file to see exactly what I am doing..
    • Christopher Dobrian
      Aug 13 2012 | 4:17 am
      These are old examples, and don't really answer all your questions, but they might be helpful.http://music.arts.uci.edu/dobrian/IAP2006/examples.htm Scroll down to the examples titled "make a mask image", "mask by multiplication", and "mask by alphablend".
      I could be wrong, but I think the GPU advantages you gain by doing the alphablending in GL would be mitigated somewhat if you convert the result back to a jit.matrix. So the way shown in these examples might be as good as any...
    • Guilherme Martins
      Aug 13 2012 | 9:44 am
      I understand the point that the final conversion to a jit.matrix is not the best thing to do.. perhaps I will do all the composition in argb, and after the final result I will convert everything to uyvy and go to the gl land. Oh, and thanks for pointing this good set of examples!!
    • Rob Ramirez
      Aug 13 2012 | 6:50 pm
      hello. here is a patch that performs an alphablend on the GPU using a very simple jit.gl.pix gen-patch. it also shows how to properly use @colormode uyvy to read quicktime movies, and convert them to rgba textures.
    • Guilherme Martins
      Aug 14 2012 | 11:55 pm
      Hello Robert, thank you so much for this example, I am going to digest it now and try to understand the gen patch wich is something very new for me..