Hi,
On Sat, Jun 13, 2009 at 10:13 PM, Tyler Laing <[email protected]> wrote:
> Hmm, from my (admittedly limited) experience of codecs and video files
> during the development of the new movie module, it looks like a few things
> are wrong. The red and green channels are coming out in the buffer in the
> opposite order to what the Surface format expects them. I only have Linux,
> but have you tried changing the mode from RGB to BGR? I ask because of this
> line:
>
> im = Image.fromstring('RGB', (width, height), buffer, 'raw', 'BGR', 0,
> -1)
>
Yes, that's my theory. I already tried it, and unfortunately, "BGR" doesn't
seem to be a valid argument to the function.
> leads me to realize that the format coming out of vidcap.pyd is in BGR
> format, not RGB format like the Surfaces expect. Looking at the
> documentation for the Image.fromstring method, it says that putting a -1 at
> the end flips the image. Then looking at pygame.image.fromstring:
> http://www.pygame.org/docs/ref/image.html#pygame.image.fromstring there is
> a flipped boolean. Use it. ;)
>
> It does seem strange that frombuffer doesn't have a flipped argument, and
> I'm not sure why. Anyone else able to add some insight?
>
I think it's because it returns a reference to already existing data in such
a way that PyGame can use it, maybe?
On Sat, Jun 13, 2009 at 10:25 PM, Nirav Patel <[email protected]> wrote:
> I don't know exactly how VideoCapture is implemented, but the camera
> buffer is apparently in BGR color order and the pixels are in reverse
> order.
>
> Thus, you can't use it directly as a Surface. You could fix the
> upsidedown image by using pygame.image.fromstring() with the last
> argument as True. It would probably be faster than going through PIL,
> but then once you switch R and B with Numpy, it'll be slower again.
> It would only be worth it if you don't want PIL as a dependancy.
I'm going to need NumPy for image processing anyway, so it shouldn't be too
bad. And yes, I don't want PIL as a dependency.
This is what I was trying originally. The code I provided is all set up. I
just am having trouble implementing the reg/blue flip. After some failed
attempts, I scrapped that section so people could add suggestions for what
to put in-between lines 39 and 40 to fix the problem. Any thoughts there?
On Sat, Jun 13, 2009 at 10:40 PM, Nirav Patel <[email protected]> wrote:
> Anyway, in general, it probably isn't worth the effort. Native
> Windows camera support for pygame is coming eventually...
I know, but it would be nice to have something that works now. How soon is
"eventually"?
> Nirav
Thanks,
Ian
