[pygame] VideoCapture, PIL, and PyGame

[Ian Mallett]

Hi,

So, I'm trying to get VideoCapture working with PyGame.  I've modified the
standard VideoCapture.py file to make it simpler and easier to read.  I've
attached it as well as my program, main.py.

VideoCapture.py defines a class Device.  Device has two functions that I'm
concerned with: .getBuffer(), which returns (string_data,width,height), and
.getImage(), which returns a PIL image made with .getBuffer().

I'm trying to get a PyGame surface from all this.  Every code sample I've
seen converts the PIL image (returned from .getImage()) *back* into a
string, and then makes a PyGame image with pygame.image.frombuffer(...):
im = Camera.getImage()
image = pygame.image.frombuffer(im.tostring(), im.size, im.mode)

Though this works nicely, it seems terribly
inefficient--VideoCapture.pytakes the data as a string from
.getBuffer(), and makes a PIL image.  The main, main.py, must then change
this PIL image *back* into a string again, and then make a PyGame surface
from *that*.  (Basically: STRING->PIL->STRING->PYGAME).  This setup doesn't
fly realtime.  Moreover, it requires an extra dependency, PIL.

So, I tried just converting the original string from .getBuffer() directly
into a PyGame surface.  (Basically: STRING->PYGAME):
data = Camera.getBuffer()
image = pygame.image.frombuffer(data[0],(data[1],data[2]),"RGB")

But this has problems.  It doesn't crash, but the image is upsidedown and
the red and blue color channels appear to be flopped.  I tried fixing it
with surfarray, which didn't work.  Then I tried finding what was wrong, and
got inconsistent results.

How can I get the second method (method 2: STRING->PYGAME) to look like the
first method (method 1: STRING->PIL->STRING->PYGAME)?  main.py lets you
switch back and forth (press 1 for method 1, 2 for method 2).

Ian

VideoCapture.py
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main.py
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