mGBA Python bindings example

golfed.py

from mgba import core,image
c=core.loadPath('ruby.gba')
i=image.Image(*c.desiredVideoDimensions())
c.setVideoBuffer(i)
c.reset()
for x in range(800): c.runFrame()
with open("out.png", "w") as f: i.savePNG(f)

ungolfed.py

import mgba.core
import mgba.image

core = mgba.core.loadPath('ruby.gba')
screen = mgba.image.Image(*core.desiredVideoDimensions())
core.setVideoBuffer(screen)
core.reset()
for i in range(800):
    core.runFrame()

with open("out.png", "w") as f:
    screen.savePNG(f)

How can I set the width and height of the game ?