def get_palette(dc):
count = GetSystemPaletteEntries(dc, 0, 0, None)
log("palette size: %s", count)
palette = []
if count > 0:
buf = (PALETTEENTRY * count)()
r = GetSystemPaletteEntries(dc, 0, count, ctypes.byref(buf))
for i in range(min(count, r)):
p = buf[i]
#we expect 16-bit values, so bit-shift them:
palette.append((p.peRed << 8, p.peGreen << 8, p.peBlue << 8))
return palette
def get_image(self, x=0, y=0, width=0, height=0):
start = time.time()
metrics = get_virtualscreenmetrics()
if self.metrics is None or self.metrics != metrics:
#new metrics, start from scratch:
self.metrics = metrics
self.clean()
log("get_image%s metrics=%s", (x, y, width, height), metrics)
dx, dy, dw, dh = metrics
if width == 0:
width = dw
if height == 0:
height = dh
#clamp rectangle requested to the virtual desktop size:
if x < dx:
width -= x - dx
x = dx
if y < dy:
height -= y - dy
y = dy
if width > dw:
width = dw
if height > dh:
height = dh
if not self.dc:
self.wnd = GetDesktopWindow()
self.dc = GetWindowDC(self.wnd)
assert self.dc, "failed to get a drawing context from the desktop window %s" % self.wnd
self.bit_depth = GetDeviceCaps(self.dc, win32con.BITSPIXEL)
self.memdc = CreateCompatibleDC(self.dc)
assert self.memdc, "failed to get a compatible drawing context from %s" % self.dc
bitmap = CreateCompatibleBitmap(self.dc, width, height)
assert bitmap, "failed to get a compatible bitmap from %s" % self.dc
r = SelectObject(self.memdc, bitmap)
if r == 0:
log.error("Error: cannot select bitmap object")
return None
select_time = time.time()
log("get_image up to SelectObject (%s) took %ims",
REGION_CONSTS.get(r, r), (select_time - start) * 1000)
try:
if BitBlt(self.memdc, 0, 0, width, height, self.dc, x, y,
win32con.SRCCOPY) == 0:
e = ctypes.get_last_error()
#rate limit the error message:
now = time.time()
if now - self.bitblt_err_time > 10:
log.error("Error: failed to blit the screen, error %i", e)
self.bitblt_err_time = now
return None
except Exception as e:
log("BitBlt error", exc_info=True)
log.error("Error: cannot capture screen")
log.error(" %s", e)
return None
bitblt_time = time.time()
log("get_image BitBlt took %ims", (bitblt_time - select_time) * 1000)
rowstride = roundup(width * self.bit_depth // 8, 2)
buf_size = rowstride * height
pixels = ctypes.create_string_buffer(b"", buf_size)
log("GetBitmapBits(%#x, %#x, %#x)", bitmap, buf_size,
ctypes.addressof(pixels))
r = GetBitmapBits(bitmap, buf_size, ctypes.byref(pixels))
if r == 0:
log.error("Error: failed to copy screen bitmap data")
return None
if r != buf_size:
log.warn(
"Warning: truncating pixel buffer, got %i bytes but expected %i",
r, buf_size)
pixels = pixels[:r]
log("get_image GetBitmapBits took %ims",
(time.time() - bitblt_time) * 1000)
DeleteObject(bitmap)
assert pixels, "no pixels returned from GetBitmapBits"
if self.bit_depth == 32:
rgb_format = "BGRX"
elif self.bit_depth == 30:
rgb_format = "r210"
elif self.bit_depth == 24:
rgb_format = "BGR"
elif self.bit_depth == 16:
rgb_format = "BGR565"
elif self.bit_depth == 8:
rgb_format = "RLE8"
else:
raise Exception("unsupported bit depth: %s" % self.bit_depth)
bpp = self.bit_depth // 8
v = ImageWrapper(0,
0,
width,
height,
pixels,
rgb_format,
self.bit_depth,
rowstride,
bpp,
planes=ImageWrapper.PACKED,
thread_safe=True)
if self.bit_depth == 8:
count = GetSystemPaletteEntries(self.dc, 0, 0, None)
log("palette size: %s", count)
palette = []
if count > 0:
buf = (PALETTEENTRY * count)()
r = GetSystemPaletteEntries(self.dc, 0, count,
ctypes.byref(buf))
#we expect 16-bit values, so bit-shift them:
for p in buf:
palette.append(
(p.peRed << 8, p.peGreen << 8, p.peBlue << 8))
v.set_palette(palette)
log("get_image%s=%s took %ims", (x, y, width, height), v,
(time.time() - start) * 1000)
return v