Error? in Example 4.8 Unencoded video capture

[stdsmile]

When trying to execute the Code Example 4.8 in the docs. i get:

Traceback (most recent call last): File "Example48.py", line 41, in camera.add_overlay(memoryview(box), size=(160, 90), layer=3, alpha=64) File "/usr/lib/python2.7/dist-packages/picamera/camera.py", line 892, in add_overlay renderer = PiOverlayRenderer(self, source, size, format, *options) File "/usr/lib/python2.7/dist-packages/picamera/renderers.py", line 413, in init source_len = mo.buffer_bytes(source) File "/usr/lib/python2.7/dist-packages/picamera/mmalobj.py", line 466, in buffer_bytes return m.itemsize reduce(mul, m.shape) UnboundLocalError: local variable 'm' referenced before assignment

when starting with python3

Traceback (most recent call last): File "Example48.py", line 41, in camera.add_overlay(memoryview(box), size=(160, 90), layer=3, alpha=64) File "/usr/lib/python3/dist-packages/picamera/camera.py", line 892, in add_overlay renderer = PiOverlayRenderer(self, source, size, format, *options) File "/usr/lib/python3/dist-packages/picamera/renderers.py", line 413, in init source_len = mo.buffer_bytes(source) File "/usr/lib/python3/dist-packages/picamera/mmalobj.py", line 466, in buffer_bytes return m.itemsize reduce(mul, m.shape) UnboundLocalError: local variable 'm' referenced before assignment

Greetings

[stdsmile]

In mmalobj.py in line 466 findet man:

Given an object which implements the :ref:buffer protocol <bufferobjects>, this function returns the size of the object in bytes. The object can be multi-dimensional or include items larger than byte-size.

def buffer_bytes(buf):

if not isinstance(buf, memoryview):
    m = memoryview(buf)
return m.itemsize * reduce(mul, m.shape)

[jjsanderson]

I've just stumbled across the same issue, in the same example code. Pity - it looks like a useful example!

I've nothing to offer by way of help, I'm afraid, other than reassurance that this isn't an isolated case.