'MovieWriter
Parameters
fps: int
Framerate for movie.
codec: string or None, optional
The codec to use. If None (the default) the setting in the
rcParam `animation.codec` is used.
bitrate: int or None, optional
The bitrate for the saved movie file, which is one way to control
the output file size and quality. The default value is None,
which uses the value stored in the rcParam `animation.bitrate`.
A value of -1 implies that the bitrate should be determined
automatically by the underlying utility.
extra_args: list of strings or None
A list of extra string arguments to be passed to the underlying
movie utility. The default is None, which passes the additional
arguments in the \'animation.extra_args\' rcParam.
metadata: dict of string:string or None
A dictionary of keys and values for metadata to include in the
output file. Some keys that may be of use include:
title, artist, genre, subject, copyright, srcform, comment.'

def __init__(self, fps=5, codec=None, bitrate=None, extra_args=None, metadata=None):

    self.fps = fps
    self.frame_format = u'rgba'
    if (codec is None):
        self.codec = rcParams[u'animation.codec']
    else:
        self.codec = codec
    if (bitrate is None):
        self.bitrate = rcParams[u'animation.bitrate']
    else:
        self.bitrate = bitrate
    if (extra_args is None):
        self.extra_args = list(rcParams[self.args_key])
    else:
        self.extra_args = extra_args
    if (metadata is None):
        self.metadata = dict()
    else:
        self.metadata = metadata
