Re: [matplotlib-devel] Saving animations

[Benjamin R. <ben...@ou...>]

On Sat, Apr 7, 2012 at 1:34 PM, Tony Yu <ts...@gm...> wrote:

> I've been using the animations subpackage since it was introduced, but I
> only recently tried to save an animation using the `save` method.
> Unfortnately, I get a RuntimeError whenever I try to use it:
>
> ...
>   File
> "/Users/Tony/python/devel/mpl/lib/matplotlib/backends/backend_agg.py", line
> 4
> 52, in print_raw
>     renderer._renderer.write_rgba(filename_or_obj)
> RuntimeError: Error writing to file
>
>
> This can be reproduced with any animation example, e.g. simple_anim.py<http://matplotlib.sourceforge.net/examples/animation/simple_anim.html>, by
> replacing `plt.show()` with `ani.save('simple_anim.avi')`. The actual error
> is from a shell call to ffmpeg, which roughly boils down to:
>
> #~~~~
>     import subprocess
>     import matplotlib.pyplot as plt
>
>     fig, ax = plt.subplots()
>     ax.plot([0, 1])
>     command = ['ffmpeg', '-f', 'rawvideo', '-vcodec', 'rawvideo',
>                '-s', '800x600', '-pix_fmt', 'rgba', '-r', '5.0',
>                '-i', 'pipe:', '-vcodec', 'mpeg4', '-y', 'test.avi']
>     proc= subprocess.Popen(command, shell=False, stdout=subprocess.PIPE,
>                            stderr=subprocess.STDOUT, stdin=subprocess.PIPE)
>     fileobj = proc.stdin
>     fig.savefig(fileobj, format='rgba', dpi=100)
> #~~~~
>
> (I just copied the ffmpeg command from an example run, so the option
> values may vary on other systems.) The error here is the same, and,
> unfortunately, not very informative. Is this saving functionality platform
> dependent? (I'm on osx.)
>
> Thanks,
> -Tony
>
>
Tony,

The animation saving feature has be completely rewritten by Ryan recently
and is in master.  Could you give that a try?

Ben Root