[Matplotlib-users] Broken pipe error when saving animation for html5

[Kyle Douglass]

Hi all,
I would like to use matplotlib's animation API to create a movie that can
be embedded into an html5 video tag. To do this, I am following a couple
2012 blog posts from Jake VanderPlas:
http://jakevdp.github.io/blog/2012/08/18/matplotlib-animation-tutorial/ and
http://jakevdp.github.io/blog/2013/05/12/embedding-matplotlib-animations/

My understanding is that I need to use the x264 codec to do this.
Unfortunately, I get a Broken Pipe Error when running the basic example
below. I get the same error when calling the animation.to_html5_video()
method.

Does anyone have an idea about why I'm getting the Broken Pipe error? Do I
really need the x264 codec to embed matplotlib animations into html? Thanks!

Kyle

*Example code:*

*import numpy as np*

*import matplotlib.pyplot as plt*

*from matplotlib import animate*
























*fig = plt.figure()ax = plt.axes(xlim = (0, 2), ylim = (-2, 2))line, =
ax.plot([], [], linewidth = 2)# initialization function: plot the
background of each framedef init(): line.set_data([], []) return
line,# animation function. This is called sequentiallydef animate(i): x
= np.linspace(0, 2, 1000) y = np.sin(2 * np.pi * (x - 0.01 * i))
line.set_data(x, y) return line,# call the animatoranim =
animation.FuncAnimation(fig, animate,
init_func=init, frames=200, interval=20,
blit=True)myWriter = animation.FFMpegWriter(fps = 30,
extra_args=['-vcodec', 'libx264'])anim.save('basic_animation.mp4', writer =
myWriter)*
*plt.show()*

*Traceback:*





















*Traceback (most recent call last): File "test.py", line 26, in
<module> anim.save('basic_animation.mp4', writer = myWriter) File
"/home/kmdouglass/anaconda3/lib/python3.5/site-packages/matplotlib/animation.py",
line 810, in save
writer.grab_frame(**savefig_kwargs) File
"/home/kmdouglass/anaconda3/lib/python3.5/site-packages/matplotlib/animation.py",
line 230, in grab_frame
dpi=self.dpi, **savefig_kwargs) File
"/home/kmdouglass/anaconda3/lib/python3.5/site-packages/matplotlib/figure.py",
line 1565, in savefig
self.canvas.print_figure(*args, **kwargs) File
"/home/kmdouglass/anaconda3/lib/python3.5/site-packages/matplotlib/backends/backend_qt5agg.py",
line 196, in print_figure
FigureCanvasAgg.print_figure(self, *args, **kwargs) File
"/home/kmdouglass/anaconda3/lib/python3.5/site-packages/matplotlib/backend_bases.py",
line 2232, in print_figure
**kwargs) File
"/home/kmdouglass/anaconda3/lib/python3.5/site-packages/matplotlib/backends/backend_agg.py",
line 519, in print_raw
fileobj.write(renderer._renderer.buffer_rgba())BrokenPipeError: [Errno 32]
Broken pipe*

I'm using Anaconda/Python 3.5 with matplotlib 1.5.1. I installed FFmpeg 3.0
in Debian Jessie by compiling FFmpeg from source into a dpkg according to
these instructions:
http://superuser.com/questions/286675/how-to-install-ffmpeg-on-debian I
also have Debian packages x264 and libx264-142 installed.

[Ryan May]

Try running with '--verbose-debug' as in:

python basic_example_writer.py --verbose-debug

That should give you standard out and standard error from running ffmpeg,
which might be illustrative.

x264 is probably the most universally supported codec for html5 video.
Another option would be to use imagemagick with the ImagemagickWriter and
make an animated gif.

Ryan

Post by Kyle Douglass
Hi all,
I would like to use matplotlib's animation API to create a movie that can
be embedded into an html5 video tag. To do this, I am following a couple
http://jakevdp.github.io/blog/2012/08/18/matplotlib-animation-tutorial/ and
http://jakevdp.github.io/blog/2013/05/12/embedding-matplotlib-animations/
My understanding is that I need to use the x264 codec to do this.
Unfortunately, I get a Broken Pipe Error when running the basic example
below. I get the same error when calling the animation.to_html5_video()
method.
Does anyone have an idea about why I'm getting the Broken Pipe error? Do I
really need the x264 codec to embed matplotlib animations into html? Thanks!
Kyle
*Example code:*
*import numpy as np*
*import matplotlib.pyplot as plt*
*from matplotlib import animate*
*fig = plt.figure()ax = plt.axes(xlim = (0, 2), ylim = (-2, 2))line,
= ax.plot([], [], linewidth = 2)# initialization function: plot the
background of each framedef init(): line.set_data([], []) return
line,# animation function. This is called sequentiallydef animate(i): x
= np.linspace(0, 2, 1000) y = np.sin(2 * np.pi * (x - 0.01 * i))
line.set_data(x, y) return line,# call the animatoranim =
animation.FuncAnimation(fig, animate,
init_func=init, frames=200, interval=20,
blit=True)myWriter = animation.FFMpegWriter(fps = 30,
extra_args=['-vcodec', 'libx264'])anim.save('basic_animation.mp4', writer =
myWriter)*
*plt.show()*
*Traceback:*
*Traceback (most recent call last): File "test.py", line 26, in
<module> anim.save('basic_animation.mp4', writer = myWriter) File
"/home/kmdouglass/anaconda3/lib/python3.5/site-packages/matplotlib/animation.py",
line 810, in save
writer.grab_frame(**savefig_kwargs) File
"/home/kmdouglass/anaconda3/lib/python3.5/site-packages/matplotlib/animation.py",
line 230, in grab_frame
dpi=self.dpi, **savefig_kwargs) File
"/home/kmdouglass/anaconda3/lib/python3.5/site-packages/matplotlib/figure.py",
line 1565, in savefig
self.canvas.print_figure(*args, **kwargs) File
"/home/kmdouglass/anaconda3/lib/python3.5/site-packages/matplotlib/backends/backend_qt5agg.py",
line 196, in print_figure
FigureCanvasAgg.print_figure(self, *args, **kwargs) File
"/home/kmdouglass/anaconda3/lib/python3.5/site-packages/matplotlib/backend_bases.py",
line 2232, in print_figure
**kwargs) File
"/home/kmdouglass/anaconda3/lib/python3.5/site-packages/matplotlib/backends/backend_agg.py",
line 519, in print_raw
fileobj.write(renderer._renderer.buffer_rgba())BrokenPipeError: [Errno 32]
Broken pipe*
I'm using Anaconda/Python 3.5 with matplotlib 1.5.1. I installed FFmpeg
3.0 in Debian Jessie by compiling FFmpeg from source into a dpkg according
http://superuser.com/questions/286675/how-to-install-ffmpeg-on-debian I
also have Debian packages x264 and libx264-142 installed.
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[Kyle Douglass]

Post by Ryan May
python basic_example_writer.py --verbose-debug

Thanks for the suggestion, Ryan. By doing so I discovered that the error
was caused by ffmpeg not finding the libx264 library; the error was not at
all connected with matplotlib.

As it turns out, I neglected to use the *--enable-libx264 --enable-gpl
--enable-nonfree* flags when running the configuration script for ffmpeg
just before compiling. I recompiled ffmpeg and now everything is working
properly.

Thanks again,
Kyle