Matplotlib animation: setting fps=90 creates a movie file properly, but setting fps=120 does not?

问题

Could you help me understand why this might be the case? This is what my command looks like:

ani.save("animation.avi", codec="libx264", fps=120)

The movie file size with the above command is very small in the order of hundreds of kilobytes. Playing the movie just shows a static picture (the very first frame).

ani.save("animation.avi", codec="libx264", fps=90)

This on the other hand, creates a movie file with a reasonable size in the order of megabytes, and plays as an animation as well.

At first, I thought this was an issue with a specific writer (avconv), but this problem occurs even when I have no writer specified, so it might be a general issue with my specific case, or matplotlib.

来源：https://stackoverflow.com/questions/26088468/matplotlib-animation-setting-fps-90-creates-a-movie-file-properly-but-setting