Moviepy: Error when writing video file out

[LvInSaNevL]

Expected Behavior

Using write_videofile("data/output.mp4", fps='30') should produce a video file at data/output.mp4

Actual Behavior

Moviepy throws an error TypeError: must be real number, not str from the file ffmpeg_writer.py and exits the program.

Steps to Reproduce the Problem

Below I have included the section of code that is responsible for actually generating and saving the video file to the disk

clipData = []
for path in clipPaths:
     newClip = VideoFileClip(path)
    normalClip = audio_normalize(VideoFileClip(path))
    clipData.append(newClip)
finalVideo = concatenate_videoclips(clipData, method='compose')
finalVideo.write_videofile("data/output.mp4", fps='30')

• clipPaths is a list of paths to the clips that I am using to make the video.

I have also included the full stack trace that I get when I run the code

Moviepy - Building video data/output.mp4.
MoviePy - Writing audio in outputTEMP_MPY_wvf_snd.mp3
MoviePy - Done.                                                                                                                                                                               
Moviepy - Writing video data/output.mp4

Traceback (most recent call last):
  File "src/videoEditor.py", line 60, in <module>
    globals()[sys.argv[1]]()
  File "src/videoEditor.py", line 51, in GenerateVideo
    finalVideo.write_videofile("data/output.mp4", fps='30')
  File "<decorator-gen-55>", line 2, in write_videofile
  File "/home/mwollam/.local/lib/python3.8/site-packages/moviepy/decorators.py", line 54, in requires_duration
    return f(clip, *a, **k)
  File "<decorator-gen-54>", line 2, in write_videofile
  File "/home/mwollam/.local/lib/python3.8/site-packages/moviepy/decorators.py", line 135, in use_clip_fps_by_default
    return f(clip, *new_a, **new_kw)
  File "<decorator-gen-53>", line 2, in write_videofile
  File "/home/mwollam/.local/lib/python3.8/site-packages/moviepy/decorators.py", line 22, in convert_masks_to_RGB
    return f(clip, *a, **k)
  File "/home/mwollam/.local/lib/python3.8/site-packages/moviepy/video/VideoClip.py", line 300, in write_videofile
    ffmpeg_write_video(self, filename, fps, codec,
  File "/home/mwollam/.local/lib/python3.8/site-packages/moviepy/video/io/ffmpeg_writer.py", line 213, in ffmpeg_write_video
    with FFMPEG_VideoWriter(filename, clip.size, fps, codec = codec,
  File "/home/mwollam/.local/lib/python3.8/site-packages/moviepy/video/io/ffmpeg_writer.py", line 88, in __init__
    '-r', '%.02f' % fps,
TypeError: must be real number, not str

Specifications

• Python Version: Python 3.8.2
• Moviepy Version: moviepy 1.0.3
• Platform Name: Ubuntu 20.04.1 LTS

[dleitee]

@LvInSaNevL have you tried using a real number instead of a string here?

finalVideo.write_videofile("data/output.mp4", fps=30)

[LvInSaNevL]

@dleitee oh my goodness that was definitely the answer! Thank you so much I was banging my head against the wall haha!

[tburrows13]

write_videofile("data/output.mp4", fps='30')

Did you get that from documentation somewhere that needs changing?

[dleitee]

@tburrows13 I took a quick look into the whole code and didn't find any mention of fps as string.

[LvInSaNevL]

@tburrows13 I double checked with some googling and also could not find any reference to FPS as a string, I am not 100% sure where I got that from...

[tburrows13]

Ok thanks for the feedback. The only thing that I can think of is that I think the bitrate parameter is a string (that allows things like '50k'). That might be changed in the future though, it is fairly confusing.