MoviePy: Concatenating video clips causes weird glitches in final video

Question

Is there a way to successfully always patch up any clips together in such a way that prevents weird glitches? I put together a .mp4 from smaller .mp4 files and I got a final video with weird glitches. I am running Python 3.6.1 on Windows 10 through Sublime Text 3. I used MoviePy to do the concatenation.

The code:

from moviepy.editor import VideoFileClip, concatenate_videoclips
import os.path

path = "C:/Users/blah/videos/out/"

cliparray = []

for filename in os.listdir(path):
    cliparray.append(VideoFileClip(path + filename))

final_clip = concatenate_videoclips(cliparray)

final_clip.write_videofile(path + "concatenatedvideo.mp4", codec = "libx264")

The weird glitches:

1. One of the clips turns into a 3x3 grid of smaller clips.
2. Another has the audio not lined up with the video
3. Another is sped up faster than what was normal.

Answer 1

I had also glitch while concatenating different video clips. Some had different resolutions and that was making output video file with some sort of glitches. I fixed it with

final_clip = concatenate_videoclips(cliparray, method='compose')

Resulting output was without any glitch, but since they have different resolutions, the moviepy assigns highest resolution among video clips. To fix this you might just crop to same size.