concatenating videoclips result in laggy result video

[coralexbadea]

Expected Behavior

For short videoclips concatenation the resulted video is smooth containing all composing videos.

Actual Behavior

The resulting video has lag between the composing parts, some of the parts being completly missing and replaced with the freezed last frame of the previous composing video.

We can see the results in the following amv video: https://www.youtube.com/watch?v=3ksI-EIphXY

Steps to Reproduce the Problem

I have the following code:

beginTime = 10
endTime = beginTime + intervals[0]
for c,i in enumerate(intervals[1:-1]):
  print(f"beginTime{beginTime}")
  print(f"endTime{endTime}")
  output = "./sample%d.mp4" % (c)
  ffmpeg_extract_subclip(videoPath, beginTime, endTime, output)
  #beginTime = randint(intro_duration ,maxVideoDur) 
  beginTime = endTime + randint(1, maxRand) 
  endTime = beginTime + i 

L =[]
for root, dirs, files in os.walk("./"):
    #files = natsorted(files)
    for file in files:
        if os.path.splitext(file)[1] == '.mp4':
            filePath = os.path.join(root, file)
            video = VideoFileClip(filePath)
            L.append(video)

video = concatenate_videoclips(L)
video.to_videofile("./video/output.mp4", fps=30)

Specifications

• Python Version:3.9.2
• Moviepy Version: 1/0/3

[yemibox51]

What dependencies or packages do you have installed?