MoviePy — Python Video Editing Library

What it is

MoviePy is a Python library for video editing that handles cutting, concatenating, adding titles, applying effects, and mixing audio. Instead of using a GUI video editor, you write Python scripts that process video files programmatically. This makes it suitable for batch processing, automated video pipelines, and integration with other Python tools.

MoviePy targets developers and content creators who need automated video processing: generating social media clips from long recordings, adding watermarks to batches of videos, or building video generation pipelines.

How it saves time or tokens

MoviePy replaces manual video editing for repetitive tasks. Cutting 100 clips from a long recording, adding consistent intros/outros to a batch of videos, or resizing videos for different platforms are all tasks that take hours manually but minutes with a script.

The library wraps FFmpeg, so you get professional-grade video processing without learning FFmpeg's complex command-line syntax.

How to use

1. Install MoviePy:

pip install moviepy

1. Basic video operations:

from moviepy import VideoFileClip, TextClip, CompositeVideoClip

video = VideoFileClip('input.mp4')

# Cut a clip (seconds 10 to 30)
clip = video.subclipped(10, 30)

# Add a title
title = TextClip(
    text='My Title',
    font_size=48,
    color='white',
    duration=5
)
final = CompositeVideoClip([clip, title.with_position('center')])
final.write_videofile('output.mp4')

1. Concatenate multiple clips:

from moviepy import concatenate_videoclips

clips = [VideoFileClip(f'clip_{i}.mp4') for i in range(5)]
result = concatenate_videoclips(clips)
result.write_videofile('combined.mp4')

Example

Batch processing videos with watermark and resize:

import os
from moviepy import VideoFileClip, ImageClip, CompositeVideoClip

logo = ImageClip('logo.png').with_duration(None).resized(height=50)

for filename in os.listdir('raw_videos/'):
    if not filename.endswith('.mp4'):
        continue
    video = VideoFileClip(f'raw_videos/{filename}')
    video = video.resized(width=1080)
    watermarked = CompositeVideoClip([
        video,
        logo.with_position(('right', 'bottom'))
    ])
    watermarked.write_videofile(f'output/{filename}')

Related on TokRepo

• AI tools for video -- Video production and editing tools
• AI tools for automation -- Scripting and automation tools

Common pitfalls

• Memory issues with large video files. MoviePy loads frames into memory during processing. For long videos, process in chunks or use FFmpeg directly for simple operations.
• Font rendering on headless servers. TextClip requires ImageMagick, which may not be installed on server environments. Install ImageMagick and set the correct path in MoviePy's config.
• Slow rendering with many effects. Each effect layer adds processing time per frame. For production pipelines, pre-render assets and minimize real-time compositing.