Hey there, let's break down what's causing this error and how to fix it quickly.

The Root Cause #

That FileNotFoundError isn't about your vid.mp4 file—it means your system can't locate the actual ffmpeg executable. Remember, ffmpeg-python is just a wrapper library; it doesn't include the ffmpeg tool itself. You need to have ffmpeg installed on your system and accessible to Python.

Step-by-Step Solutions #

1. Install the ffmpeg Binary First

Grab a Windows build of ffmpeg from its official site (pick the version matching your system architecture—32-bit or 64-bit). Once downloaded:

• Extract the zip file to a folder (e.g., C:\ffmpeg)
• Inside that folder, you’ll find a bin directory containing ffmpeg.exe, ffprobe.exe, and other related tools.

2. Make Python Find ffmpeg (Two Options)

Option A: Add ffmpeg to System PATH (Permanent Fix)

This lets any program on your system access ffmpeg:

• Right-click "This PC" → "Properties" → "Advanced System Settings" → "Environment Variables"
• Under "System Variables", find the Path variable, click "Edit"
• Click "New" and paste the full path to the bin folder (e.g., C:\ffmpeg\bin)
• Save changes and restart your Python IDE/command prompt—this ensures the new PATH takes effect.

Option B: Specify ffmpeg Path Directly in Code (Temporary/Project-Specific Fix)

If you don’t want to modify system PATH, you can tell ffmpeg-python exactly where to find the executable:

import ffmpeg

# Option 1: Specify path when calling run()
videoInput = ffmpeg.input('vid.mp4')
videoOutput = videoInput.output('test.avi')
videoOutput.run(cmd='C:/ffmpeg/bin/ffmpeg.exe')  # Replace with your actual path

# Option 2: Set the executable globally at the start
ffmpeg.EXECUTABLE = 'C:/ffmpeg/bin/ffmpeg.exe'
videoInput = ffmpeg.input('vid.mp4')
videoOutput = videoInput.output('test.avi')
videoOutput.run()

Quick Validation #

To confirm ffmpeg is set up correctly, open a command prompt and run:

ffmpeg -version

If it shows the ffmpeg version info, you’re good to go—re-run your Python code and the error should be gone.

Bonus: Double-Check Your Input File Path #

While the main issue is ffmpeg itself, it’s worth confirming your vid.mp4 is in the correct directory. If you’re unsure, use an absolute path for the input:

videoInput = ffmpeg.input('C:/Users/geral/Desktop/PythonPrograms/vid.mp4')

内容的提问来源于stack exchange，提问作者Gerald Leese