Why I picked it: FFmpeg earns its place because it’s the low-level tool you grab when you want total control, scripted workflows, and zero GUI limits.
I use FFmpeg when I need surgical control over MP4 → AVI. From the terminal I can set the container, pick a compatible codec, dial in bitrate/resolution, and chain filters in one command. For quick jobs I’ll do a straight ffmpeg -i input.mp4 output.avi; when I need compatibility I switch to classic MPEG-4 + MP3/PCM inside AVI and fine-tune with flags. What I like most is how predictable it feels once you’ve learned the switches – I can batch entire folders, log results with ffprobe, and reproduce the exact encode later. FFmpeg’s docs cover containers, codecs, and filters in depth, so it’s easy to confirm what AVI supports before converting.
How to convert MP4 to AVI using FFmpeg
1. Download and install FFmpeg from the official FFmpeg website.
2. Place your MP4 video file(s) in the same folder where you installed or extracted FFmpeg (this makes the command easier).
3. Open a command window in that folder:
- On Windows: hold Shift, right-click inside the FFmpeg folder, and select Open Command Window here or Open PowerShell window here.
- On macOS/Linux: open the Terminal and navigate (cd) to the FFmpeg folder.
4. Type the conversion command and press Enter. The simplest command is: ffmpeg -i input.mp4 output.avi
5. This will create an AVI file with default codecs.
6. For better compatibility, use AVI-friendly codecs: ffmpeg -i input.mp4 -c:v mpeg4 -q:v 3 -c:a mp3 output.avi
- -c:v mpeg4 → uses MPEG-4 Part 2 video codec (well supported in AVI).
- -q:v 3 → sets video quality (lower is higher quality).
- -c:a mp3 → uses MP3 audio codec (widely supported in AVI).
7. Wait for FFmpeg to process the file. When finished, you’ll find your new .avi video in the same folder.