# FileNotFoundError: [Errno 2] No such file or directory: 'ffmpeg'

- **ID:** `python/matplotlib-animation-ffmpeg-missing`
- **Domain:** python
- **Category:** system_error
- **Verification:** ai_generated
- **Fix Rate:** 80%

## Root Cause

matplotlib.animation.FuncAnimation.save() defaults to ffmpeg writer, but ffmpeg is not on PATH.

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| 3.x | active | — | — |

## Workarounds

1. **** (95% success)
   ```
   sudo apt-get install -y ffmpeg
# or: conda install -c conda-forge ffmpeg
   ```
2. **** (90% success)
   ```
   from matplotlib.animation import PillowWriter
ani.save('anim.gif', writer=PillowWriter(fps=20))
   ```

## Dead Ends

- **** — The PyPI 'ffmpeg' package is a Python wrapper; it does not provide the ffmpeg binary. (92% fail)
- **** — The writer is already ffmpeg; the binary is what's missing. (90% fail)