## Extracting Audio with FFmpeg
FFmpeg is the standard tool for extracting audio from video. The most efficient operation: **direct extraction without re-encoding** (`-c:a copy`) — instant and lossless.
## Direct Extraction (No Re-encoding)
```bash
ffmpeg -i video.mp4 -vn -c:a copy audio.aac
ffmpeg -i video.mkv -vn -c:a copy audio.ac3
ffmpeg -i video.webm -vn -c:a copy audio.ogg
# Identify audio codec
ffprobe -v error -select_streams a:0 \
-show_entries stream=codec_name -of default=nw=1 video.mp4
```
## Extract and Convert to MP3
```bash
ffmpeg -i video.mp4 -vn -c:a libmp3lame -b:a 192k audio.mp3
ffmpeg -i video.mp4 -vn -c:a libmp3lame -b:a 320k audio_hq.mp3
ffmpeg -i video.mp4 -vn -c:a libmp3lame -q:a 2 audio_vbr.mp3
```
## Extract and Convert to AAC
```bash
ffmpeg -i video.mp4 -vn -c:a aac -b:a 128k audio.aac
ffmpeg -i video.mp4 -vn -c:a aac -b:a 256k audio.m4a
```
## Extract to FLAC (Lossless)
```bash
ffmpeg -i video.mkv -vn -c:a flac audio.flac
```
## Extract to WAV
```bash
ffmpeg -i video.mp4 -vn -c:a pcm_s16le -ar 44100 audio.wav
ffmpeg -i video.mp4 -vn -c:a pcm_s24le audio_24bit.wav
```
## Extract a Time Segment
```bash
ffmpeg -i video.mp4 -ss 00:01:30 -to 00:03:00 -vn -c:a libmp3lame -b:a 192k segment.mp3
ffmpeg -i video.mp4 -ss 90 -t 60 -vn -c:a copy segment.aac
```
## Multiple Audio Tracks (MKV)
```bash
ffprobe -v error -select_streams a \
-show_entries stream=index,codec_name -of csv video.mkv
ffmpeg -i video.mkv -map 0:a:0 -c:a flac track_1.flac
ffmpeg -i video.mkv -map 0:a:1 -c:a flac track_2.flac
```
## Batch Processing
```bash
for f in *.mp4; do
ffmpeg -i "$f" -vn -c:a libmp3lame -b:a 192k "${f%.mp4}.mp3"
done
for f in *.mkv; do
ffmpeg -i "$f" -vn -c:a flac "${f%.mkv}.flac"
done
```
## Recommended Formats
| Use | Format | Command |
|-----|--------|---------|
| Podcast / streaming | MP3 192 kbps | `-c:a libmp3lame -b:a 192k` |
| Music platforms | AAC 256 kbps | `-c:a aac -b:a 256k` |
| Professional editing | WAV 24-bit | `-c:a pcm_s24le` |
| Lossless archive | FLAC | `-c:a flac` |
## Conclusion
**FFmpeg** extracts audio from any video with a single command. Use `-c:a copy` for maximum efficiency. For distribution, MP3 at 192 kbps offers the best quality/compatibility balance.
Guide