audio-extractor

name	audio-extractor
description	Extract, enhance, and process audio from video files. Includes noise reduction, speech enhancement, and format conversion.

Audio Extractor

This skill extracts and enhances audio from video files for processing or standalone use.

When to Use This Skill

• Need just the audio from a video
• Want to enhance speech quality
• Preparing audio for transcription
• Creating audio-only content (podcasts, etc.)

What This Skill Does

1. Extract Audio: Separates audio track from video
2. Enhance Quality: Noise reduction, normalization
3. Convert Format: Export as MP3, WAV, AAC, etc.
4. Analyze Audio: Check levels, detect issues

How to Use

Basic Extraction

Extract audio from: ./output/downloads/VIDEO_ID.mp4

With Enhancement

Extract and enhance audio from VIDEO_ID

Specific Format

Extract audio as WAV for transcription

Instructions

Step 1: Analyze Source Audio

ffprobe -v quiet -print_format json -show_streams \
  -select_streams a:0 \
  "./output/downloads/VIDEO_ID.mp4"

Step 2: Extract Audio Track

To MP3 (compressed, good for sharing):

ffmpeg -i "./output/downloads/VIDEO_ID.mp4" \
  -vn -acodec libmp3lame -q:a 2 \
  "./output/downloads/VIDEO_ID.mp3"

To WAV (uncompressed, best for processing):

ffmpeg -i "./output/downloads/VIDEO_ID.mp4" \
  -vn -acodec pcm_s16le -ar 44100 \
  "./temp/VIDEO_ID.wav"

To AAC (high quality, smaller):

ffmpeg -i "./output/downloads/VIDEO_ID.mp4" \
  -vn -acodec aac -b:a 192k \
  "./output/downloads/VIDEO_ID.m4a"

Step 3: Enhance Audio (Optional)

Normalize Volume:

ffmpeg -i "./temp/VIDEO_ID.wav" \
  -af "loudnorm=I=-16:TP=-1.5:LRA=11" \
  "./output/downloads/VIDEO_ID_normalized.mp3"

Reduce Noise + Normalize:

ffmpeg -i "./temp/VIDEO_ID.wav" \
  -af "highpass=f=80,lowpass=f=12000,loudnorm=I=-16:TP=-1.5:LRA=11" \
  "./output/downloads/VIDEO_ID_enhanced.mp3"

Speech Enhancement (for voice clarity):

ffmpeg -i "./temp/VIDEO_ID.wav" \
  -af "highpass=f=100,lowpass=f=8000,loudnorm,compand=attacks=0:points=-80/-80|-45/-15|-27/-9|0/-7|20/-7:gain=5" \
  "./output/downloads/VIDEO_ID_speech.mp3"

Step 4: Report Results

## ✅ Audio Extracted

**Source**: VIDEO_ID.mp4
**Output**: VIDEO_ID.mp3

### Audio Info
- **Duration**: 10:32
- **Sample Rate**: 44.1 kHz
- **Channels**: Stereo
- **Bitrate**: 192 kbps
- **Size**: 12.5 MB

### Quality Assessment
- ✅ Speech clarity: Good
- ✅ Background noise: Minimal
- ✅ Volume levels: Normalized

**Next step**: Use `speech-transcriber` to convert to text

Output

• MP3: ./output/downloads/{video_id}.mp3
• Enhanced: ./output/downloads/{video_id}_enhanced.mp3
• WAV (temp): ./temp/{video_id}.wav

Audio Quality Tips

• Use WAV for transcription (better accuracy)
• Use MP3 for sharing (smaller files)
• Always normalize volume before adding to shorts
• High-pass filter removes rumble, low-pass removes hiss