Audio Handler

Read, analyze, convert, trim, merge, adjust volume, and transcribe audio files in multiple formats including MP3, WAV, FLAC, AAC, OGG, and more.

Analyze, convert, and process audio files.

Supported Formats

Format	Extensions	Read	Convert	Metadata
MP3	.mp3	✅	✅	✅
WAV	.wav	✅	✅	✅
FLAC	.flac	✅	✅	✅
AAC/M4A	.m4a, .aac	✅	✅	✅
OGG	.ogg	✅	✅	✅
Opus	.opus	✅	✅	✅
WMA	.wma	✅	✅	✅
AIFF	.aiff, .aif	✅	✅	✅

Quick Commands

Metadata (ffprobe)

bash

# Get all metadata
ffprobe -v quiet -print_format json -show_format -show_streams audio.mp3

# Get duration only
ffprobe -v error -show_entries format=duration -of default=noprint_wrappers=1:nokey=1 audio.mp3

# Get bitrate
ffprobe -v error -show_entries format=bit_rate -of default=noprint_wrappers=1:nokey=1 audio.mp3

# Get sample rate and channels
ffprobe -v error -select_streams a:0 -show_entries stream=sample_rate,channels -of default=noprint_wrappers=1 audio.mp3

# Human-readable info
ffprobe -hide_banner audio.mp3

Convert Formats (ffmpeg)

bash

# Convert to MP3 (good quality)
ffmpeg -i input.wav -codec:a libmp3lame -qscale:a 2 output.mp3

# Convert to MP3 (specific bitrate)
ffmpeg -i input.wav -codec:a libmp3lame -b:a 192k output.mp3

# Convert to WAV (uncompressed)
ffmpeg -i input.mp3 output.wav

# Convert to FLAC (lossless)
ffmpeg -i input.wav output.flac

# Convert to M4A/AAC
ffmpeg -i input.wav -codec:a aac -b:a 256k output.m4a

# Convert to OGG Vorbis
ffmpeg -i input.wav -codec:a libvorbis -qscale:a 5 output.ogg

# Convert to Opus (best for speech)
ffmpeg -i input.wav -codec:a libopus -b:a 64k output.opus

Trim & Clip

bash

# Trim audio (from 30s to 90s)
ffmpeg -i input.mp3 -ss 30 -to 90 -c copy output.mp3

# Trim from start to duration
ffmpeg -i input.mp3 -t 60 -c copy output.mp3  # First 60 seconds

# Trim with re-encode (more accurate)
ffmpeg -i input.mp3 -ss 30 -to 90 output.mp3

Volume & Speed

bash

# Adjust volume (2x louder)
ffmpeg -i input.mp3 -af "volume=2" output.mp3

# Reduce volume (half)
ffmpeg -i input.mp3 -af "volume=0.5" output.mp3

# Normalize audio
ffmpeg -i input.mp3 -af "loudnorm" output.mp3

# Speed up (1.5x)
ffmpeg -i input.mp3 -af "atempo=1.5" output.mp3

# Slow down (0.75x)
ffmpeg -i input.mp3 -af "atempo=0.75" output.mp3

Merge & Concatenate

bash

# Concatenate audio files
ffmpeg -i "concat:part1.mp3|part2.mp3|part3.mp3" -acodec copy output.mp3

# Merge with file list
echo "file 'part1.mp3'" > list.txt
echo "file 'part2.mp3'" >> list.txt
ffmpeg -f concat -safe 0 -i list.txt -c copy output.mp3

# Mix two audio tracks
ffmpeg -i voice.mp3 -i music.mp3 -filter_complex amix=inputs=2:duration=longest output.mp3

Extract Audio from Video

bash

# Extract audio track
ffmpeg -i video.mp4 -vn -acodec copy audio.aac

# Extract and convert
ffmpeg -i video.mp4 -vn -acodec libmp3lame -b:a 192k audio.mp3

Playback (macOS)

bash

# Play audio file
afplay audio.mp3

# Play with volume (0.0 to 1.0)
afplay -v 0.5 audio.mp3

# Play in background
afplay audio.mp3 &

# Stop playback
killall afplay

Text-to-Speech (macOS)

bash

# Speak text
say "Hello, this is a test"

# Save to file
say -o output.aiff "This will be saved as audio"

# List voices
say -v ?

# Use specific voice
say -v "Samantha" "Hello, I am Samantha"

# Convert to MP3
say -o temp.aiff "Text to convert" && ffmpeg -i temp.aiff output.mp3 && rm temp.aiff

Scripts

audio_info.sh

Get comprehensive audio metadata.

bash

~/Dropbox/jarvis/skills/audio-handler/scripts/audio_info.sh <audio_file>

convert_audio.sh

Convert between formats with quality options.

bash

~/Dropbox/jarvis/skills/audio-handler/scripts/convert_audio.sh <input> <output> [quality]

trim_audio.sh

Trim audio with start/end times.

bash

~/Dropbox/jarvis/skills/audio-handler/scripts/trim_audio.sh <input> <output> <start> <end>

normalize_audio.sh

Normalize volume level.

bash

~/Dropbox/jarvis/skills/audio-handler/scripts/normalize_audio.sh <input> <output>

Quality Guide

Use Case	Format	Settings
Music archive	FLAC	-codec:a flac
Music portable	MP3	-codec:a libmp3lame -qscale:a 2
Podcast/speech	Opus	-codec:a libopus -b:a 64k
Voice memo	M4A	-codec:a aac -b:a 128k
Uncompressed	WAV	-codec:a pcm_s16le

Notes

• ffmpeg handles almost all audio formats
• -c copy is fast but may be inaccurate for trimming
• Re-encode (-af) for precise cuts but takes longer
• Opus is best for speech at low bitrates
• Use loudnorm filter for consistent volume across files