Go Two-Tone Detector

This project is a Go application for detecting two-tone sequences (such as paging tones) in real-time audio streams. It connects to an RTSP stream, decodes G711 mu-law audio, and analyzes the audio for specific tone patterns using the Goertzel algorithm. When a valid two-tone sequence is detected, the app can record and save the relevant audio segment as a WAV file.

Features

• RTSP Client: Connects to audio streams using RTSP protocol.
• G711 mu-law Decoding: Converts mu-law encoded audio to PCM samples.
• Two-Tone Detection: Uses Goertzel algorithm to detect and confirm tone sequences.
• Recording: Automatically records and saves audio segments containing detected tones.
• Configurable Parameters: Window size, hop size, thresholds, and durations are adjustable via command-line flags.
• Graceful Shutdown: Handles interrupts and ensures recordings are saved before exit.

Usage

go run main.go -rtsp <RTSP_URL> [flags]

Example Flags

• -rtsp : RTSP stream URL (required)
• -winMs : Window size in milliseconds (default: 100)
• -hopMs : Hop size in milliseconds (default: 50)
• -ratioThresh : Power ratio threshold for tone detection
• -rmsThresh : RMS threshold for signal detection
• -minAms : Minimum duration for Tone A (ms)
• -minBms : Minimum duration for Tone B (ms)
• -gapMaxMs : Maximum allowed gap between tones (ms)
• -silenceThresh : RMS threshold for silence detection
• -silenceDurMs : Duration of silence before stopping recording (ms)

Output

• Detected tone events are logged to the console.
• Audio segments containing detected tones are saved as WAV files in the current directory.

Requirements

• Go 1.20+
• gortsplib
• go-audio/wav