ADN-DMR-Peer-Server/docs/TTS_SETUP.md

TTS (Text-to-Speech) Setup

TTS announcements convert text files to AMBE and play them on a talkgroup at intervals or hourly.

Pipeline

.txt → gTTS → .mp3 → ffmpeg → .wav (8kHz mono) → vocoder/AMBEServer → .ambe → broadcast

First-time setup

1. Create the text file in Audio/<LANGUAGE>/ondemand/<FILE>.txt

   Example for FILE: texto1 and LANGUAGE: es_ES:

   Audio/es_ES/ondemand/texto1.txt
   

   Put the text you want spoken in that file (UTF-8).

2. Configure encoding — choose one:

   • Physical AMBE (DV3000): set TTS_AMBESERVER_HOST to the host where AMBEServer runs (connected to the DV3000).
   • Software vocoder: set TTS_VOCODER_CMD with a command like /usr/local/bin/md380-vocoder -e {wav} {ambe}.

3. Enable the TTS item in TTS_ANNOUNCEMENTS:

   TTS_ANNOUNCEMENTS:
     - ENABLED: true
       FILE: texto1
       TG: 2
       MODE: interval
       INTERVAL: 60
       LANGUAGE: es_ES
   

How it works

• First run: The system reads texto1.txt, generates speech (gTTS), converts to WAV, encodes to AMBE via the configured vocoder/AMBEServer, saves texto1.ambe, and broadcasts it.
• Later runs: If texto1.ambe exists and is newer than texto1.txt, it uses the cached AMBE file directly (no conversion).
• Update text: Edit texto1.txt and save. On the next interval, the system will regenerate texto1.ambe because the .txt is newer.

Physical AMBE (AMBEServer)

When using a DV3000 or similar hardware via AMBEServer:

1. Run AMBEServer on a host with the DV3000 connected (USB/serial).
2. In adn-voice.yaml:

   TTS_AMBESERVER_HOST: "192.168.1.10"   # host where AMBEServer runs
   TTS_AMBESERVER_PORT: 2460              # default
   

3. Ensure the ADN server can reach that host:port (UDP).

Troubleshooting physical AMBE

Symptom	Check
"Text file not found"	Create Audio/<LANG>/ondemand/<FILE>.txt (e.g. Audio/es_ES/ondemand/texto1.txt)
"AMBEServer failed, trying external vocoder..."	AMBEServer unreachable or timeout. Verify host/port, firewall, AMBEServer running.
"Could not encode to AMBE"	Neither AMBEServer nor TTS_VOCODER_CMD worked. Set one of them.
"Timeout connecting to AMBEServer"	Network/firewall; AMBEServer not listening; DV3000 not connected.
No audio plays	Check logs for "(TTS) Playing TTS file" — if present, broadcast succeeded; check TG and bridge targets.

Log messages

• (TTS) Converting text to AMBE: ... — first-time conversion in progress
• (TTS) Using AMBEServer host:port — using physical AMBE
• (TTS) Using cached AMBE — .ambe exists and is newer than .txt
• (TTS) AMBEServer failed, trying external vocoder... — AMBEServer failed; fallback to TTS_VOCODER_CMD if set

Dependencies

• gTTS: pip install gTTS
• ffmpeg: system package (apt install ffmpeg etc.)
• AMBEServer (physical AMBE): marrold/AMBEServer on a host with DV3000