voice_audio_multi/examples/browser_extension/supertonic_speaker/README.md

audio.cpp Supertonic Speaker Extension

Minimal Chrome/Edge extension demo for speaking selected page text through an audiocpp_server streaming TTS model.

Start audio.cpp server

The demo includes separate CUDA and CPU server configs. The checked-in configs use models/supertonic-3 relative to the directory where audiocpp_server is started; edit the model path if your Supertonic model lives elsewhere.

• server.cuda.json: CUDA server on 127.0.0.1:8080
• server.cpu.json: CPU server on 127.0.0.1:8081

CUDA:

build/debug/bin/audiocpp_server --config examples/browser_extension/supertonic_speaker/server.cuda.json

CPU:

build/debug/bin/audiocpp_server --config examples/browser_extension/supertonic_speaker/server.cpu.json

The extension displays the current backend from /health.

The config shape is:

{
  "host": "127.0.0.1",
  "port": 8080,
  "backend": "cuda",
  "device": 0,
  "threads": 8,
  "lazy_load": true,
  "models": [
    {
      "id": "supertonic-stream",
      "family": "supertonic",
      "path": "/path/to/models/supertonic-3",
      "task": "tts",
      "mode": "streaming",
      "default_voice_preset": {
        "voice_id": "M1"
      }
    }
  ]
}

Load the extension

1. Open chrome://extensions or edge://extensions.
2. Enable Developer mode.
3. Click Load unpacked.
4. Select examples/browser_extension/supertonic_speaker.

Use

1. Open a web page.
2. Select some text.
3. Click the extension icon.
4. Confirm:
   • Server: http://127.0.0.1:8080
   • Model id: supertonic-stream
   • Sample rate: 44100
5. Click Selection.

The popup splits text into smaller chunks and sends sequential streaming SSE requests to /v1/audio/speech. Keep the popup open while it speaks.

You can also right-click a page and use:

• Read selection
• Read page

The context menu opens a small player window and starts playback immediately. The player shows live chunk progress, client-observed first-audio latency, the server-reported TTFT from speech.audio.done, and the number of audio delta events received for the current chunk.

For non-Supertonic TTS models, set the sample rate to the model's PCM output rate before speaking.

Offline Converter Demo

For long-form conversion, open the extension popup and click Offline converter. The page lets you upload a text file, choose a Supertonic preset voice, and run sequential offline conversion chunks. It shows progress, elapsed time, ETA, server wall time, generated audio duration, and RTF. As conversion runs, the page adds one playback bar and download link per generated WAV part.

CUDA offline server:

build/debug/bin/audiocpp_server --config examples/browser_extension/supertonic_speaker/server.offline.cuda.json

CPU offline server:

build/debug/bin/audiocpp_server --config examples/browser_extension/supertonic_speaker/server.offline.cpu.json

Use these URLs in the offline page:

• CUDA: http://127.0.0.1:8082
• CPU: http://127.0.0.1:8083