Adds --server and --volume option

[flatsiedatsie]

This runs the core of the project in a loop until the process receives a termination signal.

After creating this issue I thought I'd see if I could add "server" functionality myself. It's probably not optimal, since I'm not a C++ coder. The bool running = true part might not be needed.

[flatsiedatsie]

The second commit to this pull request adds a -v or --volume option, which lets users set the desired output volume of the audio.

This also works with JSON input, to change the volume while in server mode. E.g.

echo '{"text":"Bla bla bla","volume_level":"0.1"}' | ./piper --model /home/pi/tts/en_US-lessac-medium.onnx --json-input --server --output-raw -volume 0.8 --sentence_silence 0.1 | aplay -D plughw:0,0 -r22050 -fS16_LE -t raw -

[akhil3417]

how would on go about using this server(i.e make requests)? how's this different from https://github.com/rhasspy/piper/blob/master/src/python_run/README_http.md

[flatsiedatsie]

It's not really a server, it's a long-running cli process.

• Useful when using cli is prefered over server route (e.g. avoid port use / manage all sub-processes similarly)
• Output can be piped directly to aplay as it is generated

Making a request works as follows:

if self.llm_tts_process.poll() == None:
    if self.DEBUG:
        print("llm_speak: LLM TTS Process is running")
    json_voice_message = '{ "text": "' + str(voice_message).replace('"', '\\"') + '","volume_level":"' + str( int(self.persistent_data['speaker_volume'])/100) + '"}\n'
    if self.DEBUG: 
        print("piping json into Piper: " + str(json_voice_message))
    self.llm_tts_process.stdin.write(json_voice_message)
    self.llm_tts_process.stdin.flush()

Looking back, --server is probably the wrong name for this feature if a real server already exists.

[akhil3417]

thanks, since the piper-tts python package doesn't sound as good (since the binary uses patched espeak-ng), this is alternative for now. can you share the binary ?

[flatsiedatsie]

Sure, the binary can be found here: https://github.com/createcandle/voco/tree/master/llm/tts

Implementation example can be found here:
https://github.com/createcandle/voco/blob/master/pkg/voco_adapter.py

[akhil3417]

linked binary was aarch64, forgot to mention but m running x86_64 arch.

exec: Failed to execute process: './piper' the file could not be run by the operating system.

[flatsiedatsie]

Then you'll have to compile it yourself.