Unclear how to use microphone input remotely with HTTP

[timaschew]

I've tried to stream the audio via HTTP with a self written Node.js application. I was able to receive the stream with VLC but with rhasspy it didn't work.

Then I found a solution using VLC (as a server) but I only get it working with RTP in the WAVE codec:

vlc -vvv alsa://hw:1,0 --sout '#transcode{vcodec=none,acodec=s16l,channels=1,samplerate=16000,scodec=none}:rtp{dst=192.168.178.30,port=1234,sdp=rtsp://192.168.178.30:8080/test.sdp}'

and HTTP with MPEG codec:

vlc -vvv alsa://hw:1,0 --sout '#transcode{vcodec=none,acodec=mpga,ab=128,channels=2,samplerate=44100}:standard{access=http,mux=mp3,dst=192.168.178.30:8080}'

Anyway I don't know what rhasspy is exactly expecting, when using HTTP which path is used for instance? Would be nice to have some example, reference.

[synesthesiam]

It's expecting raw PCM audio in chunked transfer encoding. I designed it while trying to understand how Home Assistant/Ada worked with streaming audio.

Do you have any sense of how people might generally want to use it? It may also be fairly redundant given the GStreamer input.

[timaschew]

It's expecting raw PCM audio in chunked transfer encoding.

As I've said, I've get it working with vlc and of course it is a chunked transfer (stream) in PCM format. Since I've enabled logging on my server I was able to realize that rhasspy was not calling the HTTP endpoint at all.

So what I would expect:

• either document which path will be listened or pass the full path including the port in the settings
• test the setup somehow:
  • push a button so that rhasspy will do the HTTP request
  • record for a specific amount of time in order to verify that some data is really recorded by rhasspy

As a reference: I'm using the node-record-lpcm16 module and just pipe the stream form the microphone to response via express:

const recorder = require('node-record-lpcm16')
const express = require('express')

const recording = recorder.record()
const microphoneStream = recording.stream()
const app = express()
app.get('*', (req, res) => {
  console.log('client connected')
  res.status(200)
  res.set('Content-Type', 'audio/wav')
  microphoneStream.pipe(res)
})
app.listen(7000)

[synesthesiam]

HTTP microphone is removed in 2.5. Suggest using gstreamer instead.