kcar
4139eb8fd3
Root causes of disconnection and slow transcription:
- AudioWorklet was firing every 128 native samples (~48 kHz), sending
~375 tiny WebSocket messages/sec. Server flooded with tiny frames
during silence → keepalive ping timed out → connection dropped.
- JS resampling 48 kHz → 16 kHz added CPU overhead on every chunk.
- Audio started on ws.onopen before server sent SERVER_READY, so early
frames were dropped.
Fixes:
- audioWorklet.js: accumulate 4096 samples before posting (256 ms/chunk
at 16 kHz, ~4 messages/sec), transfer ArrayBuffer zero-copy.
- transcriptionService: AudioContext({ sampleRate: 16000 }) — browser
handles native resampling, no JS resampling needed. Remove
resampleTo16kHZ entirely.
- Wait for SERVER_READY message before calling setupAudioProcessing().
- Send 'END_OF_AUDIO' string on stop so server can finalise last segment.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
27 lines
734 B
JavaScript
27 lines
734 B
JavaScript
class AudioProcessor extends AudioWorkletProcessor {
|
|
constructor() {
|
|
super();
|
|
this._buffer = new Float32Array(4096);
|
|
this._bufferIndex = 0;
|
|
}
|
|
|
|
process(inputs) {
|
|
const input = inputs[0];
|
|
if (input.length > 0) {
|
|
const samples = input[0];
|
|
for (let i = 0; i < samples.length; i++) {
|
|
this._buffer[this._bufferIndex++] = samples[i];
|
|
if (this._bufferIndex >= 4096) {
|
|
// Transfer ownership (zero-copy) to main thread
|
|
this.port.postMessage(this._buffer.buffer, [this._buffer.buffer]);
|
|
this._buffer = new Float32Array(4096);
|
|
this._bufferIndex = 0;
|
|
}
|
|
}
|
|
}
|
|
return true;
|
|
}
|
|
}
|
|
|
|
registerProcessor('audio-processor', AudioProcessor);
|