Transcription on mac

server/dist/speech-transcriber.js

@@ -0,0 +1,124 @@
+import WebSocket from 'ws';
+export class SpeechTranscriber {
+    options;
+    logger;
+    constructor(options, logger) {
+        this.options = options;
+        this.logger = logger;
+    }
+    async transcribe(requestId, audioBase64, mimeType) {
+        const audio = this.normalizeAudioPayload(audioBase64, mimeType);
+        return await new Promise((resolve, reject) => {
+            let settled = false;
+            const socket = new WebSocket(this.options.serviceUrl);
+            const finish = (handler) => {
+                if (settled) {
+                    return;
+                }
+                settled = true;
+                clearTimeout(timeout);
+                socket.removeAllListeners();
+                if (socket.readyState === WebSocket.CONNECTING || socket.readyState === WebSocket.OPEN) {
+                    socket.close();
+                }
+                handler();
+            };
+            const timeout = setTimeout(() => {
+                finish(() => {
+                    reject(new Error(`The transcription service timed out after ${this.options.requestTimeoutMs}ms.`));
+                });
+            }, this.options.requestTimeoutMs);
+            socket.on('open', () => {
+                try {
+                    socket.send(JSON.stringify({
+                        type: 'transcribe',
+                        id: requestId,
+                        language: this.options.language,
+                        audio,
+                    }));
+                }
+                catch (error) {
+                    finish(() => {
+                        reject(error instanceof Error ? error : new Error('Could not send transcription request.'));
+                    });
+                }
+            });
+            socket.on('message', (payload) => {
+                const event = this.parseEvent(payload);
+                if (!event) {
+                    return;
+                }
+                if (event.id && event.id !== requestId) {
+                    this.logger.warn({ requestId, event }, 'Ignored transcription event for another request');
+                    return;
+                }
+                if (event.type === 'start') {
+                    this.logger.info({ requestId, model: event.model, language: event.language }, 'Speech transcription started');
+                    return;
+                }
+                if (event.type === 'delta') {
+                    return;
+                }
+                if (event.type === 'done') {
+                    finish(() => {
+                        resolve(event.text.trim());
+                    });
+                    return;
+                }
+                finish(() => {
+                    reject(new Error(event.message));
+                });
+            });
+            socket.on('error', (error) => {
+                finish(() => {
+                    reject(error instanceof Error ? error : new Error('The transcription service connection failed.'));
+                });
+            });
+            socket.on('close', (code, reasonBuffer) => {
+                if (settled) {
+                    return;
+                }
+                const reason = reasonBuffer.toString().trim();
+                const detail = reason
+                    ? `The transcription service closed the connection unexpectedly (code=${code}, reason=${reason}).`
+                    : `The transcription service closed the connection unexpectedly (code=${code}).`;
+                finish(() => {
+                    reject(new Error(detail));
+                });
+            });
+        });
+    }
+    normalizeAudioPayload(audioBase64, mimeType) {
+        const trimmedAudio = audioBase64.trim();
+        if (trimmedAudio.startsWith('data:')) {
+            return trimmedAudio;
+        }
+        const normalizedMimeType = mimeType.trim() || 'audio/webm';
+        return `data:${normalizedMimeType};base64,${trimmedAudio}`;
+    }
+    parseEvent(payload) {
+        const message = this.rawDataToString(payload).trim();
+        if (!message) {
+            return null;
+        }
+        try {
+            return JSON.parse(message);
+        }
+        catch {
+            this.logger.warn({ transcriptionPayload: message }, 'Ignored non-JSON transcription event');
+            return null;
+        }
+    }
+    rawDataToString(payload) {
+        if (typeof payload === 'string') {
+            return payload;
+        }
+        if (payload instanceof ArrayBuffer) {
+            return Buffer.from(payload).toString('utf8');
+        }
+        if (Array.isArray(payload)) {
+            return Buffer.concat(payload).toString('utf8');
+        }
+        return payload.toString('utf8');
+    }
+}