docs: add js example

Addresses #26

Author: Fedir Zadniprovskyi

examples/javascript/index.js

@@ -0,0 +1,159 @@
+/**
+ * Example provided by https://github.com/Gan-Xing in https://github.com/fedirz/faster-whisper-server/issues/26
+ */
+import fs from 'fs';
+import WebSocket from 'ws';
+import fetch from 'node-fetch';
+import FormData from 'form-data';
+import path from 'path';
+import ffmpeg from 'fluent-ffmpeg';
+import dotenv from 'dotenv';
+
+dotenv.config();
+
+const ffmpegPath = process.env.FFMPEG_PATH || '/usr/bin/ffmpeg';
+ffmpeg.setFfmpegPath(ffmpegPath);
+
+/**
+ * Transcribe an audio file using the HTTP endpoint.
+ * Supported file types include wav, mp3, webm, and other types supported by the OpenAI API.
+ * I have tested with these three types.
+ *
+ * @param {string} filePath - Path to the audio file
+ * @param {string} model - Model name
+ * @param {string} language - Language code
+ * @param {string} responseFormat - Response format
+ * @param {string} temperature - Temperature setting
+ */
+async function transcribeFile(filePath, model, language, responseFormat, temperature) {
+    const formData = new FormData();
+    formData.append('file', fs.createReadStream(filePath));
+    formData.append('model', model);
+    formData.append('language', language);
+    formData.append('response_format', responseFormat);
+    formData.append('temperature', temperature);
+
+    const response = await fetch(`${process.env.TRANSCRIPTION_API_BASE_URL}/v1/audio/transcriptions`, {
+        method: 'POST',
+        body: formData,
+    });
+
+    const transcription = await response.json();
+    console.log('Transcription Response:', transcription);
+}
+
+/**
+ * Translate an audio file using the HTTP endpoint.
+ * Only English is supported for translation.
+ * Currently, I am using GLM-4-9b-int8 to translate various voices.
+ * I am not sure if the author can add an endpoint for custom API+Key translation.
+ * I plan to package my frontend, fast-whisper-server, and vllm+glm-4-9b-int8 into one Docker container for unified deployment.
+ *
+ * @param {string} filePath - Path to the audio file
+ * @param {string} model - Model name
+ * @param {string} responseFormat - Response format
+ * @param {string} temperature - Temperature setting
+ */
+async function translateFile(filePath, model, responseFormat, temperature) {
+    const formData = new FormData();
+    formData.append('file', fs.createReadStream(filePath));
+    formData.append('model', model);
+    formData.append('response_format', responseFormat);
+    formData.append('temperature', temperature);
+
+    const response = await fetch(`${process.env.TRANSLATION_API_BASE_URL}/v1/audio/translations`, {
+        method: 'POST',
+        body: formData,
+    });
+
+    const translation = await response.json();
+    console.log('Translation Response:', translation);
+}
+
+/**
+ * Send audio data over WebSocket for transcription.
+ * Currently, the supported file type for transcription is PCM.
+ * I am not sure if other types are supported.
+ *
+ * @param {string} filePath - Path to the audio file
+ * @param {string} model - Model name
+ * @param {string} language - Language code
+ * @param {string} responseFormat - Response format
+ * @param {string} temperature - Temperature setting
+ */
+async function sendAudioOverWebSocket(filePath, model, language, responseFormat, temperature) {
+    const wsUrl = `ws://100.105.162.69:8000/v1/audio/transcriptions?model=${encodeURIComponent(model)}&language=${encodeURIComponent(language)}&response_format=${encodeURIComponent(responseFormat)}&temperature=${encodeURIComponent(temperature)}`;
+    const ws = new WebSocket(wsUrl);
+
+    ws.on('open', async () => {
+        const audioBuffer = fs.readFileSync(filePath);
+        ws.send(audioBuffer);
+    });
+
+    ws.on('message', (message) => {
+        const response = JSON.parse(message);
+        console.log('WebSocket Response:', response);
+    });
+
+    ws.on('close', () => {
+        console.log('WebSocket connection closed');
+    });
+
+    ws.on('error', (error) => {
+        console.error('WebSocket error:', error);
+    });
+}
+
+/**
+ * Convert audio file to PCM format.
+ *
+ * @param {string} filePath - Path to the audio file
+ * @returns {string} - Path to the converted PCM file
+ */
+async function convertToPcm(filePath) {
+    const pcmFilePath = filePath.replace(path.extname(filePath), '.pcm');
+
+    await new Promise((resolve, reject) => {
+        ffmpeg(filePath)
+            .audioChannels(1)
+            .audioFrequency(16000)
+            .audioCodec('pcm_s16le')
+            .toFormat('s16le')
+            .on('end', () => {
+                console.log(`Audio file successfully converted to PCM: ${pcmFilePath}`);
+                resolve(pcmFilePath);
+            })
+            .on('error', (error) => {
+                console.error(`Error converting audio to PCM: ${error.message}`);
+                reject(error);
+            })
+            .save(pcmFilePath);
+    });
+
+    return pcmFilePath;
+}
+
+async function main() {
+    const model = 'Systran/faster-whisper-large-v3';
+    const language = 'en';
+    const responseFormat = 'json';
+    const temperature = '0';
+    const filePath = './path/to/your/audio.webm';  // Replace with the actual file path
+
+    // Convert the audio file to PCM format
+    const pcmFilePath = await convertToPcm(filePath);
+
+    // Transcribe the audio file using the HTTP endpoint
+    await transcribeFile(pcmFilePath, model, language, responseFormat, temperature);
+
+    // Translate the audio file using the HTTP endpoint
+    await translateFile(pcmFilePath, model, responseFormat, temperature);
+
+    // Transcribe the audio file using the WebSocket endpoint
+    await sendAudioOverWebSocket(pcmFilePath, model, language, responseFormat, temperature);
+}
+
+// Make sure to use ffmpeg version 7 or above. The default apt-get install only installs version 4.x. Also, Ubuntu 22.04 or above is required to support version 7.x.
+main().catch(console.error);
+
+// Project URL: https://github.com/Gan-Xing/whisper