ASR

What this skill does

# ASR (Speech to Text) Skill

This skill guides the implementation of speech-to-text (ASR) functionality using the z-ai-web-dev-sdk package, enabling accurate transcription of spoken audio into text.

## Skills Path

**Skill Location**: `{project_path}/skills/ASR`

this skill is located at above path in your project.

**Reference Scripts**: Example test scripts are available in the `{Skill Location}/scripts/` directory for quick testing and reference. See `{Skill Location}/scripts/asr.ts` for a working example.

## Overview

Speech-to-Text (ASR - Automatic Speech Recognition) allows you to build applications that convert spoken language in audio files into written text, enabling voice-controlled interfaces, transcription services, and audio content analysis.

**IMPORTANT**: z-ai-web-dev-sdk MUST be used in backend code only. Never use it in client-side code.

## Prerequisites

The z-ai-web-dev-sdk package is already installed. Import it as shown in the examples below.

## CLI Usage (For Simple Tasks)

For simple audio transcription tasks, you can use the z-ai CLI instead of writing code. This is ideal for quick transcriptions, testing audio files, or batch processing.

### Basic Transcription from File

```bash
# Transcribe an audio file
z-ai asr --file ./audio.wav

# Save transcription to JSON file
z-ai asr -f ./recording.mp3 -o transcript.json

# Transcribe and view output
z-ai asr --file ./interview.wav --output result.json
```

### Transcription from Base64

```bash
# Transcribe from base64 encoded audio
z-ai asr --base64 "UklGRiQAAABXQVZFZm10..." -o result.json

# Using short option
z-ai asr -b "base64_encoded_audio_data" -o transcript.json
```

### Streaming Output

```bash
# Stream transcription results
z-ai asr -f ./audio.wav --stream
```

### CLI Parameters

- `--file, -f <path>`: **Required** (if not using --base64) - Audio file path
- `--base64, -b <base64>`: **Required** (if not using --file) - Base64 encoded audio
- `--output, -o <path>`: Optional - Output file path (JSON format)
- `--stream`: Optional - Stream the transcription output

### Supported Audio Formats

The ASR service supports various audio formats including:
- WAV (.wav)
- MP3 (.mp3)
- Other common audio formats

### When to Use CLI vs SDK

**Use CLI for:**
- Quick audio file transcriptions
- Testing audio recognition accuracy
- Simple batch processing scripts
- One-off transcription tasks

**Use SDK for:**
- Real-time audio transcription in applications
- Integration with recording systems
- Custom audio processing workflows
- Production applications with streaming audio

## Basic ASR Implementation

### Simple Audio Transcription

```javascript
import ZAI from 'z-ai-web-dev-sdk';
import fs from 'fs';

async function transcribeAudio(audioFilePath) {
  const zai = await ZAI.create();

  // Read audio file and convert to base64
  const audioFile = fs.readFileSync(audioFilePath);
  const base64Audio = audioFile.toString('base64');

  const response = await zai.audio.asr.create({
    file_base64: base64Audio
  });

  return response.text;
}

// Usage
const transcription = await transcribeAudio('./audio.wav');
console.log('Transcription:', transcription);
```

### Transcribe Multiple Audio Files

```javascript
import ZAI from 'z-ai-web-dev-sdk';
import fs from 'fs';

async function transcribeBatch(audioFilePaths) {
  const zai = await ZAI.create();
  const results = [];

  for (const filePath of audioFilePaths) {
    try {
      const audioFile = fs.readFileSync(filePath);
      const base64Audio = audioFile.toString('base64');

      const response = await zai.audio.asr.create({
        file_base64: base64Audio
      });

      results.push({
        file: filePath,
        success: true,
        transcription: response.text
      });
    } catch (error) {
      results.push({
        file: filePath,
        success: false,
        error: error.message
      });
    }
  }

  return results;
}

// Usage
const files = ['./interview1.wav', './interview2.wav', './interview3.wav'];
const transcriptions = await transcribeBatch(files);

transcriptions.forEach(result => {
  if (result.success) {
    console.log(`${result.file}: ${result.transcription}`);
  } else {
    console.error(`${result.file}: Error - ${result.error}`);
  }
});
```

## Advanced Use Cases

### Audio File Processing with Metadata

```javascript
import ZAI from 'z-ai-web-dev-sdk';
import fs from 'fs';
import path from 'path';

async function transcribeWithMetadata(audioFilePath) {
  const zai = await ZAI.create();

  // Get file metadata
  const stats = fs.statSync(audioFilePath);
  const audioFile = fs.readFileSync(audioFilePath);
  const base64Audio = audioFile.toString('base64');

  const startTime = Date.now();

  const response = await zai.audio.asr.create({
    file_base64: base64Audio
  });

  const endTime = Date.now();

  return {
    filename: path.basename(audioFilePath),
    filepath: audioFilePath,
    fileSize: stats.size,
    transcription: response.text,
    wordCount: response.text.split(/\s+/).length,
    processingTime: endTime - startTime,
    timestamp: new Date().toISOString()
  };
}

// Usage
const result = await transcribeWithMetadata('./meeting_recording.wav');
console.log('Transcription Details:', JSON.stringify(result, null, 2));
```

### Real-time Audio Processing Service

```javascript
import ZAI from 'z-ai-web-dev-sdk';
import fs from 'fs';

class ASRService {
  constructor() {
    this.zai = null;
    this.transcriptionCache = new Map();
  }

  async initialize() {
    this.zai = await ZAI.create();
  }

  generateCacheKey(audioBuffer) {
    const crypto = require('crypto');
    return crypto.createHash('md5').update(audioBuffer).digest('hex');
  }

  async transcribe(audioFilePath, useCache = true) {
    const audioBuffer = fs.readFileSync(audioFilePath);
    const cacheKey = this.generateCacheKey(audioBuffer);

    // Check cache
    if (useCache && this.transcriptionCache.has(cacheKey)) {
      return {
        transcription: this.transcriptionCache.get(cacheKey),
        cached: true
      };
    }

    // Transcribe audio
    const base64Audio = audioBuffer.toString('base64');

    const response = await this.zai.audio.asr.create({
      file_base64: base64Audio
    });

    // Cache result
    if (useCache) {
      this.transcriptionCache.set(cacheKey, response.text);
    }

    return {
      transcription: response.text,
      cached: false
    };
  }

  clearCache() {
    this.transcriptionCache.clear();
  }

  getCacheSize() {
    return this.transcriptionCache.size;
  }
}

// Usage
const asrService = new ASRService();
await asrService.initialize();

const result1 = await asrService.transcribe('./audio.wav');
console.log('First call (not cached):', result1);

const result2 = await asrService.transcribe('./audio.wav');
console.log('Second call (cached):', result2);
```

### Directory Transcription

```javascript
import ZAI from 'z-ai-web-dev-sdk';
import fs from 'fs';
import path from 'path';

async function transcribeDirectory(directoryPath, outputJsonPath) {
  const zai = await ZAI.create();

  // Get all audio files
  const files = fs.readdirSync(directoryPath);
  const audioFiles = files.filter(file => 
    /\.(wav|mp3|m4a|flac|ogg)$/i.test(file)
  );

  const results = {
    directory: directoryPath,
    totalFiles: audioFiles.length,
    processedAt: new Date().toISOString(),
    transcriptions: []
  };

  for (const filename of audioFiles) {
    const filePath = path.join(directoryPath, filename);

    try {
      const audioFile = fs.readFileSync(filePath);
      const base64Audio = audioFile.toString('base64');

      const response = await zai.audio.asr.create({
        file_base64: base64Audio
      });

      results.transcriptions.push({
        filename: filename,
        success: true,
        text: response.text,
        wordCount: response.text.split(/\s+/).length
      });

      console.log(`✓ Transcribed: ${filename}`);
    } catch (error) {
      resul