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Project Lakechain

Audio Metadata

Unstable API 0.10.0 @project-lakechain/audio-metadata-extractor TypeScript

The audio metadata extractor enriches document metadata with specific information about input audio documents, such as codec, bitrate, sample rate, duration, title, or album art information. Those metadata can then be later used by subsequent middlewares in the pipeline, or stored in a database.

🎧 Extracting Metadata

Section titled “🎧 Extracting Metadata”

To use this middleware, you import it in your CDK stack and instantiate it as part of a pipeline.

import { AudioMetadataExtractor } from '@project-lakechain/audio-metadata-extractor';
import { CacheStorage } from '@project-lakechain/core';


class Stack extends cdk.Stack {
  constructor(scope: cdk.Construct, id: string) {
    // The cache storage.
    const cache = new CacheStorage(this, 'Cache');


    // Extracts metadata from audio documents.
    const audioMetadata = new AudioMetadataExtractor.Builder()
      .withScope(this)
      .withIdentifier('AudioMetadata')
      .withCacheStorage(cache)
      .withSource(source) // 👈 Specify a data source
      .build();
  }
}

📄 Output

Section titled “📄 Output”

The audio metadata extraction middleware does not modify or alter source audio documents in any way. It instead enriches the metadata of the documents with captured information. Below is an example of metadata captured using this middleware.

💁 Click to expand example 
{
  "specversion": "1.0",
  "id": "1780d5de-fd6f-4530-98d7-82ebee85ea39",
  "type": "document-created",
  "time": "2023-10-22T13:19:10.657Z",
  "data": {
      "chainId": "6ebf76e4-f70c-440c-98f9-3e3e7eb34c79",
      "source": {
          "url": "s3://bucket/audio.mp3",
          "type": "audio/mpeg",
          "size": 245328,
          "etag": "1243cbd6cf145453c8b5519a2ada4779"
      },
      "document": {
          "url": "s3://bucket/audio.mp3",
          "type": "audio/mpeg",
          "size": 245328,
          "etag": "1243cbd6cf145453c8b5519a2ada4779"
      },
      "metadata": {
        "title": "Artist - Title",
        "properties": {
          "kind": "audio",
          "attrs": {
            "codec": "mp3",
            "bitrate": 320000,
            "sampleRate": 44100,
            "duration": 431.5
          }
        }
      },
      "callStack": []
  }
}

🏗️ Architecture

Section titled “🏗️ Architecture”

This middleware runs within a Lambda compute based on the ARM64 architecture, and packages the music-metadata library to extract the metadata of audio documents.

Architecture


🏷️ Properties

Section titled “🏷️ Properties”

Supported Inputs
Section titled “Supported Inputs”
Mime Type Description
audio/mpeg MPEG audio documents.
audio/mp3 MP3 audio documents.
audio/mp4 MP4 audio documents.
audio/wav WAV audio documents.
audio/x-wav WAV audio documents.
audio/x-m4a M4A audio documents.
audio/ogg OGG audio documents.
audio/x-flac FLAC audio documents.
audio/flac FLAC audio documents.
audio/x-aiff AIFF audio documents.
audio/aiff AIFF audio documents.
audio/x-ms-wma WMA audio documents.
audio/x-matroska MKV audio documents.
audio/webm WebM audio documents.
audio/aac AAC audio documents.
Supported Outputs
Section titled “Supported Outputs”

This middleware supports as outputs the same types as the supported inputs.

Supported Compute Types
Section titled “Supported Compute Types”
Type Description
CPU This middleware only supports CPU compute.

📖 Examples

Section titled “📖 Examples”