pcm_to_ogg

A Flutter plugin to convert raw PCM audio data into the Ogg Vorbis format. It uses native C/C++ libraries (libogg and libvorbis) for high performance and supports all major platforms through Dart FFI and WebAssembly.

This plugin is ideal for applications that work with raw audio data, such as voice recorders, and need to encode it into a standardized, compressed format for storage or streaming.

Features

• High-Performance Encoding: Utilizes the native libogg and libvorbis libraries for fast and efficient encoding.
• Cross-Platform: Works on Android, iOS, macOS, Windows, Linux, and Web.
• Simple API: A straightforward API with just two main methods: initialize() and convert().
• Web Support: Uses a pre-compiled WebAssembly module for web compatibility.

Supported Platforms

Installation

Add this to your package's pubspec.yaml file:

dependencies:
  pcm_to_ogg: ^1.0.0 # Replace with the latest version

Then, run flutter pub get.

Web Platform Setup

To use this plugin on the Web, a manual one-time setup is required. You must copy the necessary WebAssembly files into your project's web directory.

1. Locate the pcm_to_ogg package directory on your system (it is downloaded by Flutter into the pub cache).
2. Find the pre-compiled web files inside the package at lib/src/web/precompiled/.
3. Copy pcm_to_ogg.js and pcm_to_ogg.wasm from that directory.
4. Paste them into the web/ directory at the root of your Flutter application.

After copying the files, the plugin will be able to load and use them automatically.

Basic Usage

Here is a simple example of how to use the plugin.

import 'package:flutter/material.dart';
import 'dart:typed_data';
import 'package:pcm_to_ogg/pcm_to_ogg.dart';

// In a stateful widget...
Uint8List? oggData;

Future<void> runConversion(Float32List pcmData) async {
  try {
    // Initialize the plugin (especially needed for web)
    await PcmToOgg.initialize();

    // Perform the conversion
    final result = await PcmToOgg.convert(
      pcmData,
      channels: 1,
      sampleRate: 44100,
      quality: 0.7, // Quality from 0.0 to 1.0
    );

    setState(() {
      oggData = result;
    });

    print('Conversion successful! OGG size: ${result.lengthInBytes} bytes');

  } catch (e) {
    print('An error occurred: $e');
  }
}

Important Notes

• Always call PcmToOgg.initialize() before the first conversion, especially on the web, as it needs to download and compile the WebAssembly module.
• The input PCM data must be a Float32List.