encrypted_audio_source

This extension allows the playback of encrypted audios through audio_service plugin.

How it works

Basically this is an implementation of StreamAudioSource, mentioned in just_audio documentation.

The stream to be listened to will be the encrypted bytes stream. Consequently, a decryption function is needed, which will process and store the decrypted bytes internally.

encryptedStream.doOnData((encryptedBytes) {
    final List<int> decryptedBytes = _decrypter.call(encryptedBytes);
    _decryptedBytes.addAll(decryptedBytes);
})

Usage

The first step is to define the encryption logic to be implemented. Consider using packages like pointycastle, encrypt or crypto. Either way, you will need a decryption function to handle the encrypted byte stream.

class MyEncrypter {
  static List<int> encrypt(List<int> originalBytes) {
    ///
  }

  static List<int> decrypt(List<int> encryptedBytes) {
    ///
  }
}

Once this is done, provide a stream of the audio file's encrypted data, and your decrypter to a new EncryptedAudioSource. For demonstration purposes, the example was implemented using a StreamedResponse.

Then, provide your EncryptedAudioSource to your AudioPlayer, via setAudioSource method.

// [...]
final player = AudioPlayer();

final Uri uri = Uri.parse("URL_OF_ENCRYPTED_AUDIO");
final http.Request request = http.Request('GET', uri);
final StreamedResponse response = await request.send();
final ByteStream stream = response.stream;

final myCustomSource = EncryptedAudioSource(
    encryptedStream: stream,
    decrypter: MyEncrypter.decrypt
    sourceLength: response.contentLength,
    contentType: 'audio/mpeg'
);

player.setAudioSource(myCustomSource);

/// You can handle the delayed duration result through [myCustomSource.totalDurationStream]

// [...]

After all this, you will be able to play your encrypted audios, through the implementation of audio_service.