AudioMetadata.fromJson constructor
Implementation
factory AudioMetadata.fromJson(Map<String, dynamic> json) {
  return AudioMetadata(
    codec: json['Codec'] as String?,
    durationMillis: json['DurationMillis'] as int?,
    numberOfChannels: json['NumberOfChannels'] as int?,
    sampleRate: json['SampleRate'] as int?,
  );
}