public void Initialize(Stream stream, AudioInfo info, AudioMetadata metadata, SettingDictionary settings)
{
_stream = stream;
_metadata = metadata;
_settings = settings;
_bitsPerSample = info.BitsPerSample;
// Pre-allocate the whole stream (estimate worst case compression, plus cover art)
stream.SetLength(info.FrameCount * info.Channels * (long)Math.Ceiling(info.BitsPerSample / 8.0)
+ (metadata.CoverArt?.Data.Length ?? 0));
var inputDescription = GetInputDescription(info);
_audioFile = new ExtendedAudioFile(GetOutputDescription(inputDescription), AudioFileType.M4A, stream);
_audioFile.SetProperty(ExtendedAudioFilePropertyId.ClientDataFormat, inputDescription);
}
public void Finish()
{
// ReSharper disable once PossibleNullReferenceException
_audioFile.Dispose();
_audioFile = null;
// ReSharper disable once PossibleNullReferenceException
_stream.Position = 0;
// Call the external MP4 encoder for writing iTunes-compatible atoms
var metadataEncoderFactory =
ExtensionProvider.GetFactories <IAudioMetadataEncoder>("Extension", FileExtension).FirstOrDefault();
if (metadataEncoderFactory == null)
{
return;
}
using (var export = metadataEncoderFactory.CreateExport())
// ReSharper disable twice AssignNullToNotNullAttribute
export.Value.WriteMetadata(_stream, _metadata, _settings);
}
public void Initialize(Stream stream, AudioInfo info, AudioMetadata metadata, SettingDictionary settings)
{
_stream = stream;
_metadata = metadata;
_settings = settings;
InitializeReplayGainFilter(info, metadata, settings);
var inputDescription = GetInputDescription(info);
_audioFile = new ExtendedAudioFile(GetOutputDescription(inputDescription), AudioFileType.M4A, stream);
_audioFile.SetProperty(ExtendedAudioFilePropertyId.ClientDataFormat, inputDescription);
var converter = _audioFile.GetProperty <IntPtr>(ExtendedAudioFilePropertyId.AudioConverter);
var logger = LoggerManager.LoggerFactory.CreateLogger <AacAudioEncoder>();
// Enable high quality (defaults to medium, 0x40)
SetConverterProperty(converter, AudioConverterPropertyId.CodecQuality, 0x60);
if (settings.TryGetValue("BitRate", out int bitRate))
{
if (bitRate > 256 && info.Channels == 1)
{
logger.LogWarning("The maximum bitrate for 1-channel audio is 256 kbps.");
bitRate = 256;
}
else if (bitRate < 64 && info.Channels == 2)
{
logger.LogWarning("The minimum bitrate for 2-channel audio is 64 kbps.");
bitRate = 64;
}
SetConverterProperty(converter, AudioConverterPropertyId.BitRate, bitRate * 1000);
// Set the control mode (constrained is the default)
var controlMode = BitrateControlMode.VariableConstrained;
if (settings.TryGetValue("ControlMode", out string controlModeValue))
{
if (controlModeValue.Equals("Average", StringComparison.OrdinalIgnoreCase))
{
controlMode = BitrateControlMode.LongTermAverage;
}
else if (controlModeValue.Equals("Constant", StringComparison.OrdinalIgnoreCase))
{
controlMode = BitrateControlMode.Constant;
}
}
SetConverterProperty(converter, AudioConverterPropertyId.BitRateControlMode, (uint)controlMode);
}
else
{
// Enable a true variable bitrate
SetConverterProperty(converter, AudioConverterPropertyId.BitRateControlMode,
(uint)BitrateControlMode.Variable);
// Use a default VBR quality index of 9
SetConverterProperty(converter, AudioConverterPropertyId.VbrQuality,
settings.TryGetValue("VBRQuality", out int quality)
? _vbrQualities[quality]
: _vbrQualities[9]);
}
// Setting the ConverterConfig property to null resynchronizes the converter settings
_audioFile.SetProperty(ExtendedAudioFilePropertyId.ConverterConfig, IntPtr.Zero);
}
