/// <summary>
/// Initializes a new instance of AudioFileReader
/// </summary>
/// <param name="stream">The file to open</param>
public AudioDataReader(Stream stream, SelectDecoder format, PreferredDecoder preferredDecoder)
{
readerStream = CreateReaderStream(stream, format, preferredDecoder);
sourceBytesPerSample = (readerStream.WaveFormat.BitsPerSample / 8) * readerStream.WaveFormat.Channels;
sampleChannel = new SampleChannel(readerStream, false);
destBytesPerSample = 4 * sampleChannel.WaveFormat.Channels;
length = SourceToDest(readerStream.Length);
}
/// <summary>
/// Creates the reader stream, supporting all filetypes in the core NAudio library,
/// and ensuring we are in PCM format
/// </summary>
/// <param name="stream">File Name</param>
WaveStream CreateReaderStream(Stream stream, SelectDecoder format, PreferredDecoder preferredDecoder)
{
WaveStream readerStream = null;
switch (format)
{
case SelectDecoder.WAV:
readerStream = new WaveFileReader(stream);
if (readerStream.WaveFormat.Encoding != WaveFormatEncoding.Pcm && readerStream.WaveFormat.Encoding != WaveFormatEncoding.IeeeFloat)
{
readerStream = WaveFormatConversionStream.CreatePcmStream(readerStream);
readerStream = new BlockAlignReductionStream(readerStream);
}
break;
case SelectDecoder.MP3:
readerStream = new Mp3FileReader(stream, waveFormat => CreateMp3FrameDecoder(waveFormat, preferredDecoder));
break;
case SelectDecoder.AIFF:
readerStream = new AiffFileReader(stream);
break;
case SelectDecoder.Ogg:
readerStream = new NVorbis.NAudioSupport.VorbisWaveReader(stream);
break;
case SelectDecoder.AutoDetect:
UsedDecoder = UsedDecoder.None;
// try to create reader for all formats
foreach (var tryFormat in autoDetectFormatOrder)
{
stream.Seek(0, SeekOrigin.Begin);
try
{
readerStream = CreateReaderStream(stream, tryFormat, preferredDecoder);
}
catch { }
if (readerStream != null)
{
UsedDecoder = (UsedDecoder)tryFormat;
break;
}
}
if (readerStream == null)
{
throw new Exception("Failed to figure out " + typeof(SelectDecoder) + ".");
}
break;
}
return(readerStream);
}
public static IMp3FrameDecompressor CreateMp3FrameDecoder(WaveFormat waveFormat, PreferredDecoder preferredDecoder)
{
var useMannaged = false;
if (IsNativeMp3DecoderAvailable && IsManagedMp3DecoderAvailable)
{
useMannaged = preferredDecoder == PreferredDecoder.PreferManaged;
}
else if (IsNativeMp3DecoderAvailable)
{
useMannaged = false;
}
else if (IsManagedMp3DecoderAvailable)
{
useMannaged = true;
}
else
{
throw new Exception("Nor native nor mannager MP3 decoder is available.");
}
if (useMannaged)
{
//return new NLayer.NAudioSupport.Mp3FrameDecompressor(waveFormat); // compiler might not know the type if NLAyer is disabled
return((IMp3FrameDecompressor)Activator.CreateInstance(managedMp3DecoderType, waveFormat));
}
else
{
return(new AcmMp3FrameDecompressor(waveFormat));
}
}
