/// <summary>
/// Converts a WMA file to a WAV stream
/// </summary>
/// <param name="outputStream">Stream to store the converted wav.</param>
/// <param name="filePath">Path to a .wma file to convert</param>
/// <returns>The WaveFormat object of the converted wav</returns>
private static WaveFormat wmaToWav(string pathToWma, Stream outputStream, int sampleRate, int bitDepth, int numChannels)
{
if (!Path.GetExtension(pathToWma).ToLowerInvariant().Contains("wma"))
throw new ArgumentException("Must be a .wma file!");
using (var reader = new WMAFileReader(pathToWma))
{
var targetFormat = new NAudio.Wave.WaveFormat(sampleRate, bitDepth, numChannels);
var pcmStream = new WaveFormatConversionStream(targetFormat, reader);
var buffer = new byte[pcmStream.Length];
pcmStream.Read(buffer, 0, (int)pcmStream.Length);
outputStream.Write(buffer, 0, buffer.Length);
outputStream.Position = 0;
pcmStream.Close();
return targetFormat;
}
}
/// <summary>
/// Creates an input WaveChannel
/// (Audio file reader for MP3/WAV/OGG/FLAC/WMA/AIFF/Other formats in the future)
/// </summary>
/// <param name="filename"></param>
public static WaveStream CreateInputWaveChannel(string filename)
{
WaveStream m_blockAlignedStream = null;
WaveStream m_waveReader = null;
WaveChannel32 m_waveChannel = null;
string fileExt = Path.GetExtension( filename.ToLower() );
if ( fileExt == MP3Extension ) {
m_waveReader = new Mp3FileReader(filename);
m_blockAlignedStream = new BlockAlignReductionStream(m_waveReader);
// Wave channel - reads from file and returns raw wave blocks
m_waveChannel = new WaveChannel32(m_blockAlignedStream);
} else if ( fileExt == WAVExtension ) {
m_waveReader = new WaveFileReader(filename);
if (m_waveReader.WaveFormat.Encoding != WaveFormatEncoding.Pcm) {
m_waveReader = WaveFormatConversionStream.CreatePcmStream(m_waveReader);
m_waveReader = new BlockAlignReductionStream(m_waveReader);
} if (m_waveReader.WaveFormat.BitsPerSample != 16) {
var format = new WaveFormat(m_waveReader.WaveFormat.SampleRate,
16, m_waveReader.WaveFormat.Channels);
m_waveReader = new WaveFormatConversionStream(format, m_waveReader);
}
m_waveChannel = new WaveChannel32(m_waveReader);
} else if (fileExt == OGGVExtension) {
m_waveReader = new OggFileReader(filename);
if (m_waveReader.WaveFormat.Encoding != WaveFormatEncoding.Pcm) {
m_waveReader = WaveFormatConversionStream.CreatePcmStream(m_waveReader);
m_waveReader = new BlockAlignReductionStream(m_waveReader);
} if (m_waveReader.WaveFormat.BitsPerSample != 16) {
var format = new WaveFormat(m_waveReader.WaveFormat.SampleRate,
16, m_waveReader.WaveFormat.Channels);
m_waveReader = new WaveFormatConversionStream(format, m_waveReader);
}
m_waveChannel = new WaveChannel32(m_waveReader);
} else if (fileExt == FLACExtension) {
m_waveReader = new FLACFileReader(filename);
if (m_waveReader.WaveFormat.Encoding != WaveFormatEncoding.Pcm) {
m_waveReader = WaveFormatConversionStream.CreatePcmStream(m_waveReader);
m_waveReader = new BlockAlignReductionStream(m_waveReader);
} if (m_waveReader.WaveFormat.BitsPerSample != 16) {
var format = new WaveFormat(m_waveReader.WaveFormat.SampleRate,
16, m_waveReader.WaveFormat.Channels);
m_waveReader = new WaveFormatConversionStream(format, m_waveReader);
}
m_waveChannel = new WaveChannel32(m_waveReader);
}
else if (fileExt == WMAExtension) {
m_waveReader = new WMAFileReader(filename);
if (m_waveReader.WaveFormat.Encoding != WaveFormatEncoding.Pcm) {
m_waveReader = WaveFormatConversionStream.CreatePcmStream(m_waveReader);
m_waveReader = new BlockAlignReductionStream(m_waveReader);
} if (m_waveReader.WaveFormat.BitsPerSample != 16) {
var format = new WaveFormat(m_waveReader.WaveFormat.SampleRate,
16, m_waveReader.WaveFormat.Channels);
m_waveReader = new WaveFormatConversionStream(format, m_waveReader);
}
m_waveChannel = new WaveChannel32(m_waveReader);
} else if (fileExt == AIFFExtension) {
m_waveReader = new AiffFileReader(filename);
m_waveChannel = new WaveChannel32(m_waveReader);
} else {
throw new ApplicationException("Cannot create Input WaveChannel - Unknown file type: " + fileExt);
}
//return m_waveReader;
return m_waveChannel;
}
