public AudioFormatEx(WAVEFORMATEX wavFormat)
: this(
(WaveFormatType) wavFormat.FormatTag, wavFormat.Channels, wavFormat.BitsPerSample,
wavFormat.SamplesPerSec)
{
//note: WAVEFORMATEX.FormatPCM = 1 and also WaveFormatType.Pcm = 1 that's why the cast is OK
}
public static void WriteSilence(Stream outputStream, WAVEFORMATEX audioFormat, double msec)
{
if (msec <= 0) return;
long bytes = audioFormat.BufferSizeFromAudioDuration((long) (msec*10000));
//expects duration in 100-nanosecond units (hns)
var b = new BinaryWriter(outputStream);
for (uint i = 0; i < bytes; i++)
b.Write((byte) 0);
}
/// <summary>
/// Read the format block from the file and construct the WAVEFORMATEX
/// structure
/// </summary>
private void ReadFormatBlock()
{
try
{
Debug.Assert(Chunk.FCC == FourCC.WavFmt, "This is not a WavFmt chunk");
Debug.Assert(this.waveFormat == null, "The waveformat structure should have been set before");
// Some .wav files do not include the cbSize field of the WAVEFORMATEX
// structure. For uncompressed PCM audio, field is always zero.
uint formatSize = 0;
if (Chunk.Size < MinFormatSize)
{
throw new InvalidOperationException("File is not a WAV file");
}
// Allocate a buffer for the WAVEFORMAT structure.
formatSize = Chunk.Size;
this.waveFormat = new WAVEFORMATEX();
// Read the format from the current chunk in the file
byte[] data = ReadDataFromChunk(formatSize);
// Copy the read data into our WAVFORMATEX
this.waveFormat.SetFromByteArray(data);
}
catch (Exception)
{
this.waveFormat = null;
throw;
}
}
