/// <summary>
/// The number of channels is read from the flac header here.
/// This can be extracted from bits 165-167 of the stream.
/// More information: https://xiph.org/flac/format.html#metadata_block_streaminfo.
/// </summary>
/// <param name="stream">The flac file stream.</param>
/// <returns>The number of channels.</returns>
public static Fin <byte> ReadNumChannels(Stream stream)
{
long position = stream.Seek(ChannelOffset, SeekOrigin.Begin);
Debug.Assert(position == 20, $"Expected stream.Seek position to return 20, instead returned {position}");
Span <byte> buffer = stackalloc byte[1];
int bytesRead = stream.Read(buffer);
if (bytesRead != buffer.Length)
{
return(FileTooShort);
}
return((byte)(BinaryHelpers.Read3BitUnsignedBigEndianIgnoringFirstFourAndLastBit(buffer) + 1));
}
