/// <summary>
/// Open the media.
/// Create the structures.
/// </summary>
protected override void OpenMediaAsync() {
header = WaveFormatExtensible.ReadHeader(stream);
header.ValidateWaveFormat();
sampleSize = (long)header.Channels * header.BitsPerSample / 8 * numSamples;
startPosition = currentPosition = stream.Position;
pcmDataLen = stream.Length - startPosition;
duration = header.AudioDurationFromDataLen(pcmDataLen);
// Init
Dictionary<MediaStreamAttributeKeys, string> streamAttributes = new Dictionary<MediaStreamAttributeKeys, string>();
Dictionary<MediaSourceAttributesKeys, string> sourceAttributes = new Dictionary<MediaSourceAttributesKeys, string>();
List<MediaStreamDescription> availableStreams = new List<MediaStreamDescription>();
// Stream Description
streamAttributes[MediaStreamAttributeKeys.CodecPrivateData] = header.ToHexString();
MediaStreamDescription msd = new MediaStreamDescription(MediaStreamType.Audio, streamAttributes);
this.audioDesc = msd;
availableStreams.Add(this.audioDesc);
sourceAttributes[MediaSourceAttributesKeys.Duration] = duration.ToString();
ReportOpenMediaCompleted(sourceAttributes, availableStreams);
}
public bool Eq(WaveFormatExtensible fmt) {
return BitsPerSample == fmt.BitsPerSample && Channels == fmt.Channels && SamplesPerSec == fmt.SamplesPerSec;
}
public static WaveFormatExtensible ReadHeader(Stream m_Stream/*, out int DataLength, out long DataPos*/) {
BinaryReader Reader = new BinaryReader(m_Stream);
if (ReadChunk(Reader) != "RIFF") throw new Exception("Invalid RIFF");
Reader.ReadInt32(); // File length minus first 8 bytes of RIFF description, we don't use it
if (ReadChunk(Reader) != "WAVE") throw new Exception("Invalid WAVE");
if (ReadChunk(Reader) != "fmt ") throw new Exception("Invalid fmt");
int FormatLength = Reader.ReadInt32();
if (FormatLength != WaveFormatSize) throw new Exception("Invalid FormatLength");
WaveFormatExtensible Format = new WaveFormatExtensible(); // initialize to any format
Format.FormatTag = Reader.ReadInt16();
Format.Channels = Reader.ReadInt16();
Format.SamplesPerSec = Reader.ReadInt32();
Format.AverageBytesPerSecond = Reader.ReadInt32();
Format.BlockAlign = Reader.ReadInt16();
Format.BitsPerSample = Reader.ReadInt16();
if (ReadChunk(Reader) != "data") throw new Exception("Invalid data chunk");
if (m_Stream.Position >= m_Stream.Length) throw new Exception("Missing DataLen field");
Format.DataLen = Reader.ReadInt32();
if (m_Stream.Length != Format.DataLen + RIFFHeaderSize) throw new Exception("Wrong WAV stream size");
return Format;
}
public static void WriteHeader(Stream str, WaveFormatExtensible fmt, uint dataLen) {
WriteHeader(str, fmt.Channels, fmt.BitsPerSample, (uint)fmt.SamplesPerSec, dataLen);
}
