/// <summary>
/// Initializes a new instance of the <see cref="FlacReader" /> class.
/// </summary>
/// <param name="stream">Stream which contains flac data which should be decoded.</param>
/// <param name="scanFlag">Scan mode which defines how to scan the flac data for frames.</param>
/// <param name="onscanFinished">
/// Callback which gets called when the pre scan processes finished. Should be used if the
/// <paramref name="scanFlag" /> argument is set the <see cref="FlacPreScanMethodMode.Async" />.
/// </param>
public FlacReader(Stream stream, FlacPreScanMethodMode scanFlag,
Action <FlacPreScanFinishedEventArgs> onscanFinished)
{
if (stream == null)
{
throw new ArgumentNullException();
}
if (!stream.CanRead)
{
throw new ArgumentException("Stream is not readable.", "stream");
}
_stream = stream;
//skip ID3v2
NAudio.Flac.ID3v2.SkipTag(stream);
//read fLaC sync
var beginSync = new byte[4];
int read = stream.Read(beginSync, 0, beginSync.Length);
if (read < beginSync.Length)
{
throw new EndOfStreamException("Can not read \"fLaC\" sync.");
}
if (beginSync[0] == 0x66 && beginSync[1] == 0x4C && //Check for 'fLaC' signature
beginSync[2] == 0x61 && beginSync[3] == 0x43)
{
//read metadata
List <FlacMetadata> metadata = FlacMetadata.ReadAllMetadataFromStream(stream);
Metadata = metadata;
if (metadata == null || metadata.Count <= 0)
{
throw new FlacException("No Metadata found.", FlacLayer.Metadata);
}
var streamInfo =
metadata.First(x => x.MetaDataType == FlacMetaDataType.StreamInfo) as FlacMetadataStreamInfo;
if (streamInfo == null)
{
throw new FlacException("No StreamInfo-Metadata found.", FlacLayer.Metadata);
}
_streamInfo = streamInfo;
_waveFormat = new WaveFormat(streamInfo.SampleRate, (short)streamInfo.BitsPerSample,
(short)streamInfo.Channels);
Debug.WriteLine("Flac StreamInfo found -> WaveFormat: " + _waveFormat);
Debug.WriteLine("Flac-File-Metadata read.");
}
else
{
throw new FlacException("Invalid Flac-File. \"fLaC\" Sync not found.", FlacLayer.Top);
}
//prescan stream
if (scanFlag != FlacPreScanMethodMode.None)
{
var scan = new FlacPreScan(stream);
scan.ScanFinished += (s, e) =>
{
if (onscanFinished != null)
{
onscanFinished(e);
}
};
scan.ScanStream(_streamInfo, scanFlag);
_scan = scan;
}
}
private unsafe List <FlacFrameInformation> ScanThisShit(FlacMetadataStreamInfo streamInfo)
{
Stream stream = _stream;
//if (!(stream is BufferedStream))
// stream = new BufferedStream(stream);
byte[] buffer = new byte[BufferSize];
int read = 0;
stream.Position = 4; //fLaC
FlacMetadata.ReadAllMetadataFromStream(stream);
List <FlacFrameInformation> frames = new List <FlacFrameInformation>();
FlacFrameInformation frameInfo = new FlacFrameInformation();
frameInfo.IsFirstFrame = true;
FlacFrameHeader baseHeader = null;
while (true)
{
read = stream.Read(buffer, 0, buffer.Length);
if (read <= FlacConstant.FrameHeaderSize)
break;
fixed(byte *bufferPtr = buffer)
{
byte *ptr = bufferPtr;
//for (int i = 0; i < read - FlacConstant.FrameHeaderSize; i++)
while ((bufferPtr + read - FlacConstant.FrameHeaderSize) > ptr)
{
if ((*ptr++ & 0xFF) == 0xFF && (*ptr & 0xF8) == 0xF8) //check sync
{
byte *ptrSafe = ptr;
ptr--;
FlacFrameHeader tmp = null;
if (IsFrame(ref ptr, streamInfo, baseHeader, out tmp))
{
FlacFrameHeader header = tmp;
if (frameInfo.IsFirstFrame)
{
baseHeader = header;
frameInfo.IsFirstFrame = false;
}
if (baseHeader.CompareTo(header))
{
frameInfo.StreamOffset = stream.Position - read + ((ptrSafe - 1) - bufferPtr);
frameInfo.Header = header;
frames.Add(frameInfo);
frameInfo.SampleOffset += header.BlockSize;
}
else
{
ptr = ptrSafe;
}
//todo:
}
else
{
ptr = ptrSafe;
}
}
}
}
stream.Position -= FlacConstant.FrameHeaderSize;
}
return(frames);
}