private void ParseForMp3Frames(Stream stream, bool enableSeeking)
{
Mp3Frame frame = null;
long offsetOfFirstFrame = 0;
stream = new BufferedStream(stream);
if (enableSeeking)
{
while (ID3v2.SkipTag(stream))
{
/* skip all id3 tags (see https://github.com/filoe/cscore/issues/63)
* there are some files with multiple id3v2 tags
* not sure whether this is according to the id3 specification but we have to handle it anyway
* as long as the SkipTag method returns true, another id3 tag has been found
*/
}
}
while (frame == null)
{
if (enableSeeking && stream.IsEndOfStream())
{
break;
}
if (enableSeeking)
{
offsetOfFirstFrame = stream.Position;
}
frame = Mp3Frame.FromStream(stream);
}
if (frame == null)
{
throw new Exception("Could not find any MP3-Frames in the stream.");
}
if (enableSeeking)
{
XingHeader xingHeader = XingHeader.FromFrame(frame);
if (xingHeader != null)
{
offsetOfFirstFrame = stream.Position;
}
}
_inputFormat = new Mp3Format(frame.SampleRate, frame.ChannelCount, frame.FrameLength, frame.BitRate);
//Prescan stream
if (enableSeeking)
{
_frameInfoCollection = new FrameInfoCollection();
while (_frameInfoCollection.AddFromMp3Stream(stream))
{
}
stream.Position = offsetOfFirstFrame;
}
}
private void ParseForMp3Frames(Stream stream, bool enableSeeking)
{
Mp3Frame frame = null;
long offsetOfFirstFrame = 0;
ID3v2.SkipTag(stream);
while (frame == null && !stream.IsEndOfStream())
{
offsetOfFirstFrame = stream.Position;
frame = Mp3Frame.FromStream(stream);
}
if (frame == null)
{
throw new Exception("Could not find any MP3-Frames in the stream.");
}
if (stream.CanSeek)
{
XingHeader xingHeader = XingHeader.FromFrame(frame);
if (xingHeader != null)
{
offsetOfFirstFrame = stream.Position;
}
}
_inputFormat = new Mp3Format(frame.SampleRate, frame.ChannelCount, frame.FrameLength, frame.BitRate);
//todo: implement VBR
//Prescan stream
if (enableSeeking)
{
_frameInfoCollection = new FrameInfoCollection();
while (_frameInfoCollection.AddFromMp3Stream(stream))
{
}
stream.Position = offsetOfFirstFrame;
}
}
/// <summary>
/// Initializes a new instance of the <see cref="FlacFile" /> 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="FlacPreScanMode.Async" />.
/// </param>
public FlacFile(Stream stream, FlacPreScanMode scanFlag,
Action <FlacPreScanFinishedEventArgs> onscanFinished)
{
if (stream == null)
{
throw new ArgumentNullException();
}
if (!stream.CanRead)
{
throw new ArgumentException("Stream is not readable.", "stream");
}
_stream = stream;
_closeStream = true;
//skip ID3v2
while (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).ToList();
Metadata = metadata.AsReadOnly();
if (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 = CreateWaveFormat(streamInfo);
Log.Verbose("Flac StreamInfo found -> WaveFormat: " + _waveFormat);
Log.Verbose("Flac-File-Metadata read.");
}
else
{
throw new FlacException("Invalid Flac-File. \"fLaC\" Sync not found.", FlacLayer.OutSideOfFrame);
}
//prescan stream
if (scanFlag != FlacPreScanMode.None)
{
var scan = new FlacPreScan(stream);
scan.ScanFinished += (s, e) =>
{
onscanFinished?.Invoke(e);
};
scan.ScanStream(_streamInfo, scanFlag);
_scan = scan;
}
}
