/// <summary>
/// Opens MP3 from a stream rather than a file
/// Will not dispose of this stream itself
/// </summary>
/// <param name="inputStream"></param>
public Mp3FileReader(Stream inputStream)
{
int sampleRate;
int bitRate;
mp3Stream = inputStream;
id3v2Tag = Id3v2Tag.ReadTag(mp3Stream);
dataStartPosition = mp3Stream.Position;
Mp3Frame mp3Frame = new Mp3Frame(mp3Stream);
sampleRate = mp3Frame.SampleRate;
frameLengthInBytes = mp3Frame.FrameLength;
bitRate = mp3Frame.BitRate;
xingHeader = XingHeader.LoadXingHeader(mp3Frame);
this.length = mp3Stream.Length - dataStartPosition;
// try for an ID3v1 tag as well
mp3Stream.Position = mp3Stream.Length - 128;
byte[] tag = new byte[128];
mp3Stream.Read(tag, 0, 3);
if (tag[0] == 'T' && tag[1] == 'A' && tag[2] == 'G')
{
id3v1Tag = tag;
this.length -= 128;
}
mp3Stream.Position = dataStartPosition;
// TODO: choose more appropriately
waveFormat = new Mp3WaveFormat(sampleRate, 2, frameLengthInBytes, bitRate);
}
public bool IsWaveformatEqual(Mp3Frame frame)
{
//TODO : fix function. somehow it doesn't work 100% ...
//hence return false so it always re-inits backend
return false;
Mp3WaveFormat new_mp3Format = new Mp3WaveFormat(frame.SampleRate, frame.ChannelMode == ChannelMode.Mono ? 1 : 2,
frame.FrameLength, frame.BitRate);
if (waveFormat.GetType() != new_mp3Format.GetType())
return false;
Mp3WaveFormat CurrentFormat = (Mp3WaveFormat)waveFormat;
if(
CurrentFormat.SampleRate == new_mp3Format.SampleRate &&
CurrentFormat.Channels == new_mp3Format.Channels &&
CurrentFormat.BitsPerSample == new_mp3Format.BitsPerSample &&
CurrentFormat.AverageBytesPerSecond == new_mp3Format.AverageBytesPerSecond &&
CurrentFormat.blockSize == new_mp3Format.blockSize &&
CurrentFormat.ExtraSize == new_mp3Format.ExtraSize)
{
return true;
}
else
{
return false;
}
}
public void CanParseMp3FrameOffsetByN(int offset)
{
byte[] validMp3Frame = constructValidMp3Frame();
byte[] offsetBuffer = new byte[offset + validMp3Frame.Length];
Array.Copy(validMp3Frame, 0, offsetBuffer, offset, validMp3Frame.Length);
MemoryStream ms = new MemoryStream(validMp3Frame);
Mp3Frame frame = new Mp3Frame(ms);
}
public static IMp3FrameDecompressor CreateFrameDecompressor(Mp3Frame frame)
{
WaveFormat waveFormat = new Mp3WaveFormat(frame.SampleRate,
frame.ChannelMode == ChannelMode.Mono ? 1 : 2,
frame.FrameLength,
frame.BitRate
);
return new AcmMp3FrameDecompressor(waveFormat);
}
public int DecompressFrame(Mp3Frame frame, byte[] dest, int destOffset)
{
Array.Copy(frame.RawData, conversionStream.SourceBuffer, frame.FrameLength);
int sourceBytesConverted = 0;
int converted = conversionStream.Convert(frame.FrameLength, out sourceBytesConverted);
if (sourceBytesConverted != frame.FrameLength)
{
throw new InvalidOperationException("Couldn't convert the whole MP3 frame");
}
Array.Copy(conversionStream.DestBuffer, 0, dest, destOffset, converted);
return converted;
}
IEnumerable<float[]> DecompressMp3(Mp3Frame aFrame)
{
/*
WaveFormat waveFormat = new Mp3WaveFormat(aFrame.SampleRate, aFrame.ChannelMode == ChannelMode.Mono ? 1 : 2, aFrame.FrameLength, aFrame.BitRate);
var decompressor = new AcmMp3FrameDecompressor(waveFormat);
var bufferedWaveProvider = new BufferedWaveProvider(decompressor.OutputFormat);
int decompressed = decompressor..DecompressFrame(aFrame,, buffer, 0);
*/
yield return new float[] { 0, 0 };
}
/// <summary>Reads an MP3Frame from a stream</summary>
/// <remarks>http://mpgedit.org/mpgedit/mpeg_format/mpeghdr.htm has some good info
/// also see http://www.codeproject.com/KB/audio-video/mpegaudioinfo.aspx
/// </remarks>
/// <returns>A valid MP3 frame, or null if none found</returns>
public static Mp3Frame LoadFromStream(Stream input, bool readData)
{
var frame = new Mp3Frame();
frame.FileOffset = input.Position;
byte[] headerBytes = new byte[4];
int bytesRead = input.Read(headerBytes, 0, headerBytes.Length);
if (bytesRead < headerBytes.Length)
{
// reached end of stream, no more MP3 frames
return null;
}
while (!IsValidHeader(headerBytes, frame))
{
// shift down by one and try again
headerBytes[0] = headerBytes[1];
headerBytes[1] = headerBytes[2];
headerBytes[2] = headerBytes[3];
bytesRead = input.Read(headerBytes, 3, 1);
if (bytesRead < 1)
{
return null;
}
frame.FileOffset++;
}
/* no longer read the CRC since we include this in framelengthbytes
if (this.crcPresent)
this.crc = reader.ReadInt16();*/
int bytesRequired = frame.FrameLength - 4;
if (readData)
{
frame.RawData = new byte[frame.FrameLength];
Array.Copy(headerBytes, frame.RawData, 4);
bytesRead = input.Read(frame.RawData, 4, bytesRequired);
if (bytesRead < bytesRequired)
{
// TODO: could have an option to suppress this, although it does indicate a corrupt file
// for now, caller should handle this exception
throw new EndOfStreamException("Unexpected end of stream before frame complete");
}
}
else
{
// n.b. readData should not be false if input stream does not support seeking
input.Position += bytesRequired;
}
return frame;
}
/// <summary>
/// Decompresses a frame
/// </summary>
/// <param name="frame">The MP3 frame</param>
/// <param name="dest">destination buffer</param>
/// <param name="destOffset">Offset within destination buffer</param>
/// <returns>Bytes written into destination buffer</returns>
public int DecompressFrame(Mp3Frame frame, byte[] dest, int destOffset)
{
if (frame == null)
{
throw new ArgumentNullException("frame", "You must provide a non-null Mp3Frame to decompress");
}
Array.Copy(frame.RawData, conversionStream.SourceBuffer, frame.FrameLength);
int sourceBytesConverted = 0;
int converted = conversionStream.Convert(frame.FrameLength, out sourceBytesConverted);
if (sourceBytesConverted != frame.FrameLength)
{
throw new InvalidOperationException(String.Format("Couldn't convert the whole MP3 frame (converted {0}/{1})",
sourceBytesConverted, frame.FrameLength));
}
Array.Copy(conversionStream.DestBuffer, 0, dest, destOffset, converted);
return converted;
}
private Mp3FileReader(Stream inputStream, FrameDecompressorBuilder frameDecompressorBuilder, bool ownInputStream)
{
if (inputStream == null)
{
throw new ArgumentNullException(nameof(inputStream));
}
if (frameDecompressorBuilder == null)
{
throw new ArgumentNullException(nameof(frameDecompressorBuilder));
}
this.ownInputStream = ownInputStream;
try
{
mp3Stream = inputStream;
Id3v2Tag = Id3v2Tag.ReadTag(mp3Stream);
dataStartPosition = mp3Stream.Position;
var firstFrame = Mp3Frame.LoadFromStream(mp3Stream);
if (firstFrame == null)
{
throw new InvalidDataException("Invalid MP3 file - no MP3 Frames Detected");
}
double bitRate = firstFrame.BitRate;
xingHeader = XingHeader.LoadXingHeader(firstFrame);
// If the header exists, we can skip over it when decoding the rest of the file
if (xingHeader != null)
{
dataStartPosition = mp3Stream.Position;
}
// workaround for a longstanding issue with some files failing to load
// because they report a spurious sample rate change
var secondFrame = Mp3Frame.LoadFromStream(mp3Stream);
if (secondFrame != null &&
(secondFrame.SampleRate != firstFrame.SampleRate ||
secondFrame.ChannelMode != firstFrame.ChannelMode))
{
// assume that the first frame was some kind of VBR/LAME header that we failed to recognise properly
dataStartPosition = secondFrame.FileOffset;
// forget about the first frame, the second one is the first one we really care about
firstFrame = secondFrame;
}
mp3DataLength = mp3Stream.Length - dataStartPosition;
// try for an ID3v1 tag as well
mp3Stream.Position = mp3Stream.Length - 128;
byte[] tag = new byte[128];
mp3Stream.Read(tag, 0, 128);
if (tag[0] == 'T' && tag[1] == 'A' && tag[2] == 'G')
{
Id3v1Tag = tag;
mp3DataLength -= 128;
}
mp3Stream.Position = dataStartPosition;
// create a temporary MP3 format before we know the real bitrate
Mp3WaveFormat = new Mp3WaveFormat(firstFrame.SampleRate,
firstFrame.ChannelMode == ChannelMode.Mono ? 1 : 2, firstFrame.FrameLength, (int)bitRate);
CreateTableOfContents();
tocIndex = 0;
// [Bit rate in Kilobits/sec] = [Length in kbits] / [time in seconds]
// = [Length in bits ] / [time in milliseconds]
// Note: in audio, 1 kilobit = 1000 bits.
// Calculated as a double to minimize rounding errors
bitRate = (mp3DataLength * 8.0 / TotalSeconds());
mp3Stream.Position = dataStartPosition;
// now we know the real bitrate we can create an accurate MP3 WaveFormat
Mp3WaveFormat = new Mp3WaveFormat(firstFrame.SampleRate,
firstFrame.ChannelMode == ChannelMode.Mono ? 1 : 2, firstFrame.FrameLength, (int)bitRate);
decompressor = frameDecompressorBuilder(Mp3WaveFormat);
waveFormat = decompressor.OutputFormat;
bytesPerSample = (decompressor.OutputFormat.BitsPerSample) / 8 * decompressor.OutputFormat.Channels;
// no MP3 frames have more than 1152 samples in them
bytesPerDecodedFrame = 1152 * bytesPerSample;
// some MP3s I seem to get double
decompressBuffer = new byte[bytesPerDecodedFrame * 2];
}
catch (Exception)
{
if (ownInputStream)
{
inputStream.Dispose();
}
throw;
}
}
/// <summary>
/// checks if the four bytes represent a valid header,
/// if they are, will parse the values into Mp3Frame
/// </summary>
private static bool IsValidHeader(byte[] headerBytes, Mp3Frame frame)
{
if ((headerBytes[0] == 0xFF) && ((headerBytes[1] & 0xE0) == 0xE0))
{
// TODO: could do with a bitstream class here
frame.MpegVersion = (MpegVersion)((headerBytes[1] & 0x18) >> 3);
if (frame.MpegVersion == MpegVersion.Reserved)
{
//throw new FormatException("Unsupported MPEG Version");
return(false);
}
frame.MpegLayer = (MpegLayer)((headerBytes[1] & 0x06) >> 1);
if (frame.MpegLayer == MpegLayer.Reserved)
{
return(false);
}
int layerIndex = frame.MpegLayer == MpegLayer.Layer1 ? 0 : frame.MpegLayer == MpegLayer.Layer2 ? 1 : 2;
frame.CrcPresent = (headerBytes[1] & 0x01) == 0x00;
frame.BitRateIndex = (headerBytes[2] & 0xF0) >> 4;
if (frame.BitRateIndex == 15)
{
// invalid index
return(false);
}
int versionIndex = frame.MpegVersion == Wave.MpegVersion.Version1 ? 0 : 1;
frame.BitRate = bitRates[versionIndex, layerIndex, frame.BitRateIndex] * 1000;
if (frame.BitRate == 0)
{
return(false);
}
int sampleFrequencyIndex = (headerBytes[2] & 0x0C) >> 2;
if (sampleFrequencyIndex == 3)
{
return(false);
}
if (frame.MpegVersion == MpegVersion.Version1)
{
frame.SampleRate = sampleRatesVersion1[sampleFrequencyIndex];
}
else if (frame.MpegVersion == MpegVersion.Version2)
{
frame.SampleRate = sampleRatesVersion2[sampleFrequencyIndex];
}
else
{
// mpegVersion == MpegVersion.Version25
frame.SampleRate = sampleRatesVersion25[sampleFrequencyIndex];
}
bool padding = (headerBytes[2] & 0x02) == 0x02;
bool privateBit = (headerBytes[2] & 0x01) == 0x01;
frame.ChannelMode = (ChannelMode)((headerBytes[3] & 0xC0) >> 6);
frame.ChannelExtension = (headerBytes[3] & 0x30) >> 4;
if (frame.ChannelExtension != 0 && frame.ChannelMode != ChannelMode.JointStereo)
{
return(false);
}
frame.Copyright = (headerBytes[3] & 0x08) == 0x08;
bool original = (headerBytes[3] & 0x04) == 0x04;
int emphasis = (headerBytes[3] & 0x03);
int nPadding = padding ? 1 : 0;
frame.SampleCount = samplesPerFrame[versionIndex, layerIndex];
int coefficient = frame.SampleCount / 8;
if (frame.MpegLayer == MpegLayer.Layer1)
{
frame.FrameLength = (coefficient * frame.BitRate / frame.SampleRate + nPadding) * 4;
}
else
{
frame.FrameLength = (coefficient * frame.BitRate) / frame.SampleRate + nPadding;
}
if (frame.FrameLength > MaxFrameLength)
{
return(false);
}
return(true);
}
return(false);
}
/// <summary>
/// Load Xing Header
/// </summary>
/// <param name="frame">Frame</param>
/// <returns>Xing Header</returns>
public static XingHeader LoadXingHeader(Mp3Frame frame)
{
XingHeader xingHeader = new XingHeader();
xingHeader.frame = frame;
int offset = 0;
if (frame.MpegVersion == MpegVersion.Version1)
{
if (frame.ChannelMode != ChannelMode.Mono)
offset = 32 + 4;
else
offset = 17 + 4;
}
else if (frame.MpegVersion == MpegVersion.Version2)
{
if (frame.ChannelMode != ChannelMode.Mono)
offset = 17 + 4;
else
offset = 9 + 4;
}
else
{
return null;
// throw new FormatException("Unsupported MPEG Version");
}
if ((frame.RawData[offset + 0] == 'X') &&
(frame.RawData[offset + 1] == 'i') &&
(frame.RawData[offset + 2] == 'n') &&
(frame.RawData[offset + 3] == 'g'))
{
xingHeader.startOffset = offset;
offset += 4;
}
else
{
return null;
}
XingHeaderOptions flags = (XingHeaderOptions)ReadBigEndian(frame.RawData, offset);
offset += 4;
if ((flags & XingHeaderOptions.Frames) != 0)
{
xingHeader.framesOffset = offset;
offset += 4;
}
if ((flags & XingHeaderOptions.Bytes) != 0)
{
xingHeader.bytesOffset = offset;
offset += 4;
}
if ((flags & XingHeaderOptions.Toc) != 0)
{
xingHeader.tocOffset = offset;
offset += 100;
}
if ((flags & XingHeaderOptions.VbrScale) != 0)
{
xingHeader.vbrScale = ReadBigEndian(frame.RawData, offset);
offset += 4;
}
xingHeader.endOffset = offset;
return xingHeader;
}
/// <summary>
/// Reads decompressed PCM data from our MP3 file.
/// </summary>
public override int Read(byte[] sampleBuffer, int offset, int numBytes)
{
int bytesRead = 0;
lock (repositionLock)
{
if (decompressLeftovers != 0)
{
int toCopy = Math.Min(decompressLeftovers, numBytes);
Array.Copy(decompressBuffer, decompressBufferOffset, sampleBuffer, offset, toCopy);
decompressLeftovers -= toCopy;
if (decompressLeftovers == 0)
{
decompressBufferOffset = 0;
}
else
{
decompressBufferOffset += toCopy;
}
bytesRead += toCopy;
offset += toCopy;
}
int targetTocIndex = tocIndex; // the frame index that contains the requested data
if (repositionedFlag)
{
decompressor.Reset();
// Seek back a few frames of the stream to get the reset decoder decode a few
// warm-up frames before reading the requested data. Without the warm-up phase,
// the first half of the frame after the reset is attenuated and does not resemble
// the data as it would be when reading sequentially from the beginning, because
// the decoder is missing the required overlap from the previous frame.
tocIndex = Math.Max(0, tocIndex - 3); // no warm-up at the beginning of the stream
mp3Stream.Position = tableOfContents[tocIndex].FilePosition;
repositionedFlag = false;
}
while (bytesRead < numBytes)
{
Mp3Frame frame = ReadNextFrame();
if (frame != null)
{
int decompressed = decompressor.DecompressFrame(frame, decompressBuffer, 0);
if (tocIndex <= targetTocIndex || decompressed == 0)
{
// The first frame after a reset usually does not immediately yield decoded samples.
// Because the next instructions will fail if a buffer offset is set and the frame
// decoding didn't return data, we skip the part.
// We skip the following instructions also after decoding a warm-up frame.
continue;
}
// Two special cases can happen here:
// 1. We are interested in the first frame of the stream, but need to read the second frame too
// for the decoder to return decoded data
// 2. We are interested in the second frame of the stream, but because reading the first frame
// as warm-up didn't yield any data (because the decoder needs two frames to return data), we
// get data from the first and second frame.
// This case needs special handling, and we have to purge the data of the first frame.
else if (tocIndex == targetTocIndex + 1 && decompressed == bytesPerDecodedFrame * 2)
{
// Purge the first frame's data
Array.Copy(decompressBuffer, bytesPerDecodedFrame, decompressBuffer, 0, bytesPerDecodedFrame);
decompressed = bytesPerDecodedFrame;
}
int toCopy = Math.Min(decompressed - decompressBufferOffset, numBytes - bytesRead);
Array.Copy(decompressBuffer, decompressBufferOffset, sampleBuffer, offset, toCopy);
if ((toCopy + decompressBufferOffset) < decompressed)
{
decompressBufferOffset = toCopy + decompressBufferOffset;
decompressLeftovers = decompressed - decompressBufferOffset;
}
else
{
// no lefovers
decompressBufferOffset = 0;
decompressLeftovers = 0;
}
offset += toCopy;
bytesRead += toCopy;
}
else
{
break;
}
}
}
Debug.Assert(bytesRead <= numBytes, "MP3 File Reader read too much");
position += bytesRead;
return(bytesRead);
}
/// <summary>
/// Load Xing Header
/// </summary>
/// <param name="frame">Frame</param>
/// <returns>Xing Header</returns>
public static XingHeader LoadXingHeader(Mp3Frame frame)
{
XingHeader xingHeader = new XingHeader();
xingHeader.frame = frame;
int offset = 0;
if (frame.MpegVersion == MpegVersion.Version1)
{
if (frame.ChannelMode != ChannelMode.Mono)
{
offset = 32 + 4;
}
else
{
offset = 17 + 4;
}
}
else if (frame.MpegVersion == MpegVersion.Version2)
{
if (frame.ChannelMode != ChannelMode.Mono)
{
offset = 17 + 4;
}
else
{
offset = 9 + 4;
}
}
else
{
return(null);
// throw new FormatException("Unsupported MPEG Version");
}
if ((frame.RawData[offset + 0] == 'X') &&
(frame.RawData[offset + 1] == 'i') &&
(frame.RawData[offset + 2] == 'n') &&
(frame.RawData[offset + 3] == 'g'))
{
xingHeader.startOffset = offset;
offset += 4;
}
else
{
return(null);
}
XingHeaderOptions flags = (XingHeaderOptions)ReadBigEndian(frame.RawData, offset);
offset += 4;
if ((flags & XingHeaderOptions.Frames) != 0)
{
xingHeader.framesOffset = offset;
offset += 4;
}
if ((flags & XingHeaderOptions.Bytes) != 0)
{
xingHeader.bytesOffset = offset;
offset += 4;
}
if ((flags & XingHeaderOptions.Toc) != 0)
{
xingHeader.tocOffset = offset;
offset += 100;
}
if ((flags & XingHeaderOptions.VbrScale) != 0)
{
xingHeader.vbrScale = ReadBigEndian(frame.RawData, offset);
offset += 4;
}
xingHeader.endOffset = offset;
return(xingHeader);
}
public void SetupBackend(Mp3Frame frame)
{
//first cleanup the the backend. the old MP3 info could be different
StopPlayer();
bFileEnding = false;
//setup the output stream, using the provider & mp3Frame
waveOut = new NAudio.Wave.DirectSoundOut();
SetWaveFormat(frame);
decompressor = new AcmMp3FrameDecompressor(waveFormat);
out_buffer = new BufferedWaveProvider(decompressor.OutputFormat);
volumeHandler = new VolumeWaveProvider16(out_buffer);
//1.0 = full volume, 0.0 = silence
volumeHandler.Volume = volume;
waveOut.Init(volumeHandler);
//signal event we are set up
if (backendHandler != null)
backendHandler(this, true);
waveOut.Play();
}
public int AddNextFrame(Mp3Frame frame)
{
if (frame == null)
throw new ArgumentNullException("given frame = null");
//when receiving data...
if (out_buffer == null)
{
SetupBackend(frame);
}
byte[] buffer = new byte[16384 * 50];
int decompressed = 0;
if (frame != null)
{
decompressed = decompressor.DecompressFrame(frame, buffer, 0);
if (out_buffer.BufferedBytes + decompressed < out_buffer.BufferLength)
{
out_buffer.AddSamples(buffer, 0, decompressed);//AddSamples(buffer,decompressed);//out_buffer.AddSamples(buffer, 0, decompressed);
}
}
return decompressed;
}
/// <summary>
/// checks if the four bytes represent a valid header,
/// if they are, will parse the values into Mp3Frame
/// </summary>
private static bool IsValidHeader(byte[] headerBytes, Mp3Frame frame)
{
if ((headerBytes[0] == 0xFF) && ((headerBytes[1] & 0xE0) == 0xE0))
{
// TODO: could do with a bitstream class here
frame.MpegVersion = (MpegVersion)((headerBytes[1] & 0x18) >> 3);
if (frame.MpegVersion == MpegVersion.Reserved)
{
//throw new FormatException("Unsupported MPEG Version");
return false;
}
frame.MpegLayer = (MpegLayer)((headerBytes[1] & 0x06) >> 1);
if (frame.MpegLayer == MpegLayer.Reserved)
{
return false;
}
int layerIndex = frame.MpegLayer == MpegLayer.Layer1 ? 0 : frame.MpegLayer == MpegLayer.Layer2 ? 1 : 2;
frame.crcPresent = (headerBytes[1] & 0x01) == 0x00;
int bitRateIndex = (headerBytes[2] & 0xF0) >> 4;
if (bitRateIndex == 15)
{
// invalid index
return false;
}
int versionIndex = frame.MpegVersion == Wave.MpegVersion.Version1 ? 0 : 1;
frame.BitRate = bitRates[versionIndex, layerIndex, bitRateIndex] * 1000;
if (frame.BitRate == 0)
{
return false;
}
int sampleFrequencyIndex = (headerBytes[2] & 0x0C) >> 2;
if (sampleFrequencyIndex == 3)
{
return false;
}
if (frame.MpegVersion == MpegVersion.Version1)
{
frame.SampleRate = sampleRatesVersion1[sampleFrequencyIndex];
}
else if (frame.MpegVersion == MpegVersion.Version2)
{
frame.SampleRate = sampleRatesVersion2[sampleFrequencyIndex];
}
else
{
// mpegVersion == MpegVersion.Version25
frame.SampleRate = sampleRatesVersion25[sampleFrequencyIndex];
}
bool padding = (headerBytes[2] & 0x02) == 0x02;
bool privateBit = (headerBytes[2] & 0x01) == 0x01;
frame.ChannelMode = (ChannelMode)((headerBytes[3] & 0xC0) >> 6);
int channelExtension = (headerBytes[3] & 0x30) >> 4;
bool copyright = (headerBytes[3] & 0x08) == 0x08;
bool original = (headerBytes[3] & 0x04) == 0x04;
int emphasis = (headerBytes[3] & 0x03);
int nPadding = padding ? 1 : 0;
frame.SampleCount = samplesPerFrame[versionIndex, layerIndex];
int coefficient = frame.SampleCount / 8;
if (frame.MpegLayer == MpegLayer.Layer1)
{
frame.FrameLength = (coefficient * frame.BitRate / frame.SampleRate + nPadding) * 4;
}
else
{
frame.FrameLength = (coefficient * frame.BitRate) / frame.SampleRate + nPadding;
}
if (frame.FrameLength > MaxFrameLength)
{
return false;
}
return true;
}
return false;
}
private void _bufferLoop()
{
Console.WriteLine("[Buffering thread] Started.");
_wavebuffer.DiscardOnBufferOverflow = true;
// Buffering loop
do
{
if (_cancel_buffer.IsCancellationRequested)
{
Console.WriteLine("[Buffering thread] Cancellation requested.");
//_cancel_buffer_token.ThrowIfCancellationRequested();
//Console.WriteLine("[Buffering thread] WARNING: Cancellation token is not cleanly set!");
break;
}
// Checking metadata
if (Metadata != stream.Metadata)
{
this.Metadata = stream.Metadata;
Task.Factory.StartNew(() =>
{
Console.WriteLine("[Buffering thread] Metadata has been changed to \"{0}\"", stream.Metadata);
Console.WriteLine("[Buffering thread] Delaying because of the buffering...", stream.Metadata);
Thread.Sleep(_wavebuffer.BufferedDuration);
Console.WriteLine("[Buffering thread] Exposing metadata NOW.", stream.Metadata);
if (MetadataChanged != null)
MetadataChanged.Invoke(this, new EventArgs());
});
}
// Seperated buffer
long bufferSize = 1024
* (Codec == StreamCodec.MP3 ? 128 : 8); // 128 kB for MP3, 8 kB for OGG/AACplus
byte[] buffer = new byte[bufferSize];
int decompressedLength = 0;
switch (Codec)
{
case StreamCodec.MP3:
// Decompress the frame
decompressedLength = _decoderMp3.DecompressFrame(frame, buffer, 0);
// Read next frame
frame = Mp3Frame.LoadFromStream(stream);
// Add the decompressed frame (samples) into the audio buffer for later playback
_wavebuffer.AddSamples(buffer, 0, decompressedLength);
break;
default:
throw new NotSupportedException();
}
} while (true);
_decoderMp3.Dispose();
stream.Close();
stream.Dispose();
}
private static bool IsValidHeader(byte[] headerBytes, Mp3Frame frame)
{
if (headerBytes[0] != 255 || (headerBytes[1] & 224) != 224)
{
return(false);
}
frame.MpegVersion = (MpegVersion)((headerBytes[1] & 24) >> 3);
if (frame.MpegVersion == MpegVersion.Reserved)
{
return(false);
}
frame.MpegLayer = (MpegLayer)((headerBytes[1] & 6) >> 1);
if (frame.MpegLayer == MpegLayer.Reserved)
{
return(false);
}
int num = (frame.MpegLayer == MpegLayer.Layer1) ? 0 : ((frame.MpegLayer == MpegLayer.Layer2) ? 1 : 2);
frame.CrcPresent = ((headerBytes[1] & 1) == 0);
frame.BitRateIndex = (headerBytes[2] & 240) >> 4;
if (frame.BitRateIndex == 15)
{
return(false);
}
int num2 = (frame.MpegVersion == MpegVersion.Version1) ? 0 : 1;
frame.BitRate = Mp3Frame.bitRates[num2, num, frame.BitRateIndex] * 1000;
if (frame.BitRate == 0)
{
return(false);
}
int num3 = (headerBytes[2] & 12) >> 2;
if (num3 == 3)
{
return(false);
}
if (frame.MpegVersion == MpegVersion.Version1)
{
frame.SampleRate = Mp3Frame.sampleRatesVersion1[num3];
}
else if (frame.MpegVersion == MpegVersion.Version2)
{
frame.SampleRate = Mp3Frame.sampleRatesVersion2[num3];
}
else
{
frame.SampleRate = Mp3Frame.sampleRatesVersion25[num3];
}
bool flag = (headerBytes[2] & 2) == 2;
byte b = headerBytes[2];
frame.ChannelMode = (ChannelMode)((headerBytes[3] & 192) >> 6);
frame.ChannelExtension = (headerBytes[3] & 48) >> 4;
if (frame.ChannelExtension != 0 && frame.ChannelMode != ChannelMode.JointStereo)
{
return(false);
}
frame.Copyright = ((headerBytes[3] & 8) == 8);
byte b2 = headerBytes[3];
byte b3 = headerBytes[3];
int num4 = flag ? 1 : 0;
frame.SampleCount = Mp3Frame.samplesPerFrame[num2, num];
int num5 = frame.SampleCount / 8;
if (frame.MpegLayer == MpegLayer.Layer1)
{
frame.FrameLength = (num5 * frame.BitRate / frame.SampleRate + num4) * 4;
}
else
{
frame.FrameLength = num5 * frame.BitRate / frame.SampleRate + num4;
}
return(frame.FrameLength <= 16384);
}
public static Mp3Frame LoadFromStream(Stream input)
{
return(Mp3Frame.LoadFromStream(input, true));
}
public void SetWaveFormat(Mp3Frame frame)
{
if (frame == null)
return;
waveFormat = new Mp3WaveFormat(frame.SampleRate, frame.ChannelMode == ChannelMode.Mono ? 1 : 2,
frame.FrameLength, frame.BitRate);
return;
}
public static XingHeader LoadXingHeader(Mp3Frame frame)
{
XingHeader xingHeader = new XingHeader();
xingHeader.frame = frame;
int num;
if (frame.MpegVersion == MpegVersion.Version1)
{
if (frame.ChannelMode != ChannelMode.Mono)
{
num = 36;
}
else
{
num = 21;
}
}
else
{
if (frame.MpegVersion != MpegVersion.Version2)
{
return(null);
}
if (frame.ChannelMode != ChannelMode.Mono)
{
num = 21;
}
else
{
num = 13;
}
}
if (frame.RawData[num] == 88 && frame.RawData[num + 1] == 105 && frame.RawData[num + 2] == 110 && frame.RawData[num + 3] == 103)
{
xingHeader.startOffset = num;
num += 4;
XingHeader.XingHeaderOptions xingHeaderOptions = (XingHeader.XingHeaderOptions)XingHeader.ReadBigEndian(frame.RawData, num);
num += 4;
if ((xingHeaderOptions & XingHeader.XingHeaderOptions.Frames) != (XingHeader.XingHeaderOptions) 0)
{
xingHeader.framesOffset = num;
num += 4;
}
if ((xingHeaderOptions & XingHeader.XingHeaderOptions.Bytes) != (XingHeader.XingHeaderOptions) 0)
{
xingHeader.bytesOffset = num;
num += 4;
}
if ((xingHeaderOptions & XingHeader.XingHeaderOptions.Toc) != (XingHeader.XingHeaderOptions) 0)
{
xingHeader.tocOffset = num;
num += 100;
}
if ((xingHeaderOptions & XingHeader.XingHeaderOptions.VbrScale) != (XingHeader.XingHeaderOptions) 0)
{
xingHeader.vbrScale = XingHeader.ReadBigEndian(frame.RawData, num);
num += 4;
}
xingHeader.endOffset = num;
return(xingHeader);
}
return(null);
}
private void _buffer(Stream input)
{
Console.WriteLine("[Initial buffering] Meta interval: {0}", this.StationInformation.ContainsKey("icy-metaint") ? long.Parse(this.StationInformation["icy-metaint"]) : -1);
// Auto-fix the stream and auto-parse metadata
stream =
new FixedBufferedStream(
input,
this.StationInformation.ContainsKey("icy-metaint") ? long.Parse(this.StationInformation["icy-metaint"]) : -1
);
// Read first frame
this.Status = StreamStatus.Buffering;
switch (Codec)
{
case StreamCodec.MP3:
// Make a decoder which can decode that (and sequentially following) frames
// The decoder will decode to 16-bit samples
frame = Mp3Frame.LoadFromStream(stream);
_decoderMp3 = new AcmMp3FrameDecompressor(new Mp3WaveFormat(frame.SampleRate, frame.ChannelMode == ChannelMode.Mono ? 1 : 2, frame.FrameLength, frame.BitRate));
Console.WriteLine("[Initial buffering] MP3 decoder will encode to {0}-encoded wave format.", _decoderMp3.OutputFormat.Encoding);
break;
default:
throw new NotSupportedException();
}
}
public void CanParseValidMp3Frame()
{
MemoryStream ms = new MemoryStream(constructValidMp3Frame());
Mp3Frame frame = new Mp3Frame(ms);
}
public Mp3FrameInfo(Mp3Frame frame, double averageVolume)
{
this.Frame = frame;
_averageVolume = averageVolume;
}
public void FailsToParseInvalidFrame(int length)
{
MemoryStream ms = new MemoryStream(new byte[length]);
Assert.Throws<EndOfStreamException>(() => { Mp3Frame frame = new Mp3Frame(ms); });
}
private void ValidateFrameFormat(Mp3Frame frame)
{
if (frame.SampleRate != Mp3WaveFormat.SampleRate)
{
string message =
String.Format(
"Got a frame at sample rate {0}, in an MP3 with sample rate {1}. Mp3FileReader does not support sample rate changes.",
frame.SampleRate, Mp3WaveFormat.SampleRate);
throw new InvalidOperationException(message);
}
int channels = frame.ChannelMode == ChannelMode.Mono ? 1 : 2;
if (channels != Mp3WaveFormat.Channels)
{
string message =
String.Format(
"Got a frame with channel mode {0}, in an MP3 with {1} channels. Mp3FileReader does not support changes to channel count.",
frame.ChannelMode, Mp3WaveFormat.Channels);
throw new InvalidOperationException(message);
}
}
private int DecompressFrame(Mp3Frame frame, byte[] buffer)
{
// decode frame
if (_decompressor == null)
{
WaveFormat waveFormat = new Mp3WaveFormat(frame.SampleRate, frame.ChannelMode == ChannelMode.Mono ? 1 : 2, frame.FrameLength, frame.BitRate);
_decompressor = new AcmMp3FrameDecompressor(waveFormat);
_waveProvider = new BufferedWaveProvider(_decompressor.OutputFormat);
_waveProvider.BufferDuration = TimeSpan.FromSeconds(5);
_channels = _waveProvider.WaveFormat.Channels;
_sampleProvider = _waveProvider.ToSampleProvider();
}
return _decompressor.DecompressFrame(frame, buffer, 0);
}
