DSP_BufferStream Class

BASS.NET API for the Un4seen BASS Audio Library

Stream Buffer DSP (to clone a BASS stream's current sample data to a decoding stream).

Inheritance Hierarchy

SystemObject
Un4seen.Bass.MiscBaseDSP
Un4seen.Bass.MiscDSP_BufferStream

Namespace: Un4seen.Bass.Misc
Assembly: Bass.Net (in Bass.Net.dll) Version: 2.4.17.7

Syntax

[SerializableAttribute]
public sealed class DSP_BufferStream : BaseDSP

<SerializableAttribute>
Public NotInheritable Class DSP_BufferStream
	Inherits BaseDSP

The DSP_BufferStream type exposes the following members.

Constructors

	Name	Description
	DSP_BufferStream	Creates a new instance of the Stream Buffer DSP, not assigning the DSP yet.
	DSP_BufferStream(Int32, Int32)	Creates a new instance of the Stream Buffer DSP, which already assigns the DSP (Start will be called automatically).

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Properties

	Name	Description
	BufferPosition	Gets or Sets the current buffer position in bytes.
	BufferStream	Gets the buffered BASS stream (the created custom stream).
	BufferStreamFlags	Gets the channel flags of the being used.
	ChannelBitwidth	This property returns the actual bitwidth of the sample data of the channel (e.g. 8, 16, 32). (Inherited from BaseDSP.)
	ChannelHandle	Gets or Sets the channel that the DSP is being applied to. (Inherited from BaseDSP.)
	ChannelInfo	Gets the BASS_CHANNELINFO of the assigned ChannelHandle. (Inherited from BaseDSP.)
	ChannelNumChans	This property returns the actual number of channles of the sample data BASS is using with the channel (e.g. 1=mono, 2=stereo, etc.). (Inherited from BaseDSP.)
	ChannelSampleRate	This property returns the actual sample rate in Hz of the sample data BASS is using with the channel (e.g. 44100). (Inherited from BaseDSP.)
	ConfigBuffer	Gets or Sets the buffer length in milliseconds to be used (between 1 and 5000).
	ConfigBufferLength	Gets the buffer length in bytes which is being used.
	DSPHandle	Returns the actual DSP handle (or 0, if the DSP has not been assigned to the channel). (Inherited from BaseDSP.)
	DSPPriority	Sets or reassigns the priority of the DSP, which determines it's position in the DSP chain - DSPs with higher priority are called before those with lower. (Inherited from BaseDSP.)
	DSPProc	Returns the actual DSPPROC (callback delegate) which is used by the DSP. (Inherited from BaseDSP.)
	IsAssigned	Is the DSP assigned to an active channel? (=assigned, =not assigned). (Inherited from BaseDSP.)
	IsBypassed	Returns if the DSP is currently bypassed (=bypass). (Inherited from BaseDSP.)
	IsOutputBuffered	Gets or Sets, if the BufferStream should be buffered or not (default is ).
	OutputHandle	Gets or Sets a buffered output BASS stream to synchronize the position with (0 = use a non-synchronized direct buffer).
	User	Gets or Sets the value of the user instance data to pass to the callback function (see DSPCallback(Int32, Int32, IntPtr, Int32, IntPtr)). (Inherited from BaseDSP.)

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Methods

	Name	Description
	ClearBuffer	Clears the internal buffer (zeros all elements) and resets the buffer pointer.
	Dispose	Implement IDisposable. (Inherited from BaseDSP.)
	DSPCallback	User defined DSP callback function which does the stream copy operation. Not for direct use in your application! (Overrides BaseDSPDSPCallback(Int32, Int32, IntPtr, Int32, IntPtr).)
	Finalize	Finalization code. (Inherited from BaseDSP.)
	OnBypassChanged	Occures when the SetBypass(Boolean) method was called. Actually clears the internal copy buffer. (Overrides BaseDSPOnBypassChanged.)
	OnChannelChanged	Occures when the ChannelHandle has been changed. (Overrides BaseDSPOnChannelChanged.)
	OnStarted	Occures when the Start method was called. Actually creates the BufferStream custom stream here. (Overrides BaseDSPOnStarted.)
	OnStopped	Occures when the Stop method was called. Actually frees the BufferStream custom stream here. (Overrides BaseDSPOnStopped.)
	RaiseNotification	Fires the Notification event. (Inherited from BaseDSP.)
	SetBypass	Sets the Bypass mode. (Inherited from BaseDSP.)
	Start	Assigns the DSP to the channel (actually starts using the DSP). (Inherited from BaseDSP.)
	Stop	Stops (removes) the DSP from the channel. (Inherited from BaseDSP.)
	ToString	Returns the name of the DSP. (Overrides BaseDSPToString.)

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Events

	Name	Description
	Notification	Event handler used to notify that the DSP has processed some data. (Inherited from BaseDSP.)

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Remarks

A Stream Buffer DSP actually provides a synchronized clone of the ChannelHandle's sample data in a new decoding channel which can for example be used to get FFT or level data. Use the BufferStream decoding channel with the BASS_ChannelGetData(Int32, IntPtr, Int32) or BASS_ChannelGetLevel(Int32) methods to do retrieve the cloned sample data. This DSP will always provide a decoding channel (BufferStream).

The DSP automatically handles 8-, 16- or 32-bit sample data accordingly. 8- and 16-bit sample data will be clipped if needed, 32-bit floating-point values will not be clipped. Note: The channel flags of the being used are actually the same as from the original ChannelHandle, but if you have FLOATDSP enabled the FLOAT flag will be added automatically.

Use Start to assign the DSP to the channel. Use Stop to remove the DSP (you can (re)assign the DSP at any time again by calling Start). Changing the DSPPriority when the DSP is already assigned will automatically reassign the DSP.

Use the ChannelHandle property to change the channel assignment at any time. If the DSP has already been assigned, the DSP will immediately be reassigned to the new channel.

Use the BufferStream property (which represents a custom decoding stream) to get the level or FFT data from it. If the ChannelHandle is attached to a buffered output stream (e.g. via BASSmix to a mixer stream) there will be a delay due to the additional output buffer. Use the OutputHandle property in order to compensate for that (or leave to it's default 0 value in order to simply use a non-synchronized direct buffer - in such case the internal buffer will return the data as being heard).

In addition you might use the IsOutputBuffered property to specify, if the created BufferStream will be used with a buffered output stream. In such case the decoding BufferStream position will be aligned to the output buffer (default is ).

By default the internal buffer size is determined from the current BASS_CONFIG_BUFFER setting. However, that might not always be correct, since the buffer size must also be equal to the one used with the ChannelHandle. So you might change that using the ConfigBuffer property.

NOTE: This DSP does NOT support the Notification event!

Examples

Create an exact shadow copy of a decoding stream:

Copy

private DSP_BufferStream _bufferStream;
...
// create a mixer outout stream
_mixer1 = BassMix.BASS_MIXER_StreamCreate(44100, 2, BASSFlag.BASS_DEFAULT);
Bass.BASS_ChannelPlay(_mixer1, false);
_mixer2 = BassMix.BASS_MIXER_StreamCreate(44100, 2, BASSFlag.BASS_DEFAULT);
Bass.BASS_ChannelPlay(_mixer2, false);
// create a source stream and add it to the mixer1
_stream = Bass.BASS_StreamCreateFile(_fileName, 0, 0, BASSFlag.BASS_SAMPLE_FLOAT | 
                                                      BASSFlag.BASS_STREAM_DECODE);
BassMix.BASS_Mixer_StreamAddChannel(_mixer1, _stream, BASSFlag.BASS_DEFAULT);
...
// create a clone of the source stream to add it to mixer2
_bufferStream = new DSP_BufferStream();
_bufferStream.ChannelHandle = _stream; // the stream to copy
_bufferStream.DSPPriority = -4000;
_bufferStream.Start();
BassMix.BASS_Mixer_StreamAddChannel(_mixer1, _bufferStream.BufferStream, BASSFlag.BASS_DEFAULT);

Private _bufferStream As DSP_BufferStream
...
' create a mixer outout stream
_mixer1 = BassMix.BASS_MIXER_StreamCreate(44100, 2, BASSFlag.BASS_DEFAULT)
Bass.BASS_ChannelPlay(_mixer1, False)
_mixer2 = BassMix.BASS_MIXER_StreamCreate(44100, 2, BASSFlag.BASS_DEFAULT)
Bass.BASS_ChannelPlay(_mixer2, False)
' create a source stream and add it to the mixer1
_stream = Bass.BASS_StreamCreateFile(_fileName, 0, 0, BASSFlag.BASS_SAMPLE_FLOAT Or 
                                                      BASSFlag.BASS_STREAM_DECODE)
BassMix.BASS_Mixer_StreamAddChannel(_mixer1, _stream, BASSFlag.BASS_DEFAULT)
...
' create a clone of the source stream to add it to mixer2
_bufferStream = New DSP_BufferStream()
_bufferStream.ChannelHandle = _stream ' the stream to copy
_bufferStream.DSPPriority = - 4000
_bufferStream.Start()
BassMix.BASS_Mixer_StreamAddChannel(_mixer1, _bufferStream.BufferStream, BASSFlag.BASS_DEFAULT)

Create a buffered stream copy to sync a FFT or GetLevel call:

Copy

private DSP_BufferStream _bufferStream;
...
// create a mixer outout stream
_mixer = BassMix.BASS_MIXER_StreamCreate(44100, 2, BASSFlag.BASS_DEFAULT);
Bass.BASS_ChannelPlay(BASSFlag.BASS_DEFAULT, false);
// create a source stream and add it to the mixer
_stream = Bass.BASS_StreamCreateFile(_fileName, 0, 0, BASSFlag.BASS_SAMPLE_FLOAT | 
                                                      BASSFlag.BASS_STREAM_DECODE);
BassMix.BASS_Mixer_StreamAddChannel(_mixer, _stream, BASSFlag.BASS_DEFAULT);
...
// create a buffer of the source stream for level and/or FFT data retrival in sync with the mixer output
_bufferStream = new DSP_BufferStream();
_bufferStream.ChannelHandle = _stream; // the stream to copy
_bufferStream.OutputHandle = _mixer; // the stream to sync with (what's being heard)
_bufferStream.DSPPriority = -4000;
_bufferStream.Start();
...
float[] fft = new float[2048];
Bass.BASS_ChannelGetData(_bufferStream.BufferStream, fft, (int)BASSData.BASS_DATA_FFT4096);

Private _bufferStream As DSP_BufferStream
...
' create a mixer outout stream
_mixer = BassMix.BASS_MIXER_StreamCreate(44100, 2, BASSFlag.BASS_DEFAULT)
Bass.BASS_ChannelPlay(BASSFlag.BASS_DEFAULT, False)
' create a source stream and add it to the mixer
_stream = Bass.BASS_StreamCreateFile(_fileName, 0, 0, BASSFlag.BASS_SAMPLE_FLOAT Or 
                                                      BASSFlag.BASS_STREAM_DECODE)
BassMix.BASS_Mixer_StreamAddChannel(_mixer, _stream, BASSFlag.BASS_DEFAULT)
...
' create a buffer of the source stream for level and/or FFT data retrival in sync with the mixer output
_bufferStream = New DSP_BufferStream()
_bufferStream.ChannelHandle = _stream ' the stream to copy
_bufferStream.OutputHandle = _mixer ' the stream to sync with (what's being heard)
_bufferStream.DSPPriority = - 4000
_bufferStream.Start()
...
Dim fft(2048) As Single
Bass.BASS_ChannelGetData(_bufferStream.BufferStream, fft, CInt(BASSData.BASS_DATA_FFT4096))

Reference

Un4seen.Bass.Misc Namespace

DSP_BufferStreamBufferStream