BassAsioHandler Class

BASS.NET API for the Un4seen BASS Audio Library

This class provides ready-made members for direct and more simple ASIO usage together with BASS channels.

Inheritance Hierarchy

SystemObject
Un4seen.BassAsioBassAsioHandler

Namespace: Un4seen.BassAsio
Assembly: Bass.Net (in Bass.Net.dll) Version: 2.4.17.5

Syntax

public class BassAsioHandler

Public Class BassAsioHandler

The BassAsioHandler type exposes the following members.

Constructors

	Name	Description
	BassAsioHandler	Default constructor - leaving all defaults and not assigning any ASIO channel.
	BassAsioHandler(Int32, Int32, Int32, BASSASIOFormat)	Creates an instance of the ASIO handler for output - initializing and enabling the given ASIO device and channel according to the Bass stream.
	BassAsioHandler(Boolean, Int32, Int32, Int32, BASSASIOFormat, Double)	Creates an instance of the ASIO handler - initializing and enabling the given ASIO device and channel.

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Properties

	Name	Description
	BypassFullDuplex	Gets or Sets the bypass flag for full-duplex ASIO output processing (default is ).
	Channel	Returns the first ASIO channel being used.
	ChannelNumChans	Gets the total number of ASIO channel which are joined together, starting with Channel.
	Device	Returns the ASIO device being used by the Asio handler.
	DeviceVolume	Gets or Sets the master volume of the Device between 0 (silent) and 1 (full).
	Format	Gets or Sets the actual ASIO channel format (default is BASS_ASIO_FORMAT_FLOAT).
	FullDuplexChannel	Returns the first full-duplex ASIO output channel being used (or -1, if not used).
	FullDuplexDevice	Returns the full-duplex ASIO output device being used (or -1, if not used).
	InputChannel	Returns an input channel which allows you to retrieve the recorded sample data and/or apply any DSP/FX on Asio input.
	InternalAsioProc	Gets the ASIOPROC currently being used by the Asio handler.
	IsInput	Returns , if the ASIO handler is used with an ASIO input device.
	IsInputFullDuplex	Returns , if the ASIO handler is used with an ASIO input device and the full-duplex option was set via SetFullDuplex(Int32, Int32).
	IsMirrored	Returns if the ASIO Channel is being mirrored to another output channel.
	IsResampling	Returns , if resampling takes place on the used Channel and Device.
	MirrorChannel	Gets the first ASIO mirror channel (or -1 if not mirrored).
	OutputChannel	Gets or Sets the BASS output channel handle which is used with this ASIO handler.
	Pan	Gets or Sets the panning of the Channel (and all joined ChannelNumChans) between -1 (left) to +1 (right), 0=centered.
	PanMirror	Gets or Sets the panning of the MirrorChannel (and all attached ChannelNumChans) between -1 (left) to +1 (right), 0=centered.
	SampleRate	Gets or Sets the actual ASIO channel sample rate in Hz (default is 48000).
	UseInput	Enables the use of the InputChannel channel with ASIO input (which is the default for Asio input).
	Volume	Gets or Sets the volume of the Channel (and all joined ChannelNumChans) between 0 (silent) and 1 (full).
	VolumeMirror	Gets or Sets the volume of the MirrorChannel (and all attached ChannelNumChans) between 0 (silent) and 1 (full).

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Methods

	Name	Description
	AsioInputCallback	Provides a ready made ASIOPROC callback procedure which might be used for ASIO input.
	AsioOutputCallback	Provides a ready made ASIOPROC callback procedure which might be used for ASIO output.
	AsioToAsioFullDuplexCallback	Provides a ready made ASIOPROC callback procedure which might be used for full-duplex ASIO input to Asio output.
	AsioToBassFullDuplexCallback	Provides a ready made ASIOPROC callback procedure which might be used for full-duplex ASIO input to Bass output.
	AssignOutputChannel	Assigns a (new) BASS channel handle for ASIO output.
	Dispose	Disposes an instance of this class also unjoining and disabling all used ASIO channels.
	Finalize	Finalization code. (Overrides ObjectFinalize.)
	Pause	Pauses or Unpauses the ASIO Channel(s) being used.
	PauseMirror	Pauses or Unpauses the MirrorChannel(s) being used.
	RemoveFullDuplex	Removes the full-duplex option from ASIO input.
	RemoveMirror	Removes a mirror set on the current ASIO Channel.
	SetFullDuplex(Int32, Int32)	Sets the full-duplex option for ASIO input using the given ASIO output device and channel.
	SetFullDuplex(Int32, BASSFlag, Boolean)	Sets the full-duplex option for ASIO input using the given BASS output device.
	SetMirror	Mirrors the current ASIO Channel to the given output channel.
	Start	Starts the Asio Device.
	StartFullDuplex	Starts the Asio FullDuplexDevice.
	Stop	Stops the Asio Device.
	StopFullDuplex	Stops the Asio FullDuplexDevice.

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Events

	Name	Description
	Notification	Event handler used to notify that an asio handler notification event (sync) has occurred.

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Fields

	Name	Description
	UseDedicatedThreads	Gets or Sets, if the driver should be hosted in a dedicated thread.

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Remarks

You might use this class for almost all use cases in terms of Asio handling, e.g.:

Scenario:	How-To:
Asio output	A Bass decoding channel or a recording channel feeding Asio output. Simply use the corresponding output constructor to specify the Asio Device and Channel as well the OutputChannel to use and you are done. The SampleRate, ChannelNumChans and Format will automatically be aligned. Use the AssignOutputChannel(Int32) method to change the underlying bass channel on the fly.
Asio input	Directly record from Asio input. Simply use the corresponding input constructor to specify the Asio Device, Channel, SampleRate, ChannelNumChans and Format you want to record at. To retrieve the input sample data use the InputChannel channel (e.g. setup an own DSP, use it with the WaveWriter or Encoder Framework).
Asio input, full-duplex to Asio	Monitor your Asio input on any Asio output. To enable full-duplex just call the Asio overload of the SetFullDuplex(Int32, Int32) method (when done call RemoveFullDuplex(Boolean)).
Asio input, full-duplex to BASS	Monitor your Asio input on any BASS device. To enable full-duplex just call the bass overload of the SetFullDuplex(Int32, Int32) method (when done call RemoveFullDuplex(Boolean)).
DSP/FX	You can set any DSP/FX on either the input and/or the output (full-duplex). See InputChannel and OutputChannel for more details.

You might use the Volume and Pan properties to easily control your Asio input/output settings. Asio mirrors are also supported via the SetMirror(Int32) and RemoveMirror methods. Mirrors have independent VolumeMirror and PanMirror settings.

Asio channels can be paused and resumed at any time by using the Pause(Boolean) method. To physically start the used Asio device the Start(Int32, Int32) method might be used. Stop will unjoin, disable and stop the Asio device (if really needed).

Caution: Once you created an instance of this class, the respective ASIO channels are joined and enabled. The used ASIO channels will NOT be unjoined or disabled automatically when an instance of this class is being disposed by the .Net Garbage Collector! Call the Dispose method manually to completely free all assigned ASIO channels, including any full-duplex and the mirror options. However, calling Dispose will not stop the Asio device - this has to be done manually in any case (e.g. by calling Stop)!

Note: This class internally uses Un4seen.Bass, so you need to provide the native BASS.dll as well when using this class.

The AsioOutputCallback(Boolean, Int32, IntPtr, Int32, IntPtr), AsioInputCallback(Boolean, Int32, IntPtr, Int32, IntPtr), AsioToAsioFullDuplexCallback(Boolean, Int32, IntPtr, Int32, IntPtr) and AsioToBassFullDuplexCallback(Boolean, Int32, IntPtr, Int32, IntPtr) callbacks are virtual methods which might be overloaded if you want to derive your own ASIO handler with any special callback handling.

Examples

Automatic use of the BassAsioHandler (a Bass channel is feeding Asio output):

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private BassAsioHandler _asio;
...
// not playing anything via BASS, so don't need an update thread
Bass.BASS_SetConfig(BASSConfig.BASS_CONFIG_UPDATEPERIOD, 0);
// setup BASS - "no sound" device but 48000 (default for ASIO)
Bass.BASS_Init(0, 48000, BASSInit.BASS_DEVICE_DEFAULT, IntPtr.Zero);
BassAsio.BASS_ASIO_Init(0, BASSASIOInit.BASS_ASIO_THREAD);
...
int stream = Bass.BASS_StreamCreateFile(fileName, 0, 0, 
                  BASSFlag.BASS_STREAM_DECODE | BASSFlag.BASS_SAMPLE_FLOAT);
if (stream != 0)
{
    // assign ASIO output to the first device and channel
    // and assume the ASIO format, samplerate and number of channels from the BASS stream
    _asio = new BassAsioHandler(0, 0, stream);
    // start ASIO
    _asio.Start(0);
}

Private _asio As BassAsioHandler
...
' not playing anything via BASS, so don't need an update thread
Bass.BASS_SetConfig(BASSConfig.BASS_CONFIG_UPDATEPERIOD, 0)
' setup BASS - "no sound" device but 48000 (default for ASIO)
Bass.BASS_Init(0, 48000, BASSInit.BASS_DEVICE_DEFAULT, IntPtr.Zero)
BassAsio.BASS_ASIO_Init(0, BASSASIOInit.BASS_ASIO_THREAD)
...
Dim stream As Integer = Bass.BASS_StreamCreateFile(fileName, 0, 0, 
                             BASSFlag.BASS_STREAM_DECODE Or BASSFlag.BASS_SAMPLE_FLOAT)
If stream <> 0 Then
  ' assign ASIO output to the first device and channel
  ' and assume the ASIO format, samplerate and number of channels from the BASS stream
  _asio = New BassAsioHandler(0, 0, stream)
  ' start ASIO
  _asio.Start(0)
End If

Automatic use of the BassAsioHandler (Asio recording input, Asio full-duplex output):

Copy

private BassAsioHandler _asio;
...
// not playing anything via BASS, so don't need an update thread
Bass.BASS_SetConfig(BASSConfig.BASS_CONFIG_UPDATEPERIOD, 0);
// setup BASS - "no sound" device but 48000 (default for ASIO)
Bass.BASS_Init(0, 48000, BASSInit.BASS_DEVICE_DEFAULT, IntPtr.Zero);
BassAsio.BASS_ASIO_Init(0, BASSASIOInit.BASS_ASIO_THREAD);
...
// assign ASIO input to the first device and channel (stereo, 32-bit float, 48kHz)
_asio = new BassAsioHandler(true, 0, 0, 2, BASSASIOFormat.BASS_ASIO_FORMAT_FLOAT, 48000);
// set the full-duplex option to the first ASIO output device and channel
// the ASIO output format will aways be the same as the input for full-duplex
_asio.SetFullDuplex(0, 0);
// start ASIO
_asio.Start(0);
...
// when you want to disbale all associated channels, call:
_asio.Dispose();

Private _asio As BassAsioHandler
...
' not playing anything via BASS, so don't need an update thread
Bass.BASS_SetConfig(BASSConfig.BASS_CONFIG_UPDATEPERIOD, 0)
' setup BASS - "no sound" device but 48000 (default for ASIO)
Bass.BASS_Init(0, 48000, BASSInit.BASS_DEVICE_DEFAULT, IntPtr.Zero)
BassAsio.BASS_ASIO_Init(0, BASSASIOInit.BASS_ASIO_THREAD)
...
' assign ASIO input to the first device and channel (stereo, 32-bit float, 48kHz)
_asio = New BassAsioHandler(True, 0, 0, 2, BASSASIOFormat.BASS_ASIO_FORMAT_FLOAT, 48000)
' set the full-duplex option to the first ASIO output device and channel
' the ASIO output format will aways be the same as the input for full-duplex
_asio.SetFullDuplex(0, 0)
' start ASIO
_asio.Start(0)
...
' when you want to disbale all associated channels, call:
_asio.Dispose()

Reference

Un4seen.BassAsio Namespace