Class Alc

Alc = Audio Library Context

Inheritance

Object

Alc

Inherited Members

Object.ToString()

Object.Equals(Object)

Object.Equals(Object, Object)

Object.ReferenceEquals(Object, Object)

Object.GetHashCode()

Object.GetType()

Object.MemberwiseClone()

Namespace: OpenTK.Audio.OpenAL

Assembly: OpenTK.dll

Syntax

public static class Alc

Methods

CaptureCloseDevice(IntPtr)

This function closes the specified capture device.

Declaration

public static extern bool CaptureCloseDevice(IntPtr device)

Parameters

Type	Name	Description
IntPtr	device	a pointer to a capture device.

Returns

Type	Description
Boolean	Returns True if the close operation was successful, False on failure.

CaptureOpenDevice(String, Int32, ALFormat, Int32)

This function opens a capture device by name.

Declaration

public static extern IntPtr CaptureOpenDevice(string devicename, int frequency, ALFormat format, int buffersize)

Parameters

Type	Name	Description
String	devicename	a pointer to a device name string.
Int32	frequency	the frequency that the buffer should be captured at.
ALFormat	format	the requested capture buffer format.
Int32	buffersize	the size of the capture buffer in samples, not bytes.

Returns

Type	Description
IntPtr	Returns the capture device pointer, or NULL on failure.

CaptureOpenDevice(String, UInt32, ALFormat, Int32)

This function opens a capture device by name.

Declaration

[CLSCompliant(false)]
public static extern IntPtr CaptureOpenDevice(string devicename, uint frequency, ALFormat format, int buffersize)

Parameters

Type	Name	Description
String	devicename	a pointer to a device name string.
UInt32	frequency	the frequency that the buffer should be captured at.
ALFormat	format	the requested capture buffer format.
Int32	buffersize	the size of the capture buffer in samples, not bytes.

Returns

Type	Description
IntPtr	Returns the capture device pointer, or NULL on failure.

CaptureSamples(IntPtr, IntPtr, Int32)

This function completes a capture operation, and does not block.

Declaration

public static extern void CaptureSamples(IntPtr device, IntPtr buffer, int samples)

Parameters

Type	Name	Description
IntPtr	device	a pointer to a capture device.
IntPtr	buffer	a pointer to a buffer, which must be large enough to accommodate the number of samples.
Int32	samples	the number of samples to be retrieved.

CaptureSamples<T>(IntPtr, ref T, Int32)

This function completes a capture operation, and does not block.

Declaration

public static void CaptureSamples<T>(IntPtr device, ref T buffer, int samples)
    where T : struct

Parameters

Type	Name	Description
IntPtr	device	a pointer to a capture device.
T	buffer	a reference to a buffer, which must be large enough to accommodate the number of samples.
Int32	samples	the number of samples to be retrieved.

Type Parameters

Name	Description
T

CaptureSamples<T>(IntPtr, T[], Int32)

This function completes a capture operation, and does not block.

Declaration

[CLSCompliant(false)]
public static void CaptureSamples<T>(IntPtr device, T[] buffer, int samples)
    where T : struct

Parameters

Type	Name	Description
IntPtr	device	a pointer to a capture device.
T[]	buffer	a buffer, which must be large enough to accommodate the number of samples.
Int32	samples	the number of samples to be retrieved.

Type Parameters

Name	Description
T

CaptureSamples<T>(IntPtr, T[,,], Int32)

This function completes a capture operation, and does not block.

Declaration

[CLSCompliant(false)]
public static void CaptureSamples<T>(IntPtr device, T[,, ] buffer, int samples)
    where T : struct

Parameters

Type	Name	Description
IntPtr	device	a pointer to a capture device.
T[,,]	buffer	a buffer, which must be large enough to accommodate the number of samples.
Int32	samples	the number of samples to be retrieved.

Type Parameters

Name	Description
T

CaptureSamples<T>(IntPtr, T[,], Int32)

This function completes a capture operation, and does not block.

Declaration

[CLSCompliant(false)]
public static void CaptureSamples<T>(IntPtr device, T[, ] buffer, int samples)
    where T : struct

Parameters

Type	Name	Description
IntPtr	device	a pointer to a capture device.
T[,]	buffer	a buffer, which must be large enough to accommodate the number of samples.
Int32	samples	the number of samples to be retrieved.

Type Parameters

Name	Description
T

CaptureStart(IntPtr)

This function begins a capture operation.

Declaration

public static extern void CaptureStart(IntPtr device)

Parameters

Type	Name	Description
IntPtr	device	a pointer to a capture device.

Remarks

alcCaptureStart will begin recording to an internal ring buffer of the size specified when opening the capture device. The application can then retrieve the number of samples currently available using the ALC_CAPTURE_SAPMPLES token with alcGetIntegerv. When the application determines that enough samples are available for processing, then it can obtain them with a call to alcCaptureSamples.

CaptureStop(IntPtr)

This function stops a capture operation.

Declaration

public static extern void CaptureStop(IntPtr device)

Parameters

Type	Name	Description
IntPtr	device	a pointer to a capture device.

CloseDevice(IntPtr)

This function closes a device by name.

Declaration

public static extern bool CloseDevice(IntPtr device)

Parameters

Type	Name	Description
IntPtr	device	a pointer to an opened device

Returns

Type	Description
Boolean	True will be returned on success or False on failure. Closing a device will fail if the device contains any contexts or buffers.

CreateContext(IntPtr, Int32*)

This function creates a context using a specified device.

Declaration

[CLSCompliant(false)]
public static ContextHandle CreateContext(IntPtr device, int *attrlist)

Parameters

Type	Name	Description
IntPtr	device	a pointer to a device
Int32*	attrlist	a pointer to a set of attributes: ALC_FREQUENCY, ALC_MONO_SOURCES, ALC_REFRESH, ALC_STEREO_SOURCES, ALC_SYNC

Returns

Type	Description
ContextHandle	Returns a pointer to the new context (NULL on failure). The attribute list can be NULL, or a zero terminated list of integer pairs composed of valid ALC attribute tokens and requested values.

CreateContext(IntPtr, Int32[])

This function creates a context using a specified device.

Declaration

public static ContextHandle CreateContext(IntPtr device, int[] attriblist)

Parameters

Type	Name	Description
IntPtr	device	a pointer to a device
Int32[]	attriblist	an array of a set of attributes: ALC_FREQUENCY, ALC_MONO_SOURCES, ALC_REFRESH, ALC_STEREO_SOURCES, ALC_SYNC

Returns

Type	Description
ContextHandle	Returns a pointer to the new context (NULL on failure).

Remarks

The attribute list can be NULL, or a zero terminated list of integer pairs composed of valid ALC attribute tokens and requested values.

DestroyContext(ContextHandle)

This function destroys a context.

Declaration

public static void DestroyContext(ContextHandle context)

Parameters

Type	Name	Description
ContextHandle	context	a pointer to the new context.

GetContextsDevice(ContextHandle)

This function retrieves a context's device pointer.

Declaration

public static IntPtr GetContextsDevice(ContextHandle context)

Parameters

Type	Name	Description
ContextHandle	context	a pointer to a context.

Returns

Type	Description
IntPtr	Returns a pointer to the specified context's device.

GetCurrentContext()

This function retrieves the current context.

Declaration

public static ContextHandle GetCurrentContext()

Returns

Type	Description
ContextHandle	Returns a pointer to the current context.

GetEnumValue(IntPtr, String)

This function retrieves the enum value for a specified enumeration name.

Declaration

public static extern int GetEnumValue(IntPtr device, string enumname)

Parameters

Type	Name	Description
IntPtr	device	a pointer to the device to be queried.
String	enumname	a null terminated string describing the enum value.

Returns

Type	Description
Int32	Returns the enum value described by the enumName string. This is most often used for querying an enum value for an ALC extension.

GetError(IntPtr)

This function retrieves the current context error state.

Declaration

public static extern AlcError GetError(IntPtr device)

Parameters

Type	Name	Description
IntPtr	device	a pointer to the device to retrieve the error state from

Returns

Type	Description
AlcError	Errorcode Int32.

GetInteger(IntPtr, AlcGetInteger, Int32, out Int32)

This function returns integers related to the context.

Declaration

public static void GetInteger(IntPtr device, AlcGetInteger param, int size, out int data)

Parameters

Type	Name	Description
IntPtr	device	a pointer to the device to be queried.
AlcGetInteger	param	an attribute to be retrieved: ALC_MAJOR_VERSION, ALC_MINOR_VERSION, ALC_ATTRIBUTES_SIZE, ALC_ALL_ATTRIBUTES
Int32	size	the size of the destination buffer provided, in number of integers.
Int32	data	a pointer to the buffer to be returned

GetInteger(IntPtr, AlcGetInteger, Int32, Int32[])

This function returns integers related to the context.

Declaration

public static void GetInteger(IntPtr device, AlcGetInteger param, int size, int[] data)

Parameters

Type	Name	Description
IntPtr	device	a pointer to the device to be queried.
AlcGetInteger	param	an attribute to be retrieved: ALC_MAJOR_VERSION, ALC_MINOR_VERSION, ALC_ATTRIBUTES_SIZE, ALC_ALL_ATTRIBUTES
Int32	size	the size of the destination buffer provided, in number of integers.
Int32[]	data	a pointer to the buffer to be returned

GetProcAddress(IntPtr, String)

This function retrieves the address of a specified context extension function.

Declaration

public static extern IntPtr GetProcAddress(IntPtr device, string funcname)

Parameters

Type	Name	Description
IntPtr	device	a pointer to the device to be queried for the function.
String	funcname	a null-terminated string describing the function.

Returns

Type	Description
IntPtr	Returns the address of the function, or NULL if it is not found.

GetString(IntPtr, AlcGetString)

This function returns pointers to strings related to the context.

Declaration

public static string GetString(IntPtr device, AlcGetString param)

Parameters

Type	Name	Description
IntPtr	device	a pointer to the device to be queried.
AlcGetString	param	an attribute to be retrieved: ALC_DEFAULT_DEVICE_SPECIFIER, ALC_CAPTURE_DEFAULT_DEVICE_SPECIFIER, ALC_DEVICE_SPECIFIER, ALC_CAPTURE_DEVICE_SPECIFIER, ALC_EXTENSIONS

Returns

Type	Description
String	A string containing the name of the Device.

Remarks

ALC_DEFAULT_DEVICE_SPECIFIER will return the name of the default output device. ALC_CAPTURE_DEFAULT_DEVICE_SPECIFIER will return the name of the default capture device. ALC_DEVICE_SPECIFIER will return the name of the specified output device if a pointer is supplied, or will return a list of all available devices if a NULL device pointer is supplied. A list is a pointer to a series of strings separated by NULL characters, with the list terminated by two NULL characters. See Enumeration Extension for more details. ALC_CAPTURE_DEVICE_SPECIFIER will return the name of the specified capture device if a pointer is supplied, or will return a list of all available devices if a NULL device pointer is supplied. ALC_EXTENSIONS returns a list of available context extensions, with each extension separated by a space and the list terminated by a NULL character.

GetString(IntPtr, AlcGetStringList)

This function returns a List of strings related to the context.

Declaration

public static IList<string> GetString(IntPtr device, AlcGetStringList param)

Parameters

Type	Name	Description
IntPtr	device	a pointer to the device to be queried.
AlcGetStringList	param	an attribute to be retrieved: ALC_DEVICE_SPECIFIER, ALC_CAPTURE_DEVICE_SPECIFIER, ALC_ALL_DEVICES_SPECIFIER

Returns

Type	Description
IList<String>	A List of strings containing the names of the Devices.

Remarks

ALC_DEVICE_SPECIFIER will return the name of the specified output device if a pointer is supplied, or will return a list of all available devices if a NULL device pointer is supplied. A list is a pointer to a series of strings separated by NULL characters, with the list terminated by two NULL characters. See Enumeration Extension for more details. ALC_CAPTURE_DEVICE_SPECIFIER will return the name of the specified capture device if a pointer is supplied, or will return a list of all available devices if a NULL device pointer is supplied. ALC_EXTENSIONS returns a list of available context extensions, with each extension separated by a space and the list terminated by a NULL character.

IsExtensionPresent(IntPtr, String)

This function queries if a specified context extension is available.

Declaration

public static extern bool IsExtensionPresent(IntPtr device, string extname)

Parameters

Type	Name	Description
IntPtr	device	a pointer to the device to be queried for an extension.
String	extname	a null-terminated string describing the extension.

Returns

Type	Description
Boolean	Returns True if the extension is available, False if the extension is not available.

MakeContextCurrent(ContextHandle)

This function makes a specified context the current context.

Declaration

public static bool MakeContextCurrent(ContextHandle context)

Parameters

Type	Name	Description
ContextHandle	context	A pointer to the new context.

Returns

Type	Description
Boolean	Returns True on success, or False on failure.

OpenDevice(String)

This function opens a device by name.

Declaration

public static extern IntPtr OpenDevice(string devicename)

Parameters

Type	Name	Description
String	devicename	a null-terminated string describing a device.

Returns

Type	Description
IntPtr	Returns a pointer to the opened device. The return value will be NULL if there is an error.

ProcessContext(ContextHandle)

This function tells a context to begin processing. When a context is suspended, changes in OpenAL state will be accepted but will not be processed. alcSuspendContext can be used to suspend a context, and then all the OpenAL state changes can be applied at once, followed by a call to alcProcessContext to apply all the state changes immediately. In some cases, this procedure may be more efficient than application of properties in a non-suspended state. In some implementations, process and suspend calls are each a NOP.

Declaration

public static void ProcessContext(ContextHandle context)

Parameters

Type	Name	Description
ContextHandle	context	a pointer to the new context

SuspendContext(ContextHandle)

This function suspends processing on a specified context. When a context is suspended, changes in OpenAL state will be accepted but will not be processed. A typical use of alcSuspendContext would be to suspend a context, apply all the OpenAL state changes at once, and then call alcProcessContext to apply all the state changes at once. In some cases, this procedure may be more efficient than application of properties in a non-suspended state. In some implementations, process and suspend calls are each a NOP.

Declaration

public static void SuspendContext(ContextHandle context)

Parameters

Type	Name	Description
ContextHandle	context	a pointer to the context to be suspended.