Echo cancelling

Collaboration diagram for Echo cancelling:

Functions
int WINAPI	vpb_loopback_on (int handle)
	Turns on software loop-back of tx->rx in the kernel.
int WINAPI	vpb_loopback_off (int handle)
	Turns off software loop-back of tx->rx in the kernel.
int WINAPI	vpb_hostecho_on (int handle)
	Enable the host echo canceller for handle.
int WINAPI	vpb_hostecho_off (int handle)
	Disable the host echo canceller for handle.
int WINAPI	vpb_echo_canc_force_adapt_on ()
int WINAPI	vpb_echo_canc_force_adapt_off ()
int WINAPI	vpb_echo_canc_enable ()
int WINAPI	vpb_echo_canc_disable ()
int WINAPI	vpb_echo_canc_get_sup_thresh (int handle, short *thresh)
	Get the current echo suppressor threshold.
int WINAPI	vpb_echo_canc_set_sup_thresh (int handle, short *thresh)
	Set the echo suppressor threshold.

Detailed Description

Function Documentation

vpb_echo_canc_get_sup_thresh()

int WINAPI vpb_echo_canc_get_sup_thresh	(	int	handle,
		short *	thresh
	)

Get the current echo suppressor threshold.

This threshold is the same for all channels on all cards.

Parameters

handle	A handle to an open port on the card.
thresh	The returned echo suppressor threshold value.

Note

This function is only supported for V4PCI cards.

Exceptions

VpbException

will be thrown in the event of an error.

References DD_PCI, VPBREG::ddmodel, vpb_c, and Comm::vpbreg().

vpb_echo_canc_set_sup_thresh()

int WINAPI vpb_echo_canc_set_sup_thresh	(	int	handle,
		short *	thresh
	)

Set the echo suppressor threshold.

This threshold is the same for all channels on all cards.

Parameters

handle	A handle to an open port on the card.
thresh	The echo suppressor threshold value. 0x1000 gives -18db, 0x800 gives -24db, 0x0 for no suppressor.

Note

This function is only supported for V4PCI cards.

Exceptions

VpbException

will be thrown in the event of an error.

References DD_PCI, VPBREG::ddmodel, vpb_c, and Comm::vpbreg().

vpb_loopback_off()

int WINAPI vpb_loopback_off

(

int

handle

)

Turns off software loop-back of tx->rx in the kernel.

Useful for echo testing.

Parameters

handle

The handle of the port to disable loopback operations.

Returns

VPB_OK if all went well.

Exceptions

various

exceptions may be thrown if all did not go well.

Note

This function is not supported for all hardware types.

See also

vpb_loopback_on()

References Comm::PutMessageVPB(), and vpb_c.

vpb_loopback_on()

int WINAPI vpb_loopback_on

(

int

handle

)

Turns on software loop-back of tx->rx in the kernel.

Useful for echo testing.

Parameters

handle

The handle of the port to enable loopback operations.

Returns

VPB_OK if all went well.

Exceptions

various

exceptions may be thrown if all did not go well.

Note

This function is not supported for all hardware types.

See also

vpb_loopback_off()

References Comm::PutMessageVPB(), and vpb_c.