Audio Channel

INmChannelAudio::GetProperty

HRESULT GetProperty(
    [in] NM_AUDPROP uID,
    [out] ULONG *puValue);

Retrieves the property values of the current Audio Channel.

Returns S_OK if successful, or E_INVALIDARG if the uID or puValue parameter contains an invalid value.

uID

NM_AUDPROP that identifies the property type. This can be one of the following:

NM_AUDPROP_LEVEL	Audio level. puValue will receive values from 0 to 65535.
NM_AUDPROP_PAUSE	Audio muted. puValue will receive 0 if audio is not muted (default), or 1 if it is muted.

puValue

Pointer to a ULONG containing the audio property.

If an outgoing channel is paused, audio will not be sent. If an incoming channel is paused, audio will not be received.

Also see INmChannelAudio::SetProperty.

INmChannelAudio::GetState

HRESULT GetState(
    [out] NM_AUDIO_STATE *puState);

Retrieves the current state of an Audio Channel object.

Returns S_OK if successful, or E_POINTER if puState is an invalid pointer.

puState

Current state of an Audio Channel object. The state will be one of the following constants:

NM_AUDIO_IDLE	There is audio connection between the local and remote computers, but audio is not being sent or received.
NM_AUDIO_LOCAL_PAUSED	The channel is muted.
NM_AUDIO_TRANSFERRING	The channel is transmitting sound.

If the puState of an incoming channel is set to NM_AUDIO_LOCAL_PAUSED, the speaker is muted. If the puState of an outgoing channel is set to NM_AUDIO_LOCAL_PAUSED, the microphone is muted.

INmChannelAudio::IsIncoming

HRESULT IsIncoming(void);

Determines whether data on the Audio Channel is being sent or received.

Returns S_OK if the Audio Channel is incoming (through the speaker), or S_FALSE if it is outgoing (recording through the microphone input and sending to the remote member).

INmChannelAudio::SetProperty

HRESULT SetProperty(
    [in] NM_AUDPROP uID,
    [in] ULONG uValue);

Sets the property values of the Audio Channel.

Returns S_OK if successful, or E_INVALIDARG if the uID or uValue parameter contains an invalid value.

uID

NM_AUDPROP that identifies the property type. This can be one of the following:

NM_AUDPROP_LEVEL	Audio level. uValue must be a value from 0 to 65535.
NM_AUDPROP_PAUSE	Audio muted. uValue must be set to 0 to play audio (default), or 1 to mute audio.

uValue

Value of the audio property.

If an outgoing channel is paused, audio will not be sent. If an incoming channel is paused, audio will not be received.

MemberChanged
NmUI
PropertyChanged
StateChanged

INmChannelAudioNotify Interface

This is an event notification sink interface for the INmChannelAudio interface. The methods in this interface are called by the Audio Channel object when specific events occur.

These event sink methods should be defined and implemented by the client application to respond to notifications from an Audio Channel object. For example, the INmChannelAudioNotify::StateChanged method is notified when the state of the Audio Channel has changed. The client application implementation of this method could provide a display to the user informing him or her of this change.

INmChannelAudioNotify::MemberChanged

HRESULT MemberChanged(
    [in] NM_MEMBER_NOTIFY uNotify,
    [in] INmMember *pMember);

Receives notification that a member of the Audio Channel was added, removed, or updated. This method is inherited from INmChannelNotify. For NetMeeting 2.1, an Audio Channel will never have more than one member.

This event sink should always return S_OK to the event source.

uNotify

Identifier of an event constant. This can include the following values:

NM_MEMBER_ADDED	Another member has joined the Audio Channel.
NM_MEMBER_REMOVED	The remote user has been removed from the Audio Channel.
NM_MEMBER_UPDATED	The Audio Channel for this member has been updated.

pMember

Pointer to the INmMember Interface on the Member object that changed.

INmChannelAudioNotify::NmUI

HRESULT NmUI(
    [in] CONFN uNotify);

Receives event notification when a channel change occurs. Only the application in charge (initialized with NM_INIT_CONTROL) of the NetMeeting user interface will receive these notifications.

This method is inherited from INmChannelNotify.

This event sink should always return S_OK to the event source.

uNotify: Reserved for future use.

INmChannelAudioNotify::PropertyChanged

HRESULT PropertyChanged(
    [in] DWORD dwReserved);

Called when a property of the Audio Channel has changed.

This event sink should always return S_OK to the event source.

dwReserved

DWORD that identifies the property type.

NM_AUDPROP_PAUSE

Audio mute state has changed.

This method is not called when NM_AUDPROP_LEVEL changes.

When receiving this notification, your application should use INmChannelAudio::GetProperty to determine the new property value.

Local or remote changes to the pause property for the channel will cause this notification to be called.

INmChannelAudioNotify::StateChanged

HRESULT StateChanged(
    [in] NM_AUDIO_STATE uState);

Called when the Audio Channel's state changes.

This event sink should always return S_OK to the event source.

uState

NM_AUDIO_STATE that identifies the current state. Constants include:

NM_AUDIO_IDLE	There is audio connection between the local and remote computers, but audio is not being sent or received.
NM_AUDIO_LOCAL_PAUSED	The channel is muted.
NM_AUDIO_TRANSFERRING	The channel is transmitting sound.

Local or remote calls to INmChannelAudio::GetState can cause this notification to be called. Joining a call also causes this notification to be called.