signal

The signal command identifies a specified position in the workspace by sending the application an MM_MCISIGNAL message. Digital-video devices recognize this command. MCIAVI supports only one active signal at a time.

signal device signalflags  flags 
 

Parameters

device

Identifier of an MCI device. This identifier or alias is assigned when the device is opened.

signalflags

One of the following flags:

at position

Specifies the frame to invoke a signal.

cancel

Removes signals from the workspace. An individual signal is specified by using the “uservalue” flag. If the “uservalue” flag is not specified by using “cancel”, the device cancels all signals. The “cancel” flag is incompatible with the “at”, “every”, and “return position” flags.

every interval

Specifies the period of the signals. The interval value is specified in the current time format.

If used with “at” position, signals are placed throughout the workspace with one signal mark placed at position.

Without the “at” flag, signals are placed throughout the workspace with one signal at the current position.

If this flag is omitted, only the position indicated by the “at” flag is marked.

If the interval value is less than the minimum frequency supported by a device it will use its minimum value.

return position

Indicates the device should send the position value instead of the “uservalue” identifier in the signaling message. The “uservalue” identifier can still be used to cancel or to redefine the signal marks.

uservalue id

Specifies an identifier that is reported back with the signaling message. This identifier acts as an identifier that can be used with other signal commands to reference this signal setting. If omitted, the default value is zero.

flags

Can be “wait”, “notify”, “test”, or a combination of these. For more information about these flags, see The Wait, Notify, and Test Flags.

Return Values

Returns zero if successful or an error otherwise.

Remarks

The window handle used for notification of command completion messages is also used for signaling.

See Also

MM_MCISIGNAL