QM_StartVolumeMeteringSession

QM_StartVolumeMeteringSession(sessionRef; movieRef; whatMix):error
	sessionRef	Longint	Volume metering session reference
	movieRef	Longint	Movie reference
	whatMix	String4	Audio mix identifier
	error	Longint	Error result

Starts a volume metering session for a movie.

Parameter sessionRef receives a reference number that identifies the volume metering session. Use this reference number to retrieve volume levels with QM_GetVolumeLevels, and to end the volume metering session with QM_EndVolumeMeteringSession when you are done.

Parameter movieRef specifies the movie from which you want to receive volume levels.

Parameter whatMix specifies the audio 'mix' to be used in the volume metering session. As of QuickTime 7, the only mix supported for volume metering is the current audio device mix, which is identified by the qm_AudioDeviceMix constant.

Related commands

QM_GetVolumeLevels	Retrieves the current volume levels.
QM_EndVolumeMeteringSession	Ends a volume metering session.