Meter Control
[Mixer and Controls]

The meter control returns information about the level of the audio signal at the position of the control. More...

Functions
HPI_ERR	HPI_Meter_QueryChannels (const HPI_HSUBSYS *phSubSys, const HPI_HCONTROL hMeter, HW32 *pChannels)
	Get the number of channels supported by this meter.
HPI_ERR	HPI_MeterGetPeak (HPI_HSUBSYS *phSubSys, HPI_HCONTROL hControl, short anPeakdB[HPI_MAX_CHANNELS])
	Get the meter peak reading.
HPI_ERR	HPI_MeterGetRms (HPI_HSUBSYS *phSubSys, HPI_HCONTROL hControl, short anRmsdB[HPI_MAX_CHANNELS])
	Get the meter RMS reading in 100ths of a dB.
HPI_ERR	HPI_MeterSetRmsBallistics (HPI_HSUBSYS *phSubSys, HPI_HCONTROL hControl, unsigned short nAttack, unsigned short nDecay)
	Set the ballistics of the RMS part of a meter.
HPI_ERR	HPI_MeterGetRmsBallistics (HPI_HSUBSYS *phSubSys, HPI_HCONTROL hControl, unsigned short *pnAttack, unsigned short *pnDecay)
	Get the ballistics settings of the RMS part of a meter.
HPI_ERR	HPI_MeterSetPeakBallistics (HPI_HSUBSYS *phSubSys, HPI_HCONTROL hControl, unsigned short nAttack, unsigned short nDecay)
	Set the ballistics of the Peak part of a meter.
HPI_ERR	HPI_MeterGetPeakBallistics (HPI_HSUBSYS *phSubSys, HPI_HCONTROL hControl, unsigned short *pnAttack, unsigned short *pnDecay)
	Get the ballistics settings of the Peak part of a meter.

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Detailed Description

The meter control returns information about the level of the audio signal at the position of the control.

Depending on the adapter, Peak and RMS readings are available. On some adapters meter ballistics may be set (on older adapters the meter gives an instantaneous reading)

Readings are in units of 0.01dB

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Function Documentation

HPI_ERR HPI_Meter_QueryChannels (  const HPI_HSUBSYS *  phSubSys, const HPI_HCONTROL  hMeter, HW32 *  pChannels )

Get the number of channels supported by this meter. Parameters: phSubSys  Pointer to HPI subsystem handle hMeter  Control to query pChannels  number of channels

HPI_ERR HPI_MeterGetPeak (  HPI_HSUBSYS *  phSubSys, HPI_HCONTROL  hControl, short  anPeakdB[HPI_MAX_CHANNELS] )

Get the meter peak reading. Returns: 0 on success, or one of the HPI Error codes. Parameters: phSubSys  HPI subsystem handle hControl  meter control handle anPeakdB  meter peaks in millibels

HPI_ERR HPI_MeterGetRms (  HPI_HSUBSYS *  phSubSys, HPI_HCONTROL  hControl, short  anRmsdB[HPI_MAX_CHANNELS] )

Get the meter RMS reading in 100ths of a dB. Returns: 0 on success, or one of the HPI Error codes. Parameters: phSubSys  HPI subsystem handle hControl  meter control handle anRmsdB  meter RMS values in millibels

HPI_ERR HPI_MeterSetRmsBallistics (  HPI_HSUBSYS *  phSubSys, HPI_HCONTROL  hControl, unsigned short  nAttack, unsigned short  nDecay )

Set the ballistics of the RMS part of a meter. The attack and decay values represent the time constants of the equivalent single pole low pass filter used to create the ballistics. With a time constant of T, if the meter is stable at full scale and the input is suddenly removed, the meter will decay. Setting nAttack to 0 gives the meter instantaneous rise time. Setting nDecay to a value smaller than a few times your meter polling interval is not advised. The meter will appear to read something approaching the instantaneous value at the time of polling rather than the maximum peak since the previous reading. Returns: 0 on success, or one of the HPI Error codes. Parameters: phSubSys  HPI subsystem handle hControl  Handle to control of type HPI_CONTROL_METER nAttack  Attack timeconstant in milliseconds nDecay  Decay timeconstant in milliseconds

HPI_ERR HPI_MeterGetRmsBallistics (  HPI_HSUBSYS *  phSubSys, HPI_HCONTROL  hControl, unsigned short *  pnAttack, unsigned short *  pnDecay )

Get the ballistics settings of the RMS part of a meter. Returns: 0 on success, or one of the HPI Error codes. Parameters: phSubSys  HPI subsystem handle hControl  Handle to control of type HPI_CONTROL_METER pnAttack  Attack timeconstant in milliseconds pnDecay  Decay timeconstant in milliseconds

HPI_ERR HPI_MeterSetPeakBallistics (  HPI_HSUBSYS *  phSubSys, HPI_HCONTROL  hControl, unsigned short  nAttack, unsigned short  nDecay )

Set the ballistics of the Peak part of a meter. Returns: 0 on success, or one of the HPI Error codes. Parameters: phSubSys  HPI subsystem handle hControl  Handle to control of type HPI_CONTROL_METER nAttack  Attack timeconstant in milliseconds nDecay  Decay timeconstant in milliseconds

HPI_ERR HPI_MeterGetPeakBallistics (  HPI_HSUBSYS *  phSubSys, HPI_HCONTROL  hControl, unsigned short *  pnAttack, unsigned short *  pnDecay )

Get the ballistics settings of the Peak part of a meter. Returns: 0 on success, or one of the HPI Error codes. Parameters: phSubSys  HPI subsystem handle hControl  Handle to control of type HPI_CONTROL_METER pnAttack  Attack timeconstant in milliseconds pnDecay  Decay timeconstant in milliseconds

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