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IPerChannelDbLevel::GetLevelRange

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IPerChannelDbLevel::GetLevelRange

The GetLevelRange method gets the range, in decibels, of the volume level of the specified channel.

HRESULT GetLevelRange(
  UINT  nChannel,
  float  *pfMinLevelDB,
  float  *pfMaxLevelDB,
  float  *pfStepping
);

Parameters

nChannel

[in]  The number of the selected channel. If the audio stream has n channels, the channels are numbered from 0 to n – 1. To get the number of channels in the stream, call the IPerChannelDbLevel::GetChannelCount method.

pfMinLevelDB

[out]  Pointer to a float variable into which the method writes the minimum volume level in decibels.

pfMaxLevelDB

[out]  Pointer to a float variable into which the method writes the maximum volume level in decibels.

pfStepping

[out]  Pointer to a float variable into which the method writes the stepping value between consecutive volume levels in the range *pfMinLevelDB to *pfMaxLevelDB. If the difference between the maximum and minimum volume levels is d decibels, and the range is divided into n steps (uniformly sized intervals), then the volume can have *n *+ 1 discrete levels and the size of the step between consecutive levels is *d */ n decibels.

Return Value

If the method succeeds, it returns S_OK. If it fails, possible return codes include, but are not limited to, the values shown in the following table.

Return code Description
E_INVALIDARG Parameter nChannel is out of range.
E_POINTER Pointer pfminLevelDB, pfmaxLevelDB, or pfmaxLevelDB is NULL.

Requirements

Client: Windows Vista

Header: Include Devicetopology.h.

See Also

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