📄 wmaudiosignals.c
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/* Now work out the dB value (in 1/16dB steps) */
regVol -= pSignalDetails->zerodB;
step = pSignalDetails->step;
baseVol = regVol * step;
/*
* Now convert into the appropriate units.
*/
if ( baseUnit > 1 )
{
/*
* Work out what is the largest value less than half a unit
* (i.e. the largest value we can add to an exact multiple
* of the unit so we can guarantee it will not change on
* rounding.
*/
int halfUnit = baseUnit/2;
halfUnit = halfUnit - 1;
/*
* Add it to the baseVol so it will round the right way.
*/
if ( baseVol > 0 )
baseVol += halfUnit;
else
baseVol -= halfUnit;
baseVol = baseVol / baseUnit;
}
/* And we're done */
break;
}
}
}
/* Did we find it? */
if ( WM_REG_INVALID == reg )
{
status = WMS_UNSUPPORTED;
goto error;
}
/*
* Return the value.
*/
*pVol = baseVol;
return WMS_SUCCESS;
error:
return status;
}
/*-----------------------------------------------------------------------------
* Function: WMAudioSetOutputAttenuations
*
* Called to set the left and right channel attenuations applied to a
* given analogue output. For example, a 0dBFS input with 6dB attenuation
* would result in a -6dBFS signal from the output.
*
* Note: the underlying device may not use dB step sizes. In this case the
* applied attenuation will be rounded to the nearest available step.
* For example, if the device has a 1.5dB step size
* (typical of AC'97 devices), an attenuation of either 4dB or 5dB would
* result in a -4.5dBFS signal.
*
* Parameters:
* hDevice handle to the device (from WMOpenDevice)
* outputL left output to attenuate
* outputR right output to attenuate
* attenuationdBLeft left channel attenuation to apply in dB steps.
* attenuationdBRight right channel attenuation to apply in dB steps.
*
*
* Returns: WMSTATUS
* See WMStatus.h.
*---------------------------------------------------------------------------*/
WMSTATUS WMAudioSetOutputAttenuations( WM_DEVICE_HANDLE hDevice,
WM_AUDIO_SIGNAL outputL,
WM_AUDIO_SIGNAL outputR,
int attenuationdBLeft,
int attenuationdBRight
)
{
WMSTATUS status;
/*
* Call through to our helper function.
*/
status = private_Set2ChannelVolumeBase( hDevice,
outputL,
outputR,
WM_SIGNAL_LEVEL( -attenuationdBLeft ),
WM_SIGNAL_LEVEL( -attenuationdBRight )
);
return status;
}
/*-----------------------------------------------------------------------------
* Function: WMAudioSetInputGains
*
* Called to set the gain applied to a given input.
* For example, a 0dBFS input with 6dB gain would result in the input signal
* being increased by +6dBFS.
*
* Note: the underlying device may not use dB step sizes. In this case the
* applied gain will be rounded to the nearest available step. For
* example, if the device has a 1.5dB step size (typical of AC'97 devices),
* an gain of either 4dB or 5dB would result in a +4.5dBFS signal.
*
* Parameters:
* hDevice handle to the device (from WMOpenDevice)
* inputL left input to gain
* inputR right input to gain
* gain_dBL left channel gain to apply in dB steps.
* gain_dBR right channel gain to apply in dB steps.
*
* Returns: WMSTATUS
* See WMStatus.h.
*---------------------------------------------------------------------------*/
WMSTATUS WMAudioSetInputGains( WM_DEVICE_HANDLE hDevice,
WM_AUDIO_SIGNAL inputL,
WM_AUDIO_SIGNAL inputR,
int gain_dBL,
int gain_dBR
)
{
WMSTATUS status;
/*
* Call through to our helper function.
*/
status = private_Set2ChannelVolumeBase( hDevice,
inputL,
inputR,
WM_SIGNAL_LEVEL( gain_dBL ),
WM_SIGNAL_LEVEL( gain_dBR )
);
return status;
}
/*-----------------------------------------------------------------------------
* Function: WMAudioSetOutputVolumes
*
* Called to set the perceived volume for the left and right channels
* of a given analogue output.
*
* Note: Linearly reducing the perceived volume does _not_ result in a linear
* attenuation of the output signal.
*
* Parameters:
* hDevice handle to the device (from WMOpenDevice)
* output output to attenuate
* volPercentL left channel perceived output volume,
* as a percentage of full-scale
* volPercentR Right channel perceived output volume,
* as a percentage of full-scale
* channels indicates channel(s) to set attenuation on.
*
* Returns: WMSTATUS
* See WMStatus.h.
*---------------------------------------------------------------------------*/
WMSTATUS WMAudioSetOutputVolumes( WM_DEVICE_HANDLE hDevice,
WM_AUDIO_SIGNAL output,
unsigned int volPercentL,
unsigned int volPercentR,
WM_AUDIO_CHANNELS channels
)
{
WMSTATUS status;
unsigned int leftVol, rightVol;
leftVol = 65535 * volPercentL / 100;
rightVol = 65535 * volPercentR / 100;
status = WMAudioSetSignalVolumes( hDevice, output, leftVol, rightVol );
return status;
}
/*-----------------------------------------------------------------------------
* Function: WMAudioSetOutputAttenuationsAC97
*
* Called to set the left and right channel attenuations applied to a given
* analogue output, using the AC97 attenuation values to write to the register
* - 1.5dB steps.
* Note:
* At the moment we only support setting the attenuation on 2 outputs if they
* have the same control register
*
* Parameters:
* hDevice handle to the device (from WMOpenDevice)
* outputL left output to attenuate
* outputR right output to attenuate
* rawValL left channel attenuation to apply in 1.5dB steps.
* rawValR right channel attenuation to apply in 1.5dB steps.
*
* Returns: WMSTATUS
* See WMStatus.h.
*---------------------------------------------------------------------------*/
WMSTATUS WMAudioSetOutputAttenuationsAC97( WM_DEVICE_HANDLE hDevice,
WM_AUDIO_SIGNAL outputL,
WM_AUDIO_SIGNAL outputR,
int rawValL,
int rawValR
)
{
WMSTATUS status;
/*
* Call through to our helper function.
*/
status = private_Set2ChannelVolumeBase( hDevice,
outputL,
outputR,
WM_SIGNAL_LEVEL_AC97( -rawValL ),
WM_SIGNAL_LEVEL_AC97( -rawValR )
);
return status;
}
/*-----------------------------------------------------------------------------
* Function: WMAudioGetOutputAttenuationsAC97
*
* Called to get the left and right channel attenuations set at a given
* analogue output, outputiing the AC97 attenuation values obtained from the
* registers - 1.5dB steps.
*
* Parameters:
* hDevice handle to the device (from WMOpenDevice)
* output output to attenuate
* rawValL left channel attenuation to get.
* rawValR right channel attenuation to get.
* channels indicates channel(s) attenuations to get.
*
* Returns: WMSTATUS
* See WMStatus.h.
*---------------------------------------------------------------------------*/
WMSTATUS WMAudioGetOutputAttenuationsAC97( WM_DEVICE_HANDLE hDevice,
WM_AUDIO_SIGNAL output,
int *rawValL,
int *rawValR,
WM_AUDIO_CHANNELS channels
)
{
WMSTATUS status;
/*
* Get left if asked for.
*/
if ( rawValL && channels & WM_CHANNEL_LEFT )
{
status = private_GetSignalVolumeUnits( hDevice,
output,
rawValL,
WM_CHANNEL_LEFT,
WM_SIGNAL_LEVEL_AC97( -1 )
);
if ( WM_ERROR( status ) )
{
goto finish;
}
}
/*
* And right.
*/
if ( rawValR && channels & WM_CHANNEL_RIGHT )
{
status = private_GetSignalVolumeUnits( hDevice,
output,
rawValR,
WM_CHANNEL_RIGHT,
WM_SIGNAL_LEVEL_AC97( -1 )
);
if ( WM_ERROR( status ) )
{
goto finish;
}
}
/*
* And return.
*/
finish:
return status;
}
/*-----------------------------------------------------------------------------
* Function: WMAudioSetInputGainsAC97
*
* Called to set the gain applied to a given input, using the AC97
* gain value to write to the register - All the inputs have a range of
* +12dB to -34.5dB gain in 1.5dB steps except for PCBEEP.
* PCBEEP on WM9705/07 has a range of 0dB to -45dB in 3dB steps.
* PCBEEP on WM9712/13 has a range of 6dB to -15dB in 3dB steps.
*
* NOTE: If we need to set gains for two entirely different inputs we will need
* to set (seperate) details for both the left and right imputs simultaneously.
* This is not currently supported so WMAudioSetInputGainsAC97 must be called
* separately to alter the left and right signals.
*
* Parameters:
* hDevice handle to the device (from WMOpenDevice)
* inputL left input to apply gain to.
* inputR right input to apply gain to.
* rawValL left channel gain to apply in 1.5dB steps.
* rawValR right channel gain to apply in 1.5dB steps.
*
* Returns: WMSTATUS
* See WMStatus.h.
*---------------------------------------------------------------------------*/
WMSTATUS WMAudioSetInputGainsAC97( WM_DEVICE_HANDLE hDevice,
WM_AUDIO_SIGNAL inputL,
WM_AUDIO_SIGNAL inputR,
WM_REGVAL rawValL,
WM_REGVAL rawValR
)
{
WMSTATUS status;
/*
* Call through to our helper function.
*/
status = private_Set2ChannelVolumeBase( hDevice,
inputL,
inputR,
WM_SIGNAL_LEVEL_AC97( rawValL ),
WM_SIGNAL_LEVEL_AC97( rawValR )
);
return status;
}
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