ioctl(ixj, PHONE_PLAY_LEVEL)
Return Value
Returns the average signal level as a 16 bit value.
Parameters
None.
Remarks
This returns the average signal level (not r.m.s.) on the most recently played frame as a 16 bit value. This is used to measure the audio volume on the Internet PhoneJACK and the PSTN volume on the Internet LineJACK.
The threshold level scale is relative to the maximum positive full scale value of 0x7FFF (decimal 32767). This corresponds to an input signal level of approximately +3dBm0 from the external CODEC.
The precise input signal level can be calculated by:
Output level in dBm0 = +3.17 - 20 log10(output level/32767)
So the default threshold level of 0x0100 (256 decimal), corresponds to 44.753 dBm0.
See Also:
Example:
iPlev = ioctl(ixj, PHONE_PLAY_LEVEL);
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