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HH
VS1005 VSOS A
UDIO
S
UBSYSTEM
VS1005g
has vanished practically completely by sample 150).
Another issue in audio is excessive dynamic range. This is not a problem when recording
well-mixed, pre-recorded music, but it may be a big issue when recording speech from
the microphone. To compensate for the audio level differences of close and faw away
speakers, and Automatic Gain Control (AGC) unit may often be useful. Note, however,
that AGC should not be used for HiFi recording applications!
8.2.1
Driver FTIDCBL.DL3
The DC Block driver FTIDCBL.DL3 connects to
stdaudioin
as shown in Figure 10 on
page 28.
The driver may be controlled either through C ioctl() function calls as described in the
README.TXT file for the driver itself, or from the VSOS Shell using the SETAGC.DL3
command.
8.2.2
Driver FTIAGC.DL3
In addition to the DC Block driver described in 8.2.1, the AGC driver offers an Automatic
Gain Control function.
The driver may be controlled either through C ioctl() function calls as described in the
README.TXT file for the driver itself, or from the VSOS Shell using the SETAGC.DL3
command.
8.2.3
Control Program SETAGC.DL3
Usage: SetAgc [-i|-o] [-a x|-d x|-t x|-max x|-min x|-d x] [-h]
-i
Set stdaudioin (default)
-o
Set stdaudioout
-a x
Set attack (ms)
-d x
Set decay (ms)
-t x
Set target level (dB)
-max x Set maximum gain (dB)
-min x Set minimum gain (dB)
-b x
Set DC Block Filter (0x4000 = HiFi, 0x8000 = Speech,
0x0
= Auto, 0xC00x = Set to x)
-h
Show this help
With no parameters SetAgc will show current values
Sets/Prints AGC and/or DC Block Filter parameters. For the DC Block Filters only the -b
setting option is available.
Rev. 3.57
2019-04-10
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