Client:
# netcat <banana ip> 9000 | vlc
Works? Great! Live listening is important to play around and test the mic.
Listen and record at same time
# rec -c 2 -C 64 -t mp3 - | tee test.mp3 | netcat -l -p 9000
Poor man's streaming server
# apt-get install openbsd-inetd tcpd
Edit config file:
# nano /etc/inetd.conf
Insert this at the end:
9000 stream tcp nowait nobody /usr/bin/tail tail -f /test.mp3
Restart service
# service openbsd-inetd restart
Start recording on banana:
# rec -c 2 -C 64 /test.mp3
Connect via client:
# netcat <banana ip> 9000 | vlc -
C. Advanced Recording
Devide recording and postprocessing in two parts
# rec -t raw - remix - | sox -t raw -r 48000 -c 1 -b 16 -e signed-integer - -t mp3 -c 1 -C 32 test.mp3
Recording:
-t raw
- forward raw input to pipe
remix
- Mix the two channels to one
Encoding:
-t raw -r 48000 -c 1 -b 16 -e signed-integer
- tell sox what kind of strean comes from stdin
-t mp3 -c 1 -C 32 test.mp3
and what goes out
Note that it is switched to mono from here with -c 1 and the mp3 bitrate is cut in half. Live listening to the strean does not
work anymore, i asume it is because of the non regulare output from pipeing and processing in a second step.
Reduce noise
The mic input is pretty bad, lot of white noise. Sox can deal with it.
Make a sample "silent" file:
BPI-R1 MIC
23
Summary of Contents for BPI-R1
Page 5: ...BPI R1 hardware interface BPI R1 hardware interface Front Back BPI R1 hardware interface 5...
Page 6: ...Hardware connect sketch map Front Back BPI R1 hardware interface 6...
Page 7: ...BPI R1 hardware interface 7...
Page 8: ...BPI R1 hardware spec BPI R1 hardware spec 8...
Page 14: ...J13 P01 UART0 RX PB23 J13 P02 UART0 TX PB22 BPI R1 GPIO Pin define 14...
Page 28: ...please note value 0 value 1 press is 1 unpress is 0 BPI R1 IR interface 28...
Page 41: ...BPI R1 RoHS Certification BPI R1 CE FCC RoHS Certification 41...
Page 42: ...BPI R1 CE FCC RoHS Certification 42...
Page 43: ...BPI R1 Software BPI R1 support linux android and openwrt system BPI R1 Software 43...
Page 59: ...Linux kernel 3 4 BSP image 59...