Difference between revisions of "JACK in Elphel cameras"
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- connect USB sound card to camera | - connect USB sound card to camera | ||
- login via telnet and start jackd: | - login via telnet and start jackd: | ||
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[root@Elphel353 /]# jackd -dalsa -dhw:0 -n3 -p512 -s -S | [root@Elphel353 /]# jackd -dalsa -dhw:0 -n3 -p512 -s -S | ||
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jackd 0.116.2 | jackd 0.116.2 | ||
Copyright 2001-2005 Paul Davis and others. | Copyright 2001-2005 Paul Davis and others. |
Revision as of 00:17, 17 November 2009
This is example how using JACK on camera
- connect USB sound card to camera - login via telnet and start jackd:
[root@Elphel353 /]# jackd -dalsa -dhw:0 -n3 -p512 -s -S
jackd 0.116.2 Copyright 2001-2005 Paul Davis and others. jackd comes with ABSOLUTELY NO WARRANTY This is free software, and you are welcome to redistribute it under certain conditions; see the file COPYING for details JACK compiled with System V SHM support. loading driver .. creating alsa driver ... hw:0|hw:0|512|3|48000|0|0|nomon|swmeter|soft-mode|16bit control device hw:0 configuring for 48000Hz, period = 512 frames (10.7 ms), buffer = 3 periods ALSA: final selected sample format for capture: 16bit little-endian ALSA: use 3 periods for capture ALSA: final selected sample format for playback: 16bit little-endian ALSA: use 3 periods for playback playback and capture sample rates do not match (48000 vs. 24000)
if You have different samplerate for capture/playback(as example, on my USB sound card) cancel jackd via ctrl-c and restart it via next command
[root@Elphel353 /]# jackd -dalsa -dplug:hw:0 -n3 -p512 -s -S
You can start JACK server in foreground as
jackd -dalsa -dplug:hw:0 -n3 -p512 -s -S 1>/dev/null &
Ok, now we can look avialable audio channels. (login another telnet session, session #2, if You not started jackd as foreground) [root@Elphel353 /]# jack_lsp system:capture_1 system:capture_2 system:playback_1 system:playback_2
For test output channels starting simple software metronom
[root@Elphel353 /]# jack_metro -b 120 &
Look at avialable channels:
[root@Elphel353 /]# jack_lsp system:capture_1 system:capture_2 system:playback_1 system:playback_2 metro:120_bpm
Connect headphones to audio card. Now "connect" metronom output to playback channels of soundcard as [root@Elphel353 /]# jack_connect metro:120_bpm system:playback_1 [root@Elphel353 /]# jack_connect metro:120_bpm system:playback_2
You can hear "beep" in headphones. Ok, disconnect metronom from output channels [root@Elphel353 /]# jack_disconnect metro:120_bpm system:playback_1 [root@Elphel353 /]# jack_disconnect metro:120_bpm system:playback_2
For dump audio to wav files You can use timemachine [root@Elphel353 /]# timemachine -c1 -t1 -p/var/tmp/hdd/tm -f wav -n dmpaudio
where /var/tmp/hdd - path to directory where stored dump file tm - prefix of file, filename look as "tm2009-09-27T05:08:44.wav" dmpaudio - the JACK name timemachine will use
Connect, for example, metro:120_bpm to dmpaudio:in_1. Go to session #2 and enter
[root@Elphel353]# jack_connect metro:120_bpm dmpaudio:in_1 [root@Elphel353]# jack_lsp -c system:capture_1 system:capture_2 system:playback_1 system:playback_2 metro:120_bpm
dmpaudio:in_1
dmpaudio:in_1
metro:120_bpm
Go to session #3 and enter "start" waiting some time - enter "stop" Now You can play *.wav file and hear "beep" Ok, disconnect metro:120_bpm from dmpaudio:in_1
Go to session #1 and enter "start"
waiting some time - enter "stop"
Now You can play *.wav file and hear "beep"
Ok, disconnect metro:120_bpm from dmpaudio:in_1 and connect audio capture channel to our dump program
Connect mic to sound card.
[root@Elphel353]# jack_disconnect metro:120_bpm dmpaudio:in_1 [root@Elphel353]# jack_connect system:capture_1 dmpaudio:in_1
Go to session #1, enter command "start". Now You starting record from mic. Playing some time and stop record Enter command "stop". Trying play dumped wav file - You can hear sound from mic. Ok, now mixing two sources to dump file, go to session #2 Usage ./timemachine: [-h] [-i] [-c channels] [-n jack-name]
[-t buffer-length] [-p file prefix] [-f format] [-a] [-b begin-threshold] [-e end-threshold] [-T end-time] [port-name ...]
-h show this help -i interactive mode (console instead of X11) also enabled if DISPLAY is unset -c specify number of recording channels -n specify the JACK name timemachine will use -t specify the pre-recording buffer length -p specify the saved file prefix, may include path -s use safer characters in filename (windows compatibility) -f specify the saved file format -a enable automatic sound-triggered recording -b specify threshold above which automatic recording will begin -e specify threshold below which automatic recording will end -T specify silence length before automatic recording ends
channels must be in the range 1-8, default 2 jack-name, default "TimeMachine" file-prefix, default "tm-" buffer-length, default 10 secs format, default 'w64', options: wav, w64 begin-threshold, default -35.0 dB end-threshold, default -35.0 dB end-time, default 10 secs