[asterisk-dev] Questions about app_jack.c

Fabien COMTE fabien.comte at ercogener.com
Mon Oct 5 09:17:57 CDT 2009


My configuration is :
Card 0 - kernel dummy sound card
Card 1 - my soundcard

I have a jackd running in background. My jackd launch command is :
jackd --port-max 16 --realtime --no-mlock -d alsa --playback hw:1,0
--capture hw:1,0 --rate 8000 --period 1024 --shorts --inchannels 2
--outchannels 2 --dither triangular &

1 ) I open asterisk with chan_alsa.so connected (with asoundrc) to the
kernel dummy sound card (allow me dial command). I do a call with a
JACK_HOOK from app_jack.so, sound is sent but no one is received.

My extensions.conf :
exten => _0.,1,Answer 
exten =>
exten => _0.,n,Dial(SIP/freephonie-out/${EXTEN:1})

Asterisk command :
console dial 0xxxxxxxx

2) Jackd works well with anothers applications when I force them to use jack
as input/output. -> probably not a jack configuration problem.

3) If I kill jackd and I use chan_alsa.so with the real soundcard, it works.
-> probably not a network or sip configuration problem.

4) If I replace "f_buf[i] = s_buf[i] * (1.0 / SHRT_MAX);" with "f_buf[i] =
0.5 * sin(0.3454 * ((float) i));" in app_jack.c and I retry the test 2, I
get test sound. 
It looks like no sound was read in channel...

Do you have any idea ?


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