[LAD] zita-ajbridge and aloop

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 hi all, (apologies if this is the wrong mailing list, but i'm currently only subscribed to LAD and not LAU. anyhow:) i'm having serious troubles using zita-ajbridge with alsa loopback devices. my basic requirement is, to allow *any* ALSA-only application to be "jackified". i'm on debian, and my current tests are done on i386 resp. x86_64, but my target platform is armel (wandboard solo, powered by a single-core ARM cortex-A9) the basic problem i'm facing is, that i don't get much output. occasionally i do get output (e.g. with mplayer) so here's what i did: # modprobe snd-aloop (with all the default parameters) which gives me: $ cat /proc/asound/cards 0 [Generic ]: HDA-Intel - HD-Audio Generic HD-Audio Generic at 0xf0244000 irq 43 1 [SB ]: HDA-Intel - HDA ATI SB HDA ATI SB at 0xf0240000 irq 16 2 [Loopback ]: Loopback - Loopback Loopback 1 $ zita-a2j -v -d hw:Loopback,0 -L playback : not enabled capture : nchan : 2 fsamp : 48000 fsize : 256 nfrag : 2 format : S16_LE Starting synchronisation. 0.460 0.999864 [...] on another terminal i do: $ mplayer -ao alsa:device=hw=Loopback.1 STE48.wav and after connecting zita-a2j to my system's output, i can hear sound. cool! ok, so i stop mplayer, and start some other application e.g. Pd (what else). hooking it up to the loopback device, i start my testpatch: silence :-( ok, so mabye Pd is broken, i try some zita app, e.g. zita_delay (from libzita-alsa-pcmi) $ alsa_delay hw:Loopback,0 hw:Loopback,0 48000 1024 2 playback : nchan : 32 fsamp : 48000 fsize : 1024 nfrag : 2 format : FLOAT_LE capture : nchan : 32 fsamp : 48000 fsize : 1024 nfrag : 2 format : FLOAT_LE synced Signal below threshold... Signal below threshold... [...] not very surprisingly, it doesn't detect any input signal (zita-j2a is not running), but i also don't hear any output signal. hmm. stopping jack (which quits zita-a2j), i try a alsa_delay on my soundcard: $ alsa_delay hw:SB,0 hw:SB,0 48000 1024 2 playback : nchan : 2 fsamp : 48000 fsize : 1024 nfrag : 2 format : S32_LE capture : nchan : 2 fsamp : 48000 fsize : 1024 nfrag : 2 format : S32_LE synced 2176.341 frames 45.340 ms ?? 2176.405 frames 45.342 ms ?? and i hear nice sine-tones. checking the output of alsa_delay vs that of zita-a2j, i notice that one uses latter S32_LE whereas the former uses FLOAT_LE. since i cannot change the format of alsa_delay without recompilation, i try to match the two formats with zita-a2j, by running: $ zita-a2j -v -d hw:Loopback,0 -p 1024 $ zita-a2j -v -d hw:Loopback,0 -p 1024 playback : not enabled capture : nchan : 32 fsamp : 48000 fsize : 1024 nfrag : 2 format : FLOAT_LE Starting synchronisation. 3.716 0.999042 2.713 0.998499 [...] which gives me pretty much the same config as is used with alsa_delay. re-starting `alsa_delay`: still no sound. just in case: starting zita-j2a as well: $ zita-j2a -v -d hw:Loopback,0 -p 1024 playback : nchan : 32 fsamp : 48000 fsize : 1024 nfrag : 2 format : FLOAT_LE capture : not enabled Starting synchronisation. -2.919 1.000933 -1.457 1.001286 [...] and making sure that zita-*2* are jack-connected to system, but still no luck. hmm, what is going on here? currently the *only* application that i can convince to use zita-ajbridge seems to be mplayer, and only in S16_LE mode. what are the requirements for an application to use zita-ajbridge? shouldn't other zita applications (like alsa_delay) automagically fullfill these requirements through libzita-alsa-pcmi? do my application either have to support FLOAT_LE or be stuck with S16_LE/2channels forever? is there a tutorial out there on how to use zita-ajbridge with snd-aloop? masdr IOhannes