>Could you try the above with a single CPU kernel?? i don't have one. there is some boot-time magic to ignore multiple processors, but i don't remember what it is. anybody?
>I will hack jackd tonight to do only Output. you mean the alsa-driver. they are separate pieces of code with no explicit connection. this needs to be remembered at all times. >The process() call is in app/AlsaNode.cpp, the code looks allright to >me, but I have only simple_client to compare it to :) as i've mentioned in private email, i've done a lot of debugging today. i can't find anything that explains the noise. its definitely not clipping, at least not at the jack-stage of things. if it is clipping, its way back at the disk i/o level, and somehow only shows up because of the float output ... >Sometimes an overrun will cause massive corruption with the sound, only >fixable by quitting and restarting jackd. I.e. quitting jackplayer and >reconnecting will still produce garbled sound. This happens because the >frequency of the process() calls gets erratic. Jackd will also segfault >randomly once it is in this state. I can't seem to use GDB to trace the >crash. I'll try connecting GDB to a running jackd next. i wouldn't bother. i've found and fixed several critical errors on jackd during the day today. >> the effect is strange. its not like harsh clipping. its a strange kind >> of constant buzzing, but its definitely like clipping in that its >> clearly signal level related. > >Yes, I can get rid of pops by lowering the volume of jackplayer (need >GTK+ GUI for this). But this suggest the clipping problem is inside >jackd. the effect i get is not "pops". its a strange metallic shimmer that kicks in a louder power levels. >calles where nframes is 1. I did some statistics over 5000 calls for 64 >frames per interrupt. Roughly 45% of the calls are with nframes around >64, another 45% around 1, the remaining % is evenly distributed inbetween thes >e 2 values. Doesn't this make it very inefficient? yes, this is a bug/misdesign in ALSA. i've added code to avoid it in the alsa-driver for JACK. --p
