Subject: Re: [linux-audio-dev] [ANN] AlsaPlayer 0.99.52-cvs20011126-jack
From: Paul Davis (pbd_AT_Op.Net)
Date: Tue Nov 27 2001 - 07:02:21 EET
>I'm getting very poor performance from jackd. Even on my, somewhat
>beefy, 1.33MHZ Athlon box I get horrible xruns from 10ms up to 150ms.
>Anything below 512 frames per interrupt is unworkable. As soon as I connect
OK, i just tried it on my dual PII450 box, with
jackd -d trident -R -p 64
jackplayer -i text some.wav
and got no xruns at all. this is on 2.4.0+lowish.
there is definitely some clipping or other wierd effect occuring with
"jackplayer". it is present even when jackplayer is the only client,
but then just gets worse when other clients connect and use the same
port. this is odd, since they have no input. when i run them with
input, but without jackplayer, the effect is not present.
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. i sort of suspect an issue with the
sample_move_dS_s16 function that you borrowed.
but as i said, its notable that its in place even without any other
clients, but not with other clients without jackplayer, so i sort of
suspect something inside jackplayer.
>connecting jack_simple_client. Running with "default|128|44100" will
>happily xrun every bdflush :-/ .. I'm using an UW2 SCSI disk
i hate to say this, but this sounds like 1 of only 2 possibilities:
* kernel issues
* uniprocessor issues
also, i note that your code is burning a *LOT* of CPU time. the
"jack_simple_client", which copies 1 channel from input to output,
almost doesn't register in xosview (jackd is invisible). jackplayer
with a text interface is burning chunks of CPU comparable to what
ardour uses for 8-16 tracks of highly non-contiguous audio plus a GUI,
sometimes even more.
--p
This archive was generated by hypermail 2b28 : Tue Nov 27 2001 - 07:01:32 EET