On Sun, Jan 24, 2010 at 10:31 PM, Paulo Cavalcanti <promac@gmail.com> wrote:

Hi,

I have been recording using arecord and aplay this way:

arecord -D default -d 0 -f cd | aplay -f cd -D default &

The problem is that, while this works fine on rhel5, the same is no true
for Fedora 12 using pulseaudio, since I clearly hear some random noise (specially at low volumes).

Maybe this is related to the fact that the arecord process is consuming 15% of my CPU (a quadcore, 2.4MHz). Compared to Audacious 2.2, for instance, playing an mp3 file, which consumes only 4% of the CPU, this is really too much.

I concluded that the problem has to do with recording with pulseaudio active.
I know there are parecord and paplay, but they are just symbolic links to pacat,
and I do not know how to combine them in a similar way.

Therefore, my question is what is the best way of recording with pulseadio, without wasting too much of my CPU and without noise?

In fact, 15% is the minimum. In general it can hit up to 30%.

If I use

arecord -D default -d 0 -f $tp | paplay &

the consumption drops to 7% (much better), but still too far from the
0.3% I get on rhel5.