On Mon, Jan 25, 2010 at 6:58 AM, Paulo Cavalcanti <promac(a)gmail.com> wrote:
On Sun, Jan 24, 2010 at 10:31 PM, Paulo Cavalcanti <promac(a)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.
This is the answer to my own question:
parec | pacat &
No noise and CPU below 0.3%
--
Paulo Roma Cavalcanti
LCG - UFRJ