Thanks for the quick reply. Thanks for the hint regarding @raw:1,2,3.
That will further help to reduce the CPU load. So you seem to confirm
that the CPU usage is normal for what i have done.
I don't think that one of the channels are clipping but i will
investigate. in SpecLab it show at -50 dB full scale, and the signal on
CH1 is exactly the same as on CH2. The gain (alsamixer) is equal on all
BTW there are local thunderstorm in quite a short distance. You asked
for some a few months ago :-)
I'm listening to them on VLF, using vlfrx tools for the first time to
listen to my stream from the tree using wget | vtvorbis @vlf and then
vtfilter @vlf | vtraw | aplay...
Am 06.07.2017 20:13, schrieb Paul Nicholson:
> the CPU load of vttime and vtresample increases continuously to
> very high values,
Yes, vttime will be using most of a core, @raw is 8 channels and
it's having to do a high quality resampling on them all. If you
only want 3 channels, use @raw:1,2,3 for input to vttime.
vtresample we can't do much about, it already defaults to the lowest
> strangely the process number of vtwrite is lower than vtresample,
> although vtresample has been started earlier.
This is often the case when commands are run with -B option to
put them into background. Each command forks twice to detach
itself from the controlling terminal. When a pipeline is starting
up, it's a race to claim process IDs as they're all forking.
> channel 1 seems to show some minor glitches, see attachment.
Looks bad. Run the signal through vtstat -i to see
if channel one is clipping at all.
vtread ... | vtstat -i
Maybe both channels are close to hitting 1.0 amplitude in
the stream and ch1 is slightly higher gain. You need to
look out for clipping if using integer sample formats.
> had to call the vlfrx tools from /usr/local/bin into that
As Jacek says. cron runs its commands with quite a minimal
enviroment, not quite the same as a login shell. For example it
doesn't run .bashrc as would a login shell so any extensions
to PATH or aliases wont be available unless you put them
in the crontab or in the scripts run by cron.