On Thu, 5 Nov 2020 22:31:39 +0100 Fons Adriaensen <fons@xxxxxxxxxxxxxx> wrote: Many thanks for the fast reply. Recording the old way in progress currently, so I can't try anything else today. > On Thu, Nov 05, 2020 at 09:06:19PM +0000, John Murphy wrote: > > > Wondering if there's a command line (scriptable) recorder for Jack > > which will record for a configurable duration. Because: > > > > I've been using Jack TimeMachine to record in its default 'w64' format > > and then converting to wav with sox like: > > > > sox --no-clobber -S tm-2020-10-27T22:00:15.w64 -b 16 /home/john/2710.wav > > > > It all works well and sox stat shows min and max amplitude -0.9 and 0.9 > > > > I need to make the recordings automatic and arecord seems to fit the bill > > with its ability to record for a number of seconds with -d, but the level > > seems much lower. I used PulseAudio Volume Control to get something like > > a good level with 150% on the input sliders (10.53dB) and I still only > > see around -0.5 and 0.5 using sox stat. They only go up to 11dB. > > First advice: get rid of PA and its braindead controls. If you disable > PA when using Jack, do the same when using arecord. Can't seem to do that, unfortunately. > Then recording using arecord or jack with the ALSA backend (using the > same sound card in both cases of course) should give the same result. > In both cases that will depend on the alsamixer settings if there any > for your sound card. Alsamixer shows nothing configurable for the (USB) card and using the same arecord command (arecord -f dat -d 10 test.wav) records silence. > The difference between +/-0.9 and +/-0.5 is actually quite small (less > than 6 dB). It doesn't tell you anything unless you can ensure you > recorded exactly the same signal in both cases. Normal audio signals > (speech, music,...) have level variations that are much bigger than > 6 dB. Good point. It's mainly that the level will just look wrong in the visual editor I use. My tests have been much shorter, but sox stat is suggesting Volume adjustment: 1.868 and 1.662 on new files made with +10dB (according to Pulse) and 1.000 for a previous recording made with jack TimeMachine. -- Thanks again, John. _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx https://lists.linuxaudio.org/listinfo/linux-audio-user
