capturing microphone on linux (too few volume)
Hi there,
I'm trying to capture sound from a microphone on linux. I already have succeeded in getting the capture device, getting the audio stream and all between. But the stream (which is LINEAR 44kHz captured and then processed to fitting RTP format) is by far too low in volume. Even if I set the volume in the mixer (KMix) to maximum and boost the mic I only get an humming background sound and only some fraction of my input (when i blow on the mic). I found that KRecord has an option showing the input amplitude either in Linear or in Logarithmic form, and logarithmic it is alife somewhere at 30dB but linear it is showing nothing, a green line a the leftmost side. So I think maybe I have to capture logarithmic?
I'm not a professional capturer and I know even less about sound systems on Linux. So I need some hints here to get that thing running.
Kind regards,
Kai
...
> I'm trying to capture sound from a microphone on
> linux. I already have succeeded in getting the
> capture device, getting the audio stream and all
> between.
Are you sure you have the right one?
I had a devil of a time tapping into the sound
system recently. I developed this oscilloscope
to plot the available audio lines - to help me
sort the confusion.
http://www.physci.org/test/oscilloscope/
'audiotraces.jar' is the 'double click' jar, but
you can compile it from the source if you like.
The troubles I faced were mostly about 'volume',
but I'm not sure if the causes are closely related
to those you are seeing, in any case, here is the
thread that talks about that code..
http://groups.google.com/group/comp.lang.java.programmer/browse_frm/thread/e85989a213f3b6b1/c02258a163a2a6df?#c02258a163a2a6df
You mean the right audio source? I'm sure in so far as there is only one datasource available, and it is javasound://44100. There is also just one audio device installed. And I can hear some reaction when I blow into the mic or I have a crackling sound when I plug the mic in or out. It's just that it is to few volume. I tried your tool, it comes up with three lines on the screen, but all were flat.
Kind regards,
Kai
