No sound input (11.1, MCP78S [GeForce 8200])

English Hardware
1

Hi!

I’m having problems with my sound card.

Audio output seems to work fine, at least speaker-test

speaker-test -c2 -l5 -twav

produces the expected output.

But when it comes to audio input, I can’t get my microphone working. kmix doesn’t even show the MIC section on the INPUT tab.

I’m running openSUSE 11.1, sound is onboard and identifies itself as nVidia Corporation MCP78S [GeForce 8200].

ALSA information can be found here: http://www.alsa-project.org/db/?f=5759ac1965f7a0f727c9429a5841409edc137f75

rpm -qa | grep alsa produces

alsa-firmware-1.0.17-1.42
alsa-tools-1.0.18-1.13
alsa-tools-gui-1.0.18-1.13
alsa-oss-1.0.17-1.37
tsalsa-20080914-0.pm.1
alsa-1.0.18-8.7
alsa-plugins-pulse-1.0.18-6.12
alsamixergui-0.9.0rc1-584.132
kalsatools-1.5.0-499.130
alsa-utils-1.0.18-6.4
alsa-plugins-1.0.18-6.12

rpm -qa | grep pulse:

pulseaudio-lang-0.9.14-2.2.1
pulseaudio-utils-0.9.14-2.2.1
pulseaudio-module-zeroconf-0.9.14-2.2.1
pulseaudio-esound-compat-0.9.14-2.2.1
libpulse-mainloop-glib0-0.9.14-2.2.1
pulseaudio-module-lirc-0.9.14-2.2.1
libxine1-pulse-1.1.15-23.3.3
libpulse0-0.9.14-2.2.1
pulseaudio-module-jack-0.9.14-2.2.1
pulseaudio-0.9.14-2.2.1
pulseaudio-module-bluetooth-0.9.14-2.2.1
vlc-aout-pulse-0.9.9a-2.6
pulseaudio-module-gconf-0.9.14-2.2.1
alsa-plugins-pulse-1.0.18-6.12
libpulse-browse0-0.9.14-2.2.1
pulseaudio-module-x11-0.9.14-2.2.1

Any suggestions?

2

If using kde4, you just add the extra mixer channels controls via a menu selection.

Is this an internal mic or external mic you are trying to get to work? You have to supply that information. I suspect its intuitively obvious to you, but I can’t see if you have a laptop or a desktop.

I note this in your mixer from the diagnostic script output you provided:
!!Amixer output
!!-------------
!!-------Mixer controls for card 0 [NVidia]

Card hw:0 ‘NVidia’/‘HDA NVidia at 0xfce78000 irq 20’
Mixer name : ‘Generic 10de NVIDIA MCP78 HDMI’
Simple mixer control ‘Front Mic’,0
Front Left: Playback 31 [100%] [14.00dB] [on]
Front Right: Playback 31 [100%] [14.00dB] [on]
Simple mixer control ‘Mic’,0
Front Left: Playback 31 [100%] [14.00dB] [on]
Front Right: Playback 31 [100%] [14.00dB] [on]
Simple mixer control ‘Capture’,0
Front Left: Capture 20 [100%] [35.00dB] [on]
Front Right: Capture 20 [100%] [35.00dB] [on]
Simple mixer control ‘Capture’,1
Front Left: Capture 0 [0%] [0.00dB] [on]
Front Right: Capture 0 [0%] [0.00dB] [on]
Simple mixer control ‘Digital’,0
Front Left: Capture 120 [100%] [30.00dB]
Front Right: Capture 120 [100%] [30.00dB]
Simple mixer control ‘Input Source’,0
Items: ‘Stereo Mixer’ ‘Mic’ ‘Front Mic’ ‘Line’ ‘CD’
Item0: **‘CD’**Should “Capture1” be at 0% capture?

Should the mixer input source be on CD and not on Mic or Front Mic?

Its possible you may need to update alsa to get your mic working, but you need to at least test your mixer with the best possible settings first.

Note, I am on vacation (currently in Shenzhen China) and travelling a lot every day. It may be days before I reply to any posts of yours.

Edit: What are you using for your mic test? I recommend using “arecord” for testing. If you search this forum for “arecord” and “oldcpu” you will find some simple examples I gave on using arecord.

3

Thanks for your assistance.

I’m using a desktop system, therefore it is an external mic.

In the meantime I tried most combinations of the settings in alsamixer but with little success. When talking I can hear my own voice from the speakers but no application, including arecord and krecord, do capture the sound signal.

The hardware is working fine as it works on a parallel installation of Windows Vista.

As KMix doesn’t show a microphone section on the input tab I think that either sound is not properly configured in YaST or the soundchip isn’t fully supported.

By the way

head -n 1 /proc/asound/card0/codec*

yields Codec: VIA VT1708B 8-Ch which may not be supported by alsa as I cannot find this codec in the ALSA-Configuration.txt.

I’ve already spend some time working on this problem and I’m now considering to buy a cheap PCI sound card with a well-supported chip …

4

I need to see the exact mixer settings, as you believe them to be optimal. The above script output had your mic muted at 0% capture and your CD (instead of mic) selected. Can you try again with the mixer not muted? And then run the diagnostic script so I can check your settings.

To use arecord, try to record from a simple terminal command as such: arecord -d 10 myrecording.wavand then play back “myrecording.wav” with a nominal player. The “-d 10” specifies a 10 second recording.