LinuxQuestions.org - [SOLVED] Microphone problems, arecord will not work

- Slackware (https://www.linuxquestions.org/questions/slackware-14/)

- - Microphone problems, arecord will not work (https://www.linuxquestions.org/questions/slackware-14/microphone-problems-arecord-will-not-work-4175560686/)

Microphone problems, arecord will not work

Hi,

I am having an issue getting my microphone to work so that I can record sound. I have been trying to do a screencast, and no method I used (several ffmpeg variations, recordmydesktop) would give me working audio. Other audio playback works fine.

I tried to test the mic with arecord, and got an error. Here is some information:

Code:

bash-4.2# arecord -l

**** List of CAPTURE Hardware Devices ****

card 0: PCH [HDA Intel PCH], device 0: ALC269VB Analog [ALC269VB Analog]

  Subdevices: 1/1

  Subdevice #0: subdevice #0

Code:

bash-4.2# arecord -d 10 test.wav

ALSA lib pcm_dmix.c:961:(snd_pcm_dmix_open) The dmix plugin supports only playback stream

arecord: main:722: audio open error: Invalid argument

Code:

bash-4.2# cat /etc/asound.conf

    pcm.!default {

            type hw

            card 0

    }

    ctl.!default {

            type hw

            card 0

    }

    pcm.!default {

            type plug

            slave.pcm "softvol"

    }

    pcm.softvol {

            type softvol

            slave {

                    pcm "dmix"

            }

            control {

                    name "Pre-Amp"

                    card 0

            }

            min_dB -5.0

            max_dB 20.0

            resolution 6

    }

Code:

bash-4.2# lspci              

00:00.0 Host bridge: Intel Corporation 3rd Gen Core processor DRAM Controller (rev 09)

00:02.0 VGA compatible controller: Intel Corporation 3rd Gen Core processor Graphics Controller (rev 09)

00:04.0 Signal processing controller: Intel Corporation 3rd Gen Core Processor Thermal Subsystem (rev 09)

00:14.0 USB controller: Intel Corporation 7 Series/C210 Series Chipset Family USB xHCI Host Controller (rev 04)

00:16.0 Communication controller: Intel Corporation 7 Series/C210 Series Chipset Family MEI Controller #1 (rev 04)

00:1a.0 USB controller: Intel Corporation 7 Series/C210 Series Chipset Family USB Enhanced Host Controller #2 (rev 04)

00:1b.0 Audio device: Intel Corporation 7 Series/C210 Series Chipset Family High Definition Audio Controller (rev 04)

00:1c.0 PCI bridge: Intel Corporation 7 Series/C210 Series Chipset Family PCI Express Root Port 1 (rev c4)

00:1c.1 PCI bridge: Intel Corporation 7 Series/C210 Series Chipset Family PCI Express Root Port 2 (rev c4)

00:1d.0 USB controller: Intel Corporation 7 Series/C210 Series Chipset Family USB Enhanced Host Controller #1 (rev 04)

00:1f.0 ISA bridge: Intel Corporation HM76 Express Chipset LPC Controller (rev 04)

00:1f.2 SATA controller: Intel Corporation 7 Series Chipset Family 6-port SATA Controller [AHCI mode] (rev 04)

00:1f.3 SMBus: Intel Corporation 7 Series/C210 Series Chipset Family SMBus Controller (rev 04)

00:1f.6 Signal processing controller: Intel Corporation 7 Series/C210 Series Chipset Family Thermal Management Controller (rev 04)

02:00.0 Network controller: Intel Corporation Centrino Advanced-N 6235 (rev 24)

I googled the dmix error and got a few results, but I did not see anything I could decipher about my exact situation. I seem to be out of my depth with audio, as this is the first time I have dealt with such an issue. Help would be much appreciated.

Thank you in advance.

A few things for you to try.
Run 'alsamixer' and check that the microphone is unmuted and that the microphone and capture levels are raised. (I start by pushing them all the way up, then backing off as appropriate.)
For recording, I find that I need to specify the plughw device.

Code:

arecord -d 5 -D plughw:0,0 foobar.wav

You may also want to try moving that /etc/asound.conf out of the way, then rebooting.

it should just work. I use it all the time like this

Code:

arecord -vv -f dat -t raw | oggenc - -q=10 -r -R48000 -o audio.ogg

As allend said, starts from a pristine /etc/asound.conf and adjust the capture levels with alsamixer. Within alsamixer press space bar to enable the capture channel.

Your capture device seems a bit different (PCH) than mine and the reference to the module snd_pcm_dmix_open in the error message is weird.

Code:

arecord -l

**** List of CAPTURE Hardware Devices ****

card 0: Intel [HDA Intel], device 0: ALC272 Analog [ALC272 Analog]

  Subdevices: 1/1

  Subdevice #0: subdevice #0

card 0: Intel [HDA Intel], device 2: ALC272 Alt Analog [ALC272 Alt Analog]

  Subdevices: 1/1

  Subdevice #0: subdevice #0

Thanks guys. I should have tried moving that asound.conf earlier. I did it, and that stopped the error, but I still am not able to record. The below gave me two 10 second files with no sound.

I tried playing both my test files with various media players with no success. I'm not sure it's related, but on a side note I discovered that vlc will not play audio at all. I'm using Alien's build and it has worked fine in the past.

Code:

bash-4.2$ arecord -vv -d 10 mytest.wav

Recording WAVE 'mytest.wav' : Unsigned 8 bit, Rate 8000 Hz, Mono

Plug PCM: Rate conversion PCM (48000, sformat=U8)

Converter: linear-interpolation

Protocol version: 10002

Its setup is:

  stream      : CAPTURE

  access      : RW_INTERLEAVED

  format      : U8

  subformat    : STD

  channels    : 1

  rate        : 8000

  exact rate  : 8000 (8000/1)

  msbits      : 8

  buffer_size  : 2730

  period_size  : 170

  period_time  : 21333

  tstamp_mode  : NONE

  period_step  : 1

  avail_min    : 170

  period_event : 0

  start_threshold  : 1

  stop_threshold  : 2730

  silence_threshold: 0

  silence_size : 0

  boundary    : 768426686420090880

Slave: Route conversion PCM (sformat=S32_LE)

  Transformation table:

    0 <- 0

Its setup is:

  stream      : CAPTURE

  access      : MMAP_INTERLEAVED

  format      : U8

  subformat    : STD

  channels    : 1

  rate        : 48000

  exact rate  : 48000 (48000/1)

  msbits      : 8

  buffer_size  : 16384

  period_size  : 1024

  period_time  : 21333

  tstamp_mode  : NONE

  period_step  : 1

  avail_min    : 1024

  period_event : 0

  start_threshold  : 6

  stop_threshold  : 16384

  silence_threshold: 0

  silence_size : 0

  boundary    : 4611686018427387904

Slave: Soft volume PCM

Control: Digital Capture Volume

min_dB: -30

max_dB: 30

resolution: 121

Its setup is:

  stream      : CAPTURE

  access      : MMAP_INTERLEAVED

  format      : S32_LE

  subformat    : STD

  channels    : 2

  rate        : 48000

  exact rate  : 48000 (48000/1)

  msbits      : 32

  buffer_size  : 16384

  period_size  : 1024

  period_time  : 21333

  tstamp_mode  : NONE

  period_step  : 1

  avail_min    : 1024

  period_event : 0

  start_threshold  : 6

  stop_threshold  : 16384

  silence_threshold: 0

  silence_size : 0

  boundary    : 4611686018427387904

Slave: Direct Snoop PCM

Its setup is:

  stream      : CAPTURE

  access      : MMAP_INTERLEAVED

  format      : S32_LE

  subformat    : STD

  channels    : 2

  rate        : 48000

  exact rate  : 48000 (48000/1)

  msbits      : 32

  buffer_size  : 16384

  period_size  : 1024

  period_time  : 21333

  tstamp_mode  : NONE

  period_step  : 1

  avail_min    : 1024

  period_event : 0

  start_threshold  : 6

  stop_threshold  : 16384

  silence_threshold: 0

  silence_size : 0

  boundary    : 4611686018427387904

Hardware PCM card 0 'HDA Intel PCH' device 0 subdevice 0

Its setup is:

  stream      : CAPTURE

  access      : MMAP_INTERLEAVED

  format      : S32_LE

  subformat    : STD

  channels    : 2

  rate        : 48000

  exact rate  : 48000 (48000/1)

  msbits      : 32

  buffer_size  : 16384

  period_size  : 1024

  period_time  : 21333

  tstamp_mode  : ENABLE

  period_step  : 1

  avail_min    : 1024

  period_event : 0

  start_threshold  : 1

  stop_threshold  : 4611686018427387904

  silence_threshold: 0

  silence_size : 0

  boundary    : 4611686018427387904

  appl_ptr    : 0

  hw_ptr      : 0

#+                                                | 00%

bash-4.2$ aplay mytest.wav 

Playing WAVE 'mytest.wav' : Unsigned 8 bit, Rate 8000 Hz, Mono

bash-4.2$ 

bash-4.2$ 

bash-4.2$ arecord -d 10 -D plughw:0,0 test2.wav

Recording WAVE 'test2.wav' : Unsigned 8 bit, Rate 8000 Hz, Mono

bash-4.2$ aplay test2.wav

Playing WAVE 'test2.wav' : Unsigned 8 bit, Rate 8000 Hz, Mono

bash-4.2$

I forgot to mention before that I am on a multilib 14.1 system.

Oh, the relevant alsamixer levels are all at max too. The only thing is, many releases ago I added the asound.conf to enable pre-amp functionality because my laptop sound is too weak without it. However, even when I removed it, the pre-amp remained. In fact, as you can see, I have 2. I wonder why this is? Did alsamixer change defaults? But why 2 pre-amps? My asound.conf is renamed and moved to my home directory.

screenshot: http://postimg.org/image/cgxgf217j/

hi Miranden,
on your alsamixer snapshot from you last post the capture channel looks muted to me.
Go back to alsamixer, move to this channel and press space bar to unmute it.

Oh, wow, you're right! I had no idea those little dashed lines by that control meant it was muted. I didn't even notice them. I guess you can tell I don't do much recording!

I feel like an idiot. But a happy one at least, since I can finally get this done. Thanks for the help!

Alright, this is off topic, but I just have to admit, this is not the first time something like this has happened to me. I once had a TV that suddenly stopped making sound, so I took it apart and tried to figure out what the problem was. I had no success. Finally I called a friend (who happens to be an electrical engineer at SpaceX), and he set to the task. Neither of us had any clue what was wrong. After several hours, just as we were about to give up, we discovered, hidden on the back, a small push button toggle that said "speakers."

So it figures. Maybe this time I will learn my lesson!