[pulseaudio-discuss] How to get mencoder to use, pulseaudio in capturing audio?

[Raymond Yau]

> >
> > To make sure that I have understood the problem correctly, I'll try
> > to summarize it here: You have been happily capturing video and
> > audio from a video capture card for some time now. The audio
> > capture has been done by connecting the video capture card's audio
> > output to a sound card's line-in using a physical loopback cable.
> > The audio capturing has been done so far with direct alsa access
> > without pulseaudio in the middle. This has been working fine, until
> > recently it just stopped working.
>
> You did understand the problem perfectly.
>
> > What are the symptoms of the breakage? Do you get silence instead
> > of real audio, or does mencoder refuse to do anything at all? Do
> > you get any error messages from mencoder?
>
> No error messages by mencoder, just recording silence!
>
> >
>
tv=input=1:driver=v4l2:device=/dev/video0:normid=3:input=1:alsa=1:adevice=hw.0,2:audiorate=48000:amode=1:width=768:height=576
> >
> > The audio specific parts are: alsa=1 (use alsa) adevice=hw.0,2 (use
> > direct hardware access with device 2 of card 0) audiorate=48000
> > (audio sample rate) amode=1 (stereo)

afaik, pulseaudio does not use capture device 2 of your hda realtek alc88x
for capturing as pulseaudio does not sopport multi streaming capture

did you select the "line in" in correct "input source" control ,the capture
volume and unmute capture switch of device 2

Simple mixer control 'Capture',0
  Capabilities: cvolume cswitch penum
  Capture channels: Front Left - Front Right
  Limits: Capture 0 - 46
  Front Left: Capture 16 [35%] [0.00dB] [on]
  Front Right: Capture 16 [35%] [0.00dB] [on]
Simple mixer control 'Capture',1
  Capabilities: cvolume cswitch penum
  Capture channels: Front Left - Front Right
  Limits: Capture 0 - 46
  Front Left: Capture 0 [0%] [-16.00dB] [off]
  Front Right: Capture 0 [0%] [-16.00dB] [off]

Simple mixer control 'Input Source',0
  Capabilities: cenum
  Items: 'Rear Mic' 'Front Mic' 'Line'
  Item0: 'Front Mic'
Simple mixer control 'Input Source',1
  Capabilities: cenum
  Items: 'Rear Mic' 'Front Mic' 'Line'
  Item0: 'Rear Mic'

arecord -l
**** List of CAPTURE Hardware Devices ****

> shm_open() failed: Permission denied

you have a customised asoundrc which use shm

card 0: SB [HDA ATI SB], device 0: ALC892 Analog [ALC892 Analog]
  Subdevices: 0/1
  Subdevice #0: subdevice #0
card 0: SB [HDA ATI SB], device 2: ALC892 Analog [ALC892 Analog]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 2: CX8811 [Conexant CX8811], device 0: CX88 Digital [CX88 Digital]
  Subdevices: 0/1
  Subdevice #0: subdevice #0
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