[alsa-devel] snd_device_name_hint problems

[Raymond Yau]

The name hint does not define any device for recording

if you run alsa-lib/test/namehint.c , you should notice that front device is
used for "Front Speakers".

Most likely you cannot use this "front" device for recording

The "pulse" device is in the list since I am using Fedora 10


 ./namehint
NAMEfront:CARD=au8830,DEV=0|DESCAureal Vortex au8830, adb
Front speakers
NAMEsurround40:CARD=au8830,DEV=0|DESCAureal Vortex au8830, adb
4.0 Surround output to Front and Rear speakers
NAMEiec958:CARD=au8830,DEV=0|DESCAureal Vortex au8830, spdif
IEC958 (S/PDIF) Digital Audio Output|IOIDOutput
NAMEnull|DESCDiscard all samples (playback) or generate zero samples
(capture)
NAMEpulse|DESCPulseAudio Sound Server
NAMEdefault|DESCDefault
NAMEfront:CARD=Intel,DEV=0|DESCHDA Intel, AD198x Analog
Front speakers
NAMEsurround40:CARD=Intel,DEV=0|DESCHDA Intel, AD198x Analog
4.0 Surround output to Front and Rear speakers
NAMEsurround41:CARD=Intel,DEV=0|DESCHDA Intel, AD198x Analog
4.1 Surround output to Front, Rear and Subwoofer speakers
NAMEsurround50:CARD=Intel,DEV=0|DESCHDA Intel, AD198x Analog
5.0 Surround output to Front, Center and Rear speakers
NAMEsurround51:CARD=Intel,DEV=0|DESCHDA Intel, AD198x Analog
5.1 Surround output to Front, Center, Rear and Subwoofer speakers
NAMEsurround71:CARD=Intel,DEV=0|DESCHDA Intel, AD198x Analog
7.1 Surround output to Front, Center, Side, Rear and Woofer speakers
NAMEiec958:CARD=Intel,DEV=0|DESCHDA Intel, AD198x Digital
IEC958 (S/PDIF) Digital Audio Output



arecord --list-device
**** List of CAPTURE Hardware Devices ****

card 1: Intel [HDA Intel], device 0: AD198x Analog [AD198x Analog]
  Subdevices: 3/3
  Subdevice #0: subdevice #0
  Subdevice #1: subdevice #1
  Subdevice #2: subdevice #2
card 1: Intel [HDA Intel], device 1: AD198x Digital [AD198x Digital]
  Subdevices: 1/1
  Subdevice #0: subdevice #0


2009/9/12 David Henningsson <launchpad.web at epost.diwic.se>

> Raymond Yau skrev:
> > It seem to me that name hint is not suitable for displaying recording
> > devices
>
> But what should I then use? snd_card_xxx will not show the pulse device,
> snd_names_list is deprecated, and snd_config_xxx is not recommended either.
>
> > You can get low latency by using hw device since PA use maximum buffer in
> > order to save power comsumption for those notebook / netbook.
> >
> > If your application require high quality (bypass any SRC) , you may need
> to
> > capture using hardware rate and format instead of using plughw
>
> I will not need low latency for this application, but avoiding SRC would
> probably be a good thing. But I assume the plug handling does not do any
> SRC if it can avoid it by adjusting the hardware?
>
> > For HDA , it support multiple streamming. some  HDA codecs (e.g. alc88x
> and
> > ad198x) have 3 ADC ( which you can capture three stereo streams
> concurrently
> > from internal mic, external mic and line in )
> >
> > The main problem of the recording audio application is unable to select
> the
> > correct mixer control of the three capture sources
>
> What I would like would my enumeration function to return in this case
> would be four entries, one for each ADC and one for them all combined (6
> channels, multi-channel recording).
>
> // David
>
>