CM6206, S/PDIF + JACK

CM6206, S/PDIF + JACK

[Dan MacDonald]

Hi ALSA devs!

I've got a Startech USB device based on the CM6206 chipset. It does work
with JACK although I can only access the two mic inputs as JACK capture
ports even though under alsamixer I can also see line in and SPDIF In. I
bought it in the hope of using its SPDIF input under JACK.

SPDIF is enabled under alsamixer and even when I start JACK with a signal
coming in to SPDIF, I still get no SPDIF capture port.I have posted various
ALSA logs and more details here:

http://www.linuxmusicians.com/viewtopic.php?f=27&t=8898

I've already spoke to las about this but he couldn't help me, no knowing
anything about these devices.

Might I be able to get this working under JACK? Maybe I need a special ALSA
config to enable SPDIF?

Thanks!

Dan

Re: CM6206, S/PDIF + JACK

[Clemens Ladisch]

Dan MacDonald wrote:
> I've got a Startech USB device based on the CM6206 chipset. It does work
> with JACK although I can only access the two mic inputs as JACK capture
> ports even though under alsamixer I can also see line in and SPDIF In.
>
> I get no SPDIF capture port.

Have a look at section 5 of the CM6206 datasheet.
There is no S/PDIF capture port; all inputs end up at the default
stereo input port.


Regards,
Clemens

Re: CM6206, S/PDIF + JACK

[Dan MacDonald]

Hi Clemens!

Thanks for pointing that out! I was expecting to see separate input ports
for the mic, line in and SPDIF under JACK but they must all be rolled into
one if thats what the datasheet says - I've not looked myself yet.

However, I had a quick go at capturing audio from SPDIF and the default
stereo inputs (after making sure SPDIF in was enabled under alsamixer)
 this morning but I got nothing. I have zero experience with SPDIF devices
and Linux (or any other OS) so I dunno what to watch out for - I have only
ever used SPDIF in the past to copy CDs onto Minidiscs (remember them?).

In my quick test I was trying to capture audio from a audio CDR so there
won't have been any copy protection on the disc. CDs are 44.1Khz of course
but I was running JACK at 48Khz - that shouldn't be an issue should it or
would I need to run JACK at 44.1 to capture an audio CD via SPDIF? Maybe rt
resampling isn't supported?

Another thing thats just come to mind is I think that the mic and line
inputs were also set to capture so maybe I'd need to only enable capture
for the SPDIF input but nothing else?

If there is anything else I should know about using SPDIF with
ALSA/Linux/JACK then please let me know!

Thanks!

Dan


On Tue, Nov 13, 2012 at 12:55 PM, Clemens Ladisch <clemens@ladisch.de>wrote:

> Dan MacDonald wrote:
> > I've got a Startech USB device based on the CM6206 chipset. It does work
> > with JACK although I can only access the two mic inputs as JACK capture
> > ports even though under alsamixer I can also see line in and SPDIF In.
> >
> > I get no SPDIF capture port.
>
> Have a look at section 5 of the CM6206 datasheet.
> There is no S/PDIF capture port; all inputs end up at the default
> stereo input port.
>
>
> Regards,
> Clemens
>

Re: CM6206, S/PDIF + JACK

[Clemens Ladisch]

Dan MacDonald wrote:
> However, I had a quick go at capturing audio from SPDIF and the default
> stereo inputs (after making sure SPDIF in was enabled under alsamixer)
>  this morning but I got nothing. I have zero experience with SPDIF devices
> and Linux (or any other OS) so I dunno what to watch out for

This depends entirely on how the hardware implements the routing.

> In my quick test I was trying to capture audio from a audio CDR so there
> won't have been any copy protection on the disc. CDs are 44.1Khz of course
> but I was running JACK at 48Khz - that shouldn't be an issue should it or
> would I need to run JACK at 44.1 to capture an audio CD via SPDIF? Maybe rt
> resampling isn't supported?

I didn't find a box labeled "high-quality resampler for those lazy Jack
users" in the datasheet ...

> Another thing thats just come to mind is I think that the mic and line
> inputs were also set to capture so maybe I'd need to only enable capture
> for the SPDIF input but nothing else?

In theory, only one input can be enabled at the same time.
What does "amixer contents" show for this device?


Regards,
Clemens

Re: CM6206, S/PDIF + JACK

[Dan MacDonald]

Hi Clemens!

I've at least tested SPDIF in under Windows now so I know its not a
hardware issue here.


On Tue, Nov 13, 2012 at 9:25 PM, Clemens Ladisch <clemens@ladisch.de> wrote:

> Dan MacDonald wrote:
> > However, I had a quick go at capturing audio from SPDIF and the default
> > stereo inputs (after making sure SPDIF in was enabled under alsamixer)
> >  this morning but I got nothing. I have zero experience with SPDIF
> devices
> > and Linux (or any other OS) so I dunno what to watch out for
>
> This depends entirely on how the hardware implements the routing.
>
> > In my quick test I was trying to capture audio from a audio CDR so there
> > won't have been any copy protection on the disc. CDs are 44.1Khz of
> course
> > but I was running JACK at 48Khz - that shouldn't be an issue should it or
> > would I need to run JACK at 44.1 to capture an audio CD via SPDIF? Maybe
> rt
> > resampling isn't supported?
>
> I didn't find a box labeled "high-quality resampler for those lazy Jack
> users" in the datasheet ...
>

Hehe! :)

but the box for this card says "Hard to find made easy" on every face!


>
> > Another thing thats just come to mind is I think that the mic and line
> > inputs were also set to capture so maybe I'd need to only enable capture
> > for the SPDIF input but nothing else?
>
> In theory, only one input can be enabled at the same time.
> What does "amixer contents" show for this device?
>
>
> Regards,
> Clemens
>

amixer -c 1 contents
numid=14,iface=MIXER,name='PCM Capture Source'
  ; type=ENUMERATED,access=rw------,values=1,items=4
  ; Item #0 'Mic'
  ; Item #1 'Line'
  ; Item #2 'IEC958 In'
  ; Item #3 'Mixer'
  : values=0
numid=12,iface=MIXER,name='PCM Capture Switch'
  ; type=BOOLEAN,access=rw------,values=1
  : values=off
numid=13,iface=MIXER,name='PCM Capture Volume'
  ; type=INTEGER,access=rw---R--,values=2,min=0,max=6928,step=0
  : values=4096,4096
  | dBminmax-min=-16.00dB,max=11.06dB
numid=3,iface=MIXER,name='Line Playback Switch'
  ; type=BOOLEAN,access=rw------,values=1
  : values=off
numid=4,iface=MIXER,name='Line Playback Volume'
  ; type=INTEGER,access=rw---R--,values=2,min=0,max=8065,step=0
  : values=6144,6144
  | dBminmax-min=-24.00dB,max=7.50dB
numid=9,iface=MIXER,name='Line Capture Switch'
  ; type=BOOLEAN,access=rw------,values=1
  : values=off
numid=10,iface=MIXER,name='Line Capture Volume'
  ; type=INTEGER,access=rw---R--,values=2,min=0,max=6928,step=0
  : values=4096,4096
  | dBminmax-min=-16.00dB,max=11.06dB
numid=1,iface=MIXER,name='Mic Playback Switch'
  ; type=BOOLEAN,access=rw------,values=1
  : values=off
numid=2,iface=MIXER,name='Mic Playback Volume'
  ; type=INTEGER,access=rw---R--,values=2,min=0,max=8065,step=0
  : values=6144,6144
  | dBminmax-min=-24.00dB,max=7.50dB
numid=7,iface=MIXER,name='Mic Capture Switch'
  ; type=BOOLEAN,access=rw------,values=1
  : values=off
numid=8,iface=MIXER,name='Mic Capture Volume'
  ; type=INTEGER,access=rw---R--,values=2,min=0,max=6928,step=0
  : values=4096,4096
  | dBminmax-min=-16.00dB,max=11.06dB
numid=11,iface=MIXER,name='IEC958 In Capture Switch'
  ; type=BOOLEAN,access=rw------,values=1
  : values=on
numid=5,iface=MIXER,name='Speaker Playback Switch'
  ; type=BOOLEAN,access=rw------,values=1
  : values=on
numid=6,iface=MIXER,name='Speaker Playback Volume'
  ; type=INTEGER,access=rw---R--,values=8,min=0,max=197,step=0
  : values=196,196,196,196,196,196,196,196
  | dBminmax-min=-36.93dB,max=0.00dB


Thanks Clemens!

Re: CM6206, S/PDIF + JACK

[Clemens Ladisch]

Dan MacDonald wrote:
> numid=9,iface=MIXER,name='Line Capture Switch'
>   : values=off
> numid=7,iface=MIXER,name='Mic Capture Switch'
>   : values=off
> numid=11,iface=MIXER,name='IEC958 In Capture Switch'
>   : values=on

Okay.

> numid=14,iface=MIXER,name='PCM Capture Source'
>   ; Item #0 'Mic'
>   ; Item #1 'Line'
>   ; Item #2 'IEC958 In'
>   ; Item #3 'Mixer'
>   : values=0

But this is still set to Mic, ...

> numid=12,iface=MIXER,name='PCM Capture Switch'
>   : values=off

... and capturing is disabled altogether.
(Or is this one for capturing playback data?)


Regards,
Clemens

Re: CM6206, S/PDIF + JACK

[Dan MacDonald]

Hi Clemens et al(sa)!

Yes, that was the problem and I have SPDIF capture working now!

I couldn't find any simpleton friendly docs for this process so I wrote a
short howto:

http://www.linuxmusicians.com/viewtopic.php?f=19&t=10271


Thanks for your help!


On Wed, Nov 14, 2012 at 7:40 AM, Clemens Ladisch <clemens@ladisch.de> wrote:

> Dan MacDonald wrote:
> > numid=9,iface=MIXER,name='Line Capture Switch'
> >   : values=off
> > numid=7,iface=MIXER,name='Mic Capture Switch'
> >   : values=off
> > numid=11,iface=MIXER,name='IEC958 In Capture Switch'
> >   : values=on
>
> Okay.
>
> > numid=14,iface=MIXER,name='PCM Capture Source'
> >   ; Item #0 'Mic'
> >   ; Item #1 'Line'
> >   ; Item #2 'IEC958 In'
> >   ; Item #3 'Mixer'
> >   : values=0
>
> But this is still set to Mic, ...
>
> > numid=12,iface=MIXER,name='PCM Capture Switch'
> >   : values=off
>
> ... and capturing is disabled altogether.
> (Or is this one for capturing playback data?)
>
>
> Regards,
> Clemens
>