[LAU] Record from M-Audio 2496 S/PDIF input

[david]

On 08/02/2014 10:55 AM, Ivan K wrote:

> Thanks to everyone whom responded.
>
> Len Ovens <len at ovenwerks.net> writes:
>>
>> Audacity uses the portaudio library to connect to Jackd.. so in the
>> qjackctl connections window and the audio tab you should see PortAudio on
>> the right side.
>
> and
>
> "David Jones" <gnome at hawaii.rr.com> writes:
>>
>> My experience with recording via Audacity using JACK is that the
>> PortAudio connection only appears in JACK while Audacity is actually
>> using it (playing or recording). So I guess you start recording in
>> Audacity, pause it, tweak the connections in JACK, then continue recording.
>
> Well, no matter if Audacity is recording or playing,
> all I see in qjackctl, [Connect], "Audio" tab is:
>
> == ==   Readable Clients/
> == ==   Output Ports
> == ==   - system
> == ==     capture_1
> == ==     capture_2
>
> on the right, and then on the left, I see:
>
> == ==   Writable Clients/
> == ==   Input Ports
> == ==   - system
> == ==     playback_1
> == ==     playback_2
> == ==     playback_3
> == ==     playback_4
> == ==     playback_5
> == ==     playback_6
> == ==     playback_7
> == ==     playback_8
>
> I see don't see a mention of audacity or portaudio.

Hmmm, just on off-chance ... you do have Audacity set to use JACK? 
Sorry, maybe not being very helpful here.

> Also, does "system" refer to my M-Audio card or
> the integrated audio on the motherboard?

I believe that JACK's "system" refers to the audio card you've set JACK 
to use.

> If system does refer to my M-Audio card, I don't
> see anything in the under Readable Clients/Output Ports
> that distinguishes between the s/pdif input and the
> ADC input.

Didn't someone else in this thread already post about that? That SPDIF 
was 7 & 8?

> On the other hand, when I run mhWaveEdit, as suggested by
> Mr. Ovens, I do see the word "mhwe" listed both in
> the Readable Clients/Output Ports and Writable Clients/Input Ports.

A lot of audio programs are smarter about working with JACK than Audacity.

> At this point, I can continue to work with mhWaveEdit
> as audacity appears to be problematic.
> ----
>
> So running mhWaveEdit, I still cannot create any audio
> files with actual sound, or see mhWaveEdit's VU meters
> show any volume.
>
> So, does "system" in the connect window of qjackctl
> refer to my M-Audio card?
>
> Thank you for your suggestions!

Sorry, I've run out of clues. On my simple setup here, I started JACK, 
started Audacity, set Audacity to use JACK (it defaults to ALSA on my 
laptop); hit pause, then record, then unpaused. A PortAudio connection 
appeared in JACK's writable ports window. It was already connected to my 
in ports. I paused recording in Audacity and checked JACK; connection 
still there. When I hit Stop button in Audacity, the PortAudio 
connection disappeared from JACK.

I have jackdmp (JACK2) 1.9.10, Audacity 2.0.5.

-- 
David W. Jones
gnome at hawaii.rr.com
authenticity, honesty, community
http://dancingtreefrog.com