[pulseaudio-discuss] 'Failed to find a working profile' for firewire sound devices

Alexander E. Patrakov patrakov at gmail.com
Mon Jan 13 11:48:46 PST 2014


2014/1/13 Takashi Sakamoto <o-takashi at sakamocchi.jp>:
> Hi Alexander,
>
>
>> AFAIK PulseAudio always uses this flag.
>
> I've made it clear in my previous mail.
>
>
>> No. I have deleted the table from my reply, but it looks like there
>> are  two issues here. First, the needed conversions depend on the
>> sample rate. Second, they vary between models and depend on hardware
>> switches.
>
> I agree with your analysis for this issue.
>
>
>> Is it really true that your hardware accepts two playback
>> channels at 192 kHz, but has no way, at the register level, to accept
>> two playback channels at lower rates?
>
> I cannot understand what you asked. Would you explain your intent for this
> question?
> I have already explain about relationships between channels/rate which the
> devices supports.

They are quite unusual, that's why I reasked. I wanted to know whether
these relationships are indeed due to the hardware limitations, or due
to your driver being too simplistic and allowing only the maximum
supported number of channels for a given sample rate.

I have looked at the source. There are comments mentioning tables 50
and 51. Is that datasheet (for bebob) publicly available?

>
>
>> For the second problem, I think, it is possible (but not necessarily
>> a good idea) to have per-model and maybe per-switch-position
>> configuration files. See how it is done in the cmipci driver (grep
>> for SWIEC, look for the alternative configuration file with SWIEC in
>> the name).
>
> I'm a bit negative for this idea when considering about how much work it
> takes for me. If the number of devices which my drivers support was 20 or
> less, I would have consider about it. But they support much devices than you
> expected.

I guess the best course of action would be to reask on alsa-devel.

-- 
Alexander E. Patrakov


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