[pulseaudio-discuss] 'Failed to find a working profile' for firewire sound devices
o-takashi at sakamocchi.jp
Mon Jan 13 18:22:19 PST 2014
> They are quite unusual, that's why I reasked.
I think this type of questions can't help to resolve this issue at all...
> I wanted to know whether these relationships are indeed due to
> the hardware limitations, or due to your driver being too simplistic
I've already answered this:
> AFAIK, the driver should support what the hardware supports.
Yes. It's my intent to add the rules between channels/rates.
> I have looked at the source. There are comments mentioning tables 50
> and 51. Is that datasheet (for bebob) publicly available?
It's closed. The line is just a pointer for to refer to the documents.
It's just for a few developers.
> I guess the best course of action would be to reask on alsa-devel.
I have an thought that this is an issue in PulseAudio-side. So I can
post to alsa-devel to gather good ideas, not to resolve this issue.
Here, I introduce my thought for this issue:
1.0 'alsa-lib' already gives a way to resolve channels/rates/formats
mismatch between applications and ALSA drivers.
1.2.It's 'plug' plugin.
1.3.Source package of 'alsa-lib' includes default configurations. It's
applied to all of PCM drivers. All of PCM drivers have 'plughw' in
1.4.Then ALSA applications can resolve channels/rate/formats mismatch
2.0 In a relationships to ALSA, PulseAudio is one of ALSA applications.
2.1 PulseAudio opens ALSA PCM handler with flag of
'SND_PCM_NO_AUTO_RESAMPLE', 'SND_PCM_NO_AUTO_CHANNELS' and
2.2 This means 'When PulseAudio resolve such mismatch, PulseAudio don't
use alsa-lib functionality, just manage by itself'.
2.3 This strategy works well for 'typical' sound devices with
2.4 But once PulseAudio encounter 'non-typical' sound devices, it fails
to detect automatically.
3.0 One of 'non-typical' is ICE1712 based sound device.
3.1 ICE1712 has simple rules for its channels/rates.
3.2 So configuration with 'route' plugin can be a solution for this issue.
3.3 Then, for ICE1712, PulseAudio doesn't follow strategy 2.2.
PulseAudio uses 'alsa-lib' functionality.
3.4 This was a solution for this issue, at a glance.
4.0 One of 'non-typical' is Firewire sound device for studio use.
4.1 This type of devices have variety of channels/rates.
4.2 So a solution with 'route' plugin can't apply.
4.3 Then this issue appears again.
(When applying a solution with 'route' plugin, I must maintain much
files for each configuration of devices. It may be over 100
configurations in 'alsa-lib'. This is... this is...this is not
o-takashi at sakamocchi.jp
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