> 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: http://lists.freedesktop.org/archives/pulseaudio-discuss/2014-January/019731.html > 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 user-land configuration. 1.4.Then ALSA applications can resolve channels/rate/formats mismatch with 'plughw'. 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 'SND_PCM_NO_AUTO_FORMAT'. 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 stereo/surrund channels. 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 reasonable...) Regards Takashi Sakamoto o-takashi at sakamocchi.jp
