From mboxrd@z Thu Jan 1 00:00:00 1970 From: Raymond Yau Subject: Re: Verifying mixer dB data/Invalid dB data from USB cards, especially Aureon 5.1 MkII Date: Tue, 23 Feb 2010 20:46:28 +0800 Message-ID: <4f3252891002230446g3fa96521yf51290e058473b94@mail.gmail.com> References: <20100216233825.GB23623@sirena.org.uk> <20100218023742.GC23637@tango.0pointer.de> <4f3252891002172215j7b85313ci3626a1bdad5c040c@mail.gmail.com> <20100218181322.GB5606@tango.0pointer.de> <4f3252891002190257u608073c3l48f2251d8a6458ee@mail.gmail.com> <20100219151328.GC25873@tango.0pointer.de> <4f3252891002202001gb6df8cg6c023c52e7d8394a@mail.gmail.com> <20100221192951.GD30380@tango.0pointer.de> <4B83A912.1050501@ladisch.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail-pw0-f51.google.com (mail-pw0-f51.google.com [209.85.160.51]) by alsa0.perex.cz (Postfix) with ESMTP id ABD5710387E for ; Tue, 23 Feb 2010 13:46:29 +0100 (CET) Received: by pwi9 with SMTP id 9so3266018pwi.38 for ; Tue, 23 Feb 2010 04:46:28 -0800 (PST) In-Reply-To: <4B83A912.1050501@ladisch.de> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: alsa-devel-bounces@alsa-project.org Errors-To: alsa-devel-bounces@alsa-project.org To: alsa-devel@alsa-project.org List-Id: alsa-devel@alsa-project.org 2010/2/23 Clemens Ladisch > Lennart Poettering wrote: > > On Sun, 21.02.10 12:01, Raymond Yau (superquad.vortex2@gmail.com) wrote: > > > However Simple Mixer API cannot know the subdevice number , you have to > use > > > control API ( the lower level API used by Simple Mixer API ) > > > > Unfortunately there is no way from the simple mixer to the lower level > > mixer. > > From the check_unplugged function in alsa-utils/alsamixer/mixer_widget.c: > > err = snd_mixer_get_hctl(mixer, mixer_device_name, &hctl); > if (err >= 0) > ctl = snd_hctl_ctl(hctl); > > > It would be great if the smixer would include some API that gives me a > > hint to which device/subdevice a specific snd_mixer_elem_t belongs to. > > Often, there is no 1:1 correspondence between mixer elements and PCM > devices. Only mixer controls with interface PCM (not MIXER) have (sub-) > device numbers, and at the moment this is used only for controls that > are associated with the streams of hardware-mixing-capable cards. > > Getting information about the mixer layout (like the nodes reported by > HDA and USB devices) is on the TODO list; the only reason it isn't being > implemented is lack of time. > > > Regards, > Clemens > > for hda , Since PA server open pcm device , so it still can use snd_mixer_selem_id_set_index(sid, snd_pcm_info_get_subdevice(pcm_info)); pavucontrol still can query PA server to get the sudevice numer whenever PA resum from suspend But gnome volume control has no way to know which application open which subdevice