From mboxrd@z Thu Jan 1 00:00:00 1970 From: Felix Homann Subject: Re: M-Audio Fast Track Ultra (8r) mixer: How to verify dB information? Date: Fri, 10 Sep 2010 09:48:26 +0200 Message-ID: <4C89E2CA.2090206@web.de> References: <4C89539E.8030701@web.de> <4C89DBC5.7070906@ladisch.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from vwp5738.webpack.hosteurope.de (vwp5738.webpack.hosteurope.de [83.169.30.203]) by alsa0.perex.cz (Postfix) with ESMTP id A5AFF244B6 for ; Fri, 10 Sep 2010 09:48:29 +0200 (CEST) In-Reply-To: <4C89DBC5.7070906@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: Clemens Ladisch Cc: Felix Homann , alsa-devel@alsa-project.org List-Id: alsa-devel@alsa-project.org Hi Clemens, Am 10.09.2010 09:18, schrieb Clemens Ladisch: > I'm using the mixer_vol_tlv TLV >> callback right now but I'm not sure it produces correct data. >> > Try alsamixer. Or just post the output of "amixer contents" here. > > Well, according to alsamixer the mixer values are mapped to a range from 0 to -128 dB. 'amixer contents' show entries of the form numid=112,iface=MIXER,name='DIn8 - Out7 Playback Volume' ; type=INTEGER,access=rw---R--,values=1,min=0,max=32768,step=0 : values=-32768 | unk-4-0xffffce00,0x00000000, (numid and name changing of xourse for each control ). Here are some examples of setting values with amixer: :~$ amixer -c 2 cset numid=1 50% numid=1,iface=MIXER,name='AIn1 - Out1 Playback Volume' ; type=INTEGER,access=rw---R--,values=1,min=0,max=32768,step=0 : values=16384 | unk-4-0xffffce00,0x00000000, :~$ amixer -c 2 cset numid=1 80% numid=1,iface=MIXER,name='AIn1 - Out1 Playback Volume' ; type=INTEGER,access=rw---R--,values=1,min=0,max=32768,step=0 : values=26215 | unk-4-0xffffce00,0x00000000, :~$ amixer -c 2 cset numid=1 100% numid=1,iface=MIXER,name='AIn1 - Out1 Playback Volume' ; type=INTEGER,access=rw---R--,values=1,min=0,max=32768,step=0 : values=32768 | unk-4-0xffffce00,0x00000000, cat /proc/asound/F8R/usbmixer gives lines like this: Unit: 5 Control: name="DIn8 - Out7 Playback Volume", index=0 Info: id=5, control=7, cmask=0x8000, channels=1, type="S16" Volume: min=-32768, max=0, dBmin=-12800, dBmax=0 How do I tell the controls value range is correctly mapped to the dB values? Kind regards, Felix