[alsa-devel] Should "Master" control the "Line In" volume (loopback)
Hi,
I have a question-by-proxy from a user who is confused because his "Master" kcontrol is affecting the volume via Line In (which he uses to loopback an analog signal to his speakers).
I've not got much hardware here for comparison, but I'm pretty sure that Master usually doesn't affect Line In.
So couple of questions: 1. Is it typical that Master affects Line In? 2. If not, can it be fixed for this h/w?
ALSA info here: https://bzattachment.mandriva.com/attachment.cgi?id=18170
(for reference the full bug is here: https://qa.mandriva.com/show_bug.cgi?id=62218)
Cheers Col
At Sun, 23 Jan 2011 17:37:07 +0000, Colin Guthrie wrote:
Hi,
I have a question-by-proxy from a user who is confused because his "Master" kcontrol is affecting the volume via Line In (which he uses to loopback an analog signal to his speakers).
I've not got much hardware here for comparison, but I'm pretty sure that Master usually doesn't affect Line In.
So couple of questions:
- Is it typical that Master affects Line In?
Yes, but only for the loopback volume. It's independent from the line-in capture volume.
Takashi
2011/1/24 Takashi Iwai tiwai@suse.de
At Sun, 23 Jan 2011 17:37:07 +0000, Colin Guthrie wrote:
Hi,
I have a question-by-proxy from a user who is confused because his "Master" kcontrol is affecting the volume via Line In (which he uses to loopback an analog signal to his speakers).
I've not got much hardware here for comparison, but I'm pretty sure that Master usually doesn't affect Line In.
So couple of questions:
- Is it typical that Master affects Line In?
Yes, but only for the loopback volume. It's independent from the line-in capture volume.
ALSA info here: https://bzattachment.mandriva.com/attachment.cgi?id=18170
(for reference the full bug is here: https://qa.mandriva.com/show_bug.cgi?id=62218https://qa.mandriva.com/show_bug.cgi?id=62218
)
(1) KDE kmix is now pulseaudio aware and as such, kmix does not show the individual channels in the mixer I have my Sirrus/XM satellite radio plugged into LINE-IN and I listen to
it
while using the computer.
"virtual master" already have "Front" and "Headphone" as slaves
if the user want to hear the satelite radio from LINE_IN
Why Kmix does not control those "Mic Playback" and "Line Playback" any more ?
The max dB of Line and Mic playback volume are +12dB while those slave volume controls are only +3dB
control.1 { comment.access 'read write' comment.type INTEGER comment.count 2 comment.range '0 - 63' comment.dbmin -9150 comment.dbmax 300 iface MIXER name 'Front Playback Volume' value.0 61 value.1 61 }
control.3 { comment.access 'read write' comment.type INTEGER comment.count 2 comment.range '0 - 63' comment.dbmin -9150 comment.dbmax 300 iface MIXER name 'Headphone Playback Volume' value.0 61 value.1 61 }
control.11 { comment.access 'read write' comment.type INTEGER comment.count 2 comment.range '0 - 31' comment.dbmin -3450 comment.dbmax 1200 iface MIXER name 'Line Playback Volume' value.0 28 value.1 28 }
http://www.analog.com/en/audiovideo-products/audio-codecs/ad1983/products/pr...
'Twas brillig, and Raymond Yau at 25/01/11 02:32 did gyre and gimble:
2011/1/24 Takashi Iwai tiwai@suse.de
At Sun, 23 Jan 2011 17:37:07 +0000, Colin Guthrie wrote:
Hi,
I have a question-by-proxy from a user who is confused because his "Master" kcontrol is affecting the volume via Line In (which he uses to loopback an analog signal to his speakers).
I've not got much hardware here for comparison, but I'm pretty sure that Master usually doesn't affect Line In.
So couple of questions:
- Is it typical that Master affects Line In?
Yes, but only for the loopback volume. It's independent from the line-in capture volume.
ALSA info here: https://bzattachment.mandriva.com/attachment.cgi?id=18170
(for reference the full bug is here: https://qa.mandriva.com/show_bug.cgi?id=62218https://qa.mandriva.com/show_bug.cgi?id=62218
)
(1) KDE kmix is now pulseaudio aware and as such, kmix does not show the individual channels in the mixer I have my Sirrus/XM satellite radio plugged into LINE-IN and I listen to
it
while using the computer.
"virtual master" already have "Front" and "Headphone" as slaves
if the user want to hear the satelite radio from LINE_IN
Why Kmix does not control those "Mic Playback" and "Line Playback" any more ?
The max dB of Line and Mic playback volume are +12dB while those slave volume controls are only +3dB
control.1 { comment.access 'read write' comment.type INTEGER comment.count 2 comment.range '0 - 63' comment.dbmin -9150 comment.dbmax 300 iface MIXER name 'Front Playback Volume' value.0 61 value.1 61 }
control.3 { comment.access 'read write' comment.type INTEGER comment.count 2 comment.range '0 - 63' comment.dbmin -9150 comment.dbmax 300 iface MIXER name 'Headphone Playback Volume' value.0 61 value.1 61 }
control.11 { comment.access 'read write' comment.type INTEGER comment.count 2 comment.range '0 - 31' comment.dbmin -3450 comment.dbmax 1200 iface MIXER name 'Line Playback Volume' value.0 28 value.1 28 }
http://www.analog.com/en/audiovideo-products/audio-codecs/ad1983/products/pr...
The problem is not to do with the kcontrols you mention ("Mic Playback" and "Line Playback"). The problem is that the user does NOT want Master kcontrol to interfere with it, but it does. Obviously PulseAudio controls the whole mixer pipeline, including Master and thus, the general "Sink Volume" of his device is affecting the volume of loopbacked audio.
I thought I had stated this clearly, but I guess not :s
Col
PS Of course when KMix is using PulseAudio support all this complexity is hidden from the user. We do ultimately (in PA) need to provide a neat way to pass through certain kcontrols to the user - possibly by way of a virtual stream of some kind - but this is a different issue and unrelated to the primary question I was asking.
Col
participants (3)
-
Colin Guthrie -
Raymond Yau -
Takashi Iwai