'Twas brillig, and Raymond Yau at 15/06/10 23:29 did gyre and gimble:
2010/6/16 Colin Guthrie gmane@colin.guthr.ie
'Twas brillig, and Raymond Yau at 15/06/10 00:43 did gyre and gimble:
+12dB(400%) is even larger than the software gain 150% of PA
Software gain of PA 150% = ~+11dB, so not as different as you imply.
I've explained the cubic mapping already, so please don't use arbitrary, differently calculated percentages when comparing things. It's like comparing apples to oranges.
Col
When I changed the volume slider of the gnome sound applet ( select perference ) in Fedora 13 to maximum (i.e. PA 150% )
Seem to be bug in amixer and alsamixer
alsamixer also change to 150% but press any key change back to 100%
The fact that any key changes it back to 100% is kinda expected. It's not designed to handle values >100% so it makes sense that it clamps it. Annoying, but it makes sense.
The volume range is only from 0 to 65536
why did alsa-lib allow alsa-pulse plugin to set it outside the range , alsamixer and amixer also display 150% ?
amixer -D pulse Simple mixer control 'Master',0 Capabilities: pvolume pswitch pswitch-joined Playback channels: Front Left - Front Right Limits: Playback 0 - 65536 Mono: Front Left: Playback 98304 [150%] [on] Front Right: Playback 98304 [150%] [on]
While I agree this could be thought of as a bug, it's actually the nicest possible display for a system that has no concept of volumes > 100%.
That said, the correct fix would be a nice mechanism for marking the 100% mark. e.g. specifying the limits as a triplet, lower, normal (aka 100%) and max.
AFAIK, no such system is currently in place.
An alternative would be to scale the alsa volume control to the full range, e.g. make 0 - 98304[1] the range it accepts. But this sucks as the percentage shown in alsa is not the same as the percentage shown in other GUIs.
In a practical sense, the current setup is probably less problematic than the latter suggestion.
Col
[1] FWIW, this precice value will likely change. I've not yet actioned it but it's likely to be fixed at +11dB which IIRC is slightly above 150%. 11dB is just a figure that we felt was "sensible" with regards to GUI consistency and I'll try and push this out ot all the UIs I can.