'Twas brillig, and Raymond Yau at 15/06/10 23:29 did gyre and gimble: > 2010/6/16 Colin Guthrie <gmane@xxxxxxxxxxxxxx> > >> '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. -- Colin Guthrie gmane(at)colin.guthr.ie http://colin.guthr.ie/ Day Job: Tribalogic Limited [http://www.tribalogic.net/] Open Source: Mandriva Linux Contributor [http://www.mandriva.com/] PulseAudio Hacker [http://www.pulseaudio.org/] Trac Hacker [http://trac.edgewall.org/] _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
