2010/6/15 Lennart Poettering <mznyfn@xxxxxxxxxxx> > On Mon, 14.06.10 11:22, Colin Guthrie (gmane@xxxxxxxxxxxxxx) wrote: > > > > > 'Twas brillig, and James Courtier-Dutton at 14/06/10 09:56 did gyre and > > gimble: > > > On 14 June 2010 09:33, Colin Guthrie <gmane@xxxxxxxxxxxxxx> wrote: > > >> 'Twas brillig, and Raymond Yau at 14/06/10 01:25 did gyre and gimble: > > >>> if your sound card have ac97 codec ., you can use audacity to record > the > > >>> output from hw:0,0 and you will see clipping occur when you set "PCM" > volume > > >>> above 0dB > > >> > > >> So the standard response is "don't do that then" :) > > >> > > >> That's why the base volume is shown to the user via GUIs so that they > > >> can gauge the best point on the slider to use. Currently there is no > > >> indication with alsa sliders at which point the 0dB "sweet spot" lies. > > >> > > > > > > What do you mean. > > > If you use "alsamixer", dB values are shown so it is easy to find the > > > 0dB "sweet spot". > > > I think it is pulse audio that hides this information when it combines > > > two alsa mixer controls into one pulseaudio control. > > > > But it doesn't hide it. It's shown very clearly in the volume control > > GUIs as the Base Volume. > > Let me also stress that "dB" is not at all understandable to most > people. It is a very technical unit, and showing 0dB in the UI just like > that won't be very helpful for most people. > > That's why we thought about this, and are recommending a color coded > slider to be exposed in the UI which encodes the range information in a > sane way that is intuitively understandable by users. In green, in > yellow and in red. (meaning hw attenuated, hw amplified, sw amplified > ranges) > > http://pulseaudio.org/wiki/WritingVolumeControlUIs#Colouredvolumesliders > > Lennart > > Clipping may occur at recording if there is gain above hardware 0dB point , the region should be coloured as red , What is the meaning of the yellow region ? For HDA base volume seem to be at the same point as the norm volume since max_db of playback is 0dB +12dB(400%) is even larger than the software gain 150% of PA _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
