2010/5/20 James Courtier-Dutton james.dutton@gmail.com
On 19 May 2010 17:34, Sebastian H. vand2@gmx.de wrote:
Hello everyone
I'm working on an ALSA-Mixer application for C++/Qt4 and stumbled over volume and decibel mapping for sliders. My question: Is there always an 1 to 1 mapping from volume to decibel and
vice
versa or can there be decibel values in between two volume steps?
There should be a one to one mapping. If the hardware has 200 steps on the volume scale, and those 200 steps are published to the user. With the dB scale, there will still be the same 200 steps in the dB scale. The dB information simply helps the user interface convert each step into a dB value.
a stepping function is not continuous and this is why snd_mixer_selem_set_playback_dB() cannot set decibel values in between two volume steps