>I think it would be best if Alsa would either generate samples in >floats or provide means for querying what is the 0 level. In cheap
ALSA can generate float values. Just use the "plug" or "plughw" interface. It can't tell you what you the 0dB level is. In the case of an all-digital h/w interface, there is no definition of 0dB - that's dependent on wherever D/A conversion happens. Its a constant challenge in a studio to get the meters on even 3 pieces of equipment to give consistent 0dB readings ... >So, we should have separate conversion routines for 16 and 24 bits >inputs/outputs. such routines exist in many places, including ALSA, Ardour and others (probable ecasound, and likely glame too). >But does this have anything to do with LADSPA and the original >suggestion? Value 1.0 as 0 dB level is used in both cases. you suggested tying this to code that does i/o with an audio interface. i was merely pointing out that its not advisable to assume too much about how that would work.
