Linearity of output_meter and value
Posted: Mon Jan 14, 2013 4:54 pm
I have callbacks on:
"live_set", "tracks", n (output_meter_left)
and
"live_set", "tracks", n, "mixer_device", "volume" (value)
Both these values are between 0-1.
But if I receive them in OSC and draw a tall vertical rectangle, and put a gain setting triangle like the one in Ableton's mixer at a linear position on the height of the rectangle according to the volume value, then draw proportionately linear meters according to output_meter_left -
The output_meter_left value will frequently exceed that of the volume value, when it clearly (graphically) does not in Ableton.
So - could someone who has figured it out experimentally, or someone at Ableton please tell me:
Is the output_meter_{left,right} value logarithmic, or some other function? How can I convert it to linear?
The LOM docs just say:
"Smoothed momentary peak value of left channel output meter, 0.0 to 1.0. For tracks with audio output only. This value corresponds to the meters shown in Live. Please take into account that the left/right audio meters put a significant load onto the GUI part of Live."
"live_set", "tracks", n (output_meter_left)
and
"live_set", "tracks", n, "mixer_device", "volume" (value)
Both these values are between 0-1.
But if I receive them in OSC and draw a tall vertical rectangle, and put a gain setting triangle like the one in Ableton's mixer at a linear position on the height of the rectangle according to the volume value, then draw proportionately linear meters according to output_meter_left -
The output_meter_left value will frequently exceed that of the volume value, when it clearly (graphically) does not in Ableton.
So - could someone who has figured it out experimentally, or someone at Ableton please tell me:
Is the output_meter_{left,right} value logarithmic, or some other function? How can I convert it to linear?
The LOM docs just say:
"Smoothed momentary peak value of left channel output meter, 0.0 to 1.0. For tracks with audio output only. This value corresponds to the meters shown in Live. Please take into account that the left/right audio meters put a significant load onto the GUI part of Live."