|TRWBW||JabberWalkie: but its seperable, so you can write it as applying 1D convulution twice, once in x, once in y|
|JabberWalkie||TRWBW: can i still have the relation F[ f*g]= F[f] F[g], with a 2 dimentional fourier transform?|
|holst||"Life is good" :P|
|holst||its a bit ironic|
we think of theorems as gifts of the gods
|holst||but actually they are just a product of the axioms we setup to begin with|
i'm trying to understand this magic 'decibel' curve..
i am writing some software which sets the audio level in decibels... but i want the volume to behave as a linear quantity..
but i cant work out the decibel graph, which i need to understand so i can negate it into a linear graph.
ie, 0.5 volume should be half as loud, not damn near silent as it is given half the decibel range.
|holst||the graph is monotonic right?|
|^Manu||in what sense?|
|holst||that means for any y=f(x) on the curve you can find g(y)=x. solve for x|
|^Manu||this is amplitude, not frequency.|
i have no idea.
i just know i set the level in decibels.. but i dont really understand what a decibel is..
its used in so many different fields..
|holst||but what are you saying|
|^Manu||its obviously graphable, its some sort of curve.|
well see the amplitude is set by some function of the level value in decibels...
but i dont know that function :/
i just want to set the amplitude to my value directly.. but directsound doesnt provide any interface for that..
so i need to calculate the correct level, in decibels to get what i want.. which i dont know how to do.
|holst||you insert something in [0,1] range to the directsound api?|
1 = maximum vol; 0 = silent
|JabberWalkie||^Manu: somthing at 60db is 10 times louder that 50db.....|
|^Manu||no, i insert something in [DSBVOLUME_MIN, DSBVOLUME_MAX] range to dsound./|
|JabberWalkie||70db would be 100 times louder than 50db|
|^Manu||so if i have v in [0, 1]... and i use (DSBVOLUME_MAX - DSBVOLUME_MIN) * v..|
i get a totally non-linear volume control ;)
which is obvious, but i dont know how to solve it.
|holst||decibel is related to what the human ear think is "loudness" http://www.phys.unsw.edu.au/jw/dB.html#log|
|^Manu||i realise that.. i understand its concept.. but i dont understand it mathematically...|
|holst||^Manu: most probably the volumne in the api isnt dB|
|^Manu||so i cant effectively cancel it out.. because really i just want to address the amplitude coming out my speakers directly without dsound messing with it..|