[FFmpeg-user] aevalsrc question

Nicolas George george at nsup.org
Mon Dec 19 17:23:08 EET 2016


Le nonidi 29 frimaire, an CCXXV, Muhammad Faiz a écrit :
> The formula is wrong.
> Consider sin(262*2^(t/10)*2*PI*t).
> phase, ph(t) = 262 * 2^(t/10) * 2 * PI * t
> angular freq (in radians/s), w(t) = dph(t)/dt = 262 * 2 * PI *
> (2^(t/10) + log(2)/10 * 2^(t/10) * t)
> freq(t) = 262 * (2^(t/10) + log(2)/10 * 2^(t/10) * t)
> so, at t = 10, freq(10) = 262 * (2 + log(2) * 2) = 887 Hz

Oh, good catch. I should have remembered this task needed a primitive
function, not just a multiplication.

Regards,

-- 
  Nicolas George
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