OS: All
What steps will reproduce the problem?
(1) Run the following in hoch.github.com/canopy
// @channels 1
// @duration 1.0
// @sampleRate 12800
var osc = context.createOscillator();
var quarterWaveDelay = 1 / (4 * osc.frequency.value);
console.log(quarterWaveDelay);
osc.connect(context.destination);
osc.start(quarterWaveDelay);
(2) Zoom in the waveform to show time between 0 and 0.002 (or so)
(3) Examine the waveform value at frame 8
The displayed value for frame 8 is 0.2143.
However, a quarter wave delay is 1/1760 sec, or about 7.2727 frames. If the oscillator actually started there, the waveform value at frame 8 would not be 0.2143. It should be closer to 0.1564. Why?
The waveform should be sin(2*pi*f*(t-t0)) where the frequency f is 440 Hz and t0 = 1/1760 sec. The sample for frame 8 corresponds to t = 8/12800. Thus the true value should be sin(pi/20) = 0.156.
Comment 1 by rtoy@chromium.org
, Jul 26 2016