diff options
Diffstat (limited to 'mq.py')
| -rw-r--r-- | mq.py | 60 |
1 files changed, 57 insertions, 3 deletions
@@ -63,7 +63,7 @@ class MQPeakDetection(simpl.PeakDetection): p = simpl.Peak() p.amplitude = current_mag p.frequency = (bin - 1) * self._fundamental - p.phase = np.angle(spectrum[bin-1]) + p.phase = np.angle(f[bin-1]) current_peaks.append(p) prev_mag = current_mag current_mag = next_mag @@ -147,7 +147,7 @@ class MQPartialTracking(simpl.PartialTracking): for peak in self._current_frame: if peak.is_start_of_partial(): partial = simpl.Partial() - partial.starting_frame = frame_number-1 + partial.starting_frame = frame_number partial.add_peak(peak) self.partials.append(partial) match = self._find_closest_match(peak, frame) @@ -179,7 +179,7 @@ class MQPartialTracking(simpl.PartialTracking): # create a new track by adding a peak in the current frame, matched to p, # with amplitude 0 partial = simpl.Partial() - partial.starting_frame = frame_number-1 + partial.starting_frame = frame_number new_peak = simpl.Peak() new_peak.amplitude = 0 new_peak.frequency = p.frequency @@ -189,3 +189,57 @@ class MQPartialTracking(simpl.PartialTracking): self._current_frame = frame return frame_partials + +class MQSynthesis(simpl.Synthesis): + def __init__(self): + simpl.Synthesis.__init__(self) + self._current_frame = simpl.zeros(self.frame_size) + + def hz_to_radians(self, frequency): + if not frequency: + return 0.0 + else: + return (frequency * 2.0 * np.pi) / self.sampling_rate + + def synth_frame(self, peaks): + "Synthesises a frame of audio, given a list of peaks from tracks" + self._current_frame *= 0.0 + + for p in peaks: + # get values for last amplitude, frequency and phase + # these are the initial values of the instantaneous amplitude/frequency/phase + current_freq = self.hz_to_radians(p.frequency) + if not p.previous_peak: + prev_amp = 0.0 + prev_freq = current_freq + prev_phase = p.phase - (current_freq * self.frame_size) + while prev_phase >= np.pi: prev_phase -= 2.0 * np.pi + while prev_phase < -np.pi: prev_phase += 2.0 * np.pi + else: + prev_amp = p.previous_peak.amplitude + prev_freq = self.hz_to_radians(p.previous_peak.frequency) + prev_phase = p.previous_peak.phase + + # amplitudes are linearly interpolated between frames + inst_amp = prev_amp + amp_inc = (p.amplitude - prev_amp) / self.frame_size + + # freqs/phases are calculated by cubic interpolation + freq_diff = current_freq - prev_freq + x = ((prev_phase + (prev_freq * self.frame_size) - p.phase) + + (freq_diff * (self.frame_size / 2.0))) + x /= (2.0 * np.pi) + m = int(np.round(x)) + phase_diff = p.phase - prev_phase - (prev_freq * self.frame_size) + (2.0 * np.pi * m) + alpha = ((3.0 / (self.frame_size**2)) * phase_diff) - (freq_diff / self.frame_size) + beta = ((-2.0 / (self.frame_size**3)) * phase_diff) + (freq_diff / (self.frame_size**2)) + + # calculate output samples + for i in range(self.frame_size): + inst_amp += amp_inc + inst_phase = prev_phase + (prev_freq * i) + (alpha * (i**2)) + (beta * (i**3)) + #print inst_phase + self._current_frame[i] += (2.0 * inst_amp) * np.cos(inst_phase) + + return self._current_frame + |