Difficult-Rocket/libs/pyglet/media/synthesis.py
2022-10-11 21:53:55 +08:00

367 lines
13 KiB
Python

# ----------------------------------------------------------------------------
# pyglet
# Copyright (c) 2006-2008 Alex Holkner
# Copyright (c) 2008-2022 pyglet contributors
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
#
# * Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
# * Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in
# the documentation and/or other materials provided with the
# distribution.
# * Neither the name of pyglet nor the names of its
# contributors may be used to endorse or promote products
# derived from this software without specific prior written
# permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
# FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
# COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
# BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
# ----------------------------------------------------------------------------
import math as _math
import struct as _struct
from random import uniform as _uniform
from pyglet.media.codecs.base import Source, AudioFormat, AudioData
# Envelope classes:
class _Envelope:
"""Base class for SynthesisSource amplitude envelopes."""
def get_generator(self, sample_rate, duration):
raise NotImplementedError
class FlatEnvelope(_Envelope):
"""A flat envelope, providing basic amplitude setting.
:Parameters:
`amplitude` : float
The amplitude (volume) of the wave, from 0.0 to 1.0.
Values outside this range will be clamped.
"""
def __init__(self, amplitude=0.5):
self.amplitude = max(min(1.0, amplitude), 0)
def get_generator(self, sample_rate, duration):
amplitude = self.amplitude
while True:
yield amplitude
class LinearDecayEnvelope(_Envelope):
"""A linearly decaying envelope.
This envelope linearly decays the amplitude from the peak value
to 0, over the length of the waveform.
:Parameters:
`peak` : float
The Initial peak value of the envelope, from 0.0 to 1.0.
Values outside this range will be clamped.
"""
def __init__(self, peak=1.0):
self.peak = max(min(1.0, peak), 0)
def get_generator(self, sample_rate, duration):
peak = self.peak
total_bytes = int(sample_rate * duration)
for i in range(total_bytes):
yield (total_bytes - i) / total_bytes * peak
while True:
yield 0
class ADSREnvelope(_Envelope):
"""A four part Attack, Decay, Suspend, Release envelope.
This is a four part ADSR envelope. The attack, decay, and release
parameters should be provided in seconds. For example, a value of
0.1 would be 100ms. The sustain_amplitude parameter affects the
sustain volume. This defaults to a value of 0.5, but can be provided
on a scale from 0.0 to 1.0.
:Parameters:
`attack` : float
The attack time, in seconds.
`decay` : float
The decay time, in seconds.
`release` : float
The release time, in seconds.
`sustain_amplitude` : float
The sustain amplitude (volume), from 0.0 to 1.0.
"""
def __init__(self, attack, decay, release, sustain_amplitude=0.5):
self.attack = attack
self.decay = decay
self.release = release
self.sustain_amplitude = max(min(1.0, sustain_amplitude), 0)
def get_generator(self, sample_rate, duration):
sustain_amplitude = self.sustain_amplitude
total_bytes = int(sample_rate * duration)
attack_bytes = int(sample_rate * self.attack)
decay_bytes = int(sample_rate * self.decay)
release_bytes = int(sample_rate * self.release)
sustain_bytes = total_bytes - attack_bytes - decay_bytes - release_bytes
decay_step = (1 - sustain_amplitude) / decay_bytes
release_step = sustain_amplitude / release_bytes
for i in range(1, attack_bytes + 1):
yield i / attack_bytes
for i in range(1, decay_bytes + 1):
yield 1 - (i * decay_step)
for i in range(1, sustain_bytes + 1):
yield sustain_amplitude
for i in range(1, release_bytes + 1):
yield sustain_amplitude - (i * release_step)
while True:
yield 0
class TremoloEnvelope(_Envelope):
"""A tremolo envelope, for modulation amplitude.
A tremolo envelope that modulates the amplitude of the
waveform with a sinusoidal pattern. The depth and rate
of modulation can be specified. Depth is calculated as
a percentage of the maximum amplitude. For example:
a depth of 0.2 and amplitude of 0.5 will fluctuate
the amplitude between 0.4 an 0.5.
:Parameters:
`depth` : float
The amount of fluctuation, from 0.0 to 1.0.
`rate` : float
The fluctuation frequency, in seconds.
`amplitude` : float
The peak amplitude (volume), from 0.0 to 1.0.
"""
def __init__(self, depth, rate, amplitude=0.5):
self.depth = max(min(1.0, depth), 0)
self.rate = rate
self.amplitude = max(min(1.0, amplitude), 0)
def get_generator(self, sample_rate, duration):
total_bytes = int(sample_rate * duration)
period = total_bytes / duration
max_amplitude = self.amplitude
min_amplitude = max(0.0, (1.0 - self.depth) * self.amplitude)
step = (_math.pi * 2) / period / self.rate
for i in range(total_bytes):
value = _math.sin(step * i)
yield value * (max_amplitude - min_amplitude) + min_amplitude
while True:
yield 0
# Waveform generators
def silence_generator(frequency, sample_rate):
while True:
yield 0
def noise_generator(frequency, sample_rate):
while True:
yield _uniform(-1, 1)
def sine_generator(frequency, sample_rate):
step = 2 * _math.pi * frequency / sample_rate
i = 0
while True:
yield _math.sin(i * step)
i += 1
def triangle_generator(frequency, sample_rate):
step = 4 * frequency / sample_rate
value = 0
while True:
if value > 1:
value = 1 - (value - 1)
step = -step
if value < -1:
value = -1 - (value - -1)
step = -step
yield value
value += step
def sawtooth_generator(frequency, sample_rate):
period_length = int(sample_rate / frequency)
step = 2 * frequency / sample_rate
i = 0
while True:
yield step * (i % period_length) - 1
i += 1
def pulse_generator(frequency, sample_rate, duty_cycle=50):
period_length = int(sample_rate / frequency)
duty_cycle = int(duty_cycle * period_length / 100)
i = 0
while True:
yield int(i % period_length < duty_cycle) * 2 - 1
i += 1
# Source classes:
class SynthesisSource(Source):
"""Base class for synthesized waveforms.
:Parameters:
`generator` : A non-instantiated generator object
A waveform generator that produces a stream of floats from (-1, 1)
`duration` : float
The length, in seconds, of audio that you wish to generate.
`sample_rate` : int
Audio samples per second. (CD quality is 44100).
`envelope` : :py:class:`pyglet.media.synthesis._Envelope`
An optional Envelope to apply to the waveform.
"""
def __init__(self, generator, duration, sample_rate=44800, envelope=None):
self._generator = generator
self._duration = duration
self.audio_format = AudioFormat(channels=1, sample_size=16, sample_rate=sample_rate)
self._envelope = envelope or FlatEnvelope(amplitude=1.0)
self._envelope_generator = self._envelope.get_generator(sample_rate, duration)
# Two bytes per sample (16-bit):
self._bytes_per_second = sample_rate * 2
# Maximum offset, aligned to sample:
self._max_offset = int(self._bytes_per_second * duration) & 0xfffffffe
self._offset = 0
def get_audio_data(self, num_bytes, compensation_time=0.0):
"""Return `num_bytes` bytes of audio data."""
num_bytes = min(num_bytes, self._max_offset - self._offset)
if num_bytes <= 0:
return None
timestamp = self._offset / self._bytes_per_second
duration = num_bytes / self._bytes_per_second
self._offset += num_bytes
# Generate bytes:
samples = num_bytes >> 1
generator = self._generator
envelope = self._envelope_generator
data = (int(next(generator) * next(envelope) * 0x7fff) for _ in range(samples))
data = _struct.pack(f"{samples}h", *data)
return AudioData(data, num_bytes, timestamp, duration, [])
def seek(self, timestamp):
# Bound within duration & align to sample:
offset = int(timestamp * self._bytes_per_second)
self._offset = min(max(offset, 0), self._max_offset) & 0xfffffffe
self._envelope_generator = self._envelope.get_generator(self.audio_format.sample_rate, self._duration)
class Silence(SynthesisSource):
def __init__(self, duration, frequency=440, sample_rate=44800, envelope=None):
"""Create a Silent waveform."""
super().__init__(silence_generator(frequency, sample_rate), duration, sample_rate, envelope)
class WhiteNoise(SynthesisSource):
def __init__(self, duration, frequency=440, sample_rate=44800, envelope=None):
"""Create a random white noise waveform."""
super().__init__(noise_generator(frequency, sample_rate), duration, sample_rate, envelope)
class Sine(SynthesisSource):
def __init__(self, duration, frequency=440, sample_rate=44800, envelope=None):
"""Create a sinusoid (sine) waveform."""
super().__init__(sine_generator(frequency, sample_rate), duration, sample_rate, envelope)
class Square(SynthesisSource):
def __init__(self, duration, frequency=440, sample_rate=44800, envelope=None):
"""Create a Square (pulse) waveform."""
super().__init__(pulse_generator(frequency, sample_rate), duration, sample_rate, envelope)
class Triangle(SynthesisSource):
def __init__(self, duration, frequency=440, sample_rate=44800, envelope=None):
"""Create a Triangle waveform."""
super().__init__(triangle_generator(frequency, sample_rate), duration, sample_rate, envelope)
class Sawtooth(SynthesisSource):
def __init__(self, duration, frequency=440, sample_rate=44800, envelope=None):
"""Create a Sawtooth waveform."""
super().__init__(sawtooth_generator(frequency, sample_rate), duration, sample_rate, envelope)
#############################################
# Experimental multi-operator FM synthesis:
#############################################
def sine_operator(sample_rate=44800, frequency=440, index=1, modulator=None, envelope=None):
"""A sine wave generator that can be optionally modulated with another generator.
This generator represents a single FM Operator. It can be used by itself as a
simple sine wave, or modulated by another waveform generator. Multiple operators
can be linked together in this way. For example::
operator1 = sine_operator(samplerate=44800, frequency=1.22)
operator2 = sine_operator(samplerate=44800, frequency=99, modulator=operator1)
operator3 = sine_operator(samplerate=44800, frequency=333, modulator=operator2)
operator4 = sine_operator(samplerate=44800, frequency=545, modulator=operator3)
:Parameters:
`sample_rate` : int
Audio samples per second. (CD quality is 44100).
`frequency` : float
The frequency, in Hz, of the waveform you wish to generate.
`index` : float
The modulation index. Defaults to 1
`modulator` : sine_operator
An optional operator to modulate this one.
`envelope` : :py:class:`pyglet.media.synthesis._Envelope`
An optional Envelope to apply to the waveform.
"""
# FM equation: sin((i * 2 * pi * carrier_frequency) + sin(i * 2 * pi * modulator_frequency))
envelope = envelope or FlatEnvelope(1).get_generator(sample_rate, duration=None)
sin = _math.sin
step = 2 * _math.pi * frequency / sample_rate
i = 0
if modulator:
while True:
yield sin(i * step + index * next(modulator)) * next(envelope)
i += 1
else:
while True:
yield sin(i * step) * next(envelope)
i += 1
def composite_operator(*operators):
return (sum(samples) / len(samples) for samples in zip(*operators))