Difficult-Rocket/libs/pyglet/media/synthesis.py
2022-04-30 13:56:57 +08:00

467 lines
16 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;
# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
# ----------------------------------------------------------------------------
import os
import math
import ctypes
import struct
from .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 of 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 of 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
# Source classes:
class SynthesisSource(Source):
"""Base class for synthesized waveforms.
:Parameters:
`duration` : float
The length, in seconds, of audio that you wish to generate.
`sample_rate` : int
Audio samples per second. (CD quality is 44100).
"""
def __init__(self, duration, sample_rate=44800, envelope=None):
self._duration = float(duration)
self.audio_format = AudioFormat(channels=1, sample_size=16, sample_rate=sample_rate)
self._offset = 0
self._sample_rate = sample_rate
self._bytes_per_sample = 2
self._bytes_per_second = self._bytes_per_sample * sample_rate
self._max_offset = int(self._bytes_per_second * self._duration)
self.envelope = envelope or FlatEnvelope(amplitude=1.0)
self._envelope_generator = self.envelope.get_generator(sample_rate, duration)
# Align to sample:
self._max_offset &= 0xfffffffe
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 = float(self._offset) / self._bytes_per_second
duration = float(num_bytes) / self._bytes_per_second
data = self._generate_data(num_bytes)
self._offset += num_bytes
return AudioData(data, num_bytes, timestamp, duration, [])
def _generate_data(self, num_bytes):
"""Generate `num_bytes` bytes of data.
Return data as ctypes array or bytes.
"""
raise NotImplementedError('abstract')
def seek(self, timestamp):
self._offset = int(timestamp * self._bytes_per_second)
# Bound within duration
self._offset = min(max(self._offset, 0), self._max_offset)
# Align to sample
self._offset &= 0xfffffffe
self._envelope_generator = self.envelope.get_generator(self._sample_rate, self._duration)
class Silence(SynthesisSource):
"""A silent waveform."""
def _generate_data(self, num_bytes):
return b'\0' * num_bytes
class WhiteNoise(SynthesisSource):
"""A white noise, random waveform."""
def _generate_data(self, num_bytes):
return os.urandom(num_bytes)
class Sine(SynthesisSource):
"""A sinusoid (sine) waveform.
:Parameters:
`duration` : float
The length, in seconds, of audio that you wish to generate.
`frequency` : int
The frequency, in Hz of the waveform you wish to produce.
`sample_rate` : int
Audio samples per second. (CD quality is 44100).
"""
def __init__(self, duration, frequency=440, **kwargs):
super().__init__(duration, **kwargs)
self.frequency = frequency
def _generate_data(self, num_bytes):
samples = num_bytes >> 1
amplitude = 32767
data = (ctypes.c_short * samples)()
step = self.frequency * (math.pi * 2) / self.audio_format.sample_rate
envelope = self._envelope_generator
for i in range(samples):
data[i] = int(math.sin(step * i) * amplitude * next(envelope))
return bytes(data)
class Triangle(SynthesisSource):
"""A triangle waveform.
:Parameters:
`duration` : float
The length, in seconds, of audio that you wish to generate.
`frequency` : int
The frequency, in Hz of the waveform you wish to produce.
`sample_rate` : int
Audio samples per second. (CD quality is 44100).
"""
def __init__(self, duration, frequency=440, **kwargs):
super().__init__(duration, **kwargs)
self.frequency = frequency
def _generate_data(self, num_bytes):
samples = num_bytes >> 1
value = 0
maximum = 32767
minimum = -32768
data = (ctypes.c_short * samples)()
step = (maximum - minimum) * 2 * self.frequency / self.audio_format.sample_rate
envelope = self._envelope_generator
for i in range(samples):
value += step
if value > maximum:
value = maximum - (value - maximum)
step = -step
if value < minimum:
value = minimum - (value - minimum)
step = -step
data[i] = int(value * next(envelope))
return bytes(data)
class Sawtooth(SynthesisSource):
"""A sawtooth waveform.
:Parameters:
`duration` : float
The length, in seconds, of audio that you wish to generate.
`frequency` : int
The frequency, in Hz of the waveform you wish to produce.
`sample_rate` : int
Audio samples per second. (CD quality is 44100).
"""
def __init__(self, duration, frequency=440, **kwargs):
super().__init__(duration, **kwargs)
self.frequency = frequency
def _generate_data(self, num_bytes):
samples = num_bytes >> 1
value = 0
maximum = 32767
minimum = -32768
data = (ctypes.c_short * samples)()
step = (maximum - minimum) * self.frequency / self._sample_rate
envelope = self._envelope_generator
for i in range(samples):
value += step
if value > maximum:
value = minimum + (value % maximum)
data[i] = int(value * next(envelope))
return bytes(data)
class Square(SynthesisSource):
"""A square (pulse) waveform.
:Parameters:
`duration` : float
The length, in seconds, of audio that you wish to generate.
`frequency` : int
The frequency, in Hz of the waveform you wish to produce.
`sample_rate` : int
Audio samples per second. (CD quality is 44100).
"""
def __init__(self, duration, frequency=440, **kwargs):
super().__init__(duration, **kwargs)
self.frequency = frequency
def _generate_data(self, num_bytes):
samples = num_bytes >> 1
amplitude = 32767
value = 1
count = 0
data = (ctypes.c_short * samples)()
half_period = self.audio_format.sample_rate / self.frequency / 2
envelope = self._envelope_generator
for i in range(samples):
if count >= half_period:
value = -value
count %= half_period
count += 1
data[i] = int(value * amplitude * next(envelope))
return bytes(data)
class SimpleFM(SynthesisSource):
"""A simple FM waveform.
This is a simplistic frequency modulated waveform, based on the
concepts by John Chowning. Basic sine waves are used for both
frequency carrier and modulator inputs, of which the frequencies can
be provided. The modulation index, or amplitude, can also be adjusted.
:Parameters:
`duration` : float
The length, in seconds, of audio that you wish to generate.
`carrier` : int
The carrier frequency, in Hz.
`modulator` : int
The modulator frequency, in Hz.
`mod_index` : int
The modulation index.
`sample_rate` : int
Audio samples per second. (CD quality is 44100).
"""
def __init__(self, duration, carrier=440, modulator=440, mod_index=1, **kwargs):
super().__init__(duration, **kwargs)
self.carrier = carrier
self.modulator = modulator
self.mod_index = mod_index
def _generate_data(self, num_bytes):
samples = num_bytes >> 1
amplitude = 32767
c_step = 2 * math.pi * self.carrier
m_step = 2 * math.pi * self.modulator
m_index = self.mod_index
sample_rate = self._sample_rate
envelope = self._envelope_generator
sin = math.sin
# FM equation: sin((2 * pi * carrier) + sin(2 * pi * modulator))
data = []
for i in range(samples):
increment = i / sample_rate
data.append(int(sin(c_step * increment + m_index * sin(m_step * increment)) * amplitude * next(envelope)))
return struct.pack(str(samples) + 'h', *data)
#############################################
# Experimental multi-operator FM synthesis:
#############################################
def operator(samplerate=44800, frequency=440, index=1, modulator=None, envelope=None):
# A sine generator that can be optionally modulated with another generator.
# FM equation: sin((i * 2 * pi * carrier_frequency) + sin(i * 2 * pi * modulator_frequency))
sin = math.sin
step = 2 * math.pi * frequency / samplerate
i = 0
envelope = envelope or FlatEnvelope(1).get_generator(samplerate, duration=None)
if modulator:
while True:
yield sin(i * step + index * next(modulator)) * next(envelope)
i += 1
else:
while True:
yield math.sin(i * step) * next(envelope)
i += 1
def composite_generator(*operators):
return (sum(samples) / len(samples) for samples in zip(*operators))
class Encoder(SynthesisSource):
def __init__(self, duration, generator, **kwargs):
super().__init__(duration, **kwargs)
self._generator = generator
self._total = int(duration * self.audio_format.sample_rate)
self._consumed = 0
def _generate_data(self, num_bytes):
envelope = self._envelope_generator
generator = self._generator
samples = num_bytes >> 1
amplitude = 32767
data = (int(next(generator) * amplitude * next(envelope)) for i in range(samples))
return struct.pack(f"{samples}h", *data)