#!/usr/bin/env python
"""
##########################################################################
# * * * PySynth * * *
# A very basic audio synthesizer in Python (www.python.org)
#
# Martin C. Doege, 2017-06-20 (mdoege@compuserve.com)
##########################################################################
# Based on a program by Tyler Eaves (tyler at tylereaves.com) found at
# http://mail.python.org/pipermail/python-list/2000-August/041308.html
##########################################################################
# 'song' is a Python list (or tuple) in which the song is defined,
# the format is [['note', value]]
# Notes are 'a' through 'g' of course,
# optionally with '#' or 'b' appended for sharps or flats.
# Finally the octave number (defaults to octave 4 if not given).
# An asterisk at the end makes the note a little louder (useful for the beat).
# 'r' is a rest.
# Note value is a number:
# 1=Whole Note; 2=Half Note; 4=Quarter Note, etc.
# Dotted notes can be written in two ways:
# 1.33 = -2 = dotted half
# 2.66 = -4 = dotted quarter
# 5.33 = -8 = dotted eighth
"""
from __future__ import division
from tomita.legacy.demosongs import *
from tomita.legacy.mkfreq import getfreq
pitchhz, keynum = getfreq(pr=True)
##########################################################################
#### Main program starts below
##########################################################################
# Some parameters:
# Beats (quarters) per minute
# e.g. bpm = 95
# Octave shift (neg. integer -> lower; pos. integer -> higher)
# e.g. transpose = 0
# Pause between notes as a fraction (0. = legato and e.g., 0.5 = staccato)
# e.g. pause = 0.05
# Volume boost for asterisk notes (1. = no boost)
# e.g. boost = 1.2
# Output file name
# fn = 'pysynth_output.wav'
##########################################################################
import wave, math, struct
from .mixfiles import mix_files
[docs]def make_wav(
song,
bpm=120,
transpose=0,
pause=0.05,
boost=1.1,
repeat=0,
fn="out.wav",
silent=False,
):
f = wave.open(fn, "w")
f.setnchannels(1)
f.setsampwidth(2)
f.setframerate(44100)
f.setcomptype("NONE", "Not Compressed")
bpmfac = 120.0 / bpm
def length(l):
return 88200.0 / l * bpmfac
def waves2(hz, l):
a = 44100.0 / hz
b = float(l) / 44100.0 * hz
return [a, round(b)]
def sixteenbit(x):
return struct.pack("h", round(32000 * x))
def render2(a, b, vol):
b2 = (1.0 - pause) * b
l = waves2(a, b2)
ow = b""
q = int(l[0] * l[1])
osc = -1
oscstep = 2.0 / l[0]
sp = 0
fade = 1
for x in range(q):
if q - x < 100:
fade = (q - x) / 100.0
sp += (osc - sp) / 100
ow = ow + sixteenbit(fade * vol * sp)
osc += oscstep
if osc > 1:
osc = -1
fill = max(int(ex_pos - curpos - q), 0)
f.writeframesraw((ow) + (sixteenbit(0) * fill))
return q + fill
##########################################################################
# Write to output file (in WAV format)
##########################################################################
if silent == False:
print("Writing to file", fn)
curpos = 0
ex_pos = 0.0
for rp in range(repeat + 1):
for nn, x in enumerate(song):
if not nn % 4 and silent == False:
print("[%u/%u]\t" % (nn + 1, len(song)))
if x[0] != "r":
if x[0][-1] == "*":
vol = boost
note = x[0][:-1]
else:
vol = 1.0
note = x[0]
try:
a = pitchhz[note]
except:
a = pitchhz[note + "4"] # default to fourth octave
a = a * 2 ** transpose
if x[1] < 0:
b = length(-2.0 * x[1] / 3.0)
else:
b = length(x[1])
ex_pos = ex_pos + b
curpos = curpos + render2(a, b, vol)
if x[0] == "r":
b = length(x[1])
ex_pos = ex_pos + b
f.writeframesraw(sixteenbit(0) * int(b))
curpos = curpos + int(b)
f.writeframes(b"")
f.close()
print()
##########################################################################
# Synthesize demo songs
##########################################################################
if __name__ == "__main__":
print()
print("Creating Demo Songs... (this might take about a minute)")
print()
make_wav((("c4", 1), ("g4", 1), ("c5", 1)), fn="zara.wav")
# SONG 1
make_wav(song1, fn="pysynth_scale.wav")
# SONG 2
make_wav(song2, bpm=95, boost=1.2, fn="pysynth_anthem.wav")
# SONG 3
make_wav(song3, bpm=132 / 2, pause=0.0, boost=1.1, fn="pysynth_chopin.wav")
# SONG 4
# right hand part
make_wav(
song4_rh,
bpm=130,
transpose=1,
pause=0.1,
boost=1.15,
repeat=1,
fn="pysynth_bach_rh.wav",
)
# left hand part
make_wav(
song4_lh,
bpm=130,
transpose=1,
pause=0.1,
boost=1.15,
repeat=1,
fn="pysynth_bach_lh.wav",
)
# mix both files together
mix_files("pysynth_bach_rh.wav", "pysynth_bach_lh.wav", "pysynth_bach.wav")
