#!/usr/bin/python # make_wave.py # --copyright-- Copyright 2007 (C) Tranzoa, Co. All rights reserved. Warranty: You're free and on your own here. This code is not necessarily up-to-date or of public quality. # --url-- http://www.tranzoa.net/tzpython/ # --email-- pycode is the name to send to. tranzoa.com is the place to send to. # --bodstamps-- # August 30, 2006 bar # September 2, 2006 bar --max_sample # November 18, 2007 bar turn on doxygen # November 20, 2007 bar comments # November 27, 2007 bar insert boilerplate copyright # May 17, 2008 bar email adr # February 18, 2009 bar try to keep the ends of a loopable wave a bit better stitched together # July 19, 2011 bar allow the note to be spec'd by letter, etc. # --eodstamps-- ## \file # # # Output a wav file of given frequencies - with the idea that this wave file can be looped. # # import array import math ## This logic can make waveforms of 3 types: ## Make a sine wave. SINE_SAMPLES = 0 ## Make a triangle, saw-tooth wave. TRIANGLE_SAMPLES = 1 ## Make a square wave. SQUARE_SAMPLES = 2 ## Maximum absolute 16 bit sample value. LOUD_16_BIT_SAMPLE = 32767 def make_audio_samples(sample_rate, duration, frequency, form, loudest_sample = LOUD_16_BIT_SAMPLE) : """ Make an array of 16-bit signed audio samples to the given specs. """ samples = array.array('h') sc = int(sample_rate * duration) wsc = float(sample_rate) / float(frequency) if form == TRIANGLE_SAMPLES : for i in xrange(sc) : wi = math.fmod(float(i), wsc) / wsc if wi <= 0.25 : s = (loudest_sample - 1) * wi * 4.0 elif wi <= 0.75 : s = -((loudest_sample - 1) * (wi - 0.25) * 4.0) + loudest_sample else : s = (loudest_sample * (wi - 0.75) * 4.0) - loudest_sample samples.append(int(s)) pass elif form == SQUARE_SAMPLES : for i in xrange(sc) : wi = math.fmod(float(i), wsc) / wsc if wi <= 0.5 : samples.append( loudest_sample) else : samples.append(-loudest_sample) pass pass else : for i in xrange(sc) : wi = float(i) / wsc samples.append(int(math.sin(2.0 * math.pi * wi) * loudest_sample)) pass return(samples) def add_samples(samples, max_sample = None) : """ Return an array of the sum of the samples in an array of equal-length arrays of 16-bit signed samples. """ gms = max_sample if max_sample == None : max_sample = 32767 if max_sample > 32767 : raise "max_sample " + str(max_sample) + " greater than 32767!" out_samples = array.array('h', samples[0]) ms = 0 for si in xrange(len(out_samples)) : s = out_samples[si] for i in xrange(1, len(samples)) : s += samples[i][si] ms = max(ms, abs(s)) s = min(s, max_sample) s = max(s, -max_sample) out_samples[si] = s if (gms != None) and (ms > max_sample) : mult = float(max_sample) / float(ms) out_samples = array.array('h', samples[0]) ms = 0 for si in xrange(len(out_samples)) : s = out_samples[si] for i in xrange(1, len(samples)) : s += samples[i][si] s = int(s * mult) ms = max(ms, abs(s)) s = min(s, max_sample) s = max(s, -max_sample) out_samples[si] = s if ms > max_sample : raise "Did not limit samples as requested " + str(ms) + " " + str(max_sample) + " " + str(mult) + "!" pass return(out_samples) # # # if __name__ == '__main__' : import sys import wave import replace_file import TZCommandLineAtFile import tzlib import tzmidi help_str = sys.argv[0] + """ (options) sample_rate duration_in_seconds output.wav --note MIDI-note Include this MIDI note (0..127). Or note can be of form ^([a-g])\s*([b#]?)\s*(\d*)$ Note(flat|sharp)(octave 1..11 default 6) From C1..G11. --loopable Make the output loopable (will be shorter than the duration). --max_sample value Maximum absolute sample value (1.. default 32767). --form sine | triangle | square Waveform """ sys.argv.pop(0) TZCommandLineAtFile.expand_at_sign_command_line_files(sys.argv) if tzlib.array_find(sys.argv, [ "--help", "-h", "/?" ] ) >= 0 : print help_str sys.exit(254) loopable = False form = SINE_SAMPLES notes = [] max_sample = 32767 while True : oi = tzlib.array_find(sys.argv, [ "--form", "-f" ]) if oi < 0 : break del sys.argv[oi] form = sys.argv.pop(oi).lower() if form == "sine" : form = SINE_SAMPLES elif form == "triangle" : form = TRIANGLE_SAMPLES elif form == "square" : form = SQUARE_SAMPLES else : print "--form must be sine, triangle or square!" sys.exit(254) pass while True : oi = tzlib.array_find(sys.argv, [ "--note", "-n" ]) if oi < 0 : break del sys.argv[oi] ns = sys.argv.pop(oi) try : notes.append(int(ns)) except ( ValueError, TypeError ) : n = tzmidi.name_to_midi_note(ns) if n < 0 : print "--note must be a MIDI note number or a letter (with optional optional # or b and optional octave 1..11 (C1..G11 default: 6))" sys.exit(101) notes.append(n) pass while True : oi = tzlib.array_find(sys.argv, [ "--max_sample", "-m" ]) if oi < 0 : break del sys.argv[oi] max_sample = int(sys.argv.pop(oi)) while True : oi = tzlib.array_find(sys.argv, [ "--loopable", "-l" ]) if oi < 0 : break del sys.argv[oi] loopable = True if len(sys.argv) != 3 : print "Please tell me the sample rate, the maximum duration, and the output .wav file name!" sys.exit(254) if len(notes) == 0 : print "Please tell me at least one MIDI note!" sys.exit(254) sample_rate = int(sys.argv[0]) duration = float(sys.argv[1]) ofile_name = sys.argv[2] samples = [] for n in notes : if n < 0 : print "Note %d too low!" % n sys.exit(102) samples.append(make_audio_samples(sample_rate, duration, tzmidi.midi_note_freq(n), form, LOUD_16_BIT_SAMPLE / len(notes))) if loopable : # # # Find the best good cut point. # This is the place after the first cycle of the lowest frequency # where all waves are going up, # are below zero, # and the sample furthest from zero is minimized. # (since the waves start going up from zero). # # low_freq = 1000000.0; for n in notes : low_freq = min(low_freq, tzmidi.midi_note_freq(n)) si = int(math.floor(float(sample_rate) / low_freq)) bi = si bv = 100000000 while si < len(samples[0]) : v = 0 for i in xrange(len(samples)) : s = samples[i][si] if s >= 0 : v = 100000000 # already up break d = s - samples[i][si - 1] if d < 0 : v = 100000000 # going down, not up break v = max(v, -s) if bv > v : bv = v bi = si + 1 # include this sample si += 1 for si in xrange(len(samples)) : samples[si] = samples[si][0:bi] pass data = add_samples(samples, max_sample) if loopable : while len(data) >= 4 : d1 = data[1] - data[0] # print data[-2], data[-1], data[0], data[1], d1, abs(d1 - (data[0] - data[-1])), abs(d1 - (data[0] - data[-2])) if abs(d1 - (data[0] - data[-1])) <= abs(d1 - (data[0] - data[-2])) : break data.pop() # here, we're keeping a loopable thing from having a zero at both ends pass data = data.tostring() tfname = ofile_name + ".tmp" fo = wave.open(tfname, "wb") fo.setnchannels(1) fo.setsampwidth(2) fo.setframerate(sample_rate) fo.writeframes(data) fo.close() replace_file.replace_file(ofile_name, tfname, ofile_name + ".bak") ## Public things. __ALL__ = [ 'make_audio_samples', 'add_samples', 'SINE_SAMPLES', 'TRIANGLE_SAMPLES', 'SQUARE_SAMPLES', 'LOUD_16_BIT_SAMPLE', ] # # # # eof