New RenderMan proposal

new_renderman.py

import numpy as np
from scipy.io import wavfile
import librosa

import renderman as rm

SAMPLE_RATE = 44100
BUFFER_SIZE = 512
REVERB_PLUGIN = "C:/path/to/reverb.dll"
SYNTH_PLUGIN = "C:/path/to/synth.dll"
SYNTH_PRESET1 = "C:/path/to/preset1.fxp"
SYNTH_PRESET2 = "C:/path/to/preset2.fxp"
MIDI_PATH = "C:/path/to/song.mid"

engine = rm.RenderEngine(SAMPLE_RATE, BUFFER_SIZE)

def load_audio_file(file_path, duration=None):
	sig, rate = librosa.load(file_path, duration=duration, mono=False, sr=SAMPLE_RATE)
	assert(rate == SAMPLE_RATE)
	return sig

# Example 1:
# Processing pre-recorded audio example
vocals = load_audio_file("vocals.wav", duration=5.)
piano = load_audio_file("piano.wav", duration=5.)

assert(vocals.dtype == np.float32)

# graph idea is based on https://github.com/magenta/ddsp
# https://github.com/magenta/ddsp#processorgroup-with-a-list
# Also useful for eventually using gin-config.

graph = [
	(engine.make_playback_processor("vocals", vocals), []),
	(engine.make_playback_processor("piano", piano), []),
	(engine.make_filter_processor("filter", "high", 7000.0, .1, 1.), ["vocals"]),
	(engine.make_reverb_processor("reverb"), ["piano"]),
	(engine.make_add_processor("added"), ["filter", "reverb"]),
]

assert(engine.load_graph(graph))

engine.render(3.)
audio = engine.get_audio() # returns list of lists
audio = np.array(audio, np.float32).transpose()
wavfile.write('remix.wav', SAMPLE_RATE, audio)

print('Example 1 done')

# Example 2:
# Playback of a synthesizer and vocals
serum = engine.make_plugin_processor("serum", SYNTH_PLUGIN)
assert(serum.load_preset(SYNTH_PRESET1))

graph = [
	(engine.make_playback_processor("vocals", vocals), []),
	(serum, []),
	(engine.make_plugin_processor("reverb", REVERB_PLUGIN), ["serum"]),
	(engine.make_add_processor("add1"), ["reverb", "vocals"])
]

assert(engine.load_graph(graph))

# MIDI can be added to PluginProcessor objects.
# If we have multiple PluginProcessors, we can add separate MIDI for each.
serum.add_midi_note(60, 127, 0., 1.) # note, velocity, start time sec, duration sec
serum.add_midi_note(67, 127, 0.5, .25)
# serum.load_midi(MIDI_PATH)  # we can load from MIDI file.

engine.render(3.) # render duration
audio = engine.get_audio()
audio = np.array(audio, np.float32).transpose()
wavfile.write('my_song_001.wav', SAMPLE_RATE, audio)

# Can still load a new preset without reloading/destroying the graph
assert(serum.load_preset(SYNTH_PRESET2))

serum.clear_midi()
serum.add_midi_note(65, 127, 0.25, .5)

engine.render(3.)
audio = engine.get_audio()
audio = np.array(audio, np.float32).transpose()
wavfile.write('my_song_002.wav', SAMPLE_RATE, audio)

print('Example 2 done')

print("All Done!")