diff options
Diffstat (limited to 'bindings/python/lv2_apply.py')
-rwxr-xr-x | bindings/python/lv2_apply.py | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/bindings/python/lv2_apply.py b/bindings/python/lv2_apply.py new file mode 100755 index 0000000..4c7d9b4 --- /dev/null +++ b/bindings/python/lv2_apply.py @@ -0,0 +1,159 @@ +#!/usr/bin/env python +# -*- coding: utf-8 -*- + +import math +import lilv +import sys +import wave +import numpy + +class WavFile(object): + """Helper class for accessing wav file data. Should work on the most common + formats (8 bit unsigned, 16 bit signed, 32 bit signed). Audio data is + converted to float32.""" + + # (struct format code, is_signedtype) for each sample width: + WAV_SPECS = { + 1: ("B", False), + 2: ("h", True), + 4: ("l", True), + } + + def __init__(self, wav_in_path): + self.wav_in = wave.open(wav_in_path, 'r') + self.framerate = self.wav_in.getframerate() + self.nframes = self.wav_in.getnframes() + self.nchannels = self.wav_in.getnchannels() + self.sampwidth = self.wav_in.getsampwidth() + wav_spec = self.WAV_SPECS[self.sampwidth] + self.struct_fmt_code, self.signed = wav_spec + self.range = 2 ** (8*self.sampwidth) + + def read(self): + """Read data from an open wav file. Return a list of channels, where each + channel is a list of floats.""" + raw_bytes = self.wav_in.readframes(self.nframes) + struct_fmt = "%u%s" % (len(raw_bytes) / self.sampwidth, self.struct_fmt_code) + data = wave.struct.unpack(struct_fmt, raw_bytes) + if self.signed: + data = [i / float(self.range/2) for i in data] + else: + data = [(i - float(range/2)) / float(range/2) for i in data] + + channels = [] + for i in range(self.nchannels): + channels.append([data[j] for j in range(0, len(data), self.nchannels) ]) + + return channels + + def close(self): + self.wav_in.close() + +def main(): + # Read command line arguments + if len(sys.argv) != 4: + print('USAGE: lv2_apply.py PLUGIN_URI INPUT_WAV OUTPUT_WAV') + sys.exit(1) + + # Initialise Lilv + world = lilv.World() + ns = world.ns + world.load_all() + + plugin_uri = sys.argv[1] + wav_in_path = sys.argv[2] + wav_out_path = sys.argv[3] + + # Find plugin + plugin_uri_node = world.new_uri(plugin_uri) + plugins = world.get_all_plugins() + if plugin_uri_node not in plugins: + print("Unknown plugin `%s'" % plugin_uri) + sys.exit(1) + + plugin = plugins[plugin_uri_node] + n_audio_in = plugin.get_num_ports_of_class(ns.lv2.InputPort, ns.lv2.AudioPort) + n_audio_out = plugin.get_num_ports_of_class(ns.lv2.OutputPort, ns.lv2.AudioPort) + if n_audio_out == 0: + print("Plugin has no audio outputs\n") + sys.exit(1) + + # Open input file + try: + wav_in = WavFile(wav_in_path) + except: + print("Failed to open input `%s'\n" % wav_in_path) + sys.exit(1) + + if wav_in.nchannels != n_audio_in: + print("Input has %d channels, but plugin has %d audio inputs\n" % ( + wav_in.nchannels, n_audio_in)) + sys.exit(1) + + # Open output file + wav_out = wave.open(wav_out_path, 'w') + if not wav_out: + print("Failed to open output `%s'\n" % wav_out_path) + sys.exit(1) + + # Set output file to same format as input (except possibly nchannels) + wav_out.setparams(wav_in.wav_in.getparams()) + wav_out.setnchannels(n_audio_out) + + print('%s => %s => %s @ %d Hz' + % (wav_in_path, plugin.get_name(), wav_out_path, wav_in.framerate)) + + instance = lilv.Instance(plugin, wav_in.framerate) + + channels = wav_in.read() + wav_in.close() + + # Connect all ports to buffers. NB if we fail to connect any buffer, lilv + # will segfault. + audio_input_buffers = [] + audio_output_buffers = [] + control_input_buffers = [] + control_output_buffers = [] + for index in range(plugin.get_num_ports()): + port = plugin.get_port_by_index(index) + if port.is_a(ns.lv2.InputPort): + if port.is_a(ns.lv2.AudioPort): + audio_input_buffers.append(numpy.array(channels[len(audio_input_buffers)], numpy.float32)) + instance.connect_port(index, audio_input_buffers[-1]) + elif port.is_a(ns.lv2.ControlPort): + default = float(port.get(ns.lv2.default)) + control_input_buffers.append(numpy.array([default], numpy.float32)) + instance.connect_port(index, control_input_buffers[-1]) + else: + raise ValueError("Unhandled port type") + elif port.is_a(ns.lv2.OutputPort): + if port.is_a(ns.lv2.AudioPort): + audio_output_buffers.append(numpy.array([0] * wav_in.nframes, numpy.float32)) + instance.connect_port(index, audio_output_buffers[-1]) + elif port.is_a(ns.lv2.ControlPort): + control_output_buffers.append(numpy.array([0], numpy.float32)) + instance.connect_port(index, control_output_buffers[-1]) + else: + raise ValueError("Unhandled port type") + + # Run the plugin: + instance.run(wav_in.nframes) + + # Interleave output buffers: + data = numpy.dstack(audio_output_buffers).flatten() + + # Return to original int range: + if wav_in.signed: + data = data * float(wav_in.range / 2) + else: + data = (data + 1) * float(wav_in.range/2) + + # Write output file in chunks to stop memory usage getting out of hand: + CHUNK_SIZE = 8192 + for chunk in numpy.array_split(data, CHUNK_SIZE): + wav_out.writeframes(wave.struct.pack("%u%s" % (len(chunk), wav_in.struct_fmt_code), *chunk.astype(int))) + wav_out.close() + + +if __name__ == "__main__": + main() |