applying vst to several wavfiles of various lengths

[queechy]

There are several wav files of various lengths. I want to apply vst to all of these files. Is there a good way?

[DBraun]

Could you try something like this? Note the section about dynamically changing duration based on the input audio's length divided by the chosen sample rate.

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

SAMPLE_RATE = 44100
BUFFER_SIZE = 512

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

# Make an engine. We'll only need one.
engine = daw.RenderEngine(SAMPLE_RATE, BUFFER_SIZE)
engine.set_bpm(120.)  # default is 120.

filepaths = ["file1.wav", "file2.wav", "file3.wav"]

playback = engine.make_playback_processor("playback", np.zeros((2, 1)))
plugin = engine.make_plugin_processor("plugin", "C:/path/to/effect_plugin.dll")

graph = [
  (playback, []),
  (plugin, ["playback"]),
]

engine.load_graph(graph)

for i, filepath in enumerate(filepaths):
    data = load_audio_file(filepath)

    duration = data.shape[1]/SAMPLE_RATE
    duration += 5  # add a little extra time
    playback.set_data(data)

    engine.render(duration)
    audio = engine.get_audio()  # Returns numpy.ndarray shaped (2, NUM_SAMPLES)
    wavfile.write(f'output_{i}.wav', SAMPLE_RATE, audio.transpose())