Skip to content

Instantly share code, notes, and snippets.

@kylemcdonald
Last active June 6, 2023 03:06
Show Gist options
  • Save kylemcdonald/85d70bf53e207bab3775 to your computer and use it in GitHub Desktop.
Save kylemcdonald/85d70bf53e207bab3775 to your computer and use it in GitHub Desktop.
Load audio from ffmpeg into Python using numpy.
import numpy as np
import subprocess as sp
import os
DEVNULL = open(os.devnull, 'w')
# load_audio can not detect the input type
def ffmpeg_load_audio(filename, sr=44100, mono=False, normalize=True, in_type=np.int16, out_type=np.float32):
channels = 1 if mono else 2
format_strings = {
np.float64: 'f64le',
np.float32: 'f32le',
np.int16: 's16le',
np.int32: 's32le',
np.uint32: 'u32le'
}
format_string = format_strings[in_type]
command = [
'ffmpeg',
'-i', filename,
'-f', format_string,
'-acodec', 'pcm_' + format_string,
'-ar', str(sr),
'-ac', str(channels),
'-']
p = sp.Popen(command, stdout=sp.PIPE, stderr=DEVNULL, bufsize=4096)
bytes_per_sample = np.dtype(in_type).itemsize
frame_size = bytes_per_sample * channels
chunk_size = frame_size * sr # read in 1-second chunks
raw = b''
with p.stdout as stdout:
while True:
data = stdout.read(chunk_size)
if data:
raw += data
else:
break
audio = np.fromstring(raw, dtype=in_type).astype(out_type)
if channels > 1:
audio = audio.reshape((-1, channels)).transpose()
if audio.size == 0:
return audio, sr
if issubclass(out_type, np.floating):
if normalize:
peak = np.abs(audio).max()
if peak > 0:
audio /= peak
elif issubclass(in_type, np.integer):
audio /= np.iinfo(in_type).max
return audio, sr
@maxhawkins
Copy link

thanks kyle :-)

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment