Check audio's sample rate using python

Question

I have over a thousand audio files, and I want to check if their sample rate is 16kHz. To do it manually would take me forever. Is there a way to check the sample rate using python?

Sludgy

what format are the audio files? – Ferretti

WAV file. mono channel – Sludgy

Answer 1

Python has a builtin module dealing with WAV files.

You can write a simple script that will iterate over all files in some directory. something along the general lines of:

import os
import wave
for file_name in os.listdir(FOLDER_PATH):
    with wave.open(file_name, "rb") as wave_file:
        frame_rate = wave_file.getframerate()
        .... DO WHATEVER ....

Ferretti

I'm glad to hear that! Though your comment about Python 3.x strike me a bit weird since Python 2.7 has a WAV library as well. Anyway, good luck with the rest of your work :-) – Ferretti

Below Python version 3.4, wave.open() doesn't return a context manager. For older Python versions, the call can be wrapped in contextlib.closing(). – Inquisitive

Answer 2

For .wav files the solution might be:

from scipy.io.wavfile import read as read_wav
import os
os.chdir('path') # change to the file directory
sampling_rate, data=read_wav("filename.wav") # enter your filename
print sampling_rate

Trish

Answer 3

Solution without importing external libraries

Most probably you already have 'ffmpeg' and 'ffprobe' installed on your system (this are core frameworks on which other python libraries rely on). Then you can pipe any info about the audio directly from the 'ffprobe'. This might be easier than installing any additional APIs or libraries which either way will be working with ffprobe in the background.

• ffprobe allows to export results directly in the json format
• you can specify which audio parameters to output from ffprobe

My example that gathers only 'sample_rate' from the audio files.

import json
import subprocess

# specify parameters for ffprobe
file_path = "your_audio_file.mp4"
out_data = "stream=sample_rate:format=0:stream_tags=0:format_tags=0"
command = f"ffprobe -v quiet -print_format json -show_format -select_streams a:0 -show_entries {out_data} {file_path}"

# run ffprobe as a subprocess
process = subprocess.Popen(command.split(), stdout=subprocess.PIPE)
output, error = process.communicate()

# gather output from the json
metadata = json.loads(output)
audio_stream = metadata["streams"][0] 
sample_rate = audio_stream.get("sample_rate", None)

Ensnare

Answer 4

I end up getting unknow file format error with the wave package from python. wave-error

Alternatively the sox wrapper in python works for me. pysox

!pip install sox
import sox
sox.file_info.sample_rate("file1.wav")

Hope it helps

Neuromuscular

This I have done this on windows. Installing sox in Linux could be a nightmare, because of dependency package and compatibility with Linux version. – Neuromuscular

works perfectly well on linux. Just install sox lib first: '$ sudo apt install sox' – Decaliter

Answer 5

!pip install pydub

• from pydub.utils import mediainfo
• info=mediainfo("abc.wav")
• print(info)

Ask

I assume info contains more info than sample rate. could you add which specific method to fetch sample rate? – Volant

Answer 6

I use the code given below whenever I want to find the sample rate.

import torchaudio
metadata = torchaudio.info('path/to/audio/file.extension')
print(metadata)

The output will look something like this

AudioMetaData(sample_rate=8000, num_frames=625920, num_channels=1, bits_per_sample=16, encoding=PCM_S)

Laryngeal

Answer 7

This is a solution with pydub

from pydub.utils import mediainfo
sr = int(mediainfo("file_path")['sample_rate'])

And here another way with pydub:

from pydub import AudioSegment
audio = AudioSegment.from_file(audio_file)
sr = audio.frame_rate

By the way pydub here just uses ffprobe or avprobe as cmd with popen.

Paste