How to get the duration of audio in Python?

It is possible to find the duration of the audio files using Python language which is rich in the use of its libraries. The use of some libraries like mutagen, wave, audioread, etc. is not only limited to extract the length/duration of the audio files but comes with much more functionality.

Source Audio File: 

Now let us see, how we can get the duration of any audio file using python:

Method 1: Using the Python Library ‘Mutagen’

Mutagen is a Python module to handle audio metadata. It supports various formats of audio files like wavpack, mp3, Ogg, etc. Below are the steps to use it for computing the duration of the audio files:

Step 1: Install Mutagen 

Since Mutagen is an external python library, hence first it needs to be installed using the pip command as follows:

pip install mutagen

Step 2: Import Mutagen

Once installed, its need to be imported into our script using the following command,

import mutagen

In our program, we are going to use some inbuilt functions of the Mutagen library, Let’s explore them a bit to get a better understanding of the Source Code:

1) WAVE()

Syntax: WAVE(file thing/filename)

Use: It simply creates a WAVE object of the filename being provided as a parameter.

Example: voice = WAVE(“sample.wav”)

2) info

Syntax: variable.info

Use: It fetches the metadata of the audio file whose WAVE object has been created.

Example: voice_info = voice.info

3) length

Syntax: variable.length

Use: It returns audio length in seconds. The value returned is in float(by default).

Example: voice_length = voice_info.length

Below is the actual Python Script that records the duration/length of any audio file:

Python3

import mutagen
from mutagen.wave import WAVE

# function to convert the information into
# some readable format
def audio_duration(length):
    hours = length // 3600  # calculate in hours
    length %= 3600
    mins = length // 60  # calculate in minutes
    length %= 60
    seconds = length  # calculate in seconds

    return hours, mins, seconds  # returns the duration

# Create a WAVE object
# Specify the directory address of your wavpack file
# "alarm.wav" is the name of the audiofile
audio = WAVE("alarm.wav")

# contains all the metadata about the wavpack file
audio_info = audio.info
length = int(audio_info.length)
hours, mins, seconds = audio_duration(length)
print('Total Duration: {}:{}:{}'.format(hours, mins, seconds))

Output: 

Total Duration: 0:0:2

Method 2: Using the Python Library ‘Audioread’

Audioread is cross-library audio decoding for Python. It decodes audio files using whichever backend is available. Below are the steps to use it for computing the duration of the audio files: 

Step 1: Install audioread

Since audioread is an external python library, hence first it needs to be installed using the pip command as follows:

pip install audioread

Step 2: Import audioread

Once installed, its need to be imported into our script using the following command,

import audioread

In our program, we are going to use some inbuilt functions of audioread library, Let’s explore them a bit to get a better understanding of the Source Code:

1) audio_open()

Syntax: audioread.audio_open(filename)

Use: It simply opens an audio file using a library available on the system

Example: with audioread.audio_open(‘example.wav’) as ex: 

                             #statement 1…statement n

2) duration

Syntax: fileobject.duration

Use: It returns the length of the audio in seconds (a float by default).

Example: variable= fptr.duration

Below is the actual Python Script that records the duration/length of any audio file:

Python3

# METHOD 2
import audioread

# function to convert the information into
# some readable format
def duration_detector(length):
    hours = length // 3600  # calculate in hours
    length %= 3600
    mins = length // 60  # calculate in minutes
    length %= 60
    seconds = length  # calculate in seconds

    return hours, mins, seconds


# alarm.wav is the name of the audio file
# f is the fileobject being created
with audioread.audio_open('alarm.wav') as f:

    # totalsec contains the length in float
    totalsec = f.duration
    hours, mins, seconds = duration_detector(int(totalsec))
    print('Total Duration: {}:{}:{}'.format(hours, mins, seconds))

Output: 

Total Duration: 0:0:2

Method 3: Using the Python Library ‘Scipy’

SciPy has many modules, classes, and functions available to read data from and write data to a variety of file formats like Wav sound files, MATLAB files, etc. Below are the steps to use it for computing the duration of the audio files:

Step 1: Install Scipy

Since Scipy is an external python library, hence first it needs to be installed using the pip command as follows:

pip install scipy

Step 2: Import Scipy

Once installed, its need to be imported into our script using the following command,

import scipy
from scipy.io import wavfile

In our program, we are going to use some inbuilt functions of the Scipy library, Let’s explore them a bit to get a better understanding of the Source Code:

1) scipy.io.wavfile.read()

Syntax: scipy.io.wavfile.read(filename)

Use: It returns the sample rate (in samples/sec) and data from a WAV file. The file can be an open file or a filename. The returned sample rate is a Python integer. The data is returned as a NumPy array with a data-type determined from the file.

Example: variable1,variable2 = scipy.io.wavfile.read(‘example.wav’)

Below is the actual Python Script that records the duration/length of any audio file:

Python3

# Method 3
import scipy
from scipy.io import wavfile

# function to convert the information into
# some readable format
def output_duration(length):
    hours = length // 3600  # calculate in hours
    length %= 3600
    mins = length // 60  # calculate in minutes
    length %= 60
    seconds = length  # calculate in seconds

    return hours, mins, seconds

# sample_rate holds the sample rate of the wav file
# in (sample/sec) format
# data is the numpy array that consists
# of actual data read from the wav file
sample_rate, data = wavfile.read('alarm.wav')

len_data = len(data)  # holds length of the numpy array

t = len_data / sample_rate  # returns duration but in floats

hours, mins, seconds = output_duration(int(t))
print('Total Duration: {}:{}:{}'.format(hours, mins, seconds))

Output:

Total Duration: 0:0:2