Enhancing Video Audio: Noise Reduction and Amplification with Python

Audio clarity is paramount for a satisfactory video-viewing experience. Distracting background noises or low-volume audios can hinder viewer engagement and comprehension. Thankfully, Python, combined with several powerful libraries, can offer effective solutions to these problems.

Getting Started: Installing Required Libraries

Before diving into the code, ensure you have Python installed on your system. Once that’s settled, the following libraries need to be installed:

1. MoviePy – for video and audio editing.

   pip install moviepy

2. noisereduce – an active noise reduction tool.

pip install noisereduce

1. Librosa – to analyze and process audio.

pip install librosa

1. SoundFile – for reading and writing sound files.

pip install soundfile

1. PyDub – a high-level audio library to manipulate audio.

pip install pydub

Ensure you have FFmpeg, as it is a dependency for some of these libraries:

pip install imageio[ffmpeg]

The Process: Step-by-Step Guide to Enhance Audio

Loading the Video:
With MoviePy, you can effortlessly load your video into your Python environment.

video = VideoFileClip("path_to_video")

Extracting the Audio:
Extract the audio from the video. Our example focuses on the left channel for simplicity, but adjustments can be made if stereo sound is vital.

audio = video.audio y = audio.to_soundarray(fps=22050)[:, 0]

Reducing Noise:
The noisereduce library shines by eliminating noise from the audio signal, enhancing clarity.

y_denoised = nr.reduce_noise(y=y, sr=22050)

Saving the Denoised Audio:
It’s often helpful to save intermediate steps. Here, we temporarily save the denoised audio.

sf.write('temp_denoised_audio.wav', y_denoised, 22050)

Amplifying the Audio:
Using PyDub, amplifying audio is straightforward. We’ll boost the volume by 10 dB in this example, but feel free to tweak as necessary.

sound = AudioSegment.from_wav("temp_denoised_audio.wav") amplified_sound = sound + 10 amplified_sound.export("temp_amplified_audio.wav", format="wav")

Integrating Amplified Audio with Video:
Using MoviePy, we reintegrate the enhanced audio with our video.

amplified_audio = AudioFileClip('temp_amplified_audio.wav') video_with_amplified_audio = video.set_audio(amplified_audio)

Saving the Enhanced Video:
Now, it’s time to save your video with its upgraded audio.

video_with_amplified_audio.write_videofile("path_to_save_enhanced_video", audio_codec='aac')

Post-Processing Cleanup:
Deleting temporary files ensures a tidy workspace.

os.remove('temp_denoised_audio.wav') os.remove('temp_amplified_audio.wav')

Full code:

from moviepy.editor import *
import noisereduce as nr
import librosa
import soundfile as sf
from pydub import AudioSegment
import os

# Load video
video = VideoFileClip("C:\\Users\\USERNAME\\Desktop\\part2.mp4")

# Extract audio
audio = video.audio
y = audio.to_soundarray(fps=22050)[:, 0] # Using the left channel; modify if stereo sound is important
sr = 22050

# Reduce noise
y_denoised = nr.reduce_noise(y=y, sr=sr)

# Save the denoised audio temporarily
sf.write('temp_denoised_audio.wav', y_denoised, sr)

# Amplify the denoised audio
sound = AudioSegment.from_wav("temp_denoised_audio.wav")
amplified_sound = sound + 50 # Amplify by 10 dB. You can adjust this value as needed.
amplified_sound.export("temp_amplified_audio.wav", format="wav")

# Load the amplified audio back into moviepy
amplified_audio = AudioFileClip('temp_amplified_audio.wav')

# Set the amplified audio to the video
video_with_amplified_audio = video.set_audio(amplified_audio)

# Save the video with the enhanced audio
video_with_amplified_audio.write_videofile("C:\\Users\\USERNAME\\Desktop\\part11.mp4", audio_codec='aac')

# Optional: Remove the temporary audio files
os.remove('temp_denoised_audio.wav')
os.remove('temp_amplified_audio.wav')

Through the synergy of Python and its extensive libraries, improving the audio quality of videos becomes an achievable task, even for those not versed in audio engineering. By following this guide, creators can ensure their videos deliver clear and engaging auditory experiences for their audience.