Noise suppression in Live stream.

WebRTC's ability to facilitate real-time audio and video communication has transformed online interactions. However, unwanted noise can disrupt the experience, making conversations frustrating. While various methods exist, this article explores how FFMPEG, a powerful multimedia framework, can be harnessed to suppress noise in pre-recorded WebRTC streams.

Why FFMPEG for Pre-recorded Streams?

While WebRTC excels in live communication, FFMPEG offers an alternative approach for noise reduction in pre-recorded streams. Here's why it can be valuable:

1. Offline Processing: FFMPEG operates independently, allowing noise suppression on pre-recorded WebRTC streams without affecting live interactions.
2. Granular Control: FFMPEG provides a wide range of filters and parameters, enabling users to tailor noise reduction to specific needs.
3. Batch Processing: FFMPEG can process multiple pre-recorded WebRTC streams efficiently, saving time and effort.

Identifying Noise in WebRTC Recordings

Similar to live streams, pre-recorded WebRTC content can be plagued by various noise sources:

1. Environmental Noise: Background sounds like traffic or chatter can intrude on the audio.
2. Microphone Quality: Low-quality microphones might pick up unwanted ambient noise.
3. Recording Issues: Microphone placement or improper recording settings might introduce noise.

FFMPEG Filters for the Rescue

FFMPEG offers several filters well-suited for noise suppression:

denoise: This versatile filter employs various techniques to reduce noise. Experiment with presets like "nc" (noise cleaning) or adjust parameters for customization.

ffmpeg -i noisy_webrtc_recording.webm -vf denoise=nc output_clean.webm
        

yadif: If your noise appears interlaced (flickering lines), the "yadif" filter can help by deinterlacing the video, potentially reducing noise artifacts.

ffmpeg -i noisy_webrtc_recording.webm -vf yadif output_clean.webm
        

deblock: Block noise can manifest as blocky artifacts. The "deblock" filter might help, although it primarily targets compression artifacts.

ffmpeg -i noisy_webrtc_recording.webm -vf deblock output_clean.webm
        

#Antmedia has successfully implemented noise suppression on server side

Final Thoughts:

Noise suppression is not without its trade-offs. While FFMPEG filters can effectively reduce noise, they might also introduce minor alterations to the audio. It’s crucial to carefully evaluate the output to ensure that the audio quality remains acceptable despite the noise reduction.