CRITICAL GUIDELINES
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Quick Reference
| Task | Filter | Command Pattern |
|---|---|---|
| Video denoising (best) | nlmeans | -vf nlmeans=s=3:p=7:r=15 |
| Video denoising (fast) | hqdn3d | -vf hqdn3d=4:3:6:4.5 |
| GPU video denoising | nlmeans_vulkan | -vf nlmeans_vulkan |
| Audio denoising | afftdn | -af afftdn=nf=-25 |
| Adaptive temporal | atadenoise | -vf atadenoise |
When to Use This Skill
Use for noise reduction workflows:
- •Cleaning low-light or high-ISO footage
- •Removing film grain
- •Reducing compression artifacts
- •Cleaning audio recordings
- •Broadcast signal cleanup
- •Pre-processing before encoding
FFmpeg Noise Reduction (2025)
Comprehensive guide to video and audio denoising filters.
Video Denoising
nlmeans - Non-Local Means (Best Quality)
The highest quality software denoiser, using non-local means algorithm.
bash
# Basic denoising ffmpeg -i noisy.mp4 -vf "nlmeans" output.mp4 # Medium denoising (good default) ffmpeg -i noisy.mp4 -vf "nlmeans=s=3.0:p=7:r=15" output.mp4 # Strong denoising (very noisy footage) ffmpeg -i noisy.mp4 -vf "nlmeans=s=5.0:p=7:r=15" output.mp4 # Light denoising (preserve detail) ffmpeg -i noisy.mp4 -vf "nlmeans=s=1.5:p=5:r=9" output.mp4 # Denoise only chroma (preserve luma detail) ffmpeg -i noisy.mp4 -vf "nlmeans=s=3.0:sc=5.0:p=7:r=15" output.mp4
Parameters:
| Parameter | Description | Default | Range |
|---|---|---|---|
s | Denoising strength (sigma) | 1.0 | 0-30 |
p | Patch size | 7 | 1-99 (odd) |
pc | Patch size for chroma | 0 (same as p) | 1-99 |
r | Research window size | 15 | 1-99 (odd) |
rc | Research window for chroma | 0 (same as r) | 1-99 |
Strength guidelines:
| s value | Use case |
|---|---|
| 1.0-2.0 | Light noise, preserve detail |
| 2.0-4.0 | Moderate noise (typical) |
| 4.0-6.0 | Heavy noise, low light |
| 6.0+ | Extreme noise (quality loss) |
nlmeans_opencl - GPU-Accelerated NLMeans
OpenCL accelerated version, much faster.
bash
# OpenCL denoising ffmpeg -i noisy.mp4 \ -vf "hwupload,nlmeans_opencl=s=3:p=7:r=15,hwdownload,format=yuv420p" \ output.mp4 # Strong denoising with OpenCL ffmpeg -i noisy.mp4 \ -vf "hwupload,nlmeans_opencl=s=5:p=7:r=21,hwdownload,format=yuv420p" \ output.mp4
nlmeans_vulkan - Vulkan-Accelerated NLMeans (FFmpeg 8.0+)
Cross-platform GPU acceleration using Vulkan.
bash
# Vulkan denoising ffmpeg -init_hw_device vulkan \ -i noisy.mp4 \ -vf "hwupload,nlmeans_vulkan=s=3:p=7:r=15,hwdownload,format=yuv420p" \ output.mp4 # Full Vulkan pipeline ffmpeg -init_hw_device vulkan=vk \ -filter_hw_device vk \ -hwaccel vulkan -hwaccel_output_format vulkan \ -i noisy.mp4 \ -vf "nlmeans_vulkan=s=3" \ -c:v h264_vulkan output.mp4
hqdn3d - High Quality 3D Denoiser (Fast)
Faster than nlmeans with good results for moderate noise.
bash
# Default settings ffmpeg -i noisy.mp4 -vf "hqdn3d" output.mp4 # Custom settings (luma_spatial:chroma_spatial:luma_tmp:chroma_tmp) ffmpeg -i noisy.mp4 -vf "hqdn3d=4:3:6:4.5" output.mp4 # Strong spatial denoising ffmpeg -i noisy.mp4 -vf "hqdn3d=8:6:6:4" output.mp4 # Strong temporal denoising (for static scenes) ffmpeg -i noisy.mp4 -vf "hqdn3d=4:3:12:9" output.mp4 # Light denoising ffmpeg -i noisy.mp4 -vf "hqdn3d=2:1.5:3:2" output.mp4
Parameters:
| Parameter | Description | Default | Range |
|---|---|---|---|
luma_spatial | Luma spatial strength | 4.0 | 0-255 |
chroma_spatial | Chroma spatial strength | 3.0 | 0-255 |
luma_tmp | Luma temporal strength | 6.0 | 0-255 |
chroma_tmp | Chroma temporal strength | 4.5 | 0-255 |
atadenoise - Adaptive Temporal Averaging
Temporal denoiser that preserves motion.
bash
# Basic temporal denoising ffmpeg -i noisy.mp4 -vf "atadenoise" output.mp4 # Stronger denoising ffmpeg -i noisy.mp4 -vf "atadenoise=0a=0.1:0b=0.2:1a=0.1:1b=0.2:2a=0.1:2b=0.2" output.mp4 # Adjust threshold and planes ffmpeg -i noisy.mp4 -vf "atadenoise=s=9:p=5" output.mp4
Parameters:
| Parameter | Description | Default |
|---|---|---|
0a, 1a, 2a | Threshold A for planes 0,1,2 | 0.02 |
0b, 1b, 2b | Threshold B for planes 0,1,2 | 0.04 |
s | Number of frames to average | 9 |
p | Planes to process | 7 (all) |
vaguedenoiser - Wavelet Denoiser
Uses wavelet transform for denoising.
bash
# Basic wavelet denoising ffmpeg -i noisy.mp4 -vf "vaguedenoiser" output.mp4 # Adjust threshold ffmpeg -i noisy.mp4 -vf "vaguedenoiser=threshold=3:method=soft" output.mp4 # Stronger denoising ffmpeg -i noisy.mp4 -vf "vaguedenoiser=threshold=6:nsteps=6" output.mp4
Parameters:
| Parameter | Description | Default | Values |
|---|---|---|---|
threshold | Denoising threshold | 2 | 0-inf |
method | Thresholding method | hard | hard, soft, garrote |
nsteps | Decomposition steps | 6 | 1-32 |
percent | Percent of full denoising | 85 | 0-100 |
fftdnoiz - FFT-Based Denoising
Frequency domain denoising.
bash
# Basic FFT denoising ffmpeg -i noisy.mp4 -vf "fftdnoiz" output.mp4 # Adjust sigma ffmpeg -i noisy.mp4 -vf "fftdnoiz=sigma=8" output.mp4 # Strong denoising ffmpeg -i noisy.mp4 -vf "fftdnoiz=sigma=15:block=32:overlap=0.8" output.mp4
owdenoise - Overcomplete Wavelet Denoiser
Another wavelet-based option.
bash
# Basic wavelet denoising ffmpeg -i noisy.mp4 -vf "owdenoise" output.mp4 # Adjust depth and strength ffmpeg -i noisy.mp4 -vf "owdenoise=depth=10:ls=3:cs=3" output.mp4
removegrain - RemoveGrain
Classic grain/noise removal (from AviSynth).
bash
# Mode 1 (basic) ffmpeg -i noisy.mp4 -vf "removegrain=m0=1" output.mp4 # Different modes for different noise types ffmpeg -i noisy.mp4 -vf "removegrain=m0=17:m1=17:m2=17" output.mp4
Audio Denoising
afftdn - FFT Denoiser (Recommended)
Powerful audio noise reduction using FFT.
bash
# Basic audio denoising ffmpeg -i noisy_audio.mp4 -af "afftdn" output.mp4 # Specify noise floor ffmpeg -i noisy_audio.mp4 -af "afftdn=nf=-25" output.mp4 # Stronger noise reduction ffmpeg -i noisy_audio.mp4 -af "afftdn=nf=-20:nt=w" output.mp4 # With noise profile (sample noise-only section first) ffmpeg -i noisy_audio.mp4 -af "afftdn=nr=10:nf=-30:nt=w:om=o" output.mp4 # Adaptive noise floor ffmpeg -i noisy_audio.mp4 -af "afftdn=nt=c:om=o:bn=9" output.mp4
Parameters:
| Parameter | Description | Default | Range |
|---|---|---|---|
nr | Noise reduction (dB) | 12 | 0.01-97 |
nf | Noise floor (dB) | -50 | -80 to -20 |
nt | Noise type | w | w=white, v=vinyl, s=shellac, c=custom |
bn | Number of noise bands | 15 | 3-33 |
rf | Residual floor (dB) | -38 | -80 to -20 |
om | Output mode | o | i=input, o=output, n=noise |
anlmdn - Non-Local Means Audio Denoiser
Audio equivalent of video nlmeans.
bash
# Basic NLM audio denoising ffmpeg -i noisy_audio.mp4 -af "anlmdn" output.mp4 # Adjust strength ffmpeg -i noisy_audio.mp4 -af "anlmdn=s=0.0001" output.mp4 # Stronger denoising ffmpeg -i noisy_audio.mp4 -af "anlmdn=s=0.001:p=0.01" output.mp4
Parameters:
| Parameter | Description | Default |
|---|---|---|
s | Denoising strength | 0.00001 |
p | Patch radius | 0.002 |
r | Research radius | 0.006 |
m | Output mode | o (output) |
adeclick - Remove Clicks/Pops
Removes impulsive noise from audio.
bash
# Remove clicks ffmpeg -i clicked_audio.mp4 -af "adeclick" output.mp4 # Adjust parameters ffmpeg -i clicked_audio.mp4 -af "adeclick=w=55:o=75" output.mp4
adeclip - Remove Clipping
Repairs clipped audio.
bash
# Fix clipping ffmpeg -i clipped_audio.mp4 -af "adeclip" output.mp4
Combined Workflows
Low-Light Video Enhancement
bash
# Denoise + brighten + contrast ffmpeg -i dark_noisy.mp4 \ -vf "nlmeans=s=4:p=7:r=15,eq=brightness=0.1:contrast=1.2:saturation=1.1" \ -c:v libx264 -crf 18 \ enhanced.mp4
Interview Cleanup (Video + Audio)
bash
# Clean both video and audio noise ffmpeg -i interview.mp4 \ -vf "hqdn3d=3:2:4:3" \ -af "afftdn=nf=-30:nr=10,loudnorm" \ -c:v libx264 -crf 20 \ -c:a aac -b:a 192k \ interview_clean.mp4
Film Grain Removal
bash
# Strong nlmeans for film grain ffmpeg -i grainy_film.mp4 \ -vf "nlmeans=s=5:p=7:r=21" \ -c:v libx264 -crf 18 -preset slow \ degrained.mp4 # Preserve some grain (artistic choice) ffmpeg -i grainy_film.mp4 \ -vf "nlmeans=s=2.5:p=5:r=11" \ -c:v libx264 -crf 18 \ light_degrain.mp4
Compression Artifact Removal
bash
# Remove blocking artifacts from highly compressed video ffmpeg -i compressed.mp4 \ -vf "hqdn3d=2:1.5:3:2,unsharp=5:5:0.3:5:5:0" \ -c:v libx264 -crf 18 \ cleaner.mp4
GPU-Accelerated Batch Processing
bash
#!/bin/bash
# Process multiple noisy videos with GPU
for video in noisy_*.mp4; do
output="clean_${video}"
ffmpeg -init_hw_device vulkan \
-i "$video" \
-vf "hwupload,nlmeans_vulkan=s=3,hwdownload,format=yuv420p" \
-c:v libx264 -crf 18 \
"$output"
done
Filter Comparison
Video Denoising Speed vs Quality
| Filter | Quality | Speed | GPU Option | Best For |
|---|---|---|---|---|
nlmeans | Excellent | Slow | Yes (OpenCL/Vulkan) | Final output |
hqdn3d | Good | Fast | No | Real-time, previews |
atadenoise | Good | Medium | No | Static scenes |
vaguedenoiser | Good | Medium | No | Mixed content |
fftdnoiz | Good | Medium | No | Periodic noise |
Audio Denoising Comparison
| Filter | Quality | Speed | Best For |
|---|---|---|---|
afftdn | Excellent | Fast | All-purpose |
anlmdn | Good | Medium | Speech |
adeclick | Specialized | Fast | Clicks/pops |
Parameter Tuning Tips
Video Denoising
- •Start conservative - Begin with s=2-3, increase if needed
- •Preserve edges - Lower patch size (p=5) preserves more detail
- •Test on samples - Process 10-second clips first
- •Consider GPU - nlmeans_opencl/vulkan are 5-10x faster
- •Match content - Static scenes tolerate stronger temporal denoising
Audio Denoising
- •Find noise floor - Listen to quiet sections
- •Use appropriate type - White noise vs vinyl vs custom
- •Don't over-process - Artifacts can be worse than noise
- •Check residual - Use om=n to hear what's being removed
Best Practices
- •Denoise before encoding - Noise compresses poorly
- •Preserve some texture - Over-denoising looks artificial
- •Match source quality - Don't denoise clean footage
- •Use GPU when available - Massive speed improvement
- •Combine filters carefully - Multiple denoisers can cause artifacts
- •Test different filters - Content-dependent results
This guide covers noise reduction for 2025. For video analysis and detection, see ffmpeg-video-analysis. For hardware acceleration, see ffmpeg-hardware-acceleration.