[Home]Filter Plugins/Filter Dnr

Capabilities

Video Audio RGB YUV YUV422 multiple instances processing type frames needed
yes no yes yes no no POST 1

Introduction

This filter works best in the YUV colorspace. Processing only takes place when no scene change was detected. Those are detected on the basis of the percentage of pixel of a frame which oversteped all levels (given as parameter)

The filter analyses every pixel of a frame broken down by Luma- and Chroma-parts (YUV-Mode), respectively Red, Green, Blue (RGB-Mode), so that brightness- as well as color-noise can be treated separately.

The levels of Luma-Pixellock and Chroma-Pixellock specify to which difference of a pixel between to frames a displacement through the last pixel should take place, that is wether the pixel value should be locked. Luma-Pixellock is applied to the luma-part (Red) and Chroma-Pixellock is applied to chroma-part (Green/Blue). But a pixel is refreshed at the latest of 30 locks.

As a basic principle the threshold values should be greater lock values to give a balanced ratio between locking and crossfade. The levels are compared to the differences (biased) of pixels, that is greater levels amplify the filter effect due to the fact that greater differences are filtered.

The default values of the parameters should give a usable result. The filter has then, despite the nois-reduction, a soft-focus effect. With noisy material, this filter can reduce the needed bitrate up to 25% (highly depends on the material).

Parameters

This filter uses the following syntax
 -J "dnr=<lt>:<ll>:<ct>:<cl>:<sc>"

Default values are shown in [green] in square brackets.

<lt> Luma-Threshold (1-128) [10]

<ll> Luma-Pixellock (1-128) [4]

<ct> Chroma-Threshold (1-128) [16]

<cl> Chroma-Pixellock (1-128) [8]

<sc> Scene-Change-Detection (1-90) [30]

Values outside the allowed ranges and omitted values fallback to the default.

Usage Examples

 -J dnr=20

 -J dnr=::::60

 -J dnr=20::32

Author

Gerhard Monzel

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Last edited February 14, 2005 3:22 am by Jakemsr (diff)
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