DeJitter


Author V. C. Mohan
Date 4 June 2020
EMail: mohanvc

Some vhs tapes have time sync problems, and the rows exhibit severe jitter. This plugin examines the specified window of each of the rows and tries to find the amount by which the pixels are out of alignment, adds the sync signal width and shifts, to put them in correct alignment. Dark scenes with luma less than 50 or so may give erroneous results. The resulting voids at the right ends of the rows are greyed out or end color is extended. In avisynth+ version the end is blackend, and using last determined value is not available.

RGB32, RGB24, YUY2 and YV12 (other Planar formats with 2.6 version and avisynth+ version) formats are supported. In case of RGB the minimum shift value determined for red green and blue colors is used and for YUY2 and Planar formats the Y value is used to determine shift required. The resulting blank ends are filled with either last pixel color or greyed out. In avisynth+ version the end is blackened only. The last determined shift value can be used in case determination fails(not in avisynth+ version)


Details of parameters
Description Name Type Limits Default
Input clip clip none
maximum jitter in pixels jmax integer within clip, >3 32
threshold value for detection th integer.( float for avisynth+) 1 to 255, (0.005 to 0.5 in avisynth+) 80 (0.25 in avisynth+)
sync signal width wsyn integer 0 to frame width-jmax 10
color to be extended or greyed out into blank area. Ignored in avisynth+ version extend boolean true for extend last pixel value false
use last determined value if failed on this scan line. Ignored by avisynth+ version uselast boolean true for use last value false

#Usage examples:-
DeJitter(last,jmax=40,th=80, wsyn=8, extend=true)

Below is an example of output On left input:

To my index page down load plugin To Avisynth