UM:Dvo Effects Dvo Line Sync

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DVO Line Sync

ch-dvo-effects-dvo-line-sync-intro

 

Line sync or line jitter is a very common problem with archived analog video tape.

 

It is typically caused by the lack of (or disturbances with) line synchronization pulses which prevents the the video tape recorder from locating the actual start and end of each line. This causes random line displacement (jitter).

 

The most visible effect is that vertical edges appear to be jagged. The jitter can range from +/-1 pixel to more than +/-5 pixels in severe cases. DVO Line Sync automatically detects and corrects these line displacements as well as any stretching it causes.

Parameters

Enable

ch-dvo-effects-dvo-line-sync-enable

 

When enabled, DVO Line Sync will process the input as per the settings described below.

Detection Strength

ch-dvo-effects-dvo-line-sync-detection

 

Detection Strength controls the degree of jitter detection with a higher number meaning a higher degree of detection.

 

dv_alert

If the Strength parameter is pushed too high, we may correct lines unnecessarily and introduce jitter. Analyse the resulting output before committing to a long render.

 

dv_note

Note that the processing time is dependent on detected (and processed) lines. The more line sync issues we find, the longer it will take to process.

Processing

ch-dvo-effects-dvo-line-sync-processing

Shift

Enables correction of pixel shifting (left/right)

Stretch

Enables correction of stretched/shrunken lines.

Noise Reduction

ch-dvo-effects-dvo-line-sync-noise

 

This is Adaptive Noise Reduction with non-recursive spatio-temporal filtering so ghosting will not occur.

 

dv_note

Note that processing time will be considerably higher when active since all lines have to be processed.

NR Enable

Enables Noise Reduction, independent of shift/stretch detection and correction.

NR Strength

Sets the amount of Noise Reduction to perform.

 

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