Effects » Stylize » Simulation » Quad VTR simulator


Quad VTR simulator
Author(s):
Release date: Sept. 20, 2018
Creation date: Sept. 7, 2018
License: unknown

Lightworks user effect QuadVTR.fx

This effect emulates the faults that could occur with Quadruplex videotape playback.
Tip penetration and guide height are both emulated, and chroma timebase errors are
also simulated. Note: the alpha channel is discarded with this effect.

Modified jwrl 2018-09-08:
Corrected some maths issues affecting the number of bands displayed.
Added desaturation to PAL chroma correction.
Added PAL Hanover bars setting.
Used SetTechnique to select modes, bypassing the conditionals previously used.
Added monochrome mode.

Modified jwrl 2018-09-09:
Rearranged techniques to allow support for PAL-M and other rarer formats.

Modified jwrl 2018-09-10:
Corrected guide height adjustment to be closer to actual effect.

Modified jwrl 2018-09-11:
Added oxide build up effect. That meant a further slight reworking of the maths.

Modified jwrl 2018-09-12:
Added sparkle caused by the brushes in early Ampex heads. It sort of works, but it's
not exactly great.
Added head switching dots visible in the Ampex VR-1000 series.
Added crop to 4:3 aspect ratio. The alpha channel is set to one inside the crop zone
and zero outside it. The crop is reasonably dumb and assumes that the image isn't in
portrait format.

Modified jwrl 2018-09-13:
Added Hi-band/lo-band selection. Two low band modes are provided, because the type
of modulator used differed between valve and solid state signal systems, resulting
in differing noise levels and edge artefacts.
Improved head switch simulation so that unmodified video follows switch pulse. This
also improves the buildup simulation.
Some code cleanup performed.

Modified jwrl 2018-09-14:
Corrected Hi-band/lo-band edge sharpening.
Improved brush noise sparkle generation.

Modified jwrl 2018-09-20:
Added RCA-style chroma displacement error.

Possible future projects:
Add noise displacement when build up occurs.
Work out a convincing way to make the image lose lock as it would with severe build up.
Create tracking errors. That might just be one for the "too hard" basket.
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