A source-first VapourSynth pipeline
Build a small, reproducible filter chain, then inspect what each stage changes before adding the next.
On this page
Start with a source inspection
Choose several representative scenes: motion, flat gradients, fine lineart, and dark texture. Keep their frame numbers in a notebook. One attractive screenshot cannot represent an entire episode.
Treat filters as targeted repairs. Keep an unfiltered reference available throughout the workflow.
Load the source
Install VapourSynth and a compatible source plugin first. Plugin availability varies by operating system.
import vapoursynth as vs
core = vs.core
source = core.lsmas.LWLibavSource("source.mkv")
source.set_output()Filter one problem at a time
Test debanding conservatively. Compare gradients at native resolution and check that texture and thin strokes survive. Avoid a global setting that repairs one scene and harms the rest.
A minimal debanding study
# Requires the f3kdb plugin. These are starting values, not universal settings.
filtered = core.f3kdb.Deband(
source, range=12, y=48, cb=32, cr=32,
grainy=0, grainc=0, output_depth=10
)
filtered.set_output()Export and encode a short test
Encode a small section before committing to the full run. Record the plugin versions, script, encoder build, and parameters so the result can be reproduced.
vspipe --y4m pipeline.vpy - | SvtAv1EncApp -i stdin -b test.ivf --crf 22 --preset 4Review at native pixels
Use the comparison bench to practice split and instant-toggle inspection. The included SVG pairs demonstrate the interface; replace them with lossless frame exports for actual QC.
- Compare the same frame number and color conversion.
- Inspect lineart, gradients, and texture separately.
- Review motion as well as individual still frames.
- Save notes on any scene-specific overrides.