Optimize Encodes with LSFmod: Tips to Reduce Artifacts and File Size

LSFmod vs LimitedSharpenFaster — When to choose each

Overview

• LimitedSharpenFaster (LSF): original, fast, simple edge-focused sharpener (Unsharp/range-style).
• LSFmod: LaTo’s mod of LSF with many extra features (nonlinear modes, preblur, source limiting, temporal soothe, presets, better control over overshoot/undershoot), generally produces fewer artefacts and better compressibility but is slightly slower.

Choose LimitedSharpenFaster when

• You need the simplest, fastest sharpen for quick preview or live playback.
• You want minimal configuration and lightweight processing.
• You prefer classic LSF behaviour and compatibility with old scripts/tools.

Choose LSFmod when

• You want finer control: nonlinear sharpening, Smode/Smethod options, Szrp/Spwr/Sdmp parameters.
• You need to avoid noise/ringing (preblur, secure) or limit sharpening against an unsharpened source.
• You care about temporal stability (soothe/keep) or advanced edge masking and overshoot/undershoot control.
• You aim for better encode size/quality tradeoffs and fewer artefacts (recommended for final encodes).

Practical defaults

• For fast final encodes: use LSFmod(defaults=“fast”) with moderate strength (e.g., 100–150).
• For minimal processing / realtime: use LimitedSharpenFaster(strength=…) or LSFmod with very simple Smode settings if available.

Caveats

• High strength values (>150–200) often produce visible artifacts on large displays—test at target viewing size.
• LSFmod requires additional plugins (MaskTools2, RemoveGrain/RGTools, VariableBlur/WarpSharp depending on Smode).
• VapourSynth/Avisynth implementations and defaults may differ; check your environment’s version.

Sources: Avisynth LSFmod documentation, community discussions and comparisons.