NormH.264 — 4K to 1/4 size, visually identical
NormMAP commutator-norm driven H.264 encoder. Empirical on 4K H.264 source: 110 MB → 28 MB (-74.3%), VMAF mean 83.25, visually indistinguishable from the original. Drop-in replacement for existing H.264 transcode pipelines, 100% playback compatibility (every H.264 player / hardware decoder / NLE plays it as-is). Trial version: 90 days + SLIMECODEC TRIAL logo overlay. SlimeCodec Convert v0.5.0-trial.
Visual confirmation — 4K side-by-side
Same 4K nature frame, original vs NormH.264 slime-1 (1/4 size). Click images to view full resolution:
Center crop zoom (detail comparison):
Left: original 110 MB · Right: NormH.264 28 MB (-74%, VMAF 83.25)
Download (v0.5.0-trial)
4K empirical (measured on real source)
Measured on a 4K nature clip (3840×2160 30 fps, 20.4 s, H.264 AVC):
| Output | Size | Reduction | VMAF mean | VMAF min | Visual |
|---|---|---|---|---|---|
| Source (45 Mbps) | 110 MB | — | (baseline) | — | — |
| NormH.264 slime-1 (recommended) | 28 MB | -74.3% | 83.25 | 72.31 | Indistinguishable |
| NormH.264 slime-2 (aggressive) | 25 MB | -77.2% | 80.47 | 68.90 | Mild loss |
VMAF 83 is the boundary below which viewers begin to notice loss. slime-1 lands at mean 83.25 — the sweet spot of 1/4 storage with visually indistinguishable output.
v0.5.0 trial highlights
--overlay-protect: masks watermark / overlay regions out of the commutator-norm computation. The SLIMECODEC TRIAL logo no longer disturbs bit allocation around it; no surrounding-pixel degradation.- AVX2 + FMA SIMD path, 12-thread parallelization, frame pipelining (decoder ↔ compute overlap)
- Content-aware auto-tune (surveillance / shake / sport / nature / generic auto-classification)
Quick start (Windows GUI, recommended)
- Download the GUI + CLI zip, extract to any folder
- Double-click
slimecodec-gui.exe - Click “Browse...” to select a video, then “Convert”
- Output is written to the same folder as
*_slime.mp4
Quick start (Windows CLI)
- Extract the zip to any folder
- From cmd / PowerShell:
slimecodec-convert.exe my_video.mp4 -o output.mp4 --auto-tune --keyint 2
Quick start (Linux)
tar -xzf slimecodec-convert-linux-x64-v0.5.0-trial.tar.gz
cd slimecodec-convert-linux-x64-v0.5.0-trial
./slimecodec-convert input.mp4 -o output.mp4 --auto-tune --keyint 2Quality bias dial
Fine-tune the auto-tune decision on a single size⇔quality dial.
GUI exposes a slider; CLI uses the --quality-bias flag:
| Setting | Effect | When to use |
|---|---|---|
--quality-bias -0.02 | Stronger compression, smaller files | Compression-priority, accept mild loss |
--quality-bias 0.0 (default) | Balanced | Most cases |
--quality-bias +0.02 | Weaker compression, larger files, higher VMAF floor | Quality-priority, broadcast use |
Range -0.10 to +0.10, step 0.01 recommended. Only effective with
--auto-tune.
- No user registration required — use it immediately after download (we send no emails, no DMs, ever)
- Video output is stamped with the SLIMECODEC TRIAL logo overlay (burned into the Y plane; not for commercial use)
- Stops working at the earlier of 90 days from first launch or 1000 launches
- Hardware fingerprint locked (tied to a single machine); PC date rollback is detected and rejected
- Encrypted license file:
~/.slimecodec/license_v2.dat(32-byte XOR + integrity tag)
--overlay-protect, no
visible degradation occurs around the TRIAL logo.
(Custom-logo substitution is planned for the future commercial release.)
AV1 path
For AV1-only delivery scenarios (new GPUs / iOS 17+ / AV1 decode capable browsers), see NormAV1 — research preview. AV1 hardware playback reach is around 50% of the market; for general use, NormH.264 is recommended.
Commercial release
The paid / commercial release is currently under consideration and not public. Terms and conditions are handled on an inquiry basis: sasaki@javatel.co.jp
SlimeCodec is proprietary software. Patents pending: JP 2026-046898 / 2026-046609 / 2026-046625 (PCT migration planned).