NormH.264 — 4K to 1/4 size, visually identical

NormMAP commutator-norm driven H.264 encoder. Empirical: this 45 Mbps 4K master (110 MB) → 28 MB (VMAF mean 83.25). The reduction depends on the input bitrate (a bloated source shrinks more). Versus a standard x264 transcode at equal visual quality, the efficiency gain is about 7% (content-dependent). The loss is hard to notice in normal viewing, but always verify with your own footage. 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.

For VOD, surveillance, and archive operators: Storage and CDN bandwidth costs cut to 1/4. No AV1 migration required (no new GPUs, no player upgrades, no transcoding farm overhaul). Output plays directly on existing H.264 endpoints. No need to wait for AV1 to mature.

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 (vs 45 Mbps master, VMAF 83.25)

Download (v0.5.0-trial)

Windows x64 — GUI + CLI (.zip) (recommended)

slimecodec-gui.exe (double-click to launch) + slimecodec-convert.exe (CLI) + bundled ffmpeg + DLLs

md5: dff913d311bad2d286b91d1941ebaf3d / 61.0 MB

Windows x64 — CLI only (.zip)

slimecodec-convert.exe + bundled ffmpeg + DLLs (lighter, no GUI)

md5: c873251e093a0a512b93ef7f2e4cfde5 / 59.1 MB

Linux x64 (.tar.gz)

slimecodec-convert (CLI) + README. Requires ffmpeg in PATH (apt install ffmpeg).

md5: 6dd47d8bbcd3c84ea8f91086393c298d / 531 KB

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	Hard to spot
NormH.264 slime-2 (aggressive)	25 MB	-77.2%	80.47	68.90	Mild loss

VMAF mean 83.25 (min 72.31). This is not lossless (there is a measurable PSNR difference), but at a normal viewing distance on typical content the loss is hard to notice. Perceived quality depends on the material and viewing conditions, so always verify with your own footage (free trial).

Where it fits / where it doesn't:
Fits: fixed-camera, high-quality sources for long-term archival (high-end / 4K surveillance, broadcast & production masters, medical & scientific imaging). Strongest at high quality.
Not for: (1) already low-quality / blocky footage (compression artifacts can be mistaken for detail and emphasized), (2) face- or gaze-centric intimate static scenes (the most-scrutinized detail can be dropped), (3) low-bitrate delivery (the gain fades or reverses in that range).

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 2

Quality 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.

Trial spec (license v2):

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)

Thanks to NormMAP + --overlay-protect, no visible degradation occurs around the TRIAL logo. (Custom-logo substitution is planned for the future commercial release.)

System requirements: Windows 10/11 x64 or Linux x86_64 with AVX2 + FMA CPU (Intel Haswell+ / AMD Excavator+, roughly 2014 or later).

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).