NormAV1 — research preview

NormMAP commutator-norm driven SVT-AV1 encoder. Empirical: -19.9% bitrate at VMAF 94.09 (vs plain libsvtav1 CRF 32 baseline 95.29) on a 9-min 1080p AV1 source. Research-grade, requires manual SvtAv1EncApp + ffmpeg installation.

For most users, NormH.264 is the better fit. See /slimecodec/ — NormH.264 delivers 4K to 1/4 size with 100% playback compatibility (no AV1 hardware required). NormAV1 is for AV1-only delivery scenarios where ~20% additional savings on top of plain SVT-AV1 justify the more complex pipeline.

Download

Windows x64 — GUI + CLI (.zip) (research preview)

slimecodec-svtav1-norm-gui.exe (file picker + qp_range slider) + CLI exes + bundled ffmpeg.exe + DLLs. Requires SvtAv1EncApp.exe placed in same folder (build from github.com/AOMediaCodec/SVT-AV1; no official Windows pre-build yet).

md5: 278e4111ff6699b9193a112e5adc29bb / 61 MB

Linux x64 — slimecodec-svtav1-norm + slimecodec-svtav1-roi

End-to-end pipeline binary + standalone ROI map generator. Requires SvtAv1EncApp and ffmpeg in PATH (apt install svt-av1 ffmpeg).

md5: b1786dd179fcb339856fb9615be4e801 / 698 KB

Why a separate product

FFmpeg's libsvtav1 wrapper does not expose AV1 ROI segmentation. NormAV1 bypasses FFmpeg by:

Computing NormMAP commutator-norm d-values per 8x8 block (Pass 1)
Aggregating to 64x64 SVT-AV1 superblocks (p75 default)
Quantizing to 5 QP-offset segments (AV1 spec max is 8)
Emitting an SVT-AV1 --roi-map-file (text format)
Spawning SvtAv1EncApp via Y4M pipe with the ROI map applied
Muxing AV1 + audio passthrough back to MP4

The empirical sign convention used by SvtAv1EncApp's ROI map is inverted from the AV1 spec QP delta direction; the binary applies the inversion automatically (verified on Sparks 9-min, qpr=30: +9.55% without inversion → -19.9% with inversion, with full ROI map pipeline active).

Empirical (Sparks-5994fps-AV1 1080p, 60-sec VMAF subset)

Baseline: plain libsvtav1 CRF 32 preset 8 = 154.3 MB, VMAF 95.29

Setting	Output	Size delta	VMAF mean	VMAF min	Verdict
`--qp-range 20` (mild)	134.9 MB	-12.6%	94.65	87.62	+0.66 pt vs plain CRF 36
`--qp-range 30` (default)	123.6 MB	-19.9%	94.09	86.73	+0.10 pt vs plain CRF 36 ✅
`--qp-range 40`	113.0 MB	-26.8%	93.34	85.38	parity with plain CRF interpolation
`--qp-range 60` (extreme)	96.0 MB	-37.8%	91.65	80.93	-0.84 pt vs plain CRF 40

NormMAP advantage holds at --qp-range 20 and 30, where the per-block reallocation outperforms uniform CRF compression at equivalent file size. Beyond qp-range 30, the 5-segment quantization ceiling caps the gain.

Quick start (Linux)

tar -xzf normav1-linux-x64.tar.gz
cd normav1-linux-x64

# install prerequisites once:
apt install svt-av1 ffmpeg   # or build SVT-AV1 from source

# encode with NormMAP ROI:
./slimecodec-svtav1-norm input.mp4 -o output_normav1.mp4
# default: --qp-range 30 (~-20% vs plain SVT-AV1 same CRF)

# more aggressive:
./slimecodec-svtav1-norm input.mp4 -o output.mp4 --qp-range 40

QP-range dial

Like H.264 path's --strength, this is the user-facing knob for size⇔quality trade-off:

qp_range	Typical reduction	VMAF behavior	Use case
20	~-12%	VMAF parity with plain CRF +1 pt	Quality priority
30 (default)	~-20%	VMAF parity with plain CRF +0.1 pt	Recommended
40	~-27%	VMAF parity with plain CRF	Mild compression boost
60	~-38%	VMAF -0.8 pt vs plain CRF	Aggressive, accept some loss

Trial spec: 30-day hardware-fingerprint locked. Same license-v2 mechanism as NormH.264 (encrypted file at ~/.slimecodec/license_v2.dat, PC date rollback rejected).

System requirements: Linux x86_64 with AVX2/FMA CPU (Intel Haswell+ / AMD Excavator+, ~2014+). SvtAv1EncApp v1.7+ and ffmpeg in PATH.

Contact

For commercial license / subscription inquiries: sasaki@javatel.co.jp

NormAV1 is research-grade software derived from SlimeCodec NormMAP. Patent pending JP 2026-046609.