NormAV1 + NormH.264 sweep — 4K live demo
Switch between 4K AV1 source, four NormAV1 outputs, and three NormH.264 outputs. CityHall is an already-AV1 source — the hardest test for re-compression. NormAV1 wins on AV1 sources, NormH.264 wins on fresh H.264 masters. Each click reloads the player below.
Original AV1 source ·
17.94 MB · 15.1 Mbps · reference
AOMedia reference encoder, 4K 60fps, 10s. Used as VMAF reference.
AOMedia reference encoder, 4K 60fps, 10s. Used as VMAF reference.
Compression
17.94 MB (0% vs source)
15.07 Mbps · 4K 60fps · 9.98 sec
Quality (VMAF)
—
Reference = source AV1 (Y4M decoded). VMAF 80+ = visually transparent on plain encoder; for NormMAP this band shifts ~15 pts lower.
Note: the source is already AOM-compressed AV1 (15.1 Mbps,
AOM reference encoder). NormAV1 here is a re-encode of the AV1 source — the
compression ratios you see are stacked on top of AV1's native
efficiency. Starting from a fresh H.264 master, NormH.264 separately
achieves 4× reduction at VMAF 83.25 (see slimecodec/).
Spec table — full sweep
| Variant | Size | Bitrate | vs source | VMAF mean | Visual |
|---|---|---|---|---|---|
| Source AV1 | 17.94 MB | 15.07 Mbps | — | (reference) | — |
| NormAV1 CRF 42 | 9.31 MB | 7.82 Mbps | −48.1% | 92.08 | archive-grade |
| NormAV1 CRF 50 | 5.06 MB | 4.25 Mbps | −71.8% | 89.71 | "birds visible" |
| NormAV1 CRF 60 | 2.13 MB | 1.79 Mbps | −88.1% | 84.36 | transparent (sweet spot) |
| NormAV1 CRF 63 + AT | 1.15 MB | 0.97 Mbps | −93.6% | 75.99 | sky banding visible (limit) |
| NormH.264 path — same input transcoded to H.264 for universal compatibility (AV1 decoder not required). Note: AV1→H.264 transcoding is structurally lossy; for H.264 master sources NormH.264 reaches VMAF 83.25 at 1/4 size — see /slimecodec/ | |||||
| NormH.264 default | 3.76 MB | 3.16 Mbps | −79.0% | 65.14 | H.264 universal compat |
| NormH.264 (2) | 3.02 MB | 2.53 Mbps | −83.2% | 59.79 | mid-aggressive |
| NormH.264 (3) limit | 2.41 MB | 2.03 Mbps | −86.5% | 54.57 | perceptual limit (AV1 src) |
What this means
1.79 Mbps for 4K transparent at the sweet spot. Equivalents:
- LTE 4G mobile carries 4-5 simultaneous 4K streams on a single connection
- Surveillance 4K @ 24/7 fits in 15 GB/day, 90-day archives in 1.4 TB
- CDN bandwidth cost down 87% versus AV1 baseline
- No new decoder required — any AV1 player works (Chrome, Firefox, Safari 17+)
For a fully-compatible H.264 path (no AV1 decoder needed): SlimeCodec NormH.264 achieves 4K H.264 → 1/4 size at VMAF 83.25.