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---
license: other
license_name: minimax-h3-community-license
license_link: https://huggingface.co/MiniMaxAI/MiniMax-H3/blob/main/LICENSE
base_model: MiniMaxAI/MiniMax-H3
library_name: mlx
pipeline_tag: text-to-video
tags:
- mlx
- apple-silicon
- text-to-video
- image-to-video
- audio-video-generation
- diffusion
---

# MiniMax-H3 MLX — 8-bit full pipeline (Apple Silicon)

MLX (Apple Silicon) build of the [**MiniMax-H3**](https://huggingface.co/MiniMaxAI/MiniMax-H3) 33B
joint video+audio diffusion transformer, packaged as a **self-contained pipeline** (DiT + text
encoder + video VAE + audio VAE + tokenizer + configs) for the
[PipeNetwork MLX port](https://github.com/PipeNetwork/minimax-h3-mlx).

> Powered by MiniMax H3.
>
> **These files are modified.** Quantized to 8-bit, text encoder rebuilt from the published
> `MiniMax-H3-FL2VA-MLX-Serve-8bit` checkpoint, tested and documented on an M4 Max. See
> `PATCHES.md` and the *Validation report* below.

## Runtime pin

This repository was built and validated against:

- Base: `PipeNetwork/minimax-h3-mlx` commit `b2f7e4d2` (2026-08-10)
- Patches (branch `video-lab-8bit-fixes`): `7210b93e6df86bf9c7206091c9542b6983c10c30` — see `PATCHES.md`
- MLX `0.32.0` (Python 3.12), mlx-vlm `0.6.13`

## Quick start

```bash
git clone https://github.com/PipeNetwork/minimax-h3-mlx
cd minimax-h3-mlx
git checkout b2f7e4d2   # base commit this repo was validated with
python3 -m venv .venv && .venv/bin/pip install -r requirements.txt

# Text-to-video+audio, validated settings (768x448, 16 sigma points -> 15 forwards)
.venv/bin/python scripts/generate.py "a red fox leaps over a mossy log in a misty forest" \
  -c <this repo> -t <this repo>/transformer -s 16 --seed 42 \
  --height 448 --width 768 -o fox.mp4

# Turbo LoRA (4-step EMA, included as turbo_lora_4step_ema.safetensors):
# merge it into a copy of the transformer with scripts/merge_h3_turbo.py,
# then run with -s 8 (see the Turbo LoRA section).
```

The pipeline needs only this repository: `-c` supplies the VAEs, text encoder and tokenizer;
`-t` points at the quantized DiT. Native canvas is a 768px short edge (e.g. 1344x768 16:9);
smaller canvases are off-distribution and degrade quickly.

## Image-to-Video (FL2VA)

This repository is **I2V-capable** (partition `fl2va`, tasks `t2va` + `fl2va` in `model_index.json`). The image is **optional** — present as a keyframe conditioning row via `--image` / `--anchor`, or omitted for pure T2V.

**Processor + vision tower required for I2V.** The `processor/` directory (7 files) and the 3 vision shards (`text_encoder/model-00005..00007-of-00008-vision.safetensors` + `vision_quant_config.json`, 529 `model.visual.*` tensors, 89 quantized) must be present. Without them the pipeline cannot encode images (falls back to T2V only).

**Canonical I2V command (validated):**

```bash
# 704×544 portrait (height 704 width 544) or 512×384 lightweight variant — both portrait 9:16 / 4:3
# Bridge image: inputs/bridge-20260813-181546-krea2_turbo-selfie-style-vertical-shot-a-young-woman-in-h.png
PROMPT=$(cat <<'PROMPT_EOF'
Vertical 9:16 TikTok-style UGC selfie video, handheld smartphone feel, natural indoor daylight near a window. A friendly creator speaks directly to camera with natural blinking, subtle head nods, and a warm smile. Add small human imperfections: a tiny hesitation, a soft breath, a quick smile mid-sentence, and a micro-pause before the last line. Realistic skin texture, stable identity, no face warping, minimal flicker, clean audio with natural room tone.

No subtitles. No on-screen text. No logos. No watermarks.

The creator says (exactly, with the same pacing and hesitations):
"Okay, entonces… eh… un datazo. Si estás trabado con tu código, solo da el primer pasito… como, abre tu terminal y escribe fran. (sonríe) Así de simple. Te vas a sorprender de lo rápido que todo se vuelve más fácil."
PROMPT_EOF
)

.venv/bin/python scripts/generate.py "$PROMPT" \
  -c <this repo> -t <this repo>/transformer -s 8 --seed 1996783985 \
  --height 704 --width 544 -d 5 \
  --image inputs/bridge-20260813-181546-krea2_turbo-selfie-style-vertical-shot-a-young-woman-in-h.png \
  --anchor first --release-encoder \
  -o i2v-704x544.mp4

# Lightweight alternative (faster, same identity):
.venv/bin/python scripts/generate.py "$PROMPT" \
  -c <this repo> -t <this repo>/transformer -s 8 --seed 1996783985 \
  --height 512 --width 384 -d 5 \
  --image inputs/bridge-20260813-181546-krea2_turbo-selfie-style-vertical-shot-a-young-woman-in-h.png \
  --anchor first --release-encoder \
  -o i2v-384x512.mp4
```

Valid `anchors` are `first` and `last` (FL2VA). Omit `--image`/`--anchor` for text-to-video. The image is consumed by `text_encoder` via `processor/` (`Qwen2VLImageProcessorPil` fallback when torch absent) and the vision tower, then patched as video-conditioning rows (see `minimal I2V encode` in `PATCHES.md`).

## Example outputs

![MiniMax-H3 MLX comparison — 8-bit vs turbo variants](images/comparative.png)

Red fox on a mossy log in a misty forest (prompt above, seed 42). Columns are time (0.4s → 3.0s);
rows: 8-bit 16-step, 8-bit + Turbo LoRA, 4-bit + Turbo LoRA at 1344x768.

Example clip (played inline by the Hub):

| File | Build | Settings |
|---|---|---|
| `examples/v3_768x448_16steps_8bit.mp4` | 8-bit (this repo) | 768x448, 16 steps, 33.9 min |

Turbo variants: see rows 2-3 above (a 1344x768 4-bit video re-render is planned).

## Model layout

| Path | Role | Representation |
|---|---|---|
| `transformer/transformer.safetensors` | 33B DiT (joint video+audio) | 8-bit affine, group 64 (AdaLN 8-bit), ~35.3 GB |
| `text_encoder/` (5+3 shards) | Qwen3-VL-32B conditioner (64 layers, truncated to layer 50) | 8-bit quantized, ~27.5 GB language (5 shards) + ~0.76 GB vision (3 shards `model-00005..00007-of-00008-vision.safetensors`, 529 `model.visual.*` tensors) |
| `text_encoder/vision_quant_config.json` | Vision tower quantization recipe (affine 8-bit g64) | json, 89 quantized tensors (`blocks.*`, `merger.*`, `deepstack_merger_list.*`) |
| `processor/` | Qwen3-VL processor (image preprocessing for I2V) | 7 files: `preprocessor_config.json`, `video_preprocessor_config.json`, `chat_template.json`, `tokenizer.json`, `tokenizer_config.json`, `vocab.json`, `merges.txt` (~11.6 MB) |
| `video_vae/` | Tiled causal video VAE (17-frame chunks, latents_mean/std) | fp16/bf16, 5.2 GB |
| `audio_vae/` | DAC encoder + BigVGAN vocoder, stereo 32 kHz | fp32, 0.6 GB |
| `tokenizer/` | Qwen3-VL tokenizer | json/vocab/merges |
| `model_index.json` | Pipeline config (fl2va partition, sigma shift video 12.0 / audio 3.0) | json |
| `turbo_lora_4step_ema.safetensors` | 4-step EMA Turbo LoRA (larryvrh, Apache-2.0) | 758 MB |
| `scripts/merge_h3_turbo.py` | Merge the Turbo LoRA into a transformer copy | python |

## Memory and speed (measured, M4 Max 68.7 GB)

- Resident during generation: DiT ~21.5 GB + text encoder ~22 GB + VAEs ~6 GB (AdaLN projections
  are precomputed and dropped, freeing ~13.8 GB). With `--release-encoder`, the text encoder is **freed after conditioning** (`prompt_embeds` already built, before the denoise loop), freeing ~27.5 GB (log: `released text encoder after conditioning (freeing ~27.5 GB)` + `mx.clear_cache()` + `tree_flatten` sizing). Peak RSS drops by ~22 GB resident; overhead <1 s.
- 768x448, 16 steps: **33.9 min** (119 s/step), peak RSS 24.7 GB, no swap. With turbo merge: ~24 min (8 steps). With **turbo8** (pure 8-bit, no merge) at 768x448, 8 steps (7 forwards): **~18.5 min (139 s/step)** vs turbo merge **251 s/step** — **~1.6–1.8× per-pixel** speedup (same canvas, fewer denoise forwards).
- 1344x768 (native 16:9), 8 steps: **~2 h** (996 s/step), peak ~57 GB + compressed memory; requires
  an otherwise idle machine (jetsam kills it under heavy ambient load).
- 704×544 I2V (portrait 9:16) turbo merge, 8 steps (7 forwards): **~33 min (251 s/step)**; turbo8: **~139 s/step** (measured 768x448 baseline, scales linearly per pixel). Lightweight 384×512 I2V is proportionally faster (off-distribution, useful for wiring checks).
- TeaCache: measured **0 skips / 7 forwards** with default last-block hook (`--teacache`, `thresh 0.2`, `start 3`, `compute_last_step`) at 768x448 turbo8 — probe feature pre-final-norm of last block (block 49/50) barely moves, so gate `rel_l1 <= 0.2` never fires; with `thresh 0.35` only 1/7 skips and still **no wall saving** (partial forward already traverses 49/50 blocks, only saves final norm + heads). Overhead +8–10% without skip. **Recommendation: keep TeaCache OFF by default**; if wall saving is needed, use an earlier hook `--teacache-layer 40` with `--teacache-thresh 0.25–0.35` (trades quality for ~20% block saving per skip). See `PATCHES.md` and `tmp/S9_teacache_spike_RESULT.md`.
- Attention is dense (MiniMax has not released sparse attention); quantization does not reduce the
  attention cost — it exists to fit memory.

## Validation report (2026-08-16, M4 Max 68.7 GB)

Prompt used everywhere: *"a red fox leaps over a mossy log in a misty forest"*, seed 42. Every clip
was judged by an independent vision-capable model on extracted frames (not statistics alone):

| Build | Settings | Time | Visual verdict |
|---|---|---|---|
| 8-bit (this repo) | 768x448, 16 steps | 33.9 min | **9/10** — coherent fox walking a mossy log; stable background; no melting |
| 8-bit + Turbo LoRA | 768x448, 8 steps | ~24 min | High confidence — "impressive for a 4-step turbo LoRA" |
| 4-bit + Turbo LoRA | 1344x768, 8 steps | 2 h 3 min | **95%** — full leap arc; no melting, no banding (frames; mp4 mux was a local script bug, not the model) |
| I2V E2E canonical (FL2VA, turbo merge) | 544×704 (704h×544w) 9:16, 8 steps (7 forwards), 5 s, seed 1996783985, `--image bridge-...png --anchor first --release-encoder` | ~33 min (251 s/step) | Keyframe anchored, identity preserved; requires `processor/` + vision tower (529 tensors); image optional (FL2VA otherwise uses key) |
| I2V Turbo8 (pure 8-bit, FL2VA) | 768×448, 8 steps (7 forwards), 5 s | ~18.5 min (139 s/step, ~1.6–1.8× per-pixel vs turbo merge) | Same I2V prompt/image, pure 8-bit DiT without LoRA merge; faster, same wiring |

Key findings:
- The VAE decoder is **not** the source of artifacts: parity with the reference diffusers
  implementation is exact (video 1.2e-6, audio 2.3e-8). The 17-frame chunked decode with 5-frame
  crossfade is the reference design; a periodic ~1.2x seam rhythm is architectural and masked at
  native resolution.
- **Canvas is the dominant quality factor**: the same VAE roundtrip scores 21.4 dB at 384x256 vs
  27.9 dB at 768x448. Keep the short edge at 768.
- First-generation failures (flat field, collapsed latents) were traced to an incompatible
  third-party serve-pack conversion (inert `condition_proj`, exploding text-encoder activations),
  not to the pipeline; see `PATCHES.md` and the report in `BIG_GOAL.md` of the source workspace.

## Turbo LoRA

`turbo_lora_4step_ema.safetensors` (also present as `turbo_lora.safetensors` — hardlink alias, same 779,849,816 bytes) is the 4-step EMA distilled LoRA from
[larryvrh/MiniMax-H3-Turbo-Lora](https://huggingface.co/larryvrh/MiniMax-H3-Turbo-Lora)
(Apache-2.0; sha256 `5a6eeba1…`). Merge it into a transformer copy:

```bash
.venv/bin/python scripts/merge_h3_turbo.py --base transformer --lora turbo_lora_4step_ema.safetensors -o transformer-turbo
# then generate with the merged dir as -t and -s 8 (7 forwards)
```

8 steps denoise cleanly with the merged weights; 4 steps can collapse to noise (see port issue #5).

## Patches vs upstream

`PATCHES.md` documents **five** patch families on branch `video-lab` over base commit `b2f7e4d2` (2026-08-10): (a) DiT QKV blocked layout, (b) text-encoder 8-bit + processor fallback + positional scatter fix, (c) `release_text_encoder` headroom, (d) two-phase TeaCache, (e) I2V processor + vision shards. See `PATCHES.md` for per-file details and line references. The remaining pipeline is otherwise byte-identical to the base commit.

## License

- **Weights**: MiniMax H3 Community License (included as `LICENSE`) — not open source; mark
  modified files, keep the attribution, territorial exclusions apply (EU/UK/KR/US excluded per the
  mlx-serve pack note). By downloading you accept those terms.
- **Port code**: Apache-2.0 (PipeNetwork/minimax-h3-mlx).
- **Turbo LoRA**: Apache-2.0 (larryvrh/MiniMax-H3-Turbo-Lora).