| --- |
| license: other |
| license_name: minimax-h3-community |
| license_link: https://huggingface.co/FastVideo/FastVideo-FastH3-4-step-Preview-v1-Dense-DataFree/blob/main/LICENSE |
| base_model: FastVideo/FastVideo-FastH3-4-step-Preview-v1-Dense-DataFree |
| library_name: fastvideo |
| pipeline_tag: text-to-video |
| tags: |
| - mlx |
| - apple-silicon |
| - minimax-h3 |
| - fasth3 |
| - text-to-video |
| - audio |
| - quantized |
| - int4 |
| --- |
| |
| # FastH3 Preview v1 Dense DataFree MLX INT4 |
|
|
| This repository contains the ready-to-run **INT4 MLX DiT** for |
| [FastVideo/FastVideo-FastH3-4-step-Preview-v1-Dense-DataFree](https://huggingface.co/FastVideo/FastVideo-FastH3-4-step-Preview-v1-Dense-DataFree). It avoids the local |
| conversion step and its temporary unified-memory requirement on Apple silicon. |
|
|
| The checkpoint is the dense-attention, step-1000, four-forward Preview v1 model. |
| Quantization is affine, weight-only INT4 with group size 64. Activations |
| remain BF16. This export is dense-only and does not support `--vsa`. |
|
|
| ## Files |
|
|
| | File | Purpose | |
| | --- | --- | |
| | `mlx_h3_dit.safetensors` | Quantized H3 DiT weights, 10.74 GiB | |
| | `mlx_h3_dit.json` | Architecture, quantization, and cached AdaLN schedule | |
| | `conversion_manifest.json` | Source revision, converter version, validation, and checksums | |
|
|
| Weights SHA-256: `dcee86c17197c621a0e3d3ba9541cb6ef5764cd0c258beb7b044fb12b217e948` |
|
|
| ## Download |
|
|
| Download the shared H3 components once. They include the tokenizer, Qwen3-VL |
| text encoder, video VAE, and audio VAE: |
|
|
| ```bash |
| hf download FastVideo/FastVideo-FastH3-4-step-Preview-v1-Dense-DataFree \ |
| --revision f624f08c6c279ab43534c003e556fc5b295b6558 \ |
| --local-dir ./FastH3-Preview-v1-Dense-DataFree |
| ``` |
|
|
| Then download this ready-to-run MLX DiT: |
|
|
| ```bash |
| hf download FastVideo/FastVideo-FastH3-4-step-Preview-v1-Dense-DataFree-MLX-INT4 \ |
| --local-dir ./FastH3-MLX-INT4 |
| ``` |
|
|
| ## Run on Apple silicon |
|
|
| From a current FastVideo checkout: |
|
|
| ```bash |
| uv venv --python 3.12 --seed |
| source .venv/bin/activate |
| uv pip install -e ".[mlx]" |
| ``` |
|
|
| ```bash |
| python examples/inference/basic/mlx_fasth3.py \ |
| --model-root ./FastH3-Preview-v1-Dense-DataFree \ |
| --mlx-checkpoint ./FastH3-MLX-INT4 \ |
| --prompt '(S1) A presenter says <d>[English] Fast H3 runs on Apple silicon.</d>' \ |
| --height 480 --width 832 --num-frames 124 --steps 4 --seed 2026 \ |
| --output-path ./outputs/fasth3_int4.mp4 |
| ``` |
|
|
| The MLX runtime loads one heavyweight component at a time. The source model's |
| MiniMax H3 Community License applies to this converted checkpoint. |
|
|
| ## Validation and provenance |
|
|
| The conversion used FastVideo commit |
| `cf6a00b9be4675602126d6aeab902ad9a74810ea` with MLX |
| `0.32.2` on an Apple M4 Max. FastVideo |
| verified all 13 source transformer shards, opened the safetensors header, |
| validated 1,464 tensors and the quantization manifest, loaded the checkpoint, |
| and completed a 124-frame 832x480 generation with the full H3 VAE. |
|
|
