| --- |
| license: other |
| license_name: minimax-h3-community |
| license_link: LICENSE |
| pipeline_tag: text-to-video |
| library_name: radiance |
| tags: |
| - radiance |
| - rocm |
| - amd |
| - rdna4 |
| - fp8 |
| - text-to-video |
| - text-to-audio-video |
| - distillation |
| - few-step |
| - minimax-h3 |
| - fasth3 |
| - latent-upscaler |
| base_model: |
| - FastVideo/FastVideo-FastH3-8-Step-V2 |
| - LBH-123-AI/Minimax_h3_latent_Upscaler |
| --- |
| |
| # FastH3 8-Step V2, FP8 — radiance container |
|
|
| FastVideo's [FastVideo-FastH3-8-Step-V2](https://huggingface.co/FastVideo/FastVideo-FastH3-8-Step-V2) — |
| MiniMax-H3 distilled to eight steps with video sparse attention: video with a synchronized stereo |
| soundtrack from text — as a single `.rad` container for the |
| [radiance](https://codeberg.org/StillDeadcode/radiance) inference engine (AMD RDNA4, ROCm). |
|
|
| The MiniMax H3 Community License does not cover the European Union, the United Kingdom, the |
| Republic of Korea or the United States of America; see [License](#license). |
|
|
| | | | |
| |---|---| |
| | File | `fasth3-8-step-v2-fp8.rad` — 62.30 GiB | |
| | Weights | every linear of the text encoder (the 50 layers of Qwen3-VL-32B the model reads), the token refiner and the DiT's 50 blocks, and the modulation projections, FP8 E4M3 per 128×128 block (bf16 scales); the video decoder bf16; the audio decoder f32 | |
| | Steps | 8, the schedule the model was trained on | |
| | Output | MP4: H.264 at 24 fps, up to 1344x768, 5.17 to 14.4 s; AAC at 32 kHz stereo | |
| | Latent upscaler | [LBH-123-AI/Minimax_h3_latent_Upscaler](https://huggingface.co/LBH-123-AI/Minimax_h3_latent_Upscaler) v1 (3D conv, 345M parameters, bf16; Apache-2.0) | |
| | Needs | radiance 1.8.1 or newer (the upscaler, and prompts over 16 tokens, need 1.8.1); two 32 GB cards and about 39 GiB of pinned host memory | |
|
|
| ## Serve |
|
|
| ```sh |
| radiance --model fasth3-8-step-v2-fp8.rad --tp 2 --vision-tower-placement ram --host 0.0.0.0 --port 8000 |
| |
| curl -s http://localhost:8000/v1/videos -H 'Content-Type: application/json' -d '{ |
| "prompt": "A red fox trotting through a snowy pine forest, snow crunching underfoot", |
| "seconds": "5", "size": "1344x768", "seed": 7}' # -> {"id": "video_...", "status": "queued", ...} |
| curl -s http://localhost:8000/v1/videos/video_... # poll until "status": "completed" |
| curl -s http://localhost:8000/v1/videos/video_.../content -o fox.mp4 |
| ``` |
|
|
| The model is served as `fastvideo-fasth3-8-step-v2` on OpenAI's video jobs API (`POST /v1/videos`, |
| `GET /v1/videos/{id}`, `GET /v1/videos/{id}/content`, list and delete), with SGLang's `target` |
| field: |
|
|
| - `prompt` is read as written, up to 2048 tokens. `seconds` is rounded up to the model's length steps |
| (17 frames): 5.17 to 14.4 s. `size` is `WIDTHxHEIGHT`, multiples of 32, at most 1344x768 pixels of |
| area. `seed` makes a video repeatable on the same deployment. |
| - The model runs only the schedule it was trained on: `num_inference_steps` may be left out or be 9 |
| (grid points, as diffusers counts them); any other count is refused. |
| - Text to video and audio only. FastVideo notes that difficult motion, fine detail and some audio |
| may fall below the base model's. |
|
|
| On two Radeon AI PRO R9700s (gfx1201) a 5.17 s clip takes about 68 s at 1344x768, 38 s at 1024x576 |
| and 17 s at 672x384; MiniMax-H3 at its default 50 steps takes about 8.8 minutes at 1344x768 |
| ([StillDeadcode/minimax-h3-fp8](https://huggingface.co/StillDeadcode/minimax-h3-fp8)). Attention |
| skips 80% of the 64-token video tiles, as the model was trained. The text encoder and the modulation |
| projections are read from pinned host memory, which `--vision-tower-placement ram` selects. At |
| 256x256, frames match FastVideo's reference pipeline by eye. |
|
|
| ## Latent upscaling |
|
|
| The container carries LBH-123-AI's latent upscaler. A request with `"latent_upscale": 2` runs its |
| first steps at half the size (672x384 for 1344x768), the upscaler enlarges the clean latent, and the |
| last `upscale_refine_steps` (3 of the 8 by default) run at the full size from a re-noised copy of it: |
|
|
| ```sh |
| curl -s http://localhost:8000/v1/videos -H 'Content-Type: application/json' -d '{ |
| "prompt": "...", "seconds": "5", "size": "1344x768", "seed": 7, "latent_upscale": 2}' |
| ``` |
|
|
| | 5.17 s at 1344x768, 2x R9700 | time | |
| |---|---| |
| | native, 8 steps | 68 s | |
| | `latent_upscale` 2, 3 refine steps (the default) | 41 s | |
| | `latent_upscale` 2, 4 refine steps | 46 s | |
| | `latent_upscale` 4, 3 refine steps | 35 s | |
|
|
| The factor goes up to 4. At 1344x768 a factor of 4 starts from 352x192; FastH3 still lays the scene |
| out there, a little softer than at 2. The video object of an upscaled video reports `latent_upscale`, |
| `upscale_refine_steps` and `upscale_from` (the small size). |
|
|
| ## How this file was made |
|
|
| ```sh |
| rad-convert FastVideo/FastVideo-FastH3-8-Step-V2 --recipe minimax-h3-fp8.recipe -o fasth3-8-step-v2-fp8.rad |
| ``` |
|
|
| `FastVideo/FastVideo-FastH3-8-Step-V2` is the downloaded pipeline directory; its text encoder and |
| decoders are MiniMax-H3's own files. The recipe (`minimax-h3-fp8.recipe` in this repository, the |
| same as MiniMax-H3's) names what is quantised; everything it does not name is the checkpoint's own |
| dtype: |
|
|
| ``` |
| te.blk.*.attn_qkv.weight rtn codes=fp8_e4m3 block=128x128 scale=bf16 |
| te.blk.*.attn_output.weight rtn codes=fp8_e4m3 block=128x128 scale=bf16 |
| te.blk.*.ffn_gate_up.weight rtn codes=fp8_e4m3 block=128x128 scale=bf16 |
| te.blk.*.ffn_down.weight rtn codes=fp8_e4m3 block=128x128 scale=bf16 |
| te.blk.*.attn_norm.weight cast dtype=f32 |
| te.blk.*.ffn_norm.weight cast dtype=f32 |
| ref.blk.*.attn_qkv.weight rtn codes=fp8_e4m3 block=128x128 scale=bf16 |
| ref.blk.*.attn_output.weight rtn codes=fp8_e4m3 block=128x128 scale=bf16 |
| ref.blk.*.ffn_gate_up.weight rtn codes=fp8_e4m3 block=128x128 scale=bf16 |
| ref.blk.*.ffn_down.weight rtn codes=fp8_e4m3 block=128x128 scale=bf16 |
| dit.blk.*.attn_qkv.weight rtn codes=fp8_e4m3 block=128x128 scale=bf16 |
| dit.blk.*.attn_output.weight rtn codes=fp8_e4m3 block=128x128 scale=bf16 |
| dit.blk.*.ffn_gate_up.weight rtn codes=fp8_e4m3 block=128x128 scale=bf16 |
| dit.blk.*.ffn_down.weight rtn codes=fp8_e4m3 block=128x128 scale=bf16 |
| dit.blk.*.ada*.weight rtn codes=fp8_e4m3 block=128x128 scale=bf16 |
| vae.blk.*.attn_qkv.weight cast dtype=bf16 |
| vae.blk.*.attn_out.weight cast dtype=bf16 |
| vae.blk.*.ffn_up.weight cast dtype=bf16 |
| vae.blk.*.ffn_down.weight cast dtype=bf16 |
| vae.proj_out.* cast dtype=bf16 |
| aud.*.weight cast dtype=f32 |
| ups.embed.* cast dtype=f32 |
| ups.*.emb_layers.* cast dtype=f32 |
| ``` |
|
|
| The upscaler is the companion folder `latent_upscaler/` of the pipeline directory (its |
| `minimax_h3_latent_upscaler_3d_conv_v1/config.json` and bf16 weights, renamed |
| `diffusion_pytorch_model.safetensors`); this file had it added to the 1.8.0 container in place |
| (`rad-convert ... --reuse fasth3-8-step-v2-fp8.rad --in-place`), which leaves every other weight |
| as it was. |
|
|
| ## License |
|
|
| FastH3 8-Step V2 is a modified MiniMax H3 model from the FastVideo team, and MiniMax H3 is licensed |
| under the MiniMax H3 Community License Agreement, Copyright © 2026 MiniMax (`LICENSE` in this |
| repository; `NOTICE` carries its notice and FastVideo's). The agreement grants its rights only within |
| its Applicable Territory: worldwide except the European Union, the United Kingdom, the Republic of |
| Korea and the United States of America, where it does not license using, reproducing or |
| distributing the model or this file. Its use restrictions and Acceptable Use Policy (Exhibit A of |
| `LICENSE`) apply to everyone who downloads or uses this file, and to anyone it is passed on to. |
|
|
| This container is a modified copy of FastVideo-FastH3-8-Step-V2: the linears named above are |
| re-encoded as FP8, the video decoder's linears cast from f32 to bf16, the audio decoder's weight |
| norms folded, the text encoder's last 14 layers (which the model does not read) left out, and |
| everything repacked into one `.rad` file. The text encoder is Qwen3-VL-32B, licensed under the |
| Apache License 2.0 (`LICENSE-Qwen3-VL`). The latent upscaler is LBH-123-AI's |
| Minimax_h3_latent_Upscaler v1, licensed under the Apache License 2.0 (`LICENSE-latent-upscaler`); |
| its weights are included as published, its embedding MLP cast from bf16 to f32. |
| |
