---
base_model: meituan-longcat/LongCat-Video-Avatar-1.5
license: mit
pipeline_tag: image-to-video
tags:
- longcat
- image-to-video
- video-generation
- talking-head
- audio-driven
- quantized
- fp8
- e4m3
base_model_relation: quantized
---
# LongCat-Video-Avatar-1.5-e4m3

FP8 (e4m3) quantized
[LongCat-Video-Avatar-1.5](https://huggingface.co/meituan-longcat/LongCat-Video-Avatar-1.5) —
Meituan's audio-driven avatar video model, which animates a portrait from a
speech track.

## What was changed

Only the `LongCatVideoAvatarTransformer3DModel` is included here, quantized as
described in `quantization_config.json`:

- weights: `float8_e4m3fn`, symmetric, **per output channel**
  (one fp32 scale per row)
- activations: `float8_e4m3fn`, dynamic **per row**
- matmul: `torch._scaled_mm` in RowWise mode (Hopper and newer)
- compute dtype: bf16
- `final_layer.linear` is skipped and stays bf16

Per-channel weight scales plus per-row activation scales cost slightly more
bookkeeping than a single per-tensor scale, but they keep the output stable on
a 48-layer, 4096-wide transformer where a per-tensor scale gets dragged around
by outliers.

## Usage

This repository contains the quantized transformer only. The text encoder, VAE
and audio encoder come from the upstream repository; download both and point
the upstream inference code at this transformer directory.

Running the fp8 path needs a GPU with `torch._scaled_mm` RowWise support
(H100/H200 or newer). On older hardware, use the upstream bf16 weights.

## License

MIT, inherited from LongCat-Video-Avatar-1.5.