Files
Model-Optimizer/examples/diffusers/quantization
jingyu-ml d78797b466 Update the LTX2 API calls during the calibration (#926)
## What does this PR do?

**Type of change:** Bug fix <!-- Use one of the following: Bug fix, new
feature, new example, new tests, documentation. -->

**Overview:** 

Update LTX-2 integration to match latest upstream API

1. The LTX-2 codebase removed/replaced several APIs. This MR updates all
affected files:
2. Replace cfg_guidance_scale with MultiModalGuiderParams: The pipeline
__call__ no longer accepts a single cfg_guidance_scale float. It now
requires two MultiModalGuiderParams objects (video_guider_params and
audio_guider_params) that control CFG, STG, rescale, cross-modality
guidance, and skip-step settings. Updated in ltx-2.py, ltx-2-fp8.py,
ltx-2-onestage.py, calibration.py, and models_utils.py.
3. Replace fp8transformer with QuantizationPolicy: The
TI2VidTwoStagesPipeline constructor no longer accepts the fp8transformer
boolean flag. FP8 quantization is now configured via
quantization=QuantizationPolicy.fp8_cast(). Updated in ltx-2-fp8.py and
pipeline_manager.py (with backwards-compatible support for the old
--extra-param fp8transformer=true CLI flag).
4. Remove DEFAULT_CFG_GUIDANCE_SCALE constant: Replaced by
DEFAULT_VIDEO_GUIDER_PARAMS and DEFAULT_AUDIO_GUIDER_PARAMS in all
import sites.

## Usage
<!-- You can potentially add a usage example below. -->

```bash
python quantize.py --model ltx-2 --format fp4 --batch-size 1 --calib-size 1 --n-steps 40 --extra-param checkpoint_path=./ltx-2-19b-dev-fp8.safetensors --extra-param distilled_lora_path=./ltx-2-19b-distilled-lora-384.safetensors --extra-param spatial_upsampler_path=./ltx-2-spatial-upscaler-x2-1.0.safetensors --extra-param gemma_root=./gemma-3-12b-it-qat-q4_0-unquantized --extra-param fp8transformer=true --hf-ckpt-dir ./ltx2-nvfp4
```

## Testing
<!-- Mention how have you tested your change if applicable. -->

## Before your PR is "*Ready for review*"
<!-- If you haven't finished some of the above items you can still open
`Draft` PR. -->

- **Make sure you read and follow [Contributor
guidelines](https://github.com/NVIDIA/Model-Optimizer/blob/main/CONTRIBUTING.md)**
and your commits are signed.
- **Is this change backward compatible?**: Yes/No <!--- If No, explain
why. -->
- **Did you write any new necessary tests?**: Yes/No
- **Did you add or update any necessary documentation?**: Yes/No
- **Did you update
[Changelog](https://github.com/NVIDIA/Model-Optimizer/blob/main/CHANGELOG.rst)?**:
Yes/No <!--- Only for new features, API changes, critical bug fixes or
bw breaking changes. -->

## Additional Information
<!-- E.g. related issue. -->


<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

## Release Notes

* **Updates**
  * Default resolution for LTX2 models adjusted to 768x1280
* Guidance parameter configuration updated for video and audio pipelines
  * FP8 quantization parameter handling refined

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

Signed-off-by: Jingyu Xin <jingyux@nvidia.com>
2026-02-24 14:23:28 -08:00
..
2025-01-29 01:45:47 +05:30
2025-08-26 01:12:26 +05:30
2025-08-26 01:12:26 +05:30