ynankani-nv 110a44c81e Add support for export ComfyUI compatible checkpoint for diffusion model(e.g., LTX-2) (#911)
## What does this PR do
Add support for export ComfyUI compatible checkpoint for diffusion
model(e.g., LTX-2)

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

**Overview:** 
Add support for export ComfyUI compatible checkpoint for diffusion
model(e.g., LTX-2)
1) Added a a parameter for merging the base vae, vocoder, connectors in
the quantized checkpoint
2) storing quantization metadata and export tool as modelopt , required
for ComfyUI compatibility.
3) Internally updating the transformer block prefixes to match the
expectation of ComfyUI
 
## Usage
<!-- You can potentially add a usage example below. -->

```python
    export_hf_checkpoint(
        pipeline,
        export_dir=EXPORT_DIR,
        merged_base_safetensor_path=BASE_CKPT,  # merge VAE/vocoder from base
    )
```

## Testing
<!-- Mention how have you tested your change if applicable. -->
1) Tested with ltx-2 model 
       a) initializing a twoStagePipeline object 
       b) calling mtq.quantize on transformer with NVFP4_DEFAULT_CFG 
c) then exporting with export_hf_checkpoint passing the param
merged_base_safetensor_path to generate merged
           checkpoint
2) Ran the generated checkpoint with step1 on ComfyUI to validate
3) Ran step1 without merged_base_safetensor_path to check backward
compatibility.

## 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 <!--- If No, explain why.
-->
- **Did you write any new necessary tests?**: NA
- **Did you add or update any necessary documentation?**: NA
- **Did you update
[Changelog](https://github.com/NVIDIA/Model-Optimizer/blob/main/CHANGELOG.rst)?**:
NA <!--- 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

* **New Features**
* Added support for exporting LTX-2 diffusion models with merged base
checkpoint integration
* Enhanced export functionality to preserve and attach quantization
metadata during model export
* Extended model export capabilities with automatic model type detection
for improved export handling

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

---------

Signed-off-by: ynankani <ynankani@nvidia.com>
2026-02-28 07:02:34 +00:00
2026-02-27 00:06:07 +00:00
2025-06-05 13:24:07 -07:00
2025-06-05 13:24:07 -07:00
2026-02-27 00:06:07 +00:00

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NVIDIA Model Optimizer

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NVIDIA Model Optimizer (referred to as Model Optimizer, or ModelOpt) is a library comprising state-of-the-art model optimization techniques including quantization, distillation, pruning, speculative decoding and sparsity to accelerate models.

[Input] Model Optimizer currently supports inputs of a Hugging Face, PyTorch or ONNX model.

[Optimize] Model Optimizer provides Python APIs for users to easily compose the above model optimization techniques and export an optimized quantized checkpoint. Model Optimizer is also integrated with NVIDIA Megatron-Bridge, Megatron-LM and Hugging Face Accelerate for training required inference optimization techniques.

[Export for deployment] Seamlessly integrated within the NVIDIA AI software ecosystem, the quantized checkpoint generated from Model Optimizer is ready for deployment in downstream inference frameworks like SGLang, TensorRT-LLM, TensorRT, or vLLM. The unified Hugging Face export API now supports both transformers and diffusers models.

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Install

To install stable release packages for Model Optimizer with pip from PyPI:

pip install -U nvidia-modelopt[all]

To install from source in editable mode with all development dependencies or to use the latest features, run:

# Clone the Model Optimizer repository
git clone git@github.com:NVIDIA/Model-Optimizer.git
cd Model-Optimizer

pip install -e .[dev]

You can also directly use the TensorRT-LLM docker images (e.g., nvcr.io/nvidia/tensorrt-llm/release:<version>), which have Model Optimizer pre-installed. Make sure to upgrade Model Optimizer to the latest version using pip as described above. Visit our installation guide for more fine-grained control on installed dependencies or for alternative docker images and environment variables to setup.

Techniques

Technique Description Examples Docs
Post Training Quantization Compress model size by 2x-4x, speeding up inference while preserving model quality! [LLMs] [diffusers] [VLMs] [onnx] [windows] [docs]
Quantization Aware Training Refine accuracy even further with a few training steps! [NeMo] [Hugging Face] [docs]
Pruning Reduce your model size and accelerate inference by removing unnecessary weights! [PyTorch] [docs]
Distillation Reduce deployment model size by teaching small models to behave like larger models! [NeMo] [Hugging Face] [docs]
Speculative Decoding Train draft modules to predict extra tokens during inference! [Megatron] [Hugging Face] [docs]
Sparsity Efficiently compress your model by storing only its non-zero parameter values and their locations [PyTorch] [docs]

Pre-Quantized Checkpoints

Resources

Model Support Matrix

Model Type Support Matrix
LLM Quantization View Support Matrix
Diffusers Quantization View Support Matrix
VLM Quantization View Support Matrix
ONNX Quantization View Support Matrix
Windows Quantization View Support Matrix
Quantization Aware Training View Support Matrix
Pruning View Support Matrix
Distillation View Support Matrix
Speculative Decoding View Support Matrix

Contributing

Model Optimizer is now open source! We welcome any feedback, feature requests and PRs. Please read our Contributing guidelines for details on how to contribute to this project.

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Happy optimizing!

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