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Model-Optimizer/examples/diffusers/quantization/calibration.py
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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

199 lines
8.1 KiB
Python

# SPDX-FileCopyrightText: Copyright (c) 2024 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
# SPDX-License-Identifier: Apache-2.0
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import logging
from pathlib import Path
from typing import Any
from models_utils import MODEL_DEFAULTS, ModelType
from pipeline_manager import PipelineManager
from quantize_config import CalibrationConfig
from tqdm import tqdm
from utils import load_calib_prompts
class Calibrator:
"""Handles model calibration for quantization."""
def __init__(
self,
pipeline_manager: PipelineManager,
config: CalibrationConfig,
model_type: ModelType,
logger: logging.Logger,
):
"""
Initialize calibrator.
Args:
pipeline_manager: Pipeline manager with main and upsampler pipelines
config: Calibration configuration
model_type: Type of model being calibrated
logger: Logger instance
"""
self.pipeline_manager = pipeline_manager
self.pipe = pipeline_manager.pipe
self.pipe_upsample = pipeline_manager.pipe_upsample
self.config = config
self.model_type = model_type
self.logger = logger
def load_and_batch_prompts(self) -> list[list[str]]:
"""
Load calibration prompts from file.
Returns:
List of batched calibration prompts
"""
self.logger.info(f"Loading calibration prompts from {self.config.prompts_dataset}")
if isinstance(self.config.prompts_dataset, Path):
return load_calib_prompts(
self.config.batch_size,
self.config.prompts_dataset,
)
return load_calib_prompts(
self.config.batch_size,
self.config.prompts_dataset["name"],
self.config.prompts_dataset["split"],
self.config.prompts_dataset["column"],
)
def run_calibration(self, batched_prompts: list[list[str]]) -> None:
"""
Run calibration steps on the pipeline.
Args:
batched_prompts: List of batched calibration prompts
"""
self.logger.info(f"Starting calibration with {self.config.num_batches} batches")
extra_args = MODEL_DEFAULTS.get(self.model_type, {}).get("inference_extra_args", {})
with tqdm(total=self.config.num_batches, desc="Calibration", unit="batch") as pbar:
for i, prompt_batch in enumerate(batched_prompts):
if i >= self.config.num_batches:
break
if self.model_type == ModelType.LTX2:
self._run_ltx2_calibration(prompt_batch, extra_args)
elif self.model_type == ModelType.LTX_VIDEO_DEV:
# Special handling for LTX-Video
self._run_ltx_video_calibration(prompt_batch, extra_args)
elif self.model_type in [ModelType.WAN22_T2V_14b, ModelType.WAN22_T2V_5b]:
# Special handling for WAN video models
self._run_wan_video_calibration(prompt_batch, extra_args)
else:
common_args = {
"prompt": prompt_batch,
"num_inference_steps": self.config.n_steps,
}
self.pipe(**common_args, **extra_args).images
pbar.update(1)
self.logger.debug(f"Completed calibration batch {i + 1}/{self.config.num_batches}")
self.logger.info("Calibration completed successfully")
def _run_wan_video_calibration(
self, prompt_batch: list[str], extra_args: dict[str, Any]
) -> None:
kwargs = {}
kwargs["negative_prompt"] = extra_args["negative_prompt"]
kwargs["height"] = extra_args["height"]
kwargs["width"] = extra_args["width"]
kwargs["num_frames"] = extra_args["num_frames"]
kwargs["guidance_scale"] = extra_args["guidance_scale"]
if "guidance_scale_2" in extra_args:
kwargs["guidance_scale_2"] = extra_args["guidance_scale_2"]
kwargs["num_inference_steps"] = self.config.n_steps
self.pipe(prompt=prompt_batch, **kwargs).frames
def _run_ltx2_calibration(self, prompt_batch: list[str], extra_args: dict[str, Any]) -> None:
from ltx_core.model.video_vae import TilingConfig
from ltx_pipelines.utils.constants import (
DEFAULT_AUDIO_GUIDER_PARAMS,
DEFAULT_VIDEO_GUIDER_PARAMS,
)
prompt = prompt_batch[0]
extra_params = self.pipeline_manager.config.extra_params
kwargs = {
"negative_prompt": extra_args.get(
"negative_prompt", "worst quality, inconsistent motion, blurry, jittery, distorted"
),
"seed": extra_params.get("seed", 0),
"height": extra_params.get("height", extra_args.get("height", 1024)),
"width": extra_params.get("width", extra_args.get("width", 1536)),
"num_frames": extra_params.get("num_frames", extra_args.get("num_frames", 121)),
"frame_rate": extra_params.get("frame_rate", extra_args.get("frame_rate", 24.0)),
"num_inference_steps": self.config.n_steps,
"video_guider_params": DEFAULT_VIDEO_GUIDER_PARAMS,
"audio_guider_params": DEFAULT_AUDIO_GUIDER_PARAMS,
"images": extra_params.get("images", []),
"tiling_config": extra_params.get("tiling_config", TilingConfig.default()),
}
self.pipe(prompt=prompt, **kwargs)
def _run_ltx_video_calibration(
self, prompt_batch: list[str], extra_args: dict[str, Any]
) -> None:
"""
Run calibration for LTX-Video model using the full multi-stage pipeline.
Args:
prompt_batch: Batch of prompts
extra_args: Model-specific arguments
"""
# Extract specific args for LTX-Video
expected_height = extra_args.get("height", 512)
expected_width = extra_args.get("width", 704)
num_frames = extra_args.get("num_frames", 121)
negative_prompt = extra_args.get(
"negative_prompt", "worst quality, inconsistent motion, blurry, jittery, distorted"
)
def round_to_nearest_resolution_acceptable_by_vae(height, width):
height = height - (height % self.pipe.vae_spatial_compression_ratio)
width = width - (width % self.pipe.vae_spatial_compression_ratio)
return height, width
downscale_factor = 2 / 3
# Part 1: Generate video at smaller resolution
downscaled_height, downscaled_width = (
int(expected_height * downscale_factor),
int(expected_width * downscale_factor),
)
downscaled_height, downscaled_width = round_to_nearest_resolution_acceptable_by_vae(
downscaled_height, downscaled_width
)
# Generate initial latents at lower resolution
latents = self.pipe(
conditions=None,
prompt=prompt_batch,
negative_prompt=negative_prompt,
width=downscaled_width,
height=downscaled_height,
num_frames=num_frames,
num_inference_steps=self.config.n_steps,
output_type="latent",
).frames
# Part 2: Upscale generated video using latent upsampler (if available)
if self.pipe_upsample is not None:
_ = self.pipe_upsample(latents=latents, output_type="latent").frames
# Part 3: Denoise the upscaled video with few steps to improve texture
# However, in this example code, we will omit the upscale step since its optional.