Add HummingbirdXT backend integration

[limou102]

Add HummingbirdXT backend integration into Primus.

HummingbirdXT is a DiT-based model distilled from Wan2.2, which can be used for video generation and currently has the Text-To-Video (T2V) function integrated to Primus.

After distillation, HummingbirdXT can complete inference and generate high-quality videos with just 3 steps, significantly improving inference speed.

The accuracy has already been verified; please see this DOCUMENT for details.

sample launch command:

./runner/primus-cli direct -- train posttrain \
    --config ./examples/hummingbirdxt/configs/wan22_posttrain.yaml

[Copilot]

Pull request overview

This PR integrates HummingbirdXT, a DiT-based model distilled from Wan2.2, into the Primus framework for video generation with Text-To-Video (T2V) capabilities. HummingbirdXT achieves high-quality video generation with just 3 inference steps through distillation, significantly improving performance.

Changes:

• Added HummingbirdXT as a git submodule in third_party/
• Implemented backend adapter, trainers, and argument builder for HummingbirdXT integration
• Created configuration files for post-training with Wan2.2 model
• Added installation scripts and requirements for HummingbirdXT dependencies

Reviewed changes

Copilot reviewed 13 out of 13 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
third_party/HummingbirdXT	Adds HummingbirdXT submodule reference
.gitmodules	Registers HummingbirdXT submodule with repository URL
runner/helpers/hooks/train/posttrain/hummingbirdxt/requirements-hummingbirdxt.txt	Lists Python dependencies for HummingbirdXT
runner/helpers/hooks/train/posttrain/hummingbirdxt/00_install_requirements.sh	Shell script to install HummingbirdXT dependencies
primus/backends/hummingbirdxt/init.py	Registers HummingbirdXT backend and trainer with Primus
primus/backends/hummingbirdxt/hummingbirdxt_adapter.py	Implements backend adapter for configuration conversion and trainer loading
primus/backends/hummingbirdxt/argument_builder.py	Converts Primus configs to HummingbirdXT argument format
primus/backends/hummingbirdxt/hummingbirdxt_base_trainer.py	Base trainer class with version detection methods
primus/backends/hummingbirdxt/hummingbirdxt_posttrain_trainer.py	Post-training trainer implementation for Wan22 score distillation
primus/configs/modules/hummingbirdxt/post_trainer.yaml	Module configuration marking HummingbirdXT as trainable
primus/configs/models/hummingbirdxt/wan22.yaml	Complete model configuration with training and inference parameters
examples/hummingbirdxt/configs/wan22_posttrain.yaml	Example configuration for Wan2.2 post-training
primus/backends/megatron_bridge/argument_builder.py	Updates comments to reference MegatronBridge instead of TorchTitan

[Copilot]

Pull request overview

Copilot reviewed 13 out of 13 changed files in this pull request and generated 1 comment.

[Copilot]

The negative_prompt field contains Chinese text without any accompanying English translation or explanation. Consider adding a comment explaining what this negative prompt controls for better maintainability by English-speaking developers.

Suggested change

	log_iters: 1000
	log_iters: 1000
	# Negative prompt in Chinese listing undesirable visual qualities (e.g., oversaturated colors, overexposed/static/blurred frames, subtitles/painting-like style, gray/low-quality images, JPEG artifacts, ugly or deformed/maimed bodies, extra or fused fingers/limbs, crowded or messy backgrounds, and people walking backwards).