Files
hao-ai-lab-FastVideo/examples/inference/basic/basic_lingbotworld_fast.py
T
Ishan VaishandClaude Sonnet 5 7f7431779e [new-model] Added LingBot-World-Fast image-to-video support
Wired up FastVideo/LingBot-World-Fast-Diffusers, the old LingBot-World
repo's distilled causal I2V checkpoint that was never ported. Reused
the existing LingBot World 2 causal-fast DiT unchanged (verified all
1421 parameter names and shapes against the released checkpoint) and
added the arch/pipeline configs, registry entries, preset, pipeline
subclass, example, and SSIM test needed to run it.

Fixed a model-family detector collision where the LingBot World (Cam)
detector would have wrongly claimed this checkpoint's path and
model_index name, since it only excluded the "causal-fast" spelling.

Fixed WanCrossAttention in the shared LingBot World 2 causal-fast DiT
to route through the attention() dispatcher instead of calling
flash_attention() directly, so the already-advertised TORCH_SDPA
backend actually works when flash-attn isn't installed. Self-attention
already used this dispatcher; cross-attention did not.

Verified end to end: weights load (18.54B params, 16 shards) and
generation produces a coherent video with correct prompt-following
camera motion. Not yet verified against the original implementation's
numerics (activation-trace parity) or via the SSIM regression test,
both of which need hardware unavailable in this environment.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
2026-08-09 20:39:00 -07:00

41 lines
1.3 KiB
Python

from fastvideo import VideoGenerator
OUTPUT_PATH = "video_samples_lingbotworld_fast"
def main():
generator = VideoGenerator.from_pretrained(
"FastVideo/LingBot-World-Fast-Diffusers",
num_gpus=1,
use_fsdp_inference=False, # set to True if GPU is out of memory
dit_cpu_offload=True,
vae_cpu_offload=False,
text_encoder_cpu_offload=True,
pin_cpu_memory=True,
)
prompt = (
"The video presents a soaring journey through a fantasy jungle. The "
"wind whips past the rider's blue hands gripping the reins, causing "
"the leather straps to vibrate. The ancient gothic castle approaches "
"steadily, its stone details becoming clearer against the backdrop of "
"floating islands and distant waterfalls.")
image_path = ("https://raw.githubusercontent.com/Robbyant/lingbot-world/"
"main/examples/00/image.jpg")
action_path = "examples/inference/basic/lingbotworld_examples/00"
generator.generate_video(
prompt,
image_path=image_path,
action_path=action_path,
output_path=OUTPUT_PATH,
save_video=True,
num_frames=81,
height=480,
width=832,
)
if __name__ == "__main__":
main()