CogVideoX

CogVideoX is a large diffusion transformer model - available in 2B and 5B parameters - designed to generate longer and more consistent videos from text. This model uses a 3D causal variational autoencoder to more efficiently process video data by reducing sequence length (and associated training compute) and preventing flickering in generated videos. An "expert" transformer with adaptive LayerNorm improves alignment between text and video, and 3D full attention helps accurately capture motion and time in generated videos.

You can find all the original CogVideoX checkpoints under the CogVideoX collection.

Click on the CogVideoX models in the right sidebar for more examples of other video generation tasks.

The example below demonstrates how to generate a video optimized for memory or inference speed.

Refer to the Reduce memory usage guide for more details about the various memory saving techniques.

The quantized CogVideoX 5B model below requires ~16GB of VRAM.

import torch
from diffusers import CogVideoXPipeline, AutoModel
from diffusers.quantizers import PipelineQuantizationConfig
from diffusers.hooks import apply_group_offloading
from diffusers.utils import export_to_video

# quantize weights to int8 with torchao
pipeline_quant_config = PipelineQuantizationConfig(
  quant_backend="torchao",
  quant_kwargs={"quant_type": "int8wo"},
  components_to_quantize=["transformer"]
)

# fp8 layerwise weight-casting
transformer = AutoModel.from_pretrained(
    "THUDM/CogVideoX-5b",
    subfolder="transformer",
    torch_dtype=torch.bfloat16
)
transformer.enable_layerwise_casting(
    storage_dtype=torch.float8_e4m3fn, compute_dtype=torch.bfloat16
)

pipeline = CogVideoXPipeline.from_pretrained(
    "THUDM/CogVideoX-5b",
    transformer=transformer,
    quantization_config=pipeline_quant_config,
    torch_dtype=torch.bfloat16
)
pipeline.to("cuda")

# model-offloading
pipeline.enable_model_cpu_offload()

prompt = """
A detailed wooden toy ship with intricately carved masts and sails is seen gliding smoothly over a plush, blue carpet that mimics the waves of the sea. 
The ship's hull is painted a rich brown, with tiny windows. The carpet, soft and textured, provides a perfect backdrop, resembling an oceanic expanse. 
Surrounding the ship are various other toys and children's items, hinting at a playful environment. The scene captures the innocence and imagination of childhood, 
with the toy ship's journey symbolizing endless adventures in a whimsical, indoor setting.
"""

video = pipeline(
    prompt=prompt,
    guidance_scale=6,
    num_inference_steps=50
).frames[0]
export_to_video(video, "output.mp4", fps=8)

Compilation is slow the first time but subsequent calls to the pipeline are faster.

The average inference time with torch.compile on a 80GB A100 is 76.27 seconds compared to 96.89 seconds for an uncompiled model.

import torch
from diffusers import CogVideoXPipeline
from diffusers.utils import export_to_video

pipeline = CogVideoXPipeline.from_pretrained(
    "THUDM/CogVideoX-2b",
    torch_dtype=torch.float16
).to("cuda")

# torch.compile
pipeline.transformer.to(memory_format=torch.channels_last)
pipeline.transformer = torch.compile(
    pipeline.transformer, mode="max-autotune", fullgraph=True
)

prompt = """
A detailed wooden toy ship with intricately carved masts and sails is seen gliding smoothly over a plush, blue carpet that mimics the waves of the sea. 
The ship's hull is painted a rich brown, with tiny windows. The carpet, soft and textured, provides a perfect backdrop, resembling an oceanic expanse. 
Surrounding the ship are various other toys and children's items, hinting at a playful environment. The scene captures the innocence and imagination of childhood, 
with the toy ship's journey symbolizing endless adventures in a whimsical, indoor setting.
"""

video = pipeline(
    prompt=prompt,
    guidance_scale=6,
    num_inference_steps=50
).frames[0]
export_to_video(video, "output.mp4", fps=8)

Notes

CogVideoX supports LoRAs with [~loaders.CogVideoXLoraLoaderMixin.load_lora_weights].

Show example code

import torch
from diffusers import CogVideoXPipeline
from diffusers.hooks import apply_group_offloading
from diffusers.utils import export_to_video

pipeline = CogVideoXPipeline.from_pretrained(
    "THUDM/CogVideoX-5b",
    torch_dtype=torch.bfloat16
)
pipeline.to("cuda")

# load LoRA weights
pipeline.load_lora_weights("finetrainers/CogVideoX-1.5-crush-smol-v0", adapter_name="crush-lora")
pipeline.set_adapters("crush-lora", 0.9)

# model-offloading
pipeline.enable_model_cpu_offload()

prompt = """
PIKA_CRUSH A large metal cylinder is seen pressing down on a pile of Oreo cookies, flattening them as if they were under a hydraulic press.
"""
negative_prompt = "inconsistent motion, blurry motion, worse quality, degenerate outputs, deformed outputs"

video = pipeline(
    prompt=prompt, 
    negative_prompt=negative_prompt, 
    num_frames=81, 
    height=480,
    width=768,
    num_inference_steps=50
).frames[0]
export_to_video(video, "output.mp4", fps=16)

The text-to-video (T2V) checkpoints work best with a resolution of 1360x768 because that was the resolution it was pretrained on.
The image-to-video (I2V) checkpoints work with multiple resolutions. The width can vary from 768 to 1360, but the height must be 758. Both height and width must be divisible by 16.
Both T2V and I2V checkpoints work best with 81 and 161 frames. It is recommended to export the generated video at 16fps.

Refer to the table below to view memory usage when various memory-saving techniques are enabled.

method	memory usage (enabled)	memory usage (disabled)
enable_model_cpu_offload	19GB	33GB
enable_sequential_cpu_offload	<4GB	~33GB (very slow inference speed)
enable_tiling	11GB (with enable_model_cpu_offload)	---

CogVideoXPipeline

[[autodoc]] CogVideoXPipeline

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call

CogVideoXImageToVideoPipeline

[[autodoc]] CogVideoXImageToVideoPipeline

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CogVideoXVideoToVideoPipeline

[[autodoc]] CogVideoXVideoToVideoPipeline

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CogVideoXFunControlPipeline

[[autodoc]] CogVideoXFunControlPipeline

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CogVideoXPipelineOutput

[[autodoc]] pipelines.cogvideo.pipeline_output.CogVideoXPipelineOutput