docs/source/en/api/pipelines/ltx2.md
LTX-2 is a DiT-based foundation model designed to generate synchronized video and audio within a single model. It brings together the core building blocks of modern video generation, with open weights and a focus on practical, local execution.
You can find all the original LTX-Video checkpoints under the Lightricks organization.
The original codebase for LTX-2 can be found here.
Recommended pipeline to achieve production quality generation, this pipeline is composed of two stages:
Sample usage of text-to-video two stages pipeline
import torch
from diffusers import FlowMatchEulerDiscreteScheduler
from diffusers.pipelines.ltx2 import LTX2Pipeline, LTX2LatentUpsamplePipeline
from diffusers.pipelines.ltx2.latent_upsampler import LTX2LatentUpsamplerModel
from diffusers.pipelines.ltx2.utils import STAGE_2_DISTILLED_SIGMA_VALUES
from diffusers.pipelines.ltx2.export_utils import encode_video
device = "cuda:0"
width = 768
height = 512
pipe = LTX2Pipeline.from_pretrained(
"Lightricks/LTX-2", torch_dtype=torch.bfloat16
)
pipe.enable_sequential_cpu_offload(device=device)
prompt = "A beautiful sunset over the ocean"
negative_prompt = "shaky, glitchy, low quality, worst quality, deformed, distorted, disfigured, motion smear, motion artifacts, fused fingers, bad anatomy, weird hand, ugly, transition, static."
# Stage 1 default (non-distilled) inference
frame_rate = 24.0
video_latent, audio_latent = pipe(
prompt=prompt,
negative_prompt=negative_prompt,
width=width,
height=height,
num_frames=121,
frame_rate=frame_rate,
num_inference_steps=40,
sigmas=None,
guidance_scale=4.0,
output_type="latent",
return_dict=False,
)
latent_upsampler = LTX2LatentUpsamplerModel.from_pretrained(
"Lightricks/LTX-2",
subfolder="latent_upsampler",
torch_dtype=torch.bfloat16,
)
upsample_pipe = LTX2LatentUpsamplePipeline(vae=pipe.vae, latent_upsampler=latent_upsampler)
upsample_pipe.enable_model_cpu_offload(device=device)
upscaled_video_latent = upsample_pipe(
latents=video_latent,
output_type="latent",
return_dict=False,
)[0]
# Load Stage 2 distilled LoRA
pipe.load_lora_weights(
"Lightricks/LTX-2", adapter_name="stage_2_distilled", weight_name="ltx-2-19b-distilled-lora-384.safetensors"
)
pipe.set_adapters("stage_2_distilled", 1.0)
# VAE tiling is usually necessary to avoid OOM error when VAE decoding
pipe.vae.enable_tiling()
# Change scheduler to use Stage 2 distilled sigmas as is
new_scheduler = FlowMatchEulerDiscreteScheduler.from_config(
pipe.scheduler.config, use_dynamic_shifting=False, shift_terminal=None
)
pipe.scheduler = new_scheduler
# Stage 2 inference with distilled LoRA and sigmas
video, audio = pipe(
latents=upscaled_video_latent,
audio_latents=audio_latent,
prompt=prompt,
negative_prompt=negative_prompt,
num_inference_steps=3,
noise_scale=STAGE_2_DISTILLED_SIGMA_VALUES[0], # renoise with first sigma value https://github.com/Lightricks/LTX-2/blob/main/packages/ltx-pipelines/src/ltx_pipelines/ti2vid_two_stages.py#L218
sigmas=STAGE_2_DISTILLED_SIGMA_VALUES,
guidance_scale=1.0,
output_type="np",
return_dict=False,
)
encode_video(
video[0],
fps=frame_rate,
audio=audio[0].float().cpu(),
audio_sample_rate=pipe.vocoder.config.output_sampling_rate,
output_path="ltx2_lora_distilled_sample.mp4",
)
Fastest two-stages generation pipeline using a distilled checkpoint.
import torch
from diffusers.pipelines.ltx2 import LTX2Pipeline, LTX2LatentUpsamplePipeline
from diffusers.pipelines.ltx2.latent_upsampler import LTX2LatentUpsamplerModel
from diffusers.pipelines.ltx2.utils import DISTILLED_SIGMA_VALUES, STAGE_2_DISTILLED_SIGMA_VALUES
from diffusers.pipelines.ltx2.export_utils import encode_video
device = "cuda"
width = 768
height = 512
random_seed = 42
generator = torch.Generator(device).manual_seed(random_seed)
model_path = "rootonchair/LTX-2-19b-distilled"
pipe = LTX2Pipeline.from_pretrained(
model_path, torch_dtype=torch.bfloat16
)
pipe.enable_sequential_cpu_offload(device=device)
prompt = "A beautiful sunset over the ocean"
negative_prompt = "shaky, glitchy, low quality, worst quality, deformed, distorted, disfigured, motion smear, motion artifacts, fused fingers, bad anatomy, weird hand, ugly, transition, static."
frame_rate = 24.0
video_latent, audio_latent = pipe(
prompt=prompt,
negative_prompt=negative_prompt,
width=width,
height=height,
num_frames=121,
frame_rate=frame_rate,
num_inference_steps=8,
sigmas=DISTILLED_SIGMA_VALUES,
guidance_scale=1.0,
generator=generator,
output_type="latent",
return_dict=False,
)
latent_upsampler = LTX2LatentUpsamplerModel.from_pretrained(
model_path,
subfolder="latent_upsampler",
torch_dtype=torch.bfloat16,
)
upsample_pipe = LTX2LatentUpsamplePipeline(vae=pipe.vae, latent_upsampler=latent_upsampler)
upsample_pipe.enable_model_cpu_offload(device=device)
upscaled_video_latent = upsample_pipe(
latents=video_latent,
output_type="latent",
return_dict=False,
)[0]
video, audio = pipe(
latents=upscaled_video_latent,
audio_latents=audio_latent,
prompt=prompt,
negative_prompt=negative_prompt,
num_inference_steps=3,
noise_scale=STAGE_2_DISTILLED_SIGMA_VALUES[0], # renoise with first sigma value https://github.com/Lightricks/LTX-2/blob/main/packages/ltx-pipelines/src/ltx_pipelines/distilled.py#L178
sigmas=STAGE_2_DISTILLED_SIGMA_VALUES,
generator=generator,
guidance_scale=1.0,
output_type="np",
return_dict=False,
)
encode_video(
video[0],
fps=frame_rate,
audio=audio[0].float().cpu(),
audio_sample_rate=pipe.vocoder.config.output_sampling_rate,
output_path="ltx2_distilled_sample.mp4",
)
You can use LTX2ConditionPipeline to specify image and/or video conditions at arbitrary latent indices. For example, we can specify both a first-frame and last-frame condition to perform first-last-frame-to-video (FLF2V) generation:
import torch
from diffusers import LTX2ConditionPipeline, LTX2LatentUpsamplePipeline
from diffusers.pipelines.ltx2.latent_upsampler import LTX2LatentUpsamplerModel
from diffusers.pipelines.ltx2.pipeline_ltx2_condition import LTX2VideoCondition
from diffusers.pipelines.ltx2.utils import DISTILLED_SIGMA_VALUES, STAGE_2_DISTILLED_SIGMA_VALUES
from diffusers.pipelines.ltx2.export_utils import encode_video
from diffusers.utils import load_image
device = "cuda"
width = 768
height = 512
random_seed = 42
generator = torch.Generator(device).manual_seed(random_seed)
model_path = "rootonchair/LTX-2-19b-distilled"
pipe = LTX2ConditionPipeline.from_pretrained(model_path, torch_dtype=torch.bfloat16)
pipe.enable_sequential_cpu_offload(device=device)
pipe.vae.enable_tiling()
prompt = (
"CG animation style, a small blue bird takes off from the ground, flapping its wings. The bird's feathers are "
"delicate, with a unique pattern on its chest. The background shows a blue sky with white clouds under bright "
"sunshine. The camera follows the bird upward, capturing its flight and the vastness of the sky from a close-up, "
"low-angle perspective."
)
first_image = load_image(
"https://huggingface.co/datasets/huggingface/documentation-images/resolve/main/diffusers/flf2v_input_first_frame.png",
)
last_image = load_image(
"https://huggingface.co/datasets/huggingface/documentation-images/resolve/main/diffusers/flf2v_input_last_frame.png",
)
first_cond = LTX2VideoCondition(frames=first_image, index=0, strength=1.0)
last_cond = LTX2VideoCondition(frames=last_image, index=-1, strength=1.0)
conditions = [first_cond, last_cond]
frame_rate = 24.0
video_latent, audio_latent = pipe(
conditions=conditions,
prompt=prompt,
width=width,
height=height,
num_frames=121,
frame_rate=frame_rate,
num_inference_steps=8,
sigmas=DISTILLED_SIGMA_VALUES,
guidance_scale=1.0,
generator=generator,
output_type="latent",
return_dict=False,
)
latent_upsampler = LTX2LatentUpsamplerModel.from_pretrained(
model_path,
subfolder="latent_upsampler",
torch_dtype=torch.bfloat16,
)
upsample_pipe = LTX2LatentUpsamplePipeline(vae=pipe.vae, latent_upsampler=latent_upsampler)
upsample_pipe.enable_model_cpu_offload(device=device)
upscaled_video_latent = upsample_pipe(
latents=video_latent,
output_type="latent",
return_dict=False,
)[0]
video, audio = pipe(
latents=upscaled_video_latent,
audio_latents=audio_latent,
prompt=prompt,
width=width * 2,
height=height * 2,
num_inference_steps=3,
sigmas=STAGE_2_DISTILLED_SIGMA_VALUES,
generator=generator,
guidance_scale=1.0,
output_type="np",
return_dict=False,
)
encode_video(
video[0],
fps=frame_rate,
audio=audio[0].float().cpu(),
audio_sample_rate=pipe.vocoder.config.output_sampling_rate,
output_path="ltx2_distilled_flf2v.mp4",
)
You can use both image and video conditions:
import torch
from diffusers import LTX2ConditionPipeline
from diffusers.pipelines.ltx2.pipeline_ltx2_condition import LTX2VideoCondition
from diffusers.pipelines.ltx2.export_utils import encode_video
from diffusers.pipelines.ltx2.utils import DEFAULT_NEGATIVE_PROMPT
from diffusers.utils import load_image, load_video
device = "cuda"
width = 768
height = 512
random_seed = 42
generator = torch.Generator(device).manual_seed(random_seed)
model_path = "rootonchair/LTX-2-19b-distilled"
pipe = LTX2ConditionPipeline.from_pretrained(model_path, torch_dtype=torch.bfloat16)
pipe.enable_sequential_cpu_offload(device=device)
pipe.vae.enable_tiling()
prompt = (
"The video depicts a long, straight highway stretching into the distance, flanked by metal guardrails. The road is "
"divided into multiple lanes, with a few vehicles visible in the far distance. The surrounding landscape features "
"dry, grassy fields on one side and rolling hills on the other. The sky is mostly clear with a few scattered "
"clouds, suggesting a bright, sunny day. And then the camera switch to a winding mountain road covered in snow, "
"with a single vehicle traveling along it. The road is flanked by steep, rocky cliffs and sparse vegetation. The "
"landscape is characterized by rugged terrain and a river visible in the distance. The scene captures the "
"solitude and beauty of a winter drive through a mountainous region."
)
cond_video = load_video(
"https://huggingface.co/datasets/huggingface/documentation-images/resolve/main/diffusers/cosmos/cosmos-video2world-input-vid.mp4"
)
cond_image = load_image(
"https://huggingface.co/datasets/huggingface/documentation-images/resolve/main/diffusers/cosmos/cosmos-video2world-input.jpg"
)
video_cond = LTX2VideoCondition(frames=cond_video, index=0, strength=1.0)
image_cond = LTX2VideoCondition(frames=cond_image, index=8, strength=1.0)
conditions = [video_cond, image_cond]
frame_rate = 24.0
video, audio = pipe(
conditions=conditions,
prompt=prompt,
negative_prompt=DEFAULT_NEGATIVE_PROMPT,
width=width,
height=height,
num_frames=121,
frame_rate=frame_rate,
num_inference_steps=40,
guidance_scale=4.0,
generator=generator,
output_type="np",
return_dict=False,
)
encode_video(
video[0],
fps=frame_rate,
audio=audio[0].float().cpu(),
audio_sample_rate=pipe.vocoder.config.output_sampling_rate,
output_path="ltx2_cond_video.mp4",
)
Because the conditioning is done via latent frames, the 8 data space frames corresponding to the specified latent frame for an image condition will tend to be static.
LTX-2.X pipelines support multimodal guidance. It is composed of three terms, all using a CFG-style update rule:
These are controlled by the guidance_scale, stg_scale, and modality_scale arguments and can be set separately for video and audio. Additionally, for STG the transformer block indices where self-attention is skipped needs to be specified via the spatio_temporal_guidance_blocks argument. The LTX-2.X pipelines also support guidance rescaling to help reduce over-exposure, which can be a problem when the guidance scales are set to high values.
import torch
from diffusers import LTX2ImageToVideoPipeline
from diffusers.pipelines.ltx2.export_utils import encode_video
from diffusers.pipelines.ltx2.utils import DEFAULT_NEGATIVE_PROMPT
from diffusers.utils import load_image
device = "cuda"
width = 768
height = 512
random_seed = 42
frame_rate = 24.0
generator = torch.Generator(device).manual_seed(random_seed)
model_path = "dg845/LTX-2.3-Diffusers"
pipe = LTX2ImageToVideoPipeline.from_pretrained(model_path, torch_dtype=torch.bfloat16)
pipe.enable_sequential_cpu_offload(device=device)
pipe.vae.enable_tiling()
prompt = (
"An astronaut hatches from a fragile egg on the surface of the Moon, the shell cracking and peeling apart in "
"gentle low-gravity motion. Fine lunar dust lifts and drifts outward with each movement, floating in slow arcs "
"before settling back onto the ground. The astronaut pushes free in a deliberate, weightless motion, small "
"fragments of the egg tumbling and spinning through the air. In the background, the deep darkness of space subtly "
"shifts as stars glide with the camera's movement, emphasizing vast depth and scale. The camera performs a "
"smooth, cinematic slow push-in, with natural parallax between the foreground dust, the astronaut, and the "
"distant starfield. Ultra-realistic detail, physically accurate low-gravity motion, cinematic lighting, and a "
"breath-taking, movie-like shot."
)
image = load_image(
"https://huggingface.co/datasets/huggingface/documentation-images/resolve/main/diffusers/astronaut.jpg",
)
video, audio = pipe(
image=image,
prompt=prompt,
negative_prompt=DEFAULT_NEGATIVE_PROMPT,
width=width,
height=height,
num_frames=121,
frame_rate=frame_rate,
num_inference_steps=30,
guidance_scale=3.0, # Recommended LTX-2.3 guidance parameters
stg_scale=1.0, # Note that 0.0 (not 1.0) means that STG is disabled (all other guidance is disabled at 1.0)
modality_scale=3.0,
guidance_rescale=0.7,
audio_guidance_scale=7.0, # Note that a higher CFG guidance scale is recommended for audio
audio_stg_scale=1.0,
audio_modality_scale=3.0,
audio_guidance_rescale=0.7,
spatio_temporal_guidance_blocks=[28],
use_cross_timestep=True,
generator=generator,
output_type="np",
return_dict=False,
)
encode_video(
video[0],
fps=frame_rate,
audio=audio[0].float().cpu(),
audio_sample_rate=pipe.vocoder.config.output_sampling_rate,
output_path="ltx2_3_i2v_stage_1.mp4",
)
The LTX-2.X models are sensitive to prompting style. Refer to the official prompting guide for recommendations on how to write a good prompt. Using prompt enhancement, where the supplied prompts are enhanced using the pipeline's text encoder (by default a Gemma 3 model) given a system prompt, can also improve sample quality. The optional processor pipeline component needs to be present to use prompt enhancement. Enable prompt enhancement by supplying a system_prompt argument:
import torch
from transformers import Gemma3Processor
from diffusers import LTX2Pipeline
from diffusers.pipelines.ltx2.export_utils import encode_video
from diffusers.pipelines.ltx2.utils import DEFAULT_NEGATIVE_PROMPT, T2V_DEFAULT_SYSTEM_PROMPT
device = "cuda"
width = 768
height = 512
random_seed = 42
frame_rate = 24.0
generator = torch.Generator(device).manual_seed(random_seed)
model_path = "dg845/LTX-2.3-Diffusers"
pipe = LTX2Pipeline.from_pretrained(model_path, torch_dtype=torch.bfloat16)
pipe.enable_model_cpu_offload(device=device)
pipe.vae.enable_tiling()
if getattr(pipe, "processor", None) is None:
processor = Gemma3Processor.from_pretrained("google/gemma-3-12b-it-qat-q4_0-unquantized")
pipe.processor = processor
prompt = (
"An astronaut hatches from a fragile egg on the surface of the Moon, the shell cracking and peeling apart in "
"gentle low-gravity motion. Fine lunar dust lifts and drifts outward with each movement, floating in slow arcs "
"before settling back onto the ground. The astronaut pushes free in a deliberate, weightless motion, small "
"fragments of the egg tumbling and spinning through the air. In the background, the deep darkness of space subtly "
"shifts as stars glide with the camera's movement, emphasizing vast depth and scale. The camera performs a "
"smooth, cinematic slow push-in, with natural parallax between the foreground dust, the astronaut, and the "
"distant starfield. Ultra-realistic detail, physically accurate low-gravity motion, cinematic lighting, and a "
"breath-taking, movie-like shot."
)
video, audio = pipe(
prompt=prompt,
negative_prompt=DEFAULT_NEGATIVE_PROMPT,
width=width,
height=height,
num_frames=121,
frame_rate=frame_rate,
num_inference_steps=30,
guidance_scale=3.0,
stg_scale=1.0,
modality_scale=3.0,
guidance_rescale=0.7,
audio_guidance_scale=7.0,
audio_stg_scale=1.0,
audio_modality_scale=3.0,
audio_guidance_rescale=0.7,
spatio_temporal_guidance_blocks=[28],
use_cross_timestep=True,
system_prompt=T2V_DEFAULT_SYSTEM_PROMPT,
generator=generator,
output_type="np",
return_dict=False,
)
encode_video(
video[0],
fps=frame_rate,
audio=audio[0].float().cpu(),
audio_sample_rate=pipe.vocoder.config.output_sampling_rate,
output_path="ltx2_3_t2v_stage_1.mp4",
)
[[autodoc]] LTX2Pipeline
[[autodoc]] LTX2ImageToVideoPipeline
[[autodoc]] LTX2ConditionPipeline
[[autodoc]] LTX2LatentUpsamplePipeline
[[autodoc]] pipelines.ltx2.pipeline_output.LTX2PipelineOutput