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vllm-omni/vllm_omni/diffusion/models/ltx2/ltx2_runtime.py
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2026-08-15 18:27:23 +08:00

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Python

# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
"""Shared recipe-driven runtime for LTX pipeline variants."""
from __future__ import annotations
from collections.abc import Iterable
from contextlib import nullcontext
from dataclasses import replace
from typing import Any, ClassVar
import torch
from diffusers.utils.torch_utils import randn_tensor
from torch import nn
from vllm.model_executor.models.utils import AutoWeightsLoader
from vllm_omni.diffusion.data import DiffusionOutput, OmniDiffusionConfig
from vllm_omni.diffusion.distributed.cfg_parallel import CFGParallelMixin
from vllm_omni.diffusion.distributed.parallel_state import (
get_classifier_free_guidance_world_size as get_guidance_parallel_world_size,
)
from vllm_omni.diffusion.models.interface import SupportsComponentDiscovery
from vllm_omni.diffusion.models.progress_bar import ProgressBarMixin
from vllm_omni.diffusion.profiler.diffusion_pipeline_profiler import DiffusionPipelineProfilerMixin
from vllm_omni.diffusion.worker.request_batch import DiffusionRequestBatch, split_diffusion_output_by_request
from vllm_omni.platforms import current_omni_platform
from . import ltx2_latents as latent_ops
from .ltx2_components import (
LTXComponentProfile,
detect_ltx_model_version,
initialize_pipeline_components,
resolve_ltx_component_profile,
)
from .ltx2_conditioning import LTXPromptContext, LTXTextConditioningMixin
from .ltx2_denoise import (
LTXDenoiseContext,
LTXForwardContext,
LTXPhaseExecutor,
LTXPhaseResult,
build_transformer_kwargs,
step_denoised_latents,
)
from .ltx2_guidance import (
LTX_GUIDANCE_EXECUTOR,
LTXGuidanceExecutor,
LTXGuidancePlan,
)
from .ltx2_phase_adapter import LTXPhaseAdapterRuntime, build_ltx_phase_adapter
from .ltx2_recipes import (
LTXPhaseRecipe,
LTXPipelineRecipe,
resolve_ltx_pipeline_recipe,
)
from .ltx2_request import (
LTXRequestInputs,
LTXRequestMixin,
validate_pipeline_request,
)
def _expand_per_prompt_decode_value(
value: float | list[float],
*,
prompt_batch_size: int,
effective_batch_size: int,
field_name: str,
) -> list[float]:
if not isinstance(value, list):
return [value] * effective_batch_size
if len(value) == 1:
return value * effective_batch_size
if len(value) == effective_batch_size:
return value
if prompt_batch_size > 0 and len(value) == prompt_batch_size and effective_batch_size % prompt_batch_size == 0:
repeats = effective_batch_size // prompt_batch_size
return [item for item in value for _ in range(repeats)]
raise ValueError(
f"`{field_name}` must have length 1, prompt batch size ({prompt_batch_size}), or effective batch size"
f" ({effective_batch_size}); got {len(value)}."
)
def _prepare_decode_timestep_conditioning(
*,
decode_timestep: float | list[float],
decode_noise_scale: float | list[float] | None,
prompt_batch_size: int,
effective_batch_size: int,
device: torch.device,
dtype: torch.dtype,
) -> tuple[torch.Tensor, torch.Tensor]:
decode_timestep_values = _expand_per_prompt_decode_value(
decode_timestep,
prompt_batch_size=prompt_batch_size,
effective_batch_size=effective_batch_size,
field_name="decode_timestep",
)
decode_noise_scale_values = (
decode_timestep_values
if decode_noise_scale is None
else _expand_per_prompt_decode_value(
decode_noise_scale,
prompt_batch_size=prompt_batch_size,
effective_batch_size=effective_batch_size,
field_name="decode_noise_scale",
)
)
return (
torch.tensor(decode_timestep_values, device=device, dtype=dtype),
torch.tensor(decode_noise_scale_values, device=device, dtype=dtype)[:, None, None, None, None],
)
class LTXRuntime(
LTXRequestMixin,
LTXTextConditioningMixin,
nn.Module,
CFGParallelMixin,
ProgressBarMixin,
SupportsComponentDiscovery,
DiffusionPipelineProfilerMixin,
):
"""Shared Omni runtime for recipe-driven LTX denoise phases."""
pipeline_kind: ClassVar[str] = "one_stage"
component_profile: ClassVar[LTXComponentProfile]
pipeline_recipe: ClassVar[LTXPipelineRecipe]
guidance_executor: ClassVar[LTXGuidanceExecutor] = LTX_GUIDANCE_EXECUTOR
supports_request_batch = False
connector_batches_cfg = False
distributed_video_decode = True
support_image_input = False
dummy_run_num_frames = 1
preserve_sp_padded_audio_duration = False
reports_stage_durations = False
def __init__(self, *, od_config: OmniDiffusionConfig, prefix: str = "") -> None:
del prefix
parallel_config = getattr(od_config, "parallel_config", None)
if getattr(parallel_config, "ulysses_mode", "strict") == "advanced_uaa":
raise ValueError(
f"{self.__class__.__name__} does not support ulysses_mode='advanced_uaa'. "
"Use the default ulysses_mode='strict' for LTX sequence parallelism."
)
self.model_version = detect_ltx_model_version(od_config.model, revision=getattr(od_config, "revision", None))
self.component_profile = resolve_ltx_component_profile(self.pipeline_kind, self.model_version)
self.pipeline_recipe = resolve_ltx_pipeline_recipe(self.pipeline_kind, self.model_version)
if getattr(od_config, "cache_backend", "none") == "cache_dit" and not self.pipeline_recipe.supports_cache_dit:
raise ValueError(
f"{self.__class__.__name__} does not support cache_backend='cache_dit'. "
"Cache-DiT is not qualified for this LTX recipe."
)
self._dit_modules = list(self.component_profile.dit_modules)
self._encoder_modules = list(self.component_profile.encoder_modules)
self._vae_modules = list(self.component_profile.vae_modules)
self._resident_modules = list(self.component_profile.resident_modules)
if self.model_version in ("2.3", "2.5"):
self.preserve_sp_padded_audio_duration = True
self.reports_stage_durations = True
super().__init__()
self._guidance_plan = LTXGuidancePlan.build(self.pipeline_recipe.request_guidance)
initialize_pipeline_components(self, od_config)
self._phase_adapter: LTXPhaseAdapterRuntime | None = build_ltx_phase_adapter(self)
self.setup_diffusion_pipeline_profiler(
enable_diffusion_pipeline_profiler=self.od_config.enable_diffusion_pipeline_profiler
)
def _forward_request(
self,
req: DiffusionRequestBatch,
*,
image: Any | None = None,
image_crf: int | None = None,
prompt: str | list[str] | None = None,
negative_prompt: str | list[str] | None = None,
height: int | None = None,
width: int | None = None,
num_frames: int | None = None,
frame_rate: float | None = None,
num_inference_steps: int | None = None,
sigmas: list[float] | None = None,
stage_1_sigmas: list[float] | None = None,
stage_2_sigmas: list[float] | None = None,
guidance_scale: float | None = None,
num_videos_per_prompt: int | None = 1,
generator: torch.Generator | list[torch.Generator] | None = None,
latents: torch.Tensor | None = None,
audio_latents: torch.Tensor | None = None,
prompt_embeds: torch.Tensor | None = None,
negative_prompt_embeds: torch.Tensor | None = None,
prompt_attention_mask: torch.Tensor | None = None,
negative_prompt_attention_mask: torch.Tensor | None = None,
decode_timestep: float | list[float] = 0.0,
decode_noise_scale: float | list[float] | None = None,
output_type: str = "np",
max_sequence_length: int | None = None,
) -> DiffusionOutput | list[DiffusionOutput]:
request_inputs = self._resolve_request_inputs(
req,
prompt=prompt,
negative_prompt=negative_prompt,
height=height,
width=width,
num_frames=num_frames,
frame_rate=frame_rate,
num_inference_steps=num_inference_steps,
guidance_scale=guidance_scale,
num_videos_per_prompt=num_videos_per_prompt,
generator=generator,
latents=latents,
audio_latents=audio_latents,
prompt_embeds=prompt_embeds,
negative_prompt_embeds=negative_prompt_embeds,
prompt_attention_mask=prompt_attention_mask,
negative_prompt_attention_mask=negative_prompt_attention_mask,
decode_timestep=decode_timestep,
decode_noise_scale=decode_noise_scale,
output_type=output_type,
max_sequence_length=max_sequence_length,
image_crf=image_crf,
)
image = self._resolve_request_image(req, image, request_inputs)
if image is not None and not self.support_image_input:
raise ValueError(f"{self.__class__.__name__} does not support `image` input.")
request_sigmas = self._resolve_request_sigmas(req, sigmas)
request_phase_sigmas = self._resolve_request_phase_sigmas(req, stage_1_sigmas, stage_2_sigmas)
validate_pipeline_request(
request_inputs,
pipeline_recipe=self.pipeline_recipe,
vae_spatial_compression_ratio=self.vae_spatial_compression_ratio,
vae_temporal_compression_ratio=self.vae_temporal_compression_ratio,
pipeline_name=self.__class__.__name__,
request_sigmas=request_sigmas,
request_phase_sigmas=request_phase_sigmas,
)
phase_adapter = getattr(self, "_phase_adapter", None)
if phase_adapter is not None and any(
getattr(sampling, "lora_request", None) is not None for sampling in req.sampling_params_list
):
raise ValueError(
f"{self.__class__.__name__} cannot compose a request LoRA with its internal phase adapter."
)
return self._run_recipe(
req,
request_inputs,
request_sigmas=request_sigmas,
request_phase_sigmas=request_phase_sigmas,
image=image,
)
def _run_recipe(
self,
req: DiffusionRequestBatch,
request_inputs: LTXRequestInputs,
*,
request_sigmas: list[float] | None,
request_phase_sigmas: tuple[list[float] | None, ...] | None = None,
image: Any | None = None,
) -> DiffusionOutput | list[DiffusionOutput]:
"""Execute one- and multi-phase recipes through the same control flow."""
phase_results: list[LTXPhaseResult] = []
prompt_context = None
for phase_index, phase_recipe in enumerate(self.pipeline_recipe.phases):
override_sigmas = None if request_phase_sigmas is None else request_phase_sigmas[phase_index]
phase_sigmas = (
override_sigmas
if override_sigmas is not None
else (
request_sigmas
if request_sigmas is not None
else (list(phase_recipe.sigmas) if phase_recipe.sigmas is not None else None)
)
)
self._enter_phase(phase_recipe)
phase_inputs = self._build_phase_inputs(
request_inputs,
phase_recipe,
phase_results[-1] if phase_results else None,
)
if phase_sigmas is not None:
phase_inputs = replace(phase_inputs, num_inference_steps=len(phase_sigmas) - 1)
noise_scale = phase_recipe.noise_scale
if override_sigmas is not None and phase_recipe.input_transform == "spatial_upsample":
noise_scale = float(override_sigmas[0])
phase_result = self.run_phase(
req,
phase_inputs,
noise_scale=noise_scale,
sigmas=phase_sigmas,
timesteps=None,
attention_kwargs=None,
phase_recipe=phase_recipe,
image=image,
prompt_context=prompt_context,
)
phase_results.append(phase_result)
prompt_context = phase_result.forward_context.prompt_context
final_context = phase_results[-1].forward_context
output_phase = LTXPhaseResult(
forward_context=final_context,
video=phase_results[self.pipeline_recipe.video_output_phase].video,
audio=phase_results[self.pipeline_recipe.audio_output_phase].audio,
)
return self.decode_phase(output_phase)
def _enter_phase(self, phase: LTXPhaseRecipe) -> None:
self._active_phase_name = phase.name
self._guidance_plan = LTXGuidancePlan.build(phase.guidance)
phase_adapter = getattr(self, "_phase_adapter", None)
if phase_adapter is None:
if phase.adapter_slot is not None:
raise RuntimeError(f"LTX phase {phase.name!r} requires adapter slot {phase.adapter_slot!r}.")
return
phase_adapter.activate(phase.adapter_slot)
def eval(self):
result = super().eval()
phase_adapter = getattr(self, "_phase_adapter", None)
if phase_adapter is not None:
phase_adapter.finalize()
return result
def prepare_latents(
self,
batch_size: int = 1,
num_channels_latents: int = 128,
height: int = 512,
width: int = 768,
num_frames: int = 121,
noise_scale: float = 0.0,
dtype: torch.dtype | None = None,
device: torch.device | None = None,
generator: torch.Generator | list[torch.Generator] | None = None,
latents: torch.Tensor | None = None,
) -> torch.Tensor:
return latent_ops.prepare_video_latents(
self,
batch_size,
num_channels_latents,
height,
width,
num_frames,
noise_scale,
dtype,
device,
generator,
latents,
)
def prepare_audio_latents(
self,
batch_size: int = 1,
num_channels_latents: int = 8,
audio_latent_length: int = 1,
num_mel_bins: int = 64,
noise_scale: float = 0.0,
dtype: torch.dtype | None = None,
device: torch.device | None = None,
generator: torch.Generator | list[torch.Generator] | None = None,
latents: torch.Tensor | None = None,
latents_normalized: bool = False,
) -> tuple[torch.Tensor, int, int]:
return latent_ops.prepare_audio_latents(
self,
batch_size,
num_channels_latents,
audio_latent_length,
num_mel_bins,
noise_scale,
dtype,
device,
generator,
latents,
latents_normalized,
)
@property
def guidance_scale(self):
return self._guidance_plan.spec.video.cfg_scale
@property
def do_classifier_free_guidance(self):
return self._guidance_plan.spec.do_cfg
@property
def do_guidance(self):
return len(self._guidance_plan.passes) > 1
@property
def interrupt(self):
return self._interrupt
def _transformer_cache_context(self, context_name: str):
cache_context = getattr(self.transformer, "cache_context", None)
if callable(cache_context):
return cache_context(context_name)
return nullcontext()
def predict_noise(self, **kwargs):
with self._transformer_cache_context("cond_uncond"):
noise_pred_video, noise_pred_audio = self.transformer(**kwargs)
return noise_pred_video.float(), noise_pred_audio.float()
def combine_cfg_noise(
self,
positive_noise_pred,
negative_noise_pred,
true_cfg_scale,
cfg_normalize=False,
kwargs: dict[str, Any] | None = None,
**context: Any,
):
if kwargs is not None:
context = {**kwargs, **context}
del cfg_normalize
required = ("video_latents", "audio_latents", "video_sigma", "audio_sigma")
if any(context.get(name) is None for name in required):
raise ValueError("LTX x0-space CFG requires video/audio latents and sigmas.")
video_pos, audio_pos = positive_noise_pred
video_neg, audio_neg = negative_noise_pred
return (
self.guidance_executor.combine_cfg_velocity(
context["video_latents"],
video_pos,
video_neg,
context["video_sigma"],
true_cfg_scale,
),
self.guidance_executor.combine_cfg_velocity(
context["audio_latents"],
audio_pos,
audio_neg,
context["audio_sigma"],
true_cfg_scale,
),
)
def _synchronize_guidance_parallel_step_output(
self,
latents: tuple[torch.Tensor, torch.Tensor],
guidance_parallel_ready: bool,
) -> tuple[torch.Tensor, torch.Tensor]:
if not (guidance_parallel_ready and get_guidance_parallel_world_size() > 1):
return latents
# CUDA async execution otherwise permits numerical drift to accumulate
# across guidance-parallel denoise steps.
latents = tuple(tensor.contiguous() for tensor in latents)
current_omni_platform.synchronize()
return latents
def _setup_forward_runtime(
self,
req: DiffusionRequestBatch,
request_inputs: LTXRequestInputs,
attention_kwargs: dict[str, Any] | None,
) -> bool:
self._guidance_plan = LTXGuidancePlan.build(request_inputs.guidance)
del req, attention_kwargs
self._interrupt = False
guidance_world_size = get_guidance_parallel_world_size()
self.guidance_executor.validate_guidance_world_size(self._guidance_plan, guidance_world_size)
self.guidance_executor.warn_if_imbalanced(
self._guidance_plan,
guidance_world_size,
getattr(self, "_active_phase_name", "generate"),
)
return self.do_guidance and guidance_world_size > 1
def _check_forward_inputs(
self,
request_inputs: LTXRequestInputs,
image: Any | None = None,
) -> None:
self.check_inputs(
prompt=request_inputs.prompt,
height=request_inputs.height,
width=request_inputs.width,
prompt_embeds=request_inputs.prompt_embeds,
negative_prompt_embeds=request_inputs.negative_prompt_embeds,
prompt_attention_mask=request_inputs.prompt_attention_mask,
negative_prompt_attention_mask=request_inputs.negative_prompt_attention_mask,
)
def _resolve_request_image(
self,
req: DiffusionRequestBatch,
image: Any | None,
request_inputs: LTXRequestInputs,
) -> Any | None:
del req, request_inputs
return image
def _make_output(self, output: tuple[torch.Tensor, torch.Tensor]) -> DiffusionOutput:
if self.reports_stage_durations:
return DiffusionOutput(
output=output,
stage_durations=getattr(self, "stage_durations", None),
)
return DiffusionOutput(output=output)
def _decode_output(
self,
*,
latents: torch.Tensor,
audio_latents: torch.Tensor,
output_type: str,
connector_prompt_embeds: torch.Tensor,
generator: torch.Generator | list[torch.Generator] | None,
device: torch.device,
decode_timestep: float | list[float],
decode_noise_scale: float | list[float] | None,
prompt_batch_size: int,
) -> DiffusionOutput:
if output_type == "latent":
return self._make_output((latents, audio_latents))
latents = latents.to(connector_prompt_embeds.dtype)
if not self.vae.config.timestep_conditioning:
timestep_decode = None
else:
noise = randn_tensor(latents.shape, generator=generator, device=device, dtype=latents.dtype)
timestep_decode, decode_noise_scale_t = _prepare_decode_timestep_conditioning(
decode_timestep=decode_timestep,
decode_noise_scale=decode_noise_scale,
prompt_batch_size=prompt_batch_size,
effective_batch_size=latents.shape[0],
device=device,
dtype=latents.dtype,
)
latents = (1 - decode_noise_scale_t) * latents + decode_noise_scale_t * noise
dist_initialized = torch.distributed.is_initialized()
is_output_rank = not dist_initialized or torch.distributed.get_rank() == 0
vae_decode_needs_all_ranks = False
is_distributed_vae_enabled = getattr(self.vae, "is_distributed_enabled", None)
if self.distributed_video_decode and dist_initialized and callable(is_distributed_vae_enabled):
# Distributed tiled decode is collective, so every rank must enter it.
vae_decode_needs_all_ranks = bool(is_distributed_vae_enabled())
should_decode_video = not self.distributed_video_decode or is_output_rank or vae_decode_needs_all_ranks
if should_decode_video:
video = self.vae.decode(latents.to(self.vae.dtype), timestep_decode, return_dict=False)[0]
else:
video = torch.empty(0, device=latents.device, dtype=latents.dtype)
if self.distributed_video_decode and not is_output_rank:
return self._make_output(
(
torch.empty(0, device=video.device, dtype=video.dtype),
torch.empty(0, device=audio_latents.device, dtype=audio_latents.dtype),
)
)
if video.numel() > 0:
video = self.video_processor.postprocess_video(video, output_type=output_type)
generated_mel = self.audio_vae.decode(audio_latents.to(self.audio_vae.dtype), return_dict=False)[0]
audio = self.vocoder(generated_mel)
return self._make_output((video, audio))
def _prepare_video_latents_stage(
self,
request_inputs: LTXRequestInputs,
prompt_context: LTXPromptContext,
*,
device: torch.device,
noise_scale: float,
image: Any | None = None,
) -> tuple[torch.Tensor, torch.Tensor | None]:
latents = self.prepare_latents(
batch_size=prompt_context.batch_size * request_inputs.num_videos_per_prompt,
num_channels_latents=self.transformer.config.in_channels,
height=request_inputs.height,
width=request_inputs.width,
num_frames=request_inputs.num_frames,
noise_scale=noise_scale,
dtype=prompt_context.positive_connector_prompt_embeds.dtype,
device=device,
generator=request_inputs.generator,
latents=request_inputs.latents,
)
return latents, None
def _resolve_video_latent_dimensions(self, request_inputs: LTXRequestInputs) -> tuple[int, int, int]:
latent_num_frames, latent_height, latent_width = latent_ops.resolve_video_latent_shape(
request_inputs.height,
request_inputs.width,
request_inputs.num_frames,
vae_spatial_compression_ratio=self.vae_spatial_compression_ratio,
vae_temporal_compression_ratio=self.vae_temporal_compression_ratio,
)
latents = request_inputs.latents
if latents is not None:
if latents.ndim == 5:
_, _, latent_num_frames, latent_height, latent_width = latents.shape
elif latents.ndim != 3:
raise ValueError(
f"Provided `latents` tensor has shape {latents.shape}, expected a packed 3D or unpacked 5D tensor."
)
return latent_num_frames, latent_height, latent_width
def _prepare_audio_latents_stage(
self,
request_inputs: LTXRequestInputs,
prompt_context: LTXPromptContext,
*,
device: torch.device,
noise_scale: float,
) -> tuple[torch.Tensor, int, int, int]:
duration_s = request_inputs.num_frames / request_inputs.frame_rate
audio_latents_per_second = (
self.audio_sampling_rate / self.audio_hop_length / float(self.audio_vae_temporal_compression_ratio)
)
audio_num_frames = round(duration_s * audio_latents_per_second)
audio_num_frames = self._resolve_audio_latent_length(audio_num_frames, request_inputs.audio_latents)
num_mel_bins = self.audio_vae.config.mel_bins if self.audio_vae is not None else 64
latent_mel_bins = num_mel_bins // self.audio_vae_mel_compression_ratio
num_channels = self.audio_vae.config.latent_channels if self.audio_vae is not None else 8
audio_latents, original_num_frames, padded_num_frames = self.prepare_audio_latents(
prompt_context.batch_size * request_inputs.num_videos_per_prompt,
num_channels_latents=num_channels,
audio_latent_length=audio_num_frames,
num_mel_bins=num_mel_bins,
noise_scale=noise_scale,
dtype=prompt_context.positive_connector_audio_prompt_embeds.dtype,
device=device,
generator=request_inputs.generator,
latents=request_inputs.audio_latents,
latents_normalized=request_inputs.audio_latents_normalized,
)
return audio_latents, original_num_frames, padded_num_frames, latent_mel_bins
def _resolve_audio_latent_length(
self,
requested_length: int,
audio_latents: torch.Tensor | None,
) -> int:
if audio_latents is None or audio_latents.ndim != 4:
return requested_length
provided_length = audio_latents.shape[2]
if not self.preserve_sp_padded_audio_duration:
return provided_length
sp_size = getattr(self.od_config.parallel_config, "sequence_parallel_size", 1) or 1
padded_length = latent_ops.get_sp_padded_audio_latent_length(requested_length, int(sp_size))
return requested_length if provided_length in {requested_length, padded_length} else provided_length
def _prepare_denoise_context_for_guidance(
self,
forward_ctx: LTXForwardContext,
denoise_ctx: LTXDenoiseContext,
) -> LTXDenoiseContext:
return self.guidance_executor.prepare_denoise_context(
self._guidance_plan,
forward_ctx.guidance_parallel_ready,
get_guidance_parallel_world_size(),
denoise_ctx,
)
def _denoise_timestep_kwargs(
self,
ts: torch.Tensor,
forward_ctx: LTXForwardContext,
denoise_ctx: LTXDenoiseContext,
*,
video_token_count: int,
audio_token_count: int,
) -> dict[str, torch.Tensor]:
del forward_ctx, denoise_ctx
return self.guidance_executor.timestep_kwargs(
ts,
video_token_count,
audio_token_count,
expand_for_sequence_parallel=True,
)
def _video_guidance_model_sigma(
self,
sigma: torch.Tensor,
denoise_ctx: LTXDenoiseContext,
) -> torch.Tensor:
"""Return the video timestep used to convert velocity predictions to x0."""
del denoise_ctx
return sigma
def _build_transformer_kwargs(
self,
forward_ctx: LTXForwardContext,
denoise_ctx: LTXDenoiseContext,
*,
hidden_states: torch.Tensor,
audio_hidden_states: torch.Tensor,
encoder_hidden_states: torch.Tensor,
audio_encoder_hidden_states: torch.Tensor,
encoder_attention_mask: torch.Tensor | None,
audio_encoder_attention_mask: torch.Tensor | None,
ts: torch.Tensor,
attention_kwargs: dict[str, Any] | None = None,
) -> dict[str, Any]:
return build_transformer_kwargs(
self,
forward_ctx,
denoise_ctx,
hidden_states=hidden_states,
audio_hidden_states=audio_hidden_states,
encoder_hidden_states=encoder_hidden_states,
audio_encoder_hidden_states=audio_encoder_hidden_states,
encoder_attention_mask=encoder_attention_mask,
audio_encoder_attention_mask=audio_encoder_attention_mask,
ts=ts,
attention_kwargs=attention_kwargs,
)
def _predict_noise_for_step(
self,
index: int,
timestep: torch.Tensor,
state: latent_ops.LTXAVState,
forward_ctx: LTXForwardContext,
denoise_ctx: LTXDenoiseContext,
) -> tuple[torch.Tensor, torch.Tensor]:
return self.guidance_executor.predict_noise(
self,
self._guidance_plan,
index,
timestep,
state,
forward_ctx,
denoise_ctx,
preserve_positive_velocity=forward_ctx.sampler == "euler_ancestral",
)
def _denoise_step(
self,
index: int,
timestep: torch.Tensor,
state: latent_ops.LTXAVState,
forward_ctx: LTXForwardContext,
denoise_ctx: LTXDenoiseContext,
) -> latent_ops.LTXAVState:
denoise_ctx.latents = state.video
denoise_ctx.audio_latents = state.audio
noise_pred_video, noise_pred_audio = self._predict_noise_for_step(
index,
timestep,
state,
forward_ctx,
denoise_ctx,
)
video, audio = step_denoised_latents(
self,
forward_ctx,
denoise_ctx,
noise_pred_video,
noise_pred_audio,
timestep,
)
audio = latent_ops.clear_audio_padding(audio, forward_ctx.original_audio_num_frames)
return latent_ops.LTXAVState(video=video, audio=audio)
def _unpack_and_denormalize_stage(
self,
forward_ctx: LTXForwardContext,
latents: torch.Tensor,
audio_latents: torch.Tensor,
) -> tuple[torch.Tensor, torch.Tensor]:
latents = latent_ops.unpack_latents(
latents,
forward_ctx.latent_num_frames,
forward_ctx.latent_height,
forward_ctx.latent_width,
self.transformer_spatial_patch_size,
self.transformer_temporal_patch_size,
)
latents = latent_ops.denormalize_latents(
latents,
self.vae.latents_mean,
self.vae.latents_std,
self.vae.config.scaling_factor,
)
audio_latents = latent_ops.unpad_audio_latents(audio_latents, forward_ctx.original_audio_num_frames)
audio_latents = latent_ops.denormalize_audio_latents(
audio_latents,
self.audio_vae.latents_mean,
self.audio_vae.latents_std,
)
audio_latents = latent_ops.unpack_audio_latents(
audio_latents,
num_mel_bins=forward_ctx.latent_mel_bins,
)
return latents, audio_latents
def run_phase(
self,
req: DiffusionRequestBatch,
request_inputs: LTXRequestInputs,
*,
noise_scale: float,
sigmas: list[float] | None,
timesteps: list[int] | None,
attention_kwargs: dict[str, Any] | None,
phase_recipe: LTXPhaseRecipe,
image: Any | None = None,
prompt_context: LTXPromptContext | None = None,
) -> LTXPhaseResult:
"""Prepare and execute one phase without decoding its output."""
return LTXPhaseExecutor.run(
self,
req,
request_inputs,
noise_scale=noise_scale,
sigmas=sigmas,
timesteps=timesteps,
attention_kwargs=attention_kwargs,
phase_recipe=phase_recipe,
image=image,
prompt_context=prompt_context,
)
def _build_phase_inputs(
self,
request_inputs: LTXRequestInputs,
phase: LTXPhaseRecipe,
previous_phase: LTXPhaseResult | None,
) -> LTXRequestInputs:
"""Resolve one phase from immutable request inputs and prior AV state."""
divisor = phase.spatial_downscale
if request_inputs.height % divisor != 0 or request_inputs.width % divisor != 0:
raise ValueError(
f"LTX phase {phase.name!r} cannot scale resolution "
f"{request_inputs.width}x{request_inputs.height} by {divisor}."
)
height = request_inputs.height // divisor
width = request_inputs.width // divisor
latents = request_inputs.latents
audio_latents = request_inputs.audio_latents
audio_latents_normalized = request_inputs.audio_latents_normalized
decode_timestep = request_inputs.decode_timestep
decode_noise_scale = request_inputs.decode_noise_scale
if phase.input_transform == "spatial_upsample":
if previous_phase is None:
raise ValueError(f"LTX phase {phase.name!r} requires a previous phase to upsample.")
if previous_phase.video.ndim != 5:
raise ValueError(f"LTX spatial upsampling expects a 5D video latent, got {previous_phase.video.shape}.")
latents = self._spatial_upsample_phase(previous_phase.video)
if previous_phase.audio_for_next_phase is not None:
audio_latents = previous_phase.audio_for_next_phase
audio_latents_normalized = True
else:
audio_latents = previous_phase.audio
audio_latents_normalized = False
decode_timestep = 0.0
decode_noise_scale = None
expected_shape = latent_ops.resolve_video_latent_shape(
height,
width,
request_inputs.num_frames,
vae_spatial_compression_ratio=self.vae_spatial_compression_ratio,
vae_temporal_compression_ratio=self.vae_temporal_compression_ratio,
)
if latents.shape[2:] != expected_shape:
raise ValueError(
f"LTX phase {phase.name!r} upsampler produced {tuple(latents.shape[2:])}, expected "
f"{expected_shape} for {width}x{height}."
)
elif phase.input_transform != "initial":
raise ValueError(f"Unsupported LTX phase input transform: {phase.input_transform!r}.")
guidance = request_inputs.guidance if phase.allow_guidance_override else phase.guidance
return replace(
request_inputs,
height=height,
width=width,
num_inference_steps=phase.num_inference_steps or request_inputs.num_inference_steps,
guidance=guidance,
latents=latents,
audio_latents=audio_latents,
audio_latents_normalized=audio_latents_normalized,
decode_timestep=decode_timestep,
decode_noise_scale=decode_noise_scale,
)
def _spatial_upsample_phase(self, latents: torch.Tensor) -> torch.Tensor:
"""Apply the recipe-managed spatial upsampler to unpacked latents."""
latent_upsampler = getattr(self, "latent_upsampler", None)
if latent_upsampler is None:
raise RuntimeError("This LTX pipeline recipe requires a spatial latent upsampler.")
dtype = getattr(latent_upsampler, "dtype", latents.dtype)
return latent_upsampler(latents.to(device=self.device, dtype=dtype))
def decode_phase(self, phase: LTXPhaseResult) -> DiffusionOutput | list[DiffusionOutput]:
"""Decode one completed phase and restore per-request outputs."""
forward_ctx = phase.forward_context
request_inputs = forward_ctx.request_inputs
output = self._decode_output(
latents=phase.video,
audio_latents=phase.audio,
output_type=request_inputs.output_type,
connector_prompt_embeds=forward_ctx.prompt_context.connector_prompt_embeds,
generator=request_inputs.generator,
device=forward_ctx.device,
decode_timestep=request_inputs.decode_timestep,
decode_noise_scale=request_inputs.decode_noise_scale,
prompt_batch_size=forward_ctx.batch_size,
)
if not self.supports_request_batch:
return output
return split_diffusion_output_by_request(
output,
forward_ctx.req,
num_outputs_per_prompt=forward_ctx.num_videos_per_prompt,
)
def load_weights(self, weights: Iterable[tuple[str, torch.Tensor]]) -> set[str]:
return AutoWeightsLoader(self).load_weights(weights)