Shift is a property of the trained schedule, not of the step count, so
the tab sliders take absolute values, defaulting to the shipped 12 and
3. video_minimax resolves each request from the request value or the
scheduler config inside apply_overrides, which the tab, the api and
the still path all call, so a request without values lands on the
shipped schedule. The api maps sampler_shift onto the video schedule
and gains audio_shift. Applied values are recorded as Video shift and
Audio shift; the PDD pin records what it enforces.
LTX generates 8n+1 frames and floors anything else internally, so a request
for 120 frames on the shared path silently produced 113. The tab has always
snapped the count before requesting it; the shared path now applies the same
rule, next to the width and height rounding it already did.
2.5 reuses the LTX-2 pipeline classes, so it is described through the
capability table: Gemma 4 text encoder, cross-timestep conditioning, and the
upsampler and stage 2 LoRA that now ship inside the model repo. The repo
carries the distilled scheduler config, so Dev rows restore the terminal
shift, and the Dev transformer sits in transformer_full.
Distilled rows stop forcing dynamic shifting on, which remapped their sigma
schedule. Auto duration hands the clip length to the duration head.
DiffusionPipeline.download derives ignore_patterns from the passed components and
never reads the caller's, so the kwarg set in load_override was inert and diffusers
logged it as an unexpected keyword. The unsharded connectors duplicate it was meant
to skip was fetched on every LTX-2.3 mirror load.
Resolve the repo to a snapshot built from those patterns and hand from_pretrained
the folder instead of the id. That skips its download path, so the passed component
folders it would have pruned are pruned here instead. The connectors override drops
its own copy of the kwarg, which ModelMixin never read either.
First natively modular model: the pipeline is driven directly through
ModularPipeline, with components fetched per workflow (fl2va covers
text and first/last-frame conditioning).
- per-generation overrides snap the canvas to /32, align frames to
the 17n+5 grid and duration window, and keep the bespoke scheduler
pair
- group offload for modular pipelines applied per component in
sd_offload; re-application is a guarded no-op
- audio checkbox pops the audio decode block so decode and muxing are
skipped
- frames=1 renders a single still image: the duration floor lifts per
instance and sub-floor latents pad at the vae decoder
- progress and interrupt handling via a transformer forward pre-hook
- vae scale factor override, tuple-safe patch size
Wan 2.2 A14B ships a per-model boundary_ratio (0.9 I2V, 0.875 T2V) that selects the high- or low-noise expert per step. The video and base-model image loaders both load the shipped value; the slider override is applied at generation time in set_pipeline_args, the one point both paths pass through before invoking the pipeline.
The denoising loop reads config.boundary_ratio each call, so tuning takes effect with no reload for video and base-model images alike. The slider defaults to -1, meaning use the model's value; 0 to 1 set the boundary explicitly. Single-expert stages stay load-time because they drop a transformer to free VRAM.
LTXCaps gains a `variant` field ('0.9', '2.0', '2.3') replacing
`is_ltx_2_3`; variant-specific branches check `caps.variant == '2.3'`
instead of grepping the model name.
ltx_util.load_upsample_2x mirrors load_upsample's contract so the 2.x
path owns a module-level cache and stops reloading ~2.3 GB every run.
The cached pipe is stamped with a synthetic
`CheckpointInfo('ltx-upsampler-2.x')` so it gets its own OffloadHook
slot and can go through apply_balanced_offload without invalidating
the main pipe's module map. The hardcoded `.to('cpu')` and post-pass
torch_gc are gone; the second apply_balanced_offload handles spill.
video_overrides comment on OzzyGT LTX-2.3 connectors states plainly
that mirrors pack weights twice by design; ignore_patterns is the
surgical workaround, not an hf_hub bug.
Drive-by: load_upsample log line used `__class__.__name__` (always
'type'); switched to `__name__`.
Implement the Lightricks two-stage recipe (diffusers PR #13217) for the
LTX-2.x Dev family: Stage 1 at half-res with full four-way guidance,
2x latent upsample, Stage 2 with distilled LoRA + scheduler swap + identity
guidance on STAGE_2_DISTILLED_SIGMA_VALUES.
Extends to both LTX-2.0 and LTX-2.3 Dev via per-family distilled-LoRA
repos carried on the caps; Distilled variants take the same flow minus
the LoRA swap. Auto-couples Refine with a fixed 2x upsample on any Dev
variant with a known LoRA when the user enables Refine without Upsample.
- caps: is_ltx_2_3, use_cross_timestep, default_dynamic_shift,
stage2_dev_lora_repo, supports_canonical_stage2, modality_default_scale,
guidance_rescale_default; LTX-2.x defaults realigned to canonical
cfg=3.0 / steps=30; per-variant STG block and four-way guidance wired
for non-distilled 2.x
- process: canonical Stage 1/Stage 2 helpers, scheduler + opts snapshot
under try/finally, per-family upsampler repo, audio latents threaded
from Stage 1 into Stage 2, use_cross_timestep gated per caps
- overrides: skip the redundant unsharded LTX-2.3 connectors blob and
share LTX2TextConnectors weights across 2.3 variants when te_shared_t5
- load: Gemma3 shared-TE path for LTX-2.3; gate use_dynamic_shifting=False
override to 0.9.x only so LTX-2.x stays on its canonical token-count
dynamic shift
Rework the LTX Video tab so one UI handles every registered variant
(0.9.0 through 2.3, Dev/Distilled/SDNQ-4Bit, T2V/I2V/Condition). Per-
variant behavior is driven from a single capability lookup rather than
substring matching on model names scattered across the backend.
- modules/ltx/ltx_capabilities.py: new module computing family, is_i2v,
distilled, supports_input_media, supports_multi_condition,
supports_image_cond_noise_scale, supports_decode_timestep,
supports_stg, supports_audio, supports_frame_rate_kwarg, and the
default CFG / steps / sampler_shift for a given model name by reading
its registered repo_cls in models_def.
- modules/ltx/ltx_ui.py: capability-gated UI. Selecting a model rewires
accordion visibility, slider interactivity, and defaults via a single
model.change handler. New controls: dedicated image input slot inside
the LTX tab (replaces the disconnected shared init_image for I2V),
condition strength slider, CFG / sampler shift / dynamic shift
sliders that were previously unreachable. Input media accordion
restructured so the image slot is always-visible while the video /
gallery prefix tabs only appear on Condition pipelines.
- modules/ltx/ltx_process.py: route the base pass through
processing.process_images(p) so LTX inherits standard scheduler
wiring, extra_networks activation, VAE handling, and error plumbing
from StableDiffusionProcessingVideo. The multi-pass latent path
(upsample / refine) stays on direct pipeline calls for latent
re-entry. Refine noise control gets family-specific kwargs:
denoise_strength for 0.9.x LTXConditionPipeline, noise_scale for all
2.x pipelines; the prior strength= injection crashed on 2.x and only
affected conditioning intensity on 0.9.x. Add torch_gc between every
stage boundary (base to upsample to refine to vae decode) so the
CUDA allocator cache does not retain the prior pass's allocations
across stages. Remove the TypeError fallback that silently passed
raw latents to save_video when VAE decode returned None on OOM;
those errors now surface cleanly.
- modules/ltx/ltx_util.py: get_conditions grows a family parameter and
builds LTX2VideoCondition (frames, index, strength) for 2.x or
LTXVideoCondition (image, video, frame_index, strength) for 0.9.x.
get_bucket floors to max(32, vae_spatial_compression_ratio) since LTX
pipelines validate divisibility by 32 regardless of family.
- modules/video_models/video_overrides.py: extend the I2V generator
reset to cover LTX2ImageToVideoPipeline and both Condition classes.
Keep the strength= kwarg injection gated to 0.9.x
LTXConditionPipeline only; LTX2ConditionPipeline.__call__ does not
accept it (per-condition strength lives on the LTX2VideoCondition
dataclass instead).
CalamitousFelicitousness
Vladimir Mandic