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mirror of https://github.com/huggingface/diffusers.git synced 2026-10-23 09:09:01 +03:00

6820 Commits

Author SHA1 Message Date
sayakpaul
d035dcd7cc Release: v0.40.0-release v0.40.0 2026-08-20 19:54:04 +05:30
Dhruv Nair
5900dbf0da [CI] Fix build and test step in release workflow (#14543)
update build test to use tiny flux
2026-08-20 19:48:39 +05:30
Dhruv Nair
3681e65996 Restructure skill files and reference guides for CLI based installation. (#14454)
* restructure guides as skill references

* reorganize AGENTS.md and references

* clean up

* clean up

* clean up

* fix AGENTS.md references and add check_ai to Makefile

* clean up

* update paths

* clean up
2026-08-20 18:16:49 +05:30
Sayak Paul
192cf685ec [distributed] fix corrupted gradient problem under ring CP. (#14274)
* fix corrupted gradient problem under ring CP.

* address dhruv's comments.

* handle torch version

* varlens too
2026-08-20 18:16:17 +05:30
Sayak Paul
0aa743c08d [tests] migrate lora tests for pipelines to use new mixins (#14268)
* start migrating lora tests.

* massive refactor.

* up

* remove planning doc

* address review: tighten lora bias tests

* move run_pipe()

* collapse.

* up

* done

* update

* only use diffusers api contract in tests.

* fix: pass tmp_path through AuraFlow test_lora_B_bias override

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
2026-08-20 17:19:50 +05:30
Atharva Joshi
4e0466f3e5 fix: image preprocessing for cosmos3 (#14519)
fix: preserve Cosmos3 conditioning image aspect ratio
2026-08-19 08:43:50 -10:00
Dhruv Nair
ac56fa2f25 [CI] Fix authentication on forked PRs (#14534)
fix auth for forked PRs
2026-08-19 17:41:04 +05:30
Jingya HUANG
7d2e86a85a [core] Support tensor parallelism for model inference (CUDA, Neuron) (#13718)
* draft:add neuron as a legit backend

* feat: neuron-specific changes in the pipeline

* tests: eager tests

* draft: start with tp for flux2

* fix: style

* fix:apr_02 beta

* feat:add wan

* fix:pixart

* fix: rewrite flux swiglu activation to avoid gather op in neuron IR

* test: pixart compile mode on neuron

* cleanup & fix style

* merge: another change

* review: cleanup+suggestions

* fix: CIs style

* tests: add test units for tp

* fix: in case of text-encoder(s) on CPU

* review:cleanup+add test

* fix: style

* doc: remove it for now

* Add from_single_file support for SkyReelsV2 and ChronoEdit transformers (#13946)

SkyReels-V2 and ChronoEdit are both built on Wan, and their transformers have
the same keys as WanTransformer3DModel, so they reuse
convert_wan_transformer_to_diffusers (like WanVACE / WanAnimate). This lets the
community GGUF builds load directly.

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

* multi-GPU VAE Fix for Cosmos 3 (#13924)

fix(cosmos3): pin VAE latent norm buffers to encode output device

Under sharded placement (device_map="balanced"), vae.encode() runs on the
VAE's own device while the mean/inv_std buffers were pinned to x.device,
causing a cross-device RuntimeError. Compute raw_mu first, then pin the
normalization buffers to its device so all tensors share one device.

Co-authored-by: Atharva Joshi <atjoshi@smc521ge-0036.ipp2a2.colossus.nvidia.com>
Co-authored-by: Sayak Paul <spsayakpaul@gmail.com>

* docs: fix repeated word typo in set_timesteps docstring (#13876)

* docs: fix repeated word typo in set_timesteps docstring

Removed the duplicate word "schedule" from the docstring for the sigmas argument in EulerDiscreteScheduler.set_timesteps.

* Update scheduling_euler_discrete.py

* Apply style fixes

---------

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

* clean some stuff to simplify code.

* clean more to remove permutation related shenanigans.

* revert: put torch.chunk back

* Update docs/source/en/training/distributed_inference.md

Co-authored-by: Sayak Paul <spsayakpaul@gmail.com>

* Address Sayak's TP review nits (docstrings + stale comments)

- _modeling_parallel: fix stale comment claiming attention processors read
  tp_degree at runtime (no longer true after the PackedColwise/Rowwise
  refactor; processors are TP-agnostic via head_dim).
- tensor_parallel: single backticks instead of double in docstrings, add
  input/output examples to _blocks_to_block_sizes and _resolve_tp_plan, and
  drop the stale "applies the Flux2 fused-weight permutations" line from
  apply_tensor_parallel (permuters were removed).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* Fix stale permuter reference in Flux2ParallelSelfAttnProcessor comment

The proportional QKV/MLP slice is now guaranteed by PackedColwiseParallel
block-by-block sharding, not the removed fused-weight permuter.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* Derive TP backend inside apply_tensor_parallel from the mesh device type

Drops the `backend` parameter: apply_tensor_parallel already holds the TP
mesh, so it derives neuron-vs-default from `config._mesh.device_type` itself.
The caller no longer computes it. Documents why torch_device can't be used
(Neuron reports as "cpu" via torch's accelerator API). Removes the now-unused
is_torch_neuronx_available import from modeling_utils.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* Simplify TP backend derivation to the mesh device type alone

Drop the redundant is_torch_neuronx_available() guard: a DeviceMesh("neuron", ...)
only exists when running on Neuron, so tp_mesh.device_type is the single source
of truth.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* Remove incorrect "Neuron reports as cpu" rationale from TP backend docstring

Verified on the current native torch_neuronx drop that Neuron does surface as
the torch accelerator (torch._C._get_accelerator().type == "neuron",
get_device() == "neuron"); the old "reports as cpu" claim was stale. The
mesh-device-type derivation is unchanged — it's the device being sharded onto.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* Drop stale "XLA" labels from Neuron device/runtime comments

Neuron is a native torch backend now (not XLA-routed): remove the "(XLA)"
parenthetical from the randn-on-CPU note in torch_utils and the "XLA runtime"
mention from the Neuron TP test docstring. Behavior unchanged.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* make style: reflow tensor_parallel docstrings

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* Revert "revert: put torch.chunk back"

This reverts commit 7ea75f771a.

* fix: sharding for neuron + validate flux 1

* fix: change for check_repository_consistency

* feat: support qwen image as well

* Update docs/source/en/training/distributed_inference.md

Co-authored-by: Steven Liu <59462357+stevhliu@users.noreply.github.com>

* review: keep bria and nucleusmoe out

* review: keep bria and nucleusmoe out

* review: keep bria and nucleusmoe out

* review: address agent review

* review: apply suggestions

* Update docs/source/en/training/distributed_inference.md

Co-authored-by: Sayak Paul <spsayakpaul@gmail.com>

* review: change example tp size to 4

* review: add flux tp test

* review: address comments

* review: improve the doc

* review:apply qwen rotary_emb per device

* review:remove redundant device def after PR #14383

* review: doc title suggestion

* review: restore copy comment

* review: remove cp divisibility explanation from doc on parallelism guide

* fix style

---------

Co-authored-by: Hz_Zhang <47402297+HaozheZhang6@users.noreply.github.com>
Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>
Co-authored-by: Atharva Joshi <atjoshi@nvidia.com>
Co-authored-by: Atharva Joshi <atjoshi@smc521ge-0036.ipp2a2.colossus.nvidia.com>
Co-authored-by: Sayak Paul <spsayakpaul@gmail.com>
Co-authored-by: Ramkumar R <ramkumarashvanth09@gmail.com>
Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>
Co-authored-by: Steven Liu <59462357+stevhliu@users.noreply.github.com>
2026-08-19 16:20:59 +05:30
Buffett Liu
360bef8074 Feat -- Stable Audio 3 (#14119)
* Stable Audio 3 First Version Commit, require model dict loading on GPUs

* Fixing bugs for sa3 VAE

* Make quality fix

* Fix the unit test failure

* Fix SA3 pipeline noise: learned text-padding embedding + no cross-attn mask

The diffusers Stable Audio 3 pipeline produced noise instead of music because
the cross-attention conditioning was built differently from the reference:

- The reference text conditioner uses padding_mode="learned": padded text
  positions (~245 of 256 for a short prompt) are filled with a trained
  `padding_embedding`, and the DiT attends to *all* positions (its
  cross-attention mask is intentionally disabled). Our pipeline instead zeroed
  padded positions and masked them out, wiping ~95% of the conditioning signal.

Changes:
- transformer_stable_audio3: add learned `prompt_padding_embedding`; in forward,
  replace masked text positions with it (in cond_token_dim space, before
  to_cond_embed) then attend to the full context, matching the reference.
- pipeline_stable_audio_3: stop zeroing padded positions (the DiT now handles
  them); default `silence_padding_duration` to 6.0 (reference headroom default).
- convert_..._to_diffusers: convert
  `conditioner.conditioners.prompt.padding_embedding` into the DiT.
- scheduling_ping_pong: pin schedule endpoints (sigmas[0]=1.0, sigmas[-1]=0.0)
  to match the reference LogSNRShift endpoint preservation.
- run_..._inference: coerce float16->float32 on CPU.
- tests: update transformer state-dict expectations (523 tensors, add
  prompt_padding_embedding) and ping-pong sigma endpoint assertions.

Verified against the reference with identical noise + identical conditioning:
full 8-step ping-pong trajectories agree to 4e-6 (final latent). Removed the
dev-only parity scripts (verify_*_dit_parity, verify_*_vae_parity) from the tree.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Style fix

* Autopipeline available

* Adding document description for testing examples.

* Solving fix for serge review bot suggestion

* Design review comments fix

* CI/CD Fix for ping pong scheduler md file

* Fix doc build: remove autodoc for nonexistent StableAudio3EulerSchedulerOutput

* Fix doc build: qualify non-exported autodoc references with module paths

* Fix details in scheduler and some nits

* suggestion fix

* fix-copies: propagate prepare_latents dtype fix to audio2audio/inpaint pipelines

---------

Co-authored-by: Buffett Liu <jengliu@linkedin.com>
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Co-authored-by: dg845 <58458699+dg845@users.noreply.github.com>
2026-08-18 22:09:32 -07:00
Dhruv Nair
aeda394db7 [CI] Allow single file tests to run as fast tests (#14324)
* update

* update

* update

* update

* [FA2] Use `kernels-community/aiter-flash-attn-ck` Hub kernel for ROCm FlashAttention (drop `aiter` dependency) (#14436)

Use  Hub kernel

Co-authored-by: Sayak Paul <spsayakpaul@gmail.com>

* add HF_TOKEN to pr workflow

* fix token

* clean up

* Apply suggestions from code review

Co-authored-by: Sayak Paul <spsayakpaul@gmail.com>

---------

Co-authored-by: Sayak Paul <spsayakpaul@gmail.com>
Co-authored-by: BADAOUI Abdennacer <106801897+Abdennacer-Badaoui@users.noreply.github.com>
2026-08-19 10:32:03 +05:30
Dhruv Nair
f3175baf6a [CLI] Clean up and improvements to diffusers CLI (#14381)
* [CLI] Clean up and improvements to `diffusers-cli`

Modular pipelines:
- `custom_blocks` also writes `modular_model_index.json`, so a packaged repo is
  loadable by `ModularPipeline.from_pretrained` (and runnable by `run`), not just
  importable as blocks.
- Add `--cpu-offload auto`, which offloads through the pipeline's
  `ComponentsManager`, plus `--offload-margin` to set its `memory_reserve_margin`.
- Add `--workflow` passthrough; warn and ignore it on standard pipelines.
- Route `model_index.json` repos whose `_class_name` is modular to the modular path.

Output saving:
- Resolve every media field on the output object (`images`, `frames`, `audios`,
  `audio`) instead of the first match, keeping the batch dimension. Fixes video
  output being misrouted through the image branch and LTX2's audio being dropped.
- Fix the `output_type="pt"` video transpose: `postprocess_video` returns
  `(B, F, C, H, W)`, not `(B, C, F, H, W)`.
- Save `(B, C, samples)` waveforms as multi-channel wavs (StableAudio).
- Write each video's frames to `<stem>-frames/<NNNN>.png`. Frames need no video
  backend, so they replace the `.pt` fallback when `export_to_video` fails.
- Report frame directories as a single path so hundreds of frames don't flood the
  terminal; `--push-to` and the sandbox download preserve subfolder structure.
- Raise on unrecognized payloads instead of dumping JSON/pickle.

Remote:
- Add `imageio`, `imageio-ffmpeg`, and `peft` to the default sandbox deps.
- Raise sandbox `start_timeout` to 600s; the 120s default expires while a cold node
  pulls the pytorch base image.

* Apply suggestion from @sayakpaul

Co-authored-by: Sayak Paul <spsayakpaul@gmail.com>

* update

* update

---------

Co-authored-by: Sayak Paul <spsayakpaul@gmail.com>
2026-08-19 09:55:26 +05:30
YiYi Xu
11a82a15fe replace enable_gpa with repeat_interleave for krea2 (#14523)
* Krea 2: repeat key/value heads instead of `enable_gqa`

Krea 2 always attends with a text padding mask, and no fused SDPA kernel takes
a mask together with mismatched query/key head counts — flash rejects the mask,
the memory-efficient kernel rejects the mismatch. Attention therefore fell back
to the math backend, which materializes the full
[batch_size, num_heads, seq_len, seq_len] score matrix with no error or warning.

Repeating the key/value heads in the processor computes the same thing and keeps
the memory-efficient kernel eligible: at 1024x1024 (48/12 heads, 4608 tokens) one
attention call goes from 9.02 GiB / 26.7 ms to 0.16 GiB / 4.1 ms.

It also unpins the model from the native backend, since cuDNN, flash, FA3, sage
and the hub kernels all raise on `enable_gqa`.

Fixes #14518

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

* docs: how to choose between `enable_gqa` and repeating key/value heads

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

* docs: recommend a choice rather than just reporting one

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

* docs: add enable_gqa reference model, reword performance note

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 5 <noreply@anthropic.com>
2026-08-18 10:15:09 -10:00
Sayak Paul
425b113c21 [tests] refactor pipeline-level quantization tests (#14435)
* fix(torchao): route root-level tensors around safetensors reconstruction

Models with parameters at the root of the module tree (e.g. Wan's
`scale_shift_table`) crashed torchao's `unflatten_tensor_state_dict`
when loading serialized checkpoints, since flattened tensor names are
assumed to carry a module prefix. Filter such tensors and their
metadata entries out of the reconstruction and merge them back
unchanged.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* fix(bnb): defer 8-bit weights split from their SCB stats across shards

Sharded serialization can place an 8-bit weight and its `SCB`
statistics in different shard files, in which case the shard-by-shard
loader failed with "Missing quantization component `SCB`". Hold the
incomplete half of the pair back until its counterpart arrives with a
later shard, mirroring the torchao pending mechanism, and disable
parallel shard loading for prequantized 8-bit checkpoints.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* [tests] extend model-level quantization tester mixins

Migrate remaining model-level coverage from tests/quantization into the
tester mixins so it runs for every wired model:

- base: buffer-placement assertions in the device-map test, and an
  opt-in sharded-serialization test enabled by setting
  `sharded_serialization_config`
- bnb: serialization across all configs (sharded included), dtype
  assignment and adapter training for 8-bit, device moves preserving
  the memory footprint, corrupted-state-dict loading error, and a fixed
  modules-to-not-convert test (BitsAndBytesConfig only exposes
  llm_int8_skip_modules; the old test passed an unsupported kwarg and
  only survived by being skipped)
- torchao: custom device maps with cpu/disk offload, generalized from
  the Flux-specific test
- gguf: the diffusers-format single-file loading path, wired into the
  Flux model tests

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* [tests] fix model-level quantization test wiring

- SD3.5: the quantized testers reused the random-init dummy inputs
  (4 latent channels, fp32) while the tiny Hub checkpoint has
  in_channels=8 and the quantizers load the model in half precision;
  give them matching inputs and relax the 4-bit memory expectation for
  the tiny checkpoint.
- QwenImage / Flux2: the quantized testers had no Hub checkpoint wired
  at all, so every test errored; point them at
  hf-internal-testing/tiny-qwenimage-pipe and tiny-flux2 with matching
  inputs.
- NucleusMoE: no tiny checkpoint exists on the Hub yet; comment the
  testers out like the LTX ones.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* [tests] split tests/quantization into pipeline-level and backend-level tiers

Pipeline-level quantization tests (pipeline quality slices, cpu offload,
LoRA loading, compile, PipelineQuantizationConfig) move to
tests/pipelines/testing_utils/quantization.py, marked per backend so the
nightly CI can select them with `pytest -m`. tests/quantization keeps
only backend-level tests that fit neither tier: config validation,
utility warnings, and GGUF CUDA kernel correctness. Tests already
covered by the model-level mixins are dropped.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* [ci] select nightly quantization tests by marker across test tiers

Each backend job now runs `pytest -m <marker>` over tests/models,
tests/quantization, and tests/pipelines/testing_utils/quantization.py,
giving the model-level mixin tests a nightly home with the backend
dependencies installed. The torchao job additionally installs mslk.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

---------

Co-authored-by: sayak@huggingface.co <sayak@ip-10-53-90-45.ec2.internal>
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
2026-08-18 20:53:32 +02:00
Sayak Paul
a14d630211 [tests] refactor stable diffusion pipeline tests (#14339)
* refactor stable diffusion pipeline tests

* consolidate on nightly

* define sets explicitly.

* up
2026-08-18 19:58:22 +02:00
apolinário
a0b3a073d6 Support DiffSynth-Studio MiniMax-H3 LoRAs (#14484)
* Support DiffSynth-Studio MiniMax-H3 LoRAs

* Note the DiffSynth fp32 factors in the LoRA docstring
2026-08-18 19:13:25 +02:00
iridescentWen
59c47446f2 docs: fix typos in Kandinsky 5.0 video docs (#14345)
- `qualty` -> `quality`
- `infered` -> `inferred` (x3)
- `bakend` -> `backend` (x3, in the trailing `# <--- Set attention
  bakend to Flex` comments; the actual `set_attention_backend` calls
  were already spelled correctly)
- `wothout` -> `without`

Prose and comments only, no code or behavior changes.
2026-08-18 08:55:22 -07:00
Kashif Rasul
d6bfaa71b8 Fix batched DiffusionGemma adaptive stopping (#14386)
* Fix DiffusionGemma stopping

* Test batched stopping

* Style DiffusionGemma docs

* Address DiffusionGemma review

* Update DiffusionGemma review

---------

Co-authored-by: dg845 <58458699+dg845@users.noreply.github.com>
2026-08-18 11:12:21 +02:00
Sayak Paul
356c2fc7e5 [tests] skip parallelism tests for some models. (#14505)
* skip parallelism tests for some models.

* clarify comment

* skip others too.
2026-08-18 10:06:23 +02:00
YiYi Xu
a00d536450 Drop the experimental warning from Modular Diffusers (#14525)
Modular Diffusers is no longer experimental: remove the import-time warning
and the docstring warnings from ModularPipeline, the block base classes, and
every model's modular pipeline, and drop it from the docs overview.

ComponentsManager and the Mellon integration are still moving, so they keep
a warning — added one to the ComponentsManager docs page and to
mellon_node_utils, which had none.

Co-authored-by: Claude Opus 5 <noreply@anthropic.com>
2026-08-18 09:28:43 +02:00
Sayak Paul
9284607295 ci: drop stale tokenizers<0.23.0 override (#14504)
transformers now hard-requires tokenizers>=0.23.1,<0.24.0 at import time,
so the override from #13767 breaks every job at the environment step
(ImportError: tokenizers>=0.23.1,<0.24.0 is required ... found 0.22.2).
The originally-problematic 0.23.0 is already excluded by transformers'
own lower bound, so the override can go entirely.

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
2026-08-17 13:09:05 +02:00
Sayak Paul
d5baa4fb54 tests: fix cuda model tests. (#14464)
* tests: fix cuda model tests.

* up

* up

* up

* add to docstrings.

* restore previous beehaviour.

---------

Co-authored-by: dg845 <58458699+dg845@users.noreply.github.com>
2026-08-15 16:56:06 +02:00
Sayak Paul
c401daa142 fix SVD tests (#14475)
* fix svd tests

* remove unneeded stuff
2026-08-15 07:45:10 +02:00
Sayak Paul
90b4e34e79 tests: fix qwen tests from getting oom'd in our CI. (#14474) 2026-08-14 14:25:33 +02:00
Sayak Paul
69a0d5a52b [tests] use eval() on t5 for deterministic results. (#14472)
* use eval() on t5 for deterministic results.

* fix wan
2026-08-14 14:25:26 +02:00
Benjamin Bossan
ea129f30ed FIX LoRA tests warning about unexpected keys (#14476)
Resolves https://github.com/huggingface/peft/issues/3548.

The issue appeared after merging
https://github.com/huggingface/peft/pull/3490 in PEFT. As part of a
side effect of that refactor, the adapter name is not part of the
state dict keys in the reported mismatches. The warning logic did,
however, check for the adapter name, resulting in the warning not
being emitted.

The fix simply drops the adapter name from the check for unexpected
keys. This should be safe, because we only load one adapter at a time,
so unexpected keys should not report on other adapters anyway.

While working on this function, I also changed the "lora_" in k check
to ".lora_" in k. This should be strictly more precise, but it's not
related to the fix. I also added some type annotations for good
measure.

The tests now pass with both PEFT from source and the latest PEFT
release (i.e. before the refactor merge).

Co-authored-by: Sayak Paul <spsayakpaul@gmail.com>
2026-08-14 14:25:21 +02:00
dependabot[bot]
4dea855091 Bump transformers from 4.47.0 to 5.5.0 in /examples/flux-control (#14179)
Bumps [transformers](https://github.com/huggingface/transformers) from 4.47.0 to 5.5.0.
- [Release notes](https://github.com/huggingface/transformers/releases)
- [Commits](https://github.com/huggingface/transformers/compare/v4.47.0...v5.5.0)

---
updated-dependencies:
- dependency-name: transformers
  dependency-version: 5.5.0
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
2026-08-14 12:25:41 +02:00
Sayak Paul
4c963d9b81 Revert "svd failures."
This reverts commit 875cccb3f5.
2026-08-14 10:14:57 +00:00
Sayak Paul
875cccb3f5 svd failures. 2026-08-14 10:14:26 +00:00
Sayak Paul
102c24934f split up tests in modular pipelines (#14444)
* notes from .ai

* ltx2

* cover the remaining tests

* fixes
2026-08-14 11:54:01 +02:00
BADAOUI Abdennacer
8222302f03 [FA2] Use kernels-community/aiter-flash-attn-ck Hub kernel for ROCm FlashAttention (drop aiter dependency) (#14436)
Use  Hub kernel

Co-authored-by: Sayak Paul <spsayakpaul@gmail.com>
2026-08-14 10:39:23 +02:00
apolinário
8c3dcd6da1 Add LoRA loading support for MiniMax-H3 (#14408)
* Add LoRA support for MiniMax-H3

* Address review: Copied-from loader, LoRA badge, docstring caveats, drop generic scale test

* Move the MiniMax-H3 LoRA tests to tests/lora

* Support the remaining published MiniMax-H3 LoRA layouts

Three more published H3 LoRAs did not load. Two were key-layout gaps and the
third was the reason neither was noticed: a layout that reaches no module at
all used to return without an exception.

- musubi-tuner writes one flattened `lora_unet_` name per module. It is
  un-flattened against the H3 module vocabulary, since `qkv_proj`,
  `token_refiner`, `final_layer` and the output heads carry underscores that
  are not path separators, and then goes through the existing kohya path.
- one producer publishes its own converter's output: diffusers module names
  with peft's `.default.` infix left in and no component prefix. The infix is
  dropped and the prefix added.
- a state dict that filters to nothing in both partitions now warns instead of
  loading as a silent no-op, in the wording `load_lora_adapter` uses for the same
  situation.

A fourth loaded, but at the wrong strength. One producer ships no `.alpha` scalars
and records the alpha it trained with in the file's own `__metadata__` instead,
under `alpha`. Its 8-step turbo LoRA pairs that entry's 8 with rank 128, an
effective scale of 0.0625, so synthesizing `alpha == rank` applied the adapter 16x
too strong. That entry is now read as the uniform network alpha. Per-module scalars
still win when a file carries both, since the converter has already folded them into
the weights, and a non-numeric value is warned about and ignored. `__metadata__` only
exists on a file, so `_fetch_state_dict` hands it back on request.

* Simplify the MiniMax-H3 LoRA comments

* Trim the MiniMax-H3 LoRA tests to loading and effectiveness

* Reference the alpha convention in the MiniMax-H3 LoRA docstring

* Drop a redundant format comment

* Test only diffusers-written state dicts

* Rely on get_peft_kwargs for alpha-less files

* Drop the peft version guards after the main cleanup

---------

Co-authored-by: Sayak Paul <spsayakpaul@gmail.com>
2026-08-14 09:50:12 +02:00
apolinário
2da7040be1 Add MiniMax Music 3 (#14456)
* Add MiniMax Music 3 transformer, pipeline sub-models, and conversion script

* Add MiniMax Music 3 pipeline, tests, and docs

* Wire example docstring, point diffusers-format references at MiniMaxAI/MiniMax-Music-3

* Use MiniMaxAI/MiniMax-Music3 as the official diffusers weights repo id

* Apply doc-builder style

* Use dtype in examples, demonstrate the structured prompt format

* Use soundfile in examples like the other audio pipelines

* Convert to a modular pipeline and move models under src/diffusers/models

Per review: the conditioner moves to models/condition_embedders, the RVQ depth
decoder and vocoder to models/transformers and models/autoencoders, and the
standard pipeline is replaced by MiniMaxMusic3ModularPipeline (anima-style
blocks, helios-style chunk loop, guider-abstracted CFG with a zeros
unconditional branch). Index configs now reference all components under the
diffusers library. Also applies the transformer review suggestions
(Transformer2DModelOutput, inlined rotary forward, explicit processor default).

* Point modular index loading specs at the Hub repo in the converter

* Apply doc-builder style to the modular blocks docstrings

* Address review-bot comments: overlap comment accuracy, single pipeline-level progress bar, zero-frame duration guard, import ordering, docstring cross-reference

* Support CPU offloading in the AR step: trigger offload hooks before submodule calls (minimax_h3 workaround), clear error when the AR models cannot co-reside

* Docs: PR-install tip and memory-usage section with measured offloading numbers

* Address review comments on the block assembly

Take the individual models rather than `components` in `_generate_depth_codes` and
`_embed_audio_frame`; `num_codebooks` / `audio_vocab_size` come off the depth decoder's
config, so the two pipeline properties that existed only for them are gone.

Assemble the blockset as three top-level children, each owning models and runnable on its
own — generate the semantics once and denoise it with different settings:

    semantic_generator  MiniMaxMusic3SemanticGenerationStep  [tokenize, generate]
    denoise             MiniMaxMusic3CoreDenoiseStep         [prepare_chunks, denoise]
    decode              MiniMaxMusic3VocoderDecodeStep

`MiniMaxMusic3TextEncoderStep` is renamed `MiniMaxMusic3TokenizeStep` (it only tokenizes)
and the autoregressive leaf `MiniMaxMusic3AutoregressiveStep`, freeing its old name for
the sequential.

Point the tests at `hf-internal-testing/tiny-minimax-music3-modular-pipe`; the previous
fixture repo's component specs pointed at a local path, so nothing loaded off that machine.
Drop the PR-branch install tip from the docs.

20s and 60s generations are bit-identical to before these changes.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

---------

Co-authored-by: yiyixuxu <yixu310@gmail.com>
Co-authored-by: Claude Opus 5 <noreply@anthropic.com>
2026-08-13 13:47:57 -10:00
dg845
acd9c2718a [CI][tests] Fix LTX-2.5 Diffuson Decoder Tiling CI CPU Timeout (#14462)
Add require_accelerator decorator to test_tiles_covering_the_video_match_untiled_exactly to prevent CI timeout on CPU

Co-authored-by: Sayak Paul <spsayakpaul@gmail.com>
2026-08-13 16:18:52 -07:00
YiYi Xu
35ab485bde [Agent docs] some updated based on recent integration (#14452)
* Add agent-doc lessons from the Wan-Animate-2 modular integration

- models.md: document _skip_keys (group offloading exclude_kwargs +
  device_map dispatch skip_keys) with the in-tree cache examples
- modular.md: canonical flat-blockset packing (standalone children,
  InsertableDict groups, no cross-preset-file imports); variant presets
  carry their own model_name + mapping entry (#14451); composed-blockset
  inputs/outputs overrides; guider ownership and
  requires_unconditional_embeds; always ship modular_model_index.json;
  auto-docstring drift + check_forward_call_docstrings checklist items;
  randn_tensor gotcha
- pipelines.md: the same randn_tensor gotcha

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* Apply suggestions from code review

Co-authored-by: Steven Liu <59462357+stevhliu@users.noreply.github.com>

* Address review comments

Reword the `_skip_keys` guidance: "non-tensor runtime objects holding large tensors"
contradicted itself, say "state the model places itself" instead.

Drop the paragraph claiming the guider spec is declared only by the denoise blocks —
`WanTextEncoderStep` declares one too, and the codebase is inconsistent enough that no
rule can be stated yet (see #14469).

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
Co-authored-by: Steven Liu <59462357+stevhliu@users.noreply.github.com>
2026-08-13 10:52:44 -10:00
Vinh H. Pham
788e80206a docs: document fused-kernel performance in Nunchaku Lite guide (#14458)
* docs: document fused-kernel performance in Nunchaku Lite guide

* Apply suggestions from code review

Co-authored-by: Steven Liu <59462357+stevhliu@users.noreply.github.com>

* Apply suggestion from @rootonchair

---------

Co-authored-by: Steven Liu <59462357+stevhliu@users.noreply.github.com>
2026-08-13 09:00:17 -07:00
Sayak Paul
6b3740be8f feat: clean up peft related versioning voodoo. (#14463)
* feat: clean up peft related versioning voodoo.

* USE_PEFT_BACKEND usage
2026-08-13 12:18:18 +02:00
Wang, Yi
bb56997d4b Fix AuraFlow model parallelism device mismatch and update XPU IP-Adap… (#14273)
* Fix AuraFlow model parallelism device mismatch and update XPU IP-Adapter expectations

Description

This PR fixes two test issues currently reflected in the working tree.

Changes

Fixed AuraFlow model parallelism in auraflow_transformer_2d.py.
Under device_map="auto", context_embedder can place encoder_hidden_states on a different device from the top-level register_tokens parameter. The forward pass now moves register_tokens to the projected encoder hidden states device and dtype before concatenation, avoiding cross-device torch.cat failures.

Updated XPU-specific expected slices in test_ip_adapter_stable_diffusion.py.
The IP-Adapter SD integration expectation now distinguishes XPU backend versions 3 and 5, since they produce slightly different deterministic slices.

Signed-off-by: Wang, Yi A <yi.a.wang@intel.com>

* update

Signed-off-by: Wang, Yi A <yi.a.wang@intel.com>

* update

Signed-off-by: Wang, Yi A <yi.a.wang@intel.com>

* fmt

Signed-off-by: Wang, Yi A <yi.a.wang@intel.com>

---------

Signed-off-by: Wang, Yi A <yi.a.wang@intel.com>
2026-08-13 09:36:08 +02:00
Sayak Paul
9558d918ba [tests] tighten keep_in_32 modules tests (#14399)
* tighten keep_in_32 modules tests

* remove unneeded tests

---------

Co-authored-by: dg845 <58458699+dg845@users.noreply.github.com>
2026-08-13 08:49:35 +02:00
dg845
614ae4bb9d Move LTX25AutoBlocks to new file with new model name (#14453)
Refactor LTX25AutoBlocks into its own file, give it its own model name, and add tests for it
2026-08-12 17:02:43 -07:00
YiYi Xu
3a2f35d4ef Wan-Animate-2 (authored by @kelseyee) (#14413)
* support wan-animate-2

---------

Co-authored-by: kelseyee <971704395@qq.com>
Co-authored-by: yiyi@huggingface.co <yiyi@huggingface.co>
Co-authored-by: Claude Opus 5 <noreply@anthropic.com>
Co-authored-by: sayakpaul <spsayakpaul@gmail.com>
2026-08-12 08:48:05 -10:00
Funtowicz Morgan
175fe6b241 docs: add installation instructions for NVIDIA Spark (ARM64) devices (#14448) 2026-08-11 12:17:59 -10:00
Sayak Paul
7564fb016d Ltx 2.5 (#14447)
* Add LTX-2.4 support to the LTX2 transformer, pipelines, and conversion script

LTX-2.4 reuses the existing LTX2 model and pipeline classes. The delta over
2.3 is a small set of additive config flags plus a Gemma 3 -> Gemma 4 text
encoder swap, so no new model or pipeline classes are introduced.

- transformer_ltx2.py: add `ff_bias`/`audio_ff_bias` (2.4's video FFN drops
  its bias) and `use_prompt_adaln_single` (toggles timestep-dependent prompt
  cross-attention modulation; when off, cross-attention K/V becomes
  timestep-independent and cacheable across denoising steps for a given
  prompt). Both default to their 2.3 behavior. The flag is read back from
  `self.config` rather than mirrored onto an instance attribute, and all
  three new constructor args are documented.

- pipeline_ltx2.py / pipeline_ltx2_image2video.py: add an optional
  `prompt_enhancer` component to both pipelines (previously T2V-only).
  LTX-2.4's fine-tuned text encoder is conditioning-only, so enhancement
  uses a separate off-the-shelf google/gemma-4-E2B-it checkpoint with its
  own message format and decoding recipe -- unlike LTX-2.0/2.3, where one
  checkpoint serves both roles. `enhance_prompt()` resolves the format and
  `.generate` kwargs from whichever model is active, and frees a dedicated
  enhancer from GPU memory right after use (guarded so it does not interfere
  with accelerate's offload hooks), mirroring the existing text_encoder
  handling.

  Both `__call__`s gain `enable_prompt_enhancement: bool | None = None`,
  which resolves to `True` when a dedicated `prompt_enhancer` is configured
  (LTX-2.4) or when `system_prompt` was passed explicitly (matching prior
  LTX-2.0/2.3 behavior exactly), and `False` otherwise. Explicit `False`
  disables enhancement even on 2.4. When enabled with no `system_prompt` on
  a 2.4 pipeline, the matching default system prompt is injected.

  `max_new_tokens`/`seed` keep their literal defaults (512/10)
  unconditionally: greedy decoding consumes no randomness, so `seed` is
  inert for the dedicated-enhancer case, and 512 tokens comfortably covers
  the target caption length. No public API or default changes were needed
  for LTX-2.0/2.3.

  Validation of the enhancement arguments happens in `check_inputs`, so an
  unsatisfiable request fails before the prompt is encoded rather than
  partway through generation. Text encoder, tokenizer, processor and
  enhancer type hints name the concrete Gemma classes they accept.

- utils.py: add a `PromptEnhancementConfig` dataclass plus
  `GEMMA3_PROMPT_ENHANCEMENT_CONFIG`/`GEMMA4_PROMPT_ENHANCEMENT_CONFIG` as
  the single source of truth for each model's message prefix and `.generate`
  kwargs, shared by both pipelines. Add the validated "capstyle_plus"
  LTX2_4_T2V/I2V_DEFAULT_SYSTEM_PROMPT strings, marked `docstyle-ignore` so
  `doc-builder style` cannot re-wrap them -- the prompts must stay
  byte-for-byte identical to the reference, newlines included.

- convert_ltx2_to_diffusers.py: add a "2.4" branch to all five
  get_ltx2_*_config functions. Transformer/VAE/vocoder configs are
  structurally identical to 2.3 (verified against the checkpoint's own
  safetensors metadata); only `ff_bias=False` differs. Connector
  `caption_channels`/`text_proj_in_factor` are now derived from the live
  Gemma text config rather than hardcoded, since 2.4's text encoder is not
  pinned to a single checkpoint the way Gemma-3-12B is for 2.0/2.3. Swap
  `Gemma3ForConditionalGeneration`/`Gemma3Processor` for
  `AutoModelForImageTextToText`/`AutoProcessor` so one path covers Gemma 3
  and Gemma 4. Raise a clear error when --version 2.4 is requested without
  pointing --text_encoder_model_id at a Gemma 4 (gemma4_unified) checkpoint,
  and add --prompt_enhancer_model_id, required whenever --version 2.4 is
  combined with --add_processor, since falling back to
  --text_encoder_model_id (correct for 2.0/2.3) would pair 2.4 with the
  wrong enhancement model. Also fixes a pre-existing vocoder
  class-selection bug that only checked for "2.3", and `processor` never
  being passed into the --full_pipeline LTX2Pipeline(...) construction.

- docs/source/en/api/pipelines/ltx2.md: add an "LTX-2.4" section covering
  what carries over from 2.3 unchanged (guidance recommendations, aside
  from a different STG block index) and what does not (a single-stage
  checkpoint only, with no two-stage or distilled workflow yet), plus the
  corrected prompt-enhancement recipe and its enabled-by-default behavior
  for both LTX2Pipeline and LTX2ImageToVideoPipeline.

* Fix resolution-dependent timestep shift being a no-op in all LTX2 pipelines

Every LTX2Pipeline variant's `mu = calculate_shift(...)` call passed the
scheduler's `max_image_seq_len` config value as the `image_seq_len`
argument instead of the current generation's actual packed sequence
length. Since calculate_shift's formula is a line through
(base_seq_len, base_shift) and (max_seq_len, max_shift), passing
image_seq_len == max_seq_len always evaluates to exactly max_shift --
so `mu` was pinned to a constant (2.05 for the LTX-2.4 scheduler config)
regardless of height/width/num_frames, even though `use_dynamic_shifting:
true` is set specifically to make this resolution-dependent.

Found while benchmarking LTX-2.4 diffusers output against the reference
pipeline with bit-identical starting noise: the reference computes this
shift from the real video token count (ltx_core's LTX2Scheduler.execute),
which diverges substantially from the constant diffusers was using at
any resolution other than exactly the checkpoint's max-anchor token
count. For a 768x512, 121-frame video (6144 tokens), the reference lands
on mu ~= 2.78 versus diffusers' constant 2.05.

Fixed by passing the current call's actual packed video latent length
(`latents.shape[1]`) as `image_seq_len`, matching the pattern already
used correctly in pipeline_flux.py (the source this was copied from).
Applies to all 5 LTX2 pipeline variants, each with their own independent
`__call__` (not linked via `# Copied from` for this method).

* Add LTX-2.4 duration head for automatic num_frames prediction

LTX-2.4 checkpoints ship a small regression head (~1.9M params) that predicts
the natural duration of the shot implied by a caption, from the same text
connector output the transformer is conditioned on. With it converted, a caller
can let the model choose the video length instead of picking `num_frames`.

- duration_head.py: `LTX2DurationHead` (a `ModelMixin` optional pipeline
  component) plus the `LTX2AutoDuration` request object. Modality-specific
  projections map the video and audio connector streams into a shared pooler
  dim, learnable modality embeddings tag them, one learnable query cross-attends
  the concatenation, and a small MLP regresses a log-duration. `forward` returns
  seconds as a tensor; `predict_num_frames` clamps to bounds and snaps to the
  VAE's causal temporal grid.

  The attention pooler uses explicit to_q/to_k/to_v/to_out with
  `dispatch_attention_fn` rather than `torch.nn.MultiheadAttention`, which both
  reference implementations use because that is the layout the checkpoint ships.
  `nn.MultiheadAttention` is documented in diffusers as breaking
  `enable_sequential_cpu_offload`; the split form also gets backend dispatch.

  Two details are load-bearing for numerical parity: the GELU must be
  tanh-approximated (the exact GELU gives different numbers against the
  JAX-trained head), and the clamp must precede the grid snap (a clamped frame
  count is not necessarily grid-aligned). Where narrow bounds convert to a frame
  window containing no grid point -- at 24 fps [1.0s, 1.02s] rounds to [24, 24],
  and 24 is not 8k + 1 -- the nearest grid point is used and a warning logged,
  rather than refusing to generate over a rounding artifact.

  The output MLP's config argument is `mlp_hidden_dim`, not the reference's
  `mlp_hidden`: the submodule keeps the checkpoint's `mlp_hidden` name, and
  `ModelMixin.__getattr__` resolves config keys ahead of submodules, so the two
  colliding would shadow the `nn.Linear` with an `int`.

- pipeline_ltx2.py / pipeline_ltx2_image2video.py: `num_frames` becomes
  `int | LTX2AutoDuration | None`. Omitting it auto-predicts when the checkpoint
  ships a head and keeps the legacy 121 otherwise, mirroring the reference --
  whose CLI also defaults to auto-prediction -- and matching the resolution
  these pipelines already do for `enable_prompt_enhancement`, which likewise
  switches on the presence of an optional LTX-2.4 component. Pre-2.4 pipelines
  have no head, so nothing changes for them.

  The prediction runs immediately after the connectors and before `num_frames`
  is first read. Only the positive half of the CFG-concatenated batch is used,
  and rows past the first are `num_videos_per_prompt` duplicates.

  Auto-duration is rejected from `check_inputs` -- before prompt enhancement and
  encoding, so a bad request costs nothing -- when there is no head, and when
  more than one prompt is supplied: the batch carries a single temporal
  dimension, so prompts with different natural lengths cannot share one frame
  count. Batched prompts with an explicit integer `num_frames` are unaffected.

- convert_ltx2_to_diffusers.py: `--duration_head` (with
  `--duration_head_prefix`) alongside the other per-component flags. The head's
  keys sit at the checkpoint top level rather than under the DiT prefix, so the
  existing prefix helper handles them. The checkpoint's fused `in_proj_weight`
  is split into separate q/k/v, and dimensions are read back from weight shapes
  since checkpoint metadata carries no duration_head config; only
  `num_pooler_heads` is not recoverable and is fixed at 4. Pre-2.4 checkpoints
  yield no keys and are skipped rather than failing.

Verified against ltx_core on the real 2.4 checkpoint: fed the reference's
recorded connector tokens, the converted head predicts 12.9375s (video only),
2.671875s (audio only) and 3.515625s (both) -- bit-identical to the reference --
and the same frame counts through the clamp/snap path at 24/25/30/8 fps. The
snapping arithmetic matches the reference `seconds_to_clamped_num_frames` across
260 combinations of duration, frame rate and bounds.

* Add LTX-2 modular video and audio decoder blocks

Add the first blocks of the LTX-2 modular pipeline under
modular_pipelines/ltx2/decoders.py:

- LTX2VaeDecoderStep: unpacks and decodes video latents (or returns
  latents for output_type="latent"), applying the optional decode-time
  noise on normalized latents before denormalizing, matching the
  standard LTX2Pipeline decode stage.
- LTX2AudioDecoderStep: unpacks and decodes audio latents into a
  waveform via the audio VAE and vocoder in a single block.

Pack/unpack/denormalize helpers are redefined at module level rather
than imported, since modular blocks must not import from
diffusers.pipelines.* (the vocoder class is imported from the pipelines
path for now, flagged for relocation to models/).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* Add LTX-2 modular pipeline (t2v + i2v) and parity harnesses

Add the LTX-2 modular pipeline package under modular_pipelines/ltx2/,
covering the joint video+audio text-to-video and image-to-video
workflows for LTX-2.4:

- encoders.py: dedicated Gemma-4 prompt enhancer (t2v/i2v), Gemma text
  encoder, text connectors, and the i2v image VAE encoder.
- before_denoise.py: text-input expansion, flow-match timesteps (with a
  deep-copied audio scheduler), video/audio latent prep, and RoPE coords.
- denoise.py: the joint video+audio denoise loop with manual guidance
  (CFG + spatio-temporal + modality-isolation), shared across t2v/i2v.
- decoders.py: video VAE decode and audio VAE + vocoder decode.
- modular_blocks_ltx2.py: LTX2Blocks (t2v), LTX2ImageToVideoBlocks (i2v),
  and LTX2AutoBlocks (both, default), plus the auto/conditional wrappers.
- modular_pipeline.py: LTX2ModularPipeline with the compression-ratio and
  patch-size properties the blocks read.

Wire up lazy imports and register the pipeline (top-level diffusers
exports, modular_pipelines __init__, MODULAR_PIPELINE_MAPPING, and dummy
objects).

Also add integrations/ (temporary, for-visibility) parity harnesses that
compare the modular t2v/i2v blocksets against the standard LTX-2
pipelines by sharing the same loaded components. This directory is meant
to be removed before the final integration.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* Add script to create tiny LTX-2.4 test pipeline ckpt (under assumption that it inherits all configs from LTX-2.3)

* make fix-copies

* Run modular connector once on CFG-concatenated batch for bitwise parity

Run the LTX-2 text connector once on the CFG-concatenated `[uncond, cond]`
batch (as `LTX2Pipeline` does) instead of once per branch, then split the
outputs back into uncond/cond. The connector is applied per batch element, so
both forms are mathematically equivalent, but its GEMM/attention kernels round
identically for a given row only at batch >= 2; running the branches separately
diverged from the standard pipeline by ~1e-6 at `num_videos_per_prompt=1`. The
modular path is now bitwise-identical to the standard pipeline at any batch size.

Also extend the T2V/I2V parity harnesses with a `--num_videos_per_prompt`
argument and a `--check_tensor_stats` flag for per-output min/mean/std/max.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

* Use tiny LTX2VocoderWithBWE in the LTX-2.4 test checkpoint

Swap the placeholder LTX2Vocoder for a scaled-down LTX2VocoderWithBWE that
mirrors LTX-2.3's vocoder (snakebeta + antialiasing, no final activation/bias,
16kHz -> 48kHz bandwidth extension) while keeping the same in/out channel
shapes. Dimensions are reduced but the shape invariants the two-stage forward
requires are preserved: in_channels = audio_vae.output_channels * mel_bins,
bwe_in_channels = out_channels * num_mel_channels, filter_length == window_length,
and prod(bwe_upsample_factors) == (output_sr // input_sr) * hop_length so the BWE
residual and the resampled stage-1 skip line up.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

* Match LTX-2.4 transformer flags in the test checkpoint

Only `ff_bias=False` is a transformer-level delta from LTX-2.3 per the
authoritative LTX-2.4 config in `scripts/convert_ltx2_to_diffusers.py`;
`audio_ff_bias` and `use_prompt_adaln_single` keep their `True` defaults.
The test checkpoint was incorrectly overriding both to `False`, so drop
those two overrides. T2V/I2V modular-vs-standard parity remains bitwise.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

* Add CPU offload flag to parity scripts to be able to load full checkpoints

* Support dynamic timestep shift and duration head in LTX-2 modular pipeline

Track two recent additions to the standard LTX-2.4 pipelines in the
modular blocks (t2v + i2v):

- Resolution-aware timestep shift: LTX2SetTimestepsStep now computes `mu`
  from the actual packed video sequence length (derived from
  height/width/num_frames and the transformer patch sizes) instead of a
  constant, matching the standard pipeline's `latents.shape[1]`-based
  shift. Uses the compute-from-dims approach (like LTX-1 / Flux2), so no
  block reordering is needed.

- Optional duration head: add LTX2DurationStep, which predicts a concrete
  `num_frames` from the connector text conditioning via the `duration_head`
  component when `num_frames` is an `LTX2AutoDuration` request, and
  re-emits it. Wrapped in the LTX2AutoDurationStep conditional (skipped for
  an integer `num_frames`) and wired into all three blocksets after the
  connector step, so `num_frames` is resolved before the shift and latent
  prep run.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* Add duration predictor support for tiny checkpoint and parity scripts

* Refactor LTX-2 modular guidance into video/audio guiders

Replace the manual multi-term guidance in `LTX2LoopDenoiser` with a
`LTX2Guidance` guider (in `guider.py`), instantiated once as the video
`guider` and once as the `audio_guider`. Each combines CFG + spatio-temporal
guidance (STG) + modality-isolation via the delta formulation in x0 space; the
denoiser owns a `plan_guidance_passes` union plan across the two guiders, runs
each transformer pass, converts velocity->x0, and delegates the per-modality
combine to the guiders. Guidance scales are now guider config, not `__call__`
kwargs. Parity harnesses updated to configure the guiders accordingly.

Parity investigation (not yet resolved):
- The refactor runs every guidance pass as its own single-batch transformer
  forward, whereas the standard `LTX2Pipeline` batches the cond+uncond CFG pair
  into one forward and runs STG/modality-isolation as separate single-batch
  passes. STG and modality already match (single-batch in both).
- The change is mathematically equivalent, not a logic bug: in fp32 the
  denoised latents match to ~8e-6 mean abs diff (sparse outliers up to
  ~3.5e-4), and disabling STG does not move the diff.
- But GPU matmul is not batch-invariant, so cond computed alone differs from
  cond computed inside a batch-of-2. Negligible in fp32 (~1e-6/op); ~1e-2/op in
  bf16, where amplification by the CFG delta and accumulation over sampler steps
  drives the modular vs. standard bf16 latents to ~10% mean-relative divergence.
- Net: numerical, but the modular pipeline does NOT reproduce the standard
  pipeline bitwise in bf16 (the real inference dtype). Restoring parity would
  require re-batching the cond+uncond pair into a single forward to match the
  reference execution, keeping STG/modality single-batch.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* Batch cond+uncond CFG forward to mirror standard LTX-2 pipeline

Restore fp32 bitwise parity with `LTX2Pipeline` in the modular denoiser by
running the cond+uncond CFG pair as a single batched transformer forward
(`torch.cat([latents] * 2)` + `.chunk(2)`), keeping STG and modality-isolation
as separate single-batch conditional forwards -- matching the reference
op-for-op (batch sizes, repeated coords, cache-context names).

`plan_guidance_passes` now emits forward-groups (`identifiers` / `conditioning`
aligned lists + `flags` + `cache_context`) instead of one entry per pass; the
denoiser runs each group once and chunks the CFG forward back into its
`[uncond, cond]` identifiers. The `LTX2Guidance` combine is unchanged -- only
how the four x0 tensors are obtained changed.

Parity results:
- fp32: bitwise (0.0 max abs diff), verified at full-checkpoint scale including
  under CPU offload. This is the authoritative parity gate.
- bf16: the previous single-batch-per-pass design diverged ~10% mean-relative
  from the standard pipeline (GPU matmul is not batch-invariant: cond alone vs.
  cond in a batch-of-2). Batching the CFG pair removes that gap; a smaller
  ~1% (tiny) / ~5% (full) bf16 gap remains. It is not a logic difference (fp32
  is bitwise across scale and offload); it is a bf16-kernel effect -- coarser
  mantissa amplifying non-associative accumulation order, plus bf16 using
  different kernels than fp32 (tensor-core GEMM algorithm selection, fused
  attention). bf16 is therefore a close-but-not-bitwise check, not a gate.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* Drive LTX-2 modular guidance through the guider API (per-pass inputs)

Replace the batched-CFG denoiser with one that runs each guidance pass as its
own single-batch transformer forward, driven end-to-end through the standard
guider API. `LTX2Guidance.prepare_inputs(guider_inputs)` builds one identifier-
tagged batch per active pass from a dict whose values are 4-tuples indexed by
pass [cond, uncond, stg, modality]; the per-pass model flags
(`spatio_temporal_guidance_blocks`, `isolate_modalities`) ride in those tuples
alongside the encoder inputs, so a pass fully describes its own forward. The
denoiser unions both guiders' passes by identifier, runs each once (storing
video+audio x0 on the batch), and combines each modality via its guider's
`forward`/`__call__`, filtered to that guider's active passes so the batch count
matches `num_conditions`.

Removes the bespoke `plan_guidance_passes` union helper and the empty-dict
`prepare_inputs_from_block_state` call: the plan is now expressed as the
`guider_inputs` tuples + `active_predictions()`, so guidance logic lives behind
the guider API rather than in the denoiser.

Parity trade vs. the previous batched-CFG design:
- Batched CFG matched the standard pipeline op-for-op and was fp32-bitwise.
  Running every pass single-batch is mathematically equivalent but, since GPU
  matmul is not batch-invariant, cond computed alone differs from cond inside a
  batch-of-2: ~1e-4 mean-relative in fp32 on a full checkpoint (sparse outliers
  up to ~3.5e-4 max), ~10% mean-relative in bf16.
- This is numerical, not a logic difference, and fp32-within-tolerance (not
  bitwise) is the modular-ecosystem norm. The trade buys end-to-end guider-API
  usage (swappable within the LTX-2 guidance family, per-pass flags carried the
  same way as encoder inputs) at the cost of the bitwise guarantee.

Parity harnesses: gate on magnitude-aware stats (mean abs diff relative to mean
magnitude, plus a loose max-abs ceiling) instead of assert_close's near-bitwise
fp32 defaults, which no single-batch design can clear. fp32 is the authoritative
gate (1e-3/1e-3); bf16 is a loose sanity check (0.15/0.5). `--atol`/`--rtol`
become `--mean_rel_tol`/`--max_abs_tol`; motivation documented in-file.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* Drive LTX-2 modular guidance via prepare_inputs_from_block_state

Move `LTX2LoopDenoiser` onto the standard Wan/Z-Image guider idiom: the
denoiser now owns a `guider_input_fields` map (transformer arg -> per-pass
block-state attribute names, indexed [cond, uncond, stg, modality]) and calls
`guider.prepare_inputs_from_block_state(block_state, guider_input_fields)`
instead of hand-building a literal `guider_inputs` dict in `__call__`. This
lifts the cond/uncond/stg/modality field mapping to a construction-time arg
(swappable per workflow) and resolves the connector_*->encoder_hidden_states
name mismatch via the map keys.

The two per-pass model flags (`spatio_temporal_guidance_blocks`,
`isolate_modalities`) are pass-identity constants, not block-state
conditioning, so they can't ride the name-referenced field map; the denoiser
sets them on each batch by identifier after preparation, via a
`pass_flags.get(identifier, (None, False))` lookup. The plain-conditional
default keeps this correct for any guider that emits a subset of passes (e.g.
a swapped-in `ClassifierFreeGuidance` -> just pred_cond/pred_uncond gets no STG
and no modality isolation).

`LTX2Guidance` gains `prepare_inputs_from_block_state` (names, via the base
`_prepare_batch_from_block_state` helper); `prepare_inputs` (literals) is
retained so both halves of the guider data-prep API are implemented. Pass
structure and numerics are unchanged (still four single-batch forwards), so the
fp32/bf16 parity story is untouched; user-confirmed parity OK.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

* Route LTX-2 batch-invariant denoiser kwargs via denoiser_input_fields

Tag the three upstream-produced, batch-invariant transformer kwargs
(`audio_num_frames` from the audio-latents step; `video_coords` / `audio_coords`
from the coords step) with `kwargs_type="denoiser_input_fields"`, and have
`LTX2LoopDenoiser` collect them from `block_state.denoiser_input_fields` filtered
against the transformer's forward signature (à la qwenimage/cosmos3) instead of
listing them as explicit inputs. This drops three explicit `InputParam`s in favor
of one `denoiser_input_fields` template input.

Per-pass conditioning (cond/uncond/stg/modality) stays on the guider field map --
the tag only delivers a flat dict, so it can't do the cond/uncond split or the
connector_*->encoder_hidden_states rename. The locally-computed latent dims
(num_frames/height/width/fps) are still supplied in-denoiser: they aren't upstream
outputs and their names would clash with the pixel-space values in state.

Parity unchanged (validated T2V + multi-frame I2V): the tagged values reach the
transformer identically; the first-forward capture shows them bitwise-equal.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

* Fix LTX-2 parity harnesses: guidance overrides reach both pipelines

The CLI guidance flags (`--guidance_scale`, etc.) only fed the modular guiders;
the standard pipeline was always called with the hardcoded GUIDANCE dict. So
`--guidance_scale 1.0` disabled CFG on the modular side only, comparing
standard-with-full-CFG (batch-2) against modular-no-CFG (batch-1) -- an
apples-to-oranges run that manifested as a huge (but spurious) I2V mismatch.

Add `_resolve_guidance(args)` (CLI overrides on top of GUIDANCE) and drive BOTH
the standard call and `_make_guiders` from the one resolved dict, in both the t2v
and i2v harnesses. With CFG correctly disabled on both sides, multi-frame I2V is
bitwise-ish (~5e-6 mean-rel), confirming the default-guidance ~8e-3 divergence is
the documented cond/uncond batch-invariance (amplified by I2V's per-token masked
timestep + clean anchor frame), not a logic bug.

Also:
- i2v: loosen the fp32 gate to (2e-2, 1.5e-1) to fit that amplified-but-numerical
  multi-frame divergence, with a comment pointing at the CFG-off run as the tight
  bug-catching gate.
- i2v: add `--debug_forward`, which diffs the first transformer forward
  (inputs + outputs) between the two runs via a forward hook -- the diagnostic
  that pinpointed the batch-shape mismatch above.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

* Document denoiser_input_fields standalone-run caveat for LTX-2 denoiser

`audio_num_frames` / `video_coords` / `audio_coords` reach `LTX2LoopDenoiser`
via the `denoiser_input_fields` tag, not as named inputs. Note in the docstring
that a standalone run (without the upstream tagging blocks) must pass them
through `denoiser_input_fields={...}`; plain named kwargs are silently ignored
(modular.md's kwargs_type standalone gotcha).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

* Address LTX-2 modular self-review: fix dead enhancer trigger + docstrings

Blocking fix: `enable_prompt_enhancement` was declared only as a
`block_trigger_inputs` entry / `select_block` param, never as an `InputParam`,
so it was not an accepted pipeline input -- `pipe(enable_prompt_enhancement=True)`
was dropped as "unexpected" and the prompt enhancer could never run. Declare it
on both enhancer sub-blocks so it reaches `select_block` (mirrors how the `image`
trigger is declared).

Also from the self-review:
- Regenerate the modular auto-docstrings: the guidance knobs (guidance_scale,
  stg_scale, ...) that moved onto the guider no longer show as block inputs, and
  the enhancer trigger now appears.
- Add descriptions to the 16 `InputParam`s that rendered as "TODO: Add
  description." in the generated docstrings (conversion checklist requires none).
- Drop the defensive `getattr(tokenizer, "padding_side", "left")` (a declared
  tokenizer always has it; gotcha #7).
- Rewrite two ephemeral comments (the connector-output "reconcile when denoise.py
  is written" NOTE, now resolved; the guider "batched-CFG variant in git history"
  pointer) into standing rationale.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

* Fix stale I2V parity-harness --help text for the loosened fp32 gate

The `--mean_rel_tol` / `--max_abs_tol` help strings still advertised the old
fp32 defaults (1e-3, 1e-3); the I2V gate is now (2e-2, 1.5e-1). Update the help
to match the actual DTYPE_TOLERANCES so `--help` doesn't misreport the gate.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

* make style and make quality

* Add the LTX-2.4 diffusion VAE decoder with a native-parity harness

* Add a converter for the LTX-2.4 diffusion VAE decoder

* Initialise use_slicing and document the diffusion VAE decisions

* Record real-weight parity against the reference decoder

* Add model-level tests for the LTX-2.4 diffusion VAE decoder

The generated test file needed three decisions rather than fill-ins: the class had no forward() for the
mixins to call, the decoder denoises so forward has to take a generator for any output comparison to mean
anything, and MemoryTesterMixin.test_group_offloading reused one inputs_dict across four forwards without
re-seeding it. The last is fixed in the mixin, reusing the helper test_group_offloading_with_disk already
had for the same reason, now module-level and reading the signature off the class (offloading replaces
model.forward with a *args wrapper).

* Fold the diffusion VAE converter into convert_ltx2_to_diffusers.py

--diffusion_vae now sits beside --vae instead of shipping a second script. It also drops the standalone
script's --encoder-vae: the encoder is in the same checkpoint and goes through the conv VAE's own rename
rules, with its config pinned in get_ltx2_diffusion_video_vae_config. Output verified bitwise identical to
the standalone script's on the rc2 checkpoint, 491/491 tensors and the same config.json.

* Make the diffusion decoder work through LTX2Pipeline

The documented usage -- LTX2Pipeline.from_pretrained(repo, vae=diffusion_vae) -- had never been run: every
real-weight run so far called vae.decode() directly. Through the pipeline it raised on
vae.config.timestep_conditioning, which this decoder has no reason to carry, and would have bound the
positional decode timestep to the decoder's generator. The decode step now branches on the decoder type,
skipping the decode_timestep pre-noising and passing the generator instead, which also makes decoding
seed-reproducible; two full runs from one seed agree bitwise. The conv path's own statements are unchanged.

* Make the diffusion decoder work through the modular decode step

Same fix as the standard pipeline, in LTX2VaeDecoderStep: skip the decode_timestep pre-noising and pass the
generator instead of a timestep. Verified on rc2 weights by injecting the decoder into
LTX2Blocks().init_pipeline() with update_components, the route the modular parity harness already uses -- two
runs at 320x448x17 from one seed agree bitwise, so no modular_model_index.json repo was needed to run this.

* Note that the pipeline decode block predates the LTX-2.4 integration PR

* Address diffusers self-review on the diffusion VAE decoder

Four things the project's own rules catch:

- models.md forbids unconditional torch.float64 in a model (MPS/NPU/Neuron cannot run it). The RoPE
  frequency base now goes through maybe_adjust_dtype_for_device, the helper flux/flux2/wan use for exactly
  this. Measured cost of the downcast where it applies: 1.5e-08 on the frequencies, 1e-06 on the angles.
- rope_dim_split was threaded through five classes but was never a config entry, so it was always None and
  always fell back to the default split. Removed, and the default-split helper inlined into its one caller.
- FromOriginalModelMixin was declared with no SINGLE_FILE_LOADABLE_CLASSES entry, so from_single_file raised
  rather than working. Dropped; single-file support can come with its own mapping later.
- set_attention_backend() overwrites the processor's _attention_backend, which handed the neighborhood
  BlockMask to backends that cannot read it. Guarded like AnyFlowCausalAttnProcessor does.

Also runs make fix-copies, which was missing the dummy object for the new class.

* Add the API doc page for AutoencoderKLLTX2VideoDiffusionDecoder

* Mark the parity harness transient and drop the notes doc from the diff

Matches the header the other integrations/ harnesses on this branch already carry, and states that the file
imports the native reference package. The notes doc goes to the PR description instead: the self-review skill
is explicit that it never ships in the diff.

* Accept the diffusion decoder in the image-to-video pipeline too

Same branch as the text-to-video pipeline: skip the decode_timestep pre-noising and pass the generator instead
of a timestep. The remaining LTX2 pipelines that share this decode block (condition, hdr_lora, ic_lora,
latent_upsample) are deliberately left for later, so the surface stays the two pipelines this PR actually
exercises.

* Reorganize LTX-2 modular blocks into coarser component-aligned phases

Regroup the top-level LTX-2 block assemblies so each direct child of
LTX2AutoBlocks is a coherent, component-aligned phase, mirroring Flux 2's
[text_encoder, vae_encoder, denoise, decode] shape:

- New LTX2TextConditioningStep wraps [text_encoder, text_input, connectors] as
  one "text_encoder" phase (LTX-2's text conditioning is genuinely a three-step
  model chain; text_input must precede connectors for batch-invariant parity, so
  the whole chain lives here rather than pushing text_input into denoise).
- New LTX2DecoderStep wraps [video_decode, audio_decode] as one "decode" phase.
- duration stays a top-level child: it is component-aligned (duration_head) and a
  ConditionalPipelineBlocks that self-skips for concrete num_frames, so it is a
  cleanly optional phase alongside prompt_enhancer / vae_encoder -- keeping it
  out of the (mandatory) denoise block.

Top-level children become:
  t2v:  [text_encoder, duration, denoise, decode]
  i2v:  [text_encoder, duration, vae_encoder, denoise, decode]
  auto: [prompt_enhancer, text_encoder, duration, vae_encoder, denoise, decode]

Also reorder the class definitions to follow this flow, keeping the core-denoise
trio (LTX2CoreDenoiseStep, LTX2Image2VideoCoreDenoiseStep, LTX2AutoCoreDenoiseStep)
contiguous instead of split by LTX2AutoVaeEncoderStep.

Pure re-grouping: no block bodies change and intermediate outputs still propagate,
so t2v/i2v parity is bit-identical to before (user-confirmed at 17 frames).
Docstrings regenerated.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

* Enable LTX-2 prompt enhancement by default when the enhancer is loaded

Mirror the standard pipeline's tri-state prompt-enhancement default
(pipeline_ltx2.py:559-560), where `enable_prompt_enhancement` defaults to
auto-on when a `prompt_enhancer` component is present (LTX-2.4) and off
otherwise, and wire the enhancer into the t2v/i2v assemblies.

- Both enhancer sub-blocks: default `enable_prompt_enhancement=None` (tri-state).
  Resolve `None` against component presence inside `__call__` -- select_block
  cannot see components, so the gate dispatches for None/True and the sub-block
  decides. `None` + no enhancer -> pass the prompt through unchanged (the
  Cosmos3 optional-component pattern); explicit `True` + no enhancer -> a clear
  ValueError instead of the previous cryptic `NoneType` crash from within the
  enhance helper.
- LTX2AutoPromptEnhancerStep.select_block: skip only on an explicit `False`.
- Add LTX2AutoPromptEnhancerStep to LTX2Blocks and LTX2ImageToVideoBlocks so all
  three assemblies share the prompt_enhancer-first shape (previously only
  LTX2AutoBlocks had it; passing the flag to the others was silently ignored).
- Parity harnesses: force `enable_prompt_enhancement=False` on the modular run
  too (the modular sets now carry an enhancer), and fix the now-stale
  "contains no enhancer block" docstrings.

Only the dedicated-enhancer (LTX-2.4) path is wired; the standard pipeline's
text_encoder-as-enhancer fallback for LTX-2.0/2.3 remains a follow-up. Parity
unchanged (both pipelines run with enhancement disabled in the harnesses).
Docstrings regenerated.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

* Rename LTX-2.4 product identifiers to LTX-2.5.

Update conversion --version, model ids, system-prompt constant names, and docs/comments to the public 2.5 name. Behavior is unchanged in this commit.

* Add image-conditioning H.264 CRF matching Lightricks training.

Resolve CRF 18 for LTX-2.5 (Gemma 4) and 33 for earlier generations, and apply the PyAV re-compress path for I2V and single-frame Condition/IC keyframes.

* Align LTX-2 pipelines with the Lightricks reference behavior.

Extract shared prompt-enhancement and check_inputs mixins; enable Condition duration+enhancement and IC enhancement (HDR remains encode-only); match enhancement recipe and LTX-2.3/2.5 sampling defaults.

* Update LTX-2 docs for 2.5 naming, defaults, and opt-in enhancement.

Document LTX_2_3/2.5 sampling defaults, STG block 28, and enable_prompt_enhancement=True as the opt-in path.

* Replace LTX2AutoDuration with min_seconds/max_seconds call args.

Drop the dataclass wrapper and expose duration bounds directly on the T2V, I2V, and Condition pipelines.

* Align LTX-2 modular blocks with the merged standard-pipeline changes

The standard LTX-2 pipelines moved to shared `LTX2PromptEnhancementMixin` /
`LTX2CheckInputsMixin`, dropped `LTX2AutoDuration`, adopted the Lightricks
reference defaults, and gained H.264 CRF re-compression of image
conditionings. Port all of that to the modular blocks.

- Prompt enhancement: re-derive `_enhance_prompt` from the new mixin -- the
  `user prompt:` / `User Raw Input Prompt:` templates, 896px long-side image
  prep, left-padding to a multiple of 8 for Flash Attention, `clean_response`
  on the decoded output, and `max_new_tokens=None` resolving to the Gemma-4
  budget of 600.
- Revert `enable_prompt_enhancement` to a plain `False` opt-in, matching the
  reference pipelines (the tri-state auto-on default is gone upstream). The
  friendly error for `True` with no enhancer loaded is kept.
- Auto-duration: trigger on an omitted `num_frames` instead of an
  `LTX2AutoDuration` sentinel, with `min_seconds`/`max_seconds` as call args.
  `LTX2DurationStep` raises when no `duration_head` is loaded rather than
  silently falling back to 121 frames.
- Every `num_frames` InputParam default becomes `None`: input defaults are
  seeded into the pipeline state before any block runs, so a default of 121
  would leave the auto-duration branch permanently unreachable.
- Defaults sweep: `num_inference_steps` 40 -> 30, `use_cross_timestep`
  False -> True, and the video/audio guider ComponentSpec configs updated to
  the reference guidance stack.
- `LTX2VaeEncoderStep` gains `image_crf` and re-compresses the conditioning
  image before preprocess, declaring `text_encoder` only to resolve the model
  default CRF.
- Rename LTX-2.4 -> LTX-2.5 throughout, following the upstream product rename.

Parity harnesses updated for the new duration arguments, plus an `--image_crf`
flag on the i2v harness defaulting to 0 so the comparison isolates block logic
from the PyAV codec round-trip. Verified against a real checkpoint: t2v, i2v at
`--image_crf 0`, and i2v at `--image_crf -1` all pass.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

* Evaluate the decoder's SwiGLU in token tiles

Decode-only peak VRAM at 121 frames and 512x768 was 24.6 GiB, and 17.0 GiB of that was one transient
inside the first stage-5 block: `w_gate(x)` and `w_up(x)` are both hidden-width and their product makes
a third, so the whole video's worth of hidden activations was live three times over. At that size each
one is 2,973,696 tokens x 1024 x 2 bytes = 5.67 GiB.

The MLP is pointwise across tokens, so tiling it is exact -- it changes only how many hidden-width
elements exist at once. Measured on a full-size decode: peak 24.8 -> 19.4 GiB (-22%), wall clock 2.79 ->
2.84 s (+1.6%), output bit-identical (max abs diff 0.000e+00). That also puts the diffusion decoder
below the conv decoder, which needs 23.8 GiB at the same size.

Tile size 16384 tokens is the reference decoder's own default (`DEFAULT_SWIGLU_TILE_SIZE`). Bounding a
token count rather than a number of tiles keeps peak memory independent of resolution.

This is the first of the two transients the reference's default decode mode avoids; the other is the
full-volume QKV projection plus RoPE's fp32 upcast, which it addresses by chunking attention along
width. That one is not bit-exact (it reassociates NATTEN's accumulation), so it is left for a follow-up
rather than changed here.

* Declare _no_split_modules on the diffusion decoder

Both block types close over a residual add that combines outputs from different children, which is the
case models.md says has to stay co-located, so neither can be split across devices.

Unskips three memory tests that were gated on the attribute: the file goes from 35 passed / 7 skipped to
38 passed / 4 skipped, and the three (test_cpu_offload, test_disk_offload_with_safetensors,
test_disk_offload_without_safetensors) pass.

* Match the encoder defaults to the published LTX-2.4 config

block_out_channels was (256, 512, 1024, 2048) and layers_per_block was (4, 6, 6, 2, 2); both were
inherited from the 2.0 conv VAE. The published vae_diffusion/config.json has (256, 512, 1024, 1024) and
(4, 6, 4, 2, 2). Real loads were unaffected because the config sets these explicitly, but the defaults
described a model that does not exist.

All 27 __init__ defaults that appear in the published config now match it.

* Cover the token-tiled SwiGLU path in the tests

The dummy video is 9x48x48, so its stage-5 grid is 5184 tokens against a 16384-token tile size: every
other test in the file takes the untiled branch and the tiling loop ran nowhere in CI. This shrinks the
tile size to force ~41 tiles and requires torch.equal against the untiled evaluation, since the MLP is
pointwise across tokens and tiling must be exact rather than close.

Checked the test is not vacuous: sabotaging the tiled branch alone (silu on w_up instead of w_gate)
fails it at 8.83e-01.

* Let the parity harness run against the LTX-2.5 reference too

The harness only spoke LTX-2.4's decoder API and died on `forward_pre_diffusion` against 2.5, so it could
not check the release the port is now targeted at. Three shims absorb the differences:

* 2.5 selects a decode pathway by swapping `__class__` on every block, so an as-constructed decoder has no
  `forward_combined`. Install the COMBINED pathway explicitly, uncompiled, since that is the pathway this
  port implements.
* stages 1-4 split into `forward_stages_1_to_3` + `forward_stage_4`, so the chunked pathway can defer
  stage 4.
* the trailing NATTEN ghost pad moved out to the caller while its crop stayed behind
  `forward_stage_4(pad_trailing=True)`; the two have to be paired or the context loses real frames (3 of
  17 survive at this config, which is how the mismatch first showed up).

Same numbers against both references -- context 5.367e-04, step 7.337e-04 -- which is the check that the
shims are semantically right and not just shape-compatible.

* Add LTX-2.X modular condition blocks

Ports LTX2ConditionPipeline to the modular pipeline system, including the
LTX-2.5 additions (per-condition CRF, conditions-sourced prompt enhancement,
auto-duration, the Lightricks reference defaults).

New blocks:
  - encoders.py: LTX2ConditionEncoderStep (resize/center-crop, single-frame
    H.264 re-compression at the model CRF, temporal trim, VAE encode) and
    LTX2ConditionPromptEnhancerStep (grounds the rewrite in the first PIL
    frame found in `conditions`, text-only otherwise).
  - before_denoise.py: LTX2ConditionPrepareLatentsStep (first-frame overwrite
    + keyframe token append with their own RoPE coords, emitting
    conditioning_mask / clean_latents / appended_coords / base_token_count),
    LTX2ConditionSetTimestepsStep, LTX2ConditionPrepareAudioLatentsStep,
    LTX2ConditionPrepareCoordsStep, and the _prepare_keyframe_coords helper.
  - denoise.py: LTX2ConditionLoopBeforeDenoiser (mask-scaled per-token video
    timestep), LTX2ConditionLoopAfterDenoiser (x0 blend against the clean
    condition latents, then a full-sequence scheduler step),
    LTX2ConditionDenoiseStep.
  - decoders.py: LTX2TrimConditionTokensStep.
  - modular_blocks_ltx2.py: LTX2ConditionAutoPromptEnhancerStep,
    LTX2ConditionCoreDenoiseStep, LTX2ConditionDecoderStep, LTX2ConditionBlocks.

LTX2LoopDenoiser is reused unchanged: the two LTX2Guidance guiders already
express the whole CFG + STG + modality-isolation stack the condition pipeline
uses, and the transformer takes the longer packed sequence with the base
num_frames/height/width exactly as the standard pipeline does. The standard
pipeline's CFG batch duplication (conditioning mask, coords) has no modular
counterpart, since each guidance pass is its own single-batch forward.

Block ordering: prepare-latents runs *before* set-timesteps, unlike the
text-to-video and image-to-video core denoise steps. The resolution-aware
shift `mu` is computed from the packed latent sequence length, which here
includes the appended keyframe tokens, so the latents must exist first. This
mirrors LTX2ConditionPipeline (its section 4 precedes section 5). The
text-to-video and image-to-video blocksets are unaffected: with no appended
tokens the grid-derived sequence length already equals latents.shape[1].

Two subtleties the parity harness surfaced:

  - The condition pipeline samples audio noise directly in packed shape
    [B, L, C * M], while the text-to-video and image-to-video pipelines sample
    unpacked [B, C, L, M] and pack afterwards. Both draw the same number of
    values from the generator but lay them out differently, so reusing the
    shared LTX2PrepareAudioLatentsStep silently desynchronizes the audio noise
    and, through the joint attention, the video too (1.4 mean-rel on audio,
    0.13 on video before the fix). Hence a standalone condition audio block.

  - `noise_scale` means different things across workflows: 0.0 for
    text-to-video/image-to-video, `None -> sigmas[0] or 1.0` for conditions.
    A blockset keeps the first non-None default across its blocks, so a 0.0
    would have shadowed the condition resolution and left the latents
    unnoised. Both condition-path blocks declare None; prepare-latents
    resolves once and writes the value back for the audio step.

Keyframe tokens, masks and coords are expanded to the generation batch (the
pattern the in-context pipeline already uses for reference tokens). The
standard pipeline builds them at batch 1 and cats them onto a batch-B
sequence, so it raises for num_videos_per_prompt > 1 with any condition at
latent index > 0; the modular blocks handle that case.

Verification: integrations/ltx2_condition_parity.py (transient, removed before
merge) compares LTX2ConditionBlocks against LTX2ConditionPipeline on shared
component objects. Eight cases on a tiny checkpoint -- first-frame only,
keyframe only, both plus a multi-frame video condition, two keyframes, no
conditions, --crf -1, --predict_duration, num_videos_per_prompt=2 -- all pass
at 3e-7 to 1.3e-6 mean-rel. On a full checkpoint at 768x512x17 with two
conditions through the CRF path: video 8.7e-04 mean-rel / 1.1e-02 max-abs,
audio 1.5e-04 / 2.1e-03, in line with the image-to-video figures at the same
frame count.

make style, make quality and make fix-copies are clean; auto-docstrings
regenerated with no TODO placeholders.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

* Add LTX-2.X modular in-context (IC-LoRA) blocks

Ports LTX2InContextPipeline to the modular pipeline system on top of the
condition blocks, and fixes two bugs in the standard in-context pipeline that
the parity harness surfaced.

New blocks:
  - encoders.py: LTX2ReferenceEncoderStep (preprocess, VAE-encode and pack each
    reference video, compute the coords that map its tokens into the target
    space, and build the per-token cross-attention strengths), plus the
    _downsample_mask_to_latent helper.
  - before_denoise.py: LTX2InContextPrepareLatentsStep (frame conditions as in
    the condition step, then the reference tokens appended last) and
    LTX2BuildVideoSelfAttentionMaskStep.
  - modular_blocks_ltx2.py: LTX2AutoReferenceEncoderStep,
    LTX2AutoBuildVideoSelfAttentionMaskStep, LTX2InContextCoreDenoiseStep,
    LTX2InContextBlocks.

LTX2ConditionDenoiseStep is reused unchanged: with the blend gate fixed below,
reference tokens are pinned by exactly the same x0 blend as frame conditions,
matching the reference implementation where VideoConditionByReferenceLatent and
VideoConditionByKeyframeIndex produce the same (denoise_mask, clean_latent) pair
and post_process_latent runs unconditionally. The condition encoder, timesteps,
audio-latents, coords and decoder blocks are shared as well.
video_self_attention_mask reaches the transformer through the
denoiser_input_fields tag, so LTX2LoopDenoiser needed no change.

`reference_conditions` is optional, matching LTX2InContextPipeline: IC-LoRAs
that carry their behavior in the adapter weights (camera control, style) take
no reference video, which is the shape of the standard pipeline's own docstring
example. The reference encoder and the attention-mask step are both skipped when
it is absent. There is no duration step (the in-context pipeline ships without a
duration_head), so LTX2ConditionEncoderStep now raises a concise error if
`num_frames` is still None by the time the conditions are encoded.

Per-reference token counts come from the encoder rather than an equal split of
the total, so references of differing lengths (a reference video shorter than
num_frames) get the right strengths.

Standard-pipeline fixes in pipeline_ltx2_ic_lora.py:

  - The x0 blend was gated on `has_conditions` alone, so with reference
    conditions and no frame conditions the reference tokens were seeded clean
    and given a zeroed timestep but never re-pinned. Their x0 prediction error,
    divided by sigma each step, then accumulated and drifted them away from the
    encoded reference. Now gated on `has_conditions or num_ref_tokens > 0`, in
    line with the surrounding gates and the reference implementation.

  - video_self_attention_mask was rebound in the loop rather than expanded into
    a per-pass local. The main pass expanded it to the CFG-doubled batch, after
    which the STG pass's expand() to `latents.shape[0]` raised
    "RuntimeError: The expanded size of the tensor (1) must match the existing
    size (2)". Any run combining an attention mask with STG or modality
    guidance -- i.e. the default guidance settings -- died on the first step.

Also removed the unused has_appended_tokens local and replaced the "# - TODO"
placeholder above the attention-mask construction with the block structure,
which the reference confirms.

Verification: integrations/ltx2_in_context_parity.py (transient, removed before
merge). Twelve cases on a tiny checkpoint -- reference only, reference at
partial strength, scalar attention strength, pixel-space attention mask,
downscale factor 2, references plus first-frame and keyframe conditions, two
references, the CRF path, and four reference-free variants -- all pass at 3.4e-7
to 1.3e-6 mean-rel. The seven-case condition suite still passes. On a full
checkpoint at 768x512x17 with a reference plus two conditions: video 4.4e-05
mean-rel / 5.6e-04 max-abs, audio 3.2e-05 / 2.4e-04.

Known limitation, not addressed here: transformer_ltx2.py converts the
multiplicative [0, 1] self-attention mask to an additive bias linearly, as
(1 - mask) * -10000, whereas the reference uses log space (bias = log(mask),
finfo.min at zero). Intermediate strengths therefore saturate to "fully masked",
making conditioning_attention_strength effectively binary and spatially varying
masks inert beyond their zero/non-zero pattern. Parity is unaffected -- both
pipelines feed the same mask into the same transformer -- but the feature does
not currently work as documented.

make style, make quality and make fix-copies are clean; auto-docstrings
regenerated with no TODO placeholders.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

* Make the diffusion decoder a decode pipeline instead of a VAE

Addresses the review: a full diffusion model should not be an AutoencoderKL that hides its denoising
behind `.decode()`, and it should not have to be threaded into every LTX-2 pipeline as a `vae`.

AutoencoderKLLTX2VideoDiffusionDecoder becomes LTX2VideoDiffusionDecoderModel, a plain ModelMixin with
no encoder. Encoding stays with AutoencoderKLLTX2Video, whose latent space this consumes unchanged, so
latents remain interchangeable between the two decoders. Dropping the encoder also removes the
converter's awkwardness of sourcing encoder weights and the real block_out_channels from the conv
`vae/` folder: ten encoder-only config keys are gone.

LTX2VideoDiffusionDecodePipeline drives it, shaped like LTX2LatentUpsamplePipeline: run any LTX-2
pipeline with output_type="latent", then decode. `vae` is an optional component, since it is only ever
consulted for the latent statistics, and the decoder carries its own `latents_mean` / `latents_std`
buffers to fall back on. That means a decode-only workflow never loads a second autoencoder.

The `vae=` path is removed accordingly: the isinstance branches in LTX2Pipeline,
LTX2ImageToVideoPipeline and the modular decode step are gone, along with the fixtures that built a
diffusion decoder to pass as `vae`. The model's slicing/tiling test class went with them, since
enable_tiling was an AutoencoderMixin concern and this is no longer an autoencoder.

Tests: 37 passed / 3 skipped on the model, 83 passed / 2 skipped across the t2v and i2v pipelines.

Still to come: mapping the 2.5 checkpoint to a blockset that selects the diffusion decode block, and
the KandinskyCombinedPipeline pattern for running the two-step flow by default in the standard API.

* Add a modular decode block for the LTX-2 diffusion decoder

The previous commit removed the `isinstance(vae, ...)` branch that let the diffusion decoder stand in
as the modular `vae`, which was the right call twice over: it is what the review objected to, and
modular.md says a new case gets a new block rather than a branch inside an existing one. But removing
it without a replacement left modular with no route to the diffusion decoder at all.

LTX2DiffusionVaeDecoderStep is that replacement. It declares the decoder as its own
`diffusion_decoder` component rather than borrowing the `vae` slot, and passes a generator instead of
a decode timestep, since this decoder draws the noise it denoises. `LTX2VaeDecoderStep` is untouched,
so the convolutional path is unaffected.

What is still missing is the wiring: a blockset using this block, and an `_ltx2_map_fn` so a
checkpoint that ships the diffusion decoder selects it automatically instead of the user choosing.
That lands in modular_blocks_ltx2.py, which #12 is reorganizing, so it needs sequencing against that
PR rather than racing it.

* Test the diffusion decode pipeline, and give it a video-only output

The decode pipeline had no coverage: it was never actually run. Writing the tests immediately turned
up a bug, which is that it returned `LTX2PipelineOutput`, whose `audio` field is required. This
pipeline decodes video only, so it now returns a video-only `LTX2VideoDecodeOutput` instead of
passing a meaningless `audio=None`.

Four tests: decode with no `vae` (the fallback to the decoder's own latent statistics), decode with a
`vae` supplied (its statistics take precedence, checked by making the two disagree rather than
asserting a shape), reproducibility under a seeded generator plus divergence under a different seed,
and `denormalize=False` actually skipping the statistics. The decoder's stat buffers are set to
non-trivial values in the fixture so a run that silently skipped denormalization could not pass by
coincidence.

* Fix the decode example: output_type="latent" is already denormalized

The example in the docs and the pipeline docstring both showed `output_type="latent"` feeding straight
into the decode pipeline on its defaults. That path denormalizes twice: `LTX2Pipeline` applies the
latent statistics before returning latents (pipeline_ltx2.py), and the decode pipeline applies them
again because `denormalize` defaults to True. Every channel ends up scaled by its own std a second
time, so e.g. channel 0 (std 0.238) comes out roughly 4x too small.

Passing `denormalize=False` in the example and saying so in both docstrings. Caught by running the
flow end to end on real rc4 weights, which is also where the two decoders agree at 0.9978 once the
statistics are applied only once.

Whether the *default* should flip, or `output_type="latent"` should stop denormalizing instead, is a
contract question across both pipelines and is still open.

* Fix IC-LoRA video self-attention mask grouping

The video self-attention mask deviated from the reference implementation
(`ltx_core.conditioning.mask_utils.build_attention_mask`) in two ways. Both
predate the modular blocks and applied to `LTX2InContextPipeline` as well; the
modular block had ported the same construction.

1. Keyframe conditions cross-attended with reference tokens. `num_noisy_tokens`
   was derived as `latents.shape[1] - num_ref_tokens`, which folds the appended
   keyframe tokens into the noisy group, so they received the reference cross
   mask. The reference takes `num_noisy_tokens` from the target latent shape --
   generated-video tokens only -- and tracks the extras offset separately, so
   keyframe <-> reference is 0.0. Split the two quantities apart:
   `_build_video_self_attention_mask` now takes `num_prefix_tokens` alongside
   `num_noisy_tokens`.

2. Multiple reference conditions fully attended to each other. All references
   were passed as a single attention group with a 1.0 self-block. The reference
   wraps each `LTX2ReferenceCondition` in its own
   `ConditioningItemAttentionStrengthWrapper`, building the mask once per item,
   so reference_i <-> reference_j is 0.0. The call site now splits
   `ref_cross_mask` into one group per reference before building the mask.

Threading per-reference token counts out of `_encode_reference_conditions` also
removes the equal-split assumption in `prepare_latents` and
`prepare_reference_latents`, which assigned the wrong per-token strengths when
references encoded to different token counts (reachable when a reference video
is shorter than `num_frames`).

API impact
----------

`prepare_latents` returns a 7-tuple instead of a 6-tuple, adding
`ref_token_counts` (`list[int]`) as the new final element. Elements 1-6 keep the
types they have on `main`; in particular `ref_cross_mask` remains the
concatenated `[1, num_ref_tokens]` tensor. Callers that unpack the tuple fail
immediately with a `ValueError` rather than silently receiving a changed type.

`_encode_reference_conditions` (private) likewise gains `reference_token_counts`
as a fourth return element. `prepare_reference_latents` keeps its documented
4-tuple unchanged.

Verification
------------

Correctness against the reference. Both the standard helper and the modular
block were checked for exact tensor equality (`torch.equal`) against
`build_attention_mask`, driven the way `ic_lora.py` drives it -- one
`ConditioningItemAttentionStrengthWrapper` per reference, so the reference
builds iteratively with `existing_mask` carried forward. Five layouts, all
matching, exercised through the same concatenate-then-split path the call site
uses:

  - references only, 1 reference
  - keyframes + 1 reference          (exercises fix 1)
  - keyframes + 2 references         (exercises fixes 1 and 2)
  - 2 references of unequal length   (exercises fix 2 and the token counts)
  - no keyframes, 3 references       (exercises fix 2)

Standard/modular parity on a real checkpoint, 512x512x17, fp32, via
`integrations/ltx2_in_context_parity.py`. Video latents (1, 128, 3, 16, 16),
audio latents (1, 8, 18, 16); gates are mean-rel 2e-2 and max-abs 1.5e-1:

  --reference 1.0 9 --condition 2 0.5 9 --conditioning_attention_strength 0.5
    video: max abs 4.822e-05, mean rel 7.851e-06
    audio: max abs 1.875e-04, mean rel 1.773e-05

  --reference 1.0 9 --reference 0.8 9 --conditioning_attention_strength 0.5
    video: max abs 1.953e-04, mean rel 9.101e-05
    audio: max abs 9.251e-05, mean rel 1.026e-05

The first case is the layout where `num_prefix_tokens != num_noisy_tokens`; a
wrong prefix/base split would have placed the group blocks at the wrong offsets
with valid shapes, surfacing as a parity mismatch. The returned video shape also
unpacks from exactly 768 base tokens (3 x 16 x 16), confirming
`base_token_count` is the quantity now fed as `num_noisy_tokens`.

Scope of the parity runs: both sides share this construction, so parity shows
they did not desynchronize, not that either matches the reference -- that rests
on the equality test above. Both references in the second case are 9 frames and
so encode to equal token counts, meaning the equal-split and per-count paths
coincide; the token-count change is not discriminated by these runs. A reference
pair of differing lengths (e.g. `--reference 1.0 9 --reference 0.8 17`, giving
512 vs 768 tokens) would separate them, and would have failed parity before this
commit since the modular block already used per-reference counts while the
standard pipeline split evenly.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

* Add LTX25AutoBlocks and LTX25ModularPipeline

Following the review: LTX-2.5 is a new checkpoint, so it gets its own blockset and pipeline rather
than a config flag inside the LTX-2 ones.

LTX25AutoBlocks subclasses LTX2AutoBlocks and overrides exactly one entry, `video_decode`, to
LTX2DiffusionVaeDecoderStep. Every other leaf block is reused, so the two blocksets have identical
block_names and cannot drift apart. That makes the diffusion decoder the default for LTX-2.5, which
matches what the checkpoint ships natively, without the user having to pass a decoder at all.

Going the other way stays a one-line swap rather than a second official blockset:

    blocks.sub_blocks["video_decode"] = LTX2VaeDecoderStep()

LTX25ModularPipeline carries `default_blocks_name = "LTX25AutoBlocks"` and a new "ltx2.5" key in
MODULAR_PIPELINE_MAPPING, so a repo shipping `modular_model_index.json` routes straight to the new
blockset.

The condition and in-context workflows belong in this blockset too, but those blocks live in the
modular condition/IC PR, so folding them in belongs there rather than as a competing change here.

* Drop the encoder half in the diffusion decoder converter

The converter still assembled the whole VAE checkpoint, encoder included, and handed it to a strict
`load_state_dict`. That was correct while the class was an autoencoder; after it became decoder-only
the ~84 `encoder.*` keys have nowhere to land and the load raises. Nothing caught it because no test
converts anything and every other check loads pre-converted weights, where unexpected keys are only
warned about.

Now the encoder is discarded rather than remapped, keeping the `decoder.` half and the per-channel
statistics that become `latents_mean` / `latents_std`. `strict=True` stays, since it is what guards
against a botched rename rule.

Verified by actually running it: pulled the 395 `vae.*` tensors out of the native rc4 checkpoint by
byte range, converted, and diffed against the already-published folder. 407/407 parameters, max abs
difference 0.000e+00, so the fix changes nothing about the weights it produces.

Also added a regression test, since the absence of any converter coverage is why this slipped.

* Share the neighborhood attention mask and parameterise the AdaLN chunk count

Two of the resolved review threads. Both are internal to the decoder modules and are unaffected by
the pipeline-vs-model question still open on the thread above them.

Build the FlexAttention mask once per stage instead of once per block. The mask depends only on the
grid and the kernel, both fixed within a stage, so 24 builds collapse to 5; measured at 768x512x121
that is 582ms to 132ms. build_block_mask returns None for NATTEN, which encodes the window in its
kernel. That is not merely an optimisation: create_block_mask materialises O(N^2) uncompiled, so a
69x64x96 stage would ask for 167 GiB and stage 5 for 8.2 TiB, and the mask must never be built for a
path that would not read it.

Make the AdaLN chunk count a constructor argument, num_chunks on the shared AdaLN and num_mod_params
on the diffusion block, with the decoder passing shared_adaln.num_chunks through so the two cannot
drift. num_mod_params is already the name LTX2AdaLayerNormSingle uses. The block's forward still
destructures exactly seven chunks and reads four of them, which is the reference's shape.

Decoding the test fixture is bitwise identical to before (max abs diff 0.000e+00). 39 passed, 4
skipped.

* Export the LTX-2.5 modular classes from the top-level namespace

`ModularPipeline.from_pretrained` resolves a repo's `_class_name` with
`getattr(importlib.import_module("diffusers"), class_name)`, so a class that is only reachable from
`diffusers.modular_pipelines.ltx2` cannot be selected by a checkpoint. `LTX25ModularPipeline` and
`LTX25AutoBlocks` were exported there but not from `diffusers` itself, which left the whole
checkpoint-to-blockset mapping dead: loading a repo whose index names them raised
`AttributeError: module diffusers has no attribute LTX25ModularPipeline`.

Exported alongside `LTX2ModularPipeline` / `LTX2AutoBlocks`, which is how the loader already finds
those. Verified against a real repo: `ModularPipeline.from_pretrained(...)` now resolves
LTX25ModularPipeline -> LTX25AutoBlocks -> LTX2DiffusionVaeDecoderStep, with the decoder supplied by
the repo index and nothing passed by hand.

Found by loading an actual checkpoint rather than constructing the blocks directly; calling
`LTX25AutoBlocks().init_pipeline(repo)` goes blocks-to-pipeline and never exercises the lookup.

* Name the diffusion decoder LTX-2.5 and save it to diffusion_decoder/

Two naming fixes, one of them load-bearing.

The converter wrote the decoder to a `vae_diffusion/` subfolder, a leftover from when the class was an
autoencoder. The folder name matters now: `DiffusionPipeline.from_pretrained` resolves each component
from the subfolder named after it, so `LTX2VideoDiffusionDecodePipeline` (component name
`diffusion_decoder`, same as the modular `ComponentSpec`) can never load itself out of a repo whose
folder is called `vae_diffusion`. The converter now saves to `diffusion_decoder/`, matching the layout
the LTX-2.5 weight repos already use, and the docs example loads from that name.

The docstrings also called it the LTX-2.4 decoder. The diffusion decoder ships with LTX-2.5; the
converter handles those checkpoints under the `--version 2.4` architecture family, which the version
guard's message now spells out instead of misattributing the feature.

Verified by re-running the converter on the rc4 distilled checkpoint after the change: the output lands
in `diffusion_decoder/` and is bit-identical (sha256) to the pre-change conversion, so this renames and
redocuments without touching what is produced. The converter regression test passes.

* Move the LTX-2 text-input expansion into the core denoise step

`LTX2TextInputStep` expanded the prompt embeddings to the effective batch
size inside `LTX2TextConditioningStep`, so running the text-conditioning
stage on its own baked `num_videos_per_prompt` into its outputs. Feeding
them to `LTX2CoreDenoiseStep` with a different `num_videos_per_prompt`
meant re-running the text stage or reshaping its outputs by hand.

`LTX2TextInputStep` now expands the connector conditioning (the tensors
the denoiser actually reads through `guider_input_fields`) instead of the
raw Gemma embeds, and runs as the first block of both core denoise steps.
The raw `prompt_embeds` expansion is dropped -- it only existed to feed
the connector at the expanded batch. `batch_size` / `dtype` move up to
`LTX2TextEncoderStep`, since `LTX2DurationStep` needs `batch_size` before
the denoise stage.

Two behavior notes:
- The connectors now run at one row per prompt rather than
  `num_videos_per_prompt` rows. They are applied per batch element, so
  this is mathematically identical (verified to ~3.6e-7, float32
  rounding) and N times cheaper, but not bitwise identical to
  `LTX2Pipeline` when `num_videos_per_prompt > 1`.
- Expansion uses `repeat_interleave` for the masks as well as the embeds.
  The previous code (inherited from the standard pipeline) interleaved
  the embeds but tiled the masks, which misaligned them whenever both
  `batch_size > 1` and `num_videos_per_prompt > 1`.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

* Describe the connector inputs on LTX2TextInputStep

`LTX2TextInputStep` declares the connector conditioning tensors and now
runs first in the denoise sequence, so its declarations -- not
`LTX2LoopDenoiser`'s -- are the ones the docstring generator picks up.
They carried no `description`, which left `TODO: Add description.`
placeholders on the three core denoise blocks.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

* Build the condition and in-context workflows from LTX2AutoBlocks

`LTX2AutoBlocks` covered text-to-video and image-to-video only; the
condition and in-context (IC-LoRA) workflows were reachable solely
through their own blocksets. Fold them into the auto blockset so all
four are selected from the inputs, the way t2v and i2v already were.

- Merge `LTX2ConditionAutoPromptEnhancerStep` into
  `LTX2AutoPromptEnhancerStep`, which now picks the condition, image or
  text enhancer off `conditions` / `image`.
- Add `LTX2AutoConditionEncoderStep`, triggered by `conditions` or
  `reference_conditions` so a reference-only in-context run still gets
  the empty per-condition lists `LTX2InContextPrepareLatentsStep`
  requires.
- Extend `LTX2AutoCoreDenoiseStep` to four branches and add
  `LTX2AutoDecoderStep`, which trims the appended keyframe/reference
  tokens whenever `base_token_count` is present.

Two fixes this exposed:

- `noise_scale` means an interpolation factor (t2v/i2v, 0.0) in one
  workflow and an initial noise level (condition/in-context, `None` ->
  `sigmas[0]` or 1.0) in another. A blockset keeps the first non-`None`
  default across its blocks, so sharing one blockset published 0.0 and
  silently zeroed the noise for condition workflows that omitted the
  argument. `LTX2PrepareLatentsStep` and `LTX2PrepareAudioLatentsStep`
  now declare `None` and resolve to 0.0 in the block, mirroring what the
  condition steps already do.
- `LTX2AutoBuildVideoSelfAttentionMaskStep.select_block` compared
  `conditioning_attention_strength` against 1.0, but
  `get_execution_blocks` passes unset trigger inputs as an explicit
  `None`, so resolving any in-context workflow raised `TypeError`.

The parity harnesses passed `noise_scale=None` explicitly, which took
the argument-present path and hid the shadowing bug; `--omit_noise_scale`
drops the key entirely so the default is exercised.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

* Run the text-input step in the condition and in-context denoise steps

`LTX2TextInputStep` is the only block that expands the connector text
conditioning by `num_videos_per_prompt`, and it was missing from
`LTX2ConditionCoreDenoiseStep` and `LTX2InContextCoreDenoiseStep`. The
prepare-latents/audio/coords steps all build their tensors at
`batch_size * num_videos_per_prompt`, so the video latents arrived at the
transformer at batch B*N while `encoder_hidden_states` was still at B —
a shape error in cross-attention for any `num_videos_per_prompt > 1`.

The step goes at the head of both sequences, before prepare-latents, so
the prepare-latents-before-set-timesteps ordering these workflows need
(`mu` is read off the full packed sequence length) is untouched.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

* Broadcast keyframe and reference conditioning across the generation batch

Frame conditions are VAE-encoded at batch 1, but `latents`,
`conditioning_mask` and `clean_latents` are built at
`batch_size * num_videos_per_prompt`. Appending a keyframe condition
(latent index > 0) therefore failed in `prepare_latents` with
"Sizes of tensors must match except in dimension 1" whenever the batch
was greater than 1. First-frame conditions were unaffected because they
are applied by indexed assignment, which broadcasts.

Expand the keyframe tokens, mask and coords to `batch_size` before the
concatenation, and do the same for the IC-LoRA reference coords, which
feed the same `appended_coords` block that is later concatenated onto
batch-`batch_size` `video_coords`. This is what the modular LTX-2 blocks
already do, and matches the `[B, 3, ...]` shape both docstrings promise.

Also picks up a pending `make style` docstring rewrap in the same file.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

* feat: use natten for processing. (#15)

* feat: use natten for processing.

* address dhruv's comments.

* remove unneeded test

* remove integration file

* make vae properties accessible without loading it. (#17)

* Address review: replace LTX2 mixins with Copied-from pipeline methods.

Inline check_inputs/enhance_prompt on LTX2Pipeline and sync I2V/Condition/InContext via # Copied from, and update docs for shared 2.5 defaults.

(cherry picked from commit c183923cdd9c951f9694f9f6cd903714330cff03)

* Point the modular enhance-prompt comment at LTX2Pipeline

`LTX2PromptEnhancementMixin` was inlined into the pipelines in c183923cd,
so the mirrored-from reference no longer names an existing class.

* Remove the integrations/ dev scripts

The LTX-2 parity harnesses and the tiny-checkpoint builder were local
development scaffolding and are not part of the shipped library.

* moular tests (#19)

* Keep LTX-2.5.1 keyframes_abs_pos_embedding through convert. (#20)

Distilled 2.5.1 monoliths ship this (1, inner_dim) buffer with
use_keyframes_abs_pos_embedding=True; store it on the transformer for
load/save without wiring it into the regular distilled forward yet.

* remove test_ltx2_keyframes_abs_pos_embedding_load_and_forward

* Update the LTX-2.5 docs: two stage generation, distilled default, repo id (#21)

* feat: implement tiling for the diffusion decoder. (#22)

* add a note on tiling (#23)

* fix documentation.

---------

Co-authored-by: aartyomov <aartyomov@lightricks.com>
Co-authored-by: Daniel Gu <daniel.gu@huggingface.co>
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Co-authored-by: linoytsaban <linoy.tsaban@gmail.com>
Co-authored-by: dg845 <58458699+dg845@users.noreply.github.com>
Co-authored-by: DN6 <dhruv.nair@gmail.com>
Co-authored-by: Linoy Tsaban <57615435+linoytsaban@users.noreply.github.com>
2026-08-11 07:10:00 -10:00
apolinário
90c0ffdc04 🚨 Give mixed-rank LoRAs without alpha keys their intended scale (#14409)
Give mixed-rank LoRAs without alpha keys their intended scale

Co-authored-by: Sayak Paul <spsayakpaul@gmail.com>
2026-08-10 18:27:11 +02:00
Jingya HUANG
1ca0943e59 [core] DiffusionPipeline.device deduction for split-device pipelines (#14383)
* feat:redefine device deduction

* test: unit test

* review: remove all cpu check
2026-08-10 14:32:06 +02:00
Sayak Paul
f6e1c4d1e7 [tests] guard peft imports in test_lora_loader_utils (#14434)
The Hub staging-tests job runs `pytest -m "is_staging_test" tests`, which
imports every test module at collection time, but that job doesn't install
peft. The top-level `from peft import ...` added in #14385 therefore breaks
collection with exit code 2 on every PR.

Guard the imports behind `is_peft_available()` (as `tests/lora/utils.py`
already does) and mark the one test that needs them with
`require_peft_backend`.

Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-08-10 10:40:24 +02:00
Aloys Jehwin
d6726f38a0 fix(lora): only drop adapter from _merged_adapters when unfused from all components (#14385)
* fix(lora): only drop adapter from _merged_adapters when unfused from all components

Signed-off-by: Aloys Jehwin <aloysjehwin@gmail.com>

* test(lora): add regression test for unfuse_lora partial component sync

Signed-off-by: Aloys Jehwin <aloysjehwin@gmail.com>

* test(lora): keep regression test in test_lora_loader_utils.py (standalone unit)

Signed-off-by: Aloys Jehwin <aloysjehwin@gmail.com>

* fix(lora): address review — use isinstance, shorten comment, fix imports

Signed-off-by: Aloys Jehwin <aloysjehwin@gmail.com>

* fix: restore tests/lora/utils.py to main (remove stray trailing newline)

Signed-off-by: Aloys Jehwin <aloysjehwin@gmail.com>

* Apply style fixes

---------

Signed-off-by: Aloys Jehwin <aloysjehwin@gmail.com>
Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>
2026-08-08 11:21:15 +05:30
Sayak Paul
50e7158093 [tests] fix torchao tests (#14258)
fix torchao tests

Co-authored-by: dg845 <58458699+dg845@users.noreply.github.com>
2026-08-07 20:10:08 +08:00
Sayak Paul
53e5b00d99 [tests] implement todos in the modular tests for H3 followup (#14404)
* remove doc placeholder.

* fix remaining tests

* empty

* empty
2026-08-07 13:47:04 +08:00
Sayak Paul
d94d0dc306 [tests] tighten tests for unload_components() (#14406)
* tighten tests for unload_components()

* fixes

* empty

* empty
2026-08-07 13:46:45 +08:00
Sayak Paul
3b68f8d087 [core] support cp in h3. (#14407)
* support cp in h3.

* empty
2026-08-07 13:46:33 +08:00