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…n 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.
…elines 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).
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 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 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>
…n that it inherits all configs from LTX-2.3)
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>
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>
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>
…eline 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>
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>
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>
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>
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>
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>
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>
`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>
…ings 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>
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>
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).
--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.
Picks up 6593e3b, which sources NATTEN from `shi-labs/natten` via the `kernels` package instead of a local install, and drops the now-unused `is_natten_available` helper that the previous merge had introduced. Kept `integrations/ltx2_diffusion_vae_parity.py` deleted (modify/delete conflict) — the parity scripts were removed on this branch.
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)
`LTX2PromptEnhancementMixin` was inlined into the pipelines in c183923cd, so the mirrored-from reference no longer names an existing class.
Picks up 4d32963 (#17), which adds `vae_scaling_factor`, `latents_mean`, `latents_std`, `audio_latents_mean` and `audio_latents_std` properties to `LTX2ModularPipeline`. Each falls back to the `diffusion_decoder`'s buffers and then to the `Lightricks/LTX-2` constants, so a checkpoint that decodes with the diffusion decoder no longer has to register the conv `vae` just to supply the statistics.
The LTX-2 parity harnesses and the tiny-checkpoint builder were local development scaffolding and are not part of the shipped library.
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.
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yiyixuxu
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Aug 11, 2026
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not a merge blocker, let's refactor this fater the PR is merged
should just be one forward with all the steps visible where weights layers are applied, the denoise logics should go to pipeline
cc @dg845
yiyixuxu
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Aug 11, 2026
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currently, we keep everything under the guider folder? even the pipeline specific one
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In the Lightricks/LTX-2.5-Diffusers checkpoint, we currently don't have a guider or audio_guider subdirectory, so they're currently being created with the default config dicts. I think ideally we should have folders for them as it's possible that the recommended guidance parameters could change for different checkpoints.
yiyixuxu
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Aug 11, 2026
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| class LTX25AutoBlocks(LTX2AutoBlocks): |
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we usually have a blockset per file https://github.com/huggingface/diffusers/tree/main/src/diffusers/modular_pipelines/flux2
2.5 shoud have its own model_name too
This was referenced Aug 12, 2026
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