Davids048andClaude Fable 5.1
1ea7278c00
pipeline.model is a tagged union: a mapping with exactly one key, which names the model family (ltx2, minimax_h3, longcat, or generic) and selects that family's options class. The former sibling sections pipeline.ltx2, pipeline.minimax_h3, and pipeline.longcat, and the DiT/VAE architecture override dicts pipeline.dit and pipeline.vae, live inside the family block. The parser implements tagged unions as a general mechanism (a dataclass with a TAGS table); the family is readable as pipeline.model.family. Resolution validates the tag against the family that the registry chose for model_path (validate_model_family raises and names the registry class and the right block) and fills the family's empty block when the input has none (fill_model_family), so readers never see None. Family-only fills and derivations (the MiniMax-H3 parallel-VAE environment variables, the LTX-2 tile-size derivation and refine preset copy, the LongCat BSA mirrors) run only for their family. Against the3f6893a0goldens every PipelineConfig is identical and no other field differs beyond the allowed categories; family-only settings are no longer decided on models of another family. LingBot-Video reads its refiner switch from pipeline.preset_overrides.refine.enabled and loads the refiner by default when the checkpoint has one, as at3f6893a0. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01CbSuTKA9oX4YsECdcBPAsX
LTX-2 Local Tests
Local-only parity, registry, and pipeline-smoke tests for the ltx2 FastVideo
port. Most tests depend on a checked-out LTX-2/ directory at the repo root
(FastVideo/LTX-2) and converted Diffusers weights; without those they will
skip or fail. Skipped in CI; run locally on a single GPU.
Reference Assets
| Field | Value |
|---|---|
| Model family | ltx2 |
| Workload types | T2V (video + optional audio) |
| Official reference | Lightricks/LTX-2 (local clone) |
| Local reference dir | LTX-2/ (with LTX-2/packages/ltx-core/src on sys.path) |
| Official commit/version | <TODO> |
| HF weights | Lightricks/LTX-2, FastVideo/LTX2-base, FastVideo/LTX2-Distilled-Diffusers |
| HF revision | <TODO> |
| Local weights dir | <TODO> (env: LTX2_DIFFUSERS_PATH, FASTVIDEO_LTX2_GEMMA_LOG, etc.) |
| Source layout | <TODO: diffusers / raw_official / mixed> |
| Needs conversion | <TODO> |
Use only the env-var name for tokens (e.g.,
HF_TOKEN). Never paste a token value.
Shared Environment Setup
Run from the FastVideo repo root in the same env used for FastVideo. See the
add-model-prep skill for canonical clone + install commands.
# Clone the official reference under the FastVideo repo root.
git clone <official_repo_url> LTX-2
uv pip install --no-deps -e ./LTX-2
Do not change core dependency versions (torch, diffusers, transformers,
flash-attn, triton, CUDA packages) without explicit approval.
Official Environment Status
dependency_changes: <TODO>
official_env_status: <TODO: imports_ok | private_deps_need_stubs | blocked>
private_dep_stubs: <TODO>
blocked_on: <TODO>
Tests in this directory
Run the whole family:
pytest tests/local_tests/ltx2/ -v -s
| Component | Test | Concerns | Status |
|---|---|---|---|
text encoder (Gemma) |
test_ltx2_gemma_encoder.py |
encoder + connector | <TODO> |
text encoder (Gemma, full parity) |
test_ltx2_gemma_parity.py |
full Gemma parity vs official | <TODO> |
transformer/DiT |
test_ltx2.py |
LTX2VideoConfig DiT parity | <TODO> |
transformer/DiT (audio modality) |
test_ltx2_audio.py |
audio-conditioning DiT parity (imports helpers from test_ltx2.py) |
<TODO> |
vae (video) |
test_ltx2_vae.py |
LTX2VideoEncoder/Decoder parity | <TODO> |
vae (video, official path) |
test_ltx2_vae_official.py |
LTX2VAEConfig + VAELoader path | <TODO> |
vae (audio) |
test_ltx2_audio_vae.py |
audio encoder/decoder/vocoder parity | <TODO> |
pipeline (smoke) |
test_ltx2_pipeline_smoke.py |
VideoGenerator end-to-end smoke | <TODO> |
registry |
test_ltx2_registry.py |
sampling/pipeline registry resolution | <TODO> |
Review Notes
- Required before handoff: non-skip PASS for each component parity test, including reused components that own weights or numerical behavior.
- Pipeline parity may start as a scaffold; final handoff requires non-skip PASS or an explicit blocker accepted via the escape-hatch process.