SolitaryThinker
fa9c58b419
Addresses the 'how is ltx2 separate from ltx2.3' confusion + a wrong capability:
- LTX-2 cards renamed by ARCHITECTURE (the version labels did not map to it): build_ltx2_card model_id
'ltx2.3-distilled' -> 'ltx2-2stage-distilled' (two-stage base->upsample->refine; serves the
upsampler-having FastVideo/LTX2-Distilled-Diffusers); build_ltx2_base_card 'ltx2.base' ->
'ltx2-single-stage' (one loop; serves Davids048 base + the single-stage FastVideo/LTX-2.3-Distilled,
which has NO spatial_upsampler). Dispatch already splits on has_spatial_upsampler. Updated the
model-id refs in the mini's tests/examples.
- Wan2.1 base is T2V-only: dropped the wrong Capability.IMAGE_TO_VIDEO + narrowed components'
required_for to {t2v} (i2v is the separate InP variant; v2 has no i2v path yet). build_wan21_card is
shared by wan21 + wan2.2-ti2v; the A14B card was already T2V-only.
- CPU suite green (202 passed, 2 skipped).
74 lines
3.4 KiB
Python
74 lines
3.4 KiB
Python
"""Non-linear workflow shapes — fan-out + best-of-N feedback (design_v3 §13; §9.17).
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Every workflow so far was a linear chain. These exercise the two non-linear shapes:
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* **Fan-out** (`ParallelWorkflow`): one input → N models in parallel → merged result (namespaced by
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branch). The engine can interleave the branches' steps.
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* **Best-of-N** (`BestOfNWorkflow`): generate N candidates, score each with a reward scorer, return
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the best — inference-time scaling / rejection sampling, a feedback loop composing a generator with
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the served REWARD_BATCH card (§9.15).
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"""
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from __future__ import annotations
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import numpy as np
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from v2.models import build_default_engine, build_reward_card
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from v2.program import BestOfNWorkflow, ParallelWorkflow, WorkflowStage
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from v2.request import DiffusionParams, TaskType, make_request
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from v2.training.methods.base import new_instance
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from v2.training.rewards import ServedRewardScorer
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def _t2v(model_id):
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return lambda s: make_request(TaskType.T2V, model_id, s["prompt"],
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diffusion=DiffusionParams(num_steps=4, seed=s.get("seed", 0)))
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def test_fan_out_runs_branches_and_merges():
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eng = build_default_engine()
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wf = ParallelWorkflow("variants.fanout", [
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WorkflowStage("wan2.1-1.3b", _t2v("wan2.1-1.3b"), label="wan"),
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WorkflowStage("ltx2-2stage-distilled", _t2v("ltx2-2stage-distilled"), label="ltx"),
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])
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out = wf.run(eng, prompt="a comet over the sea", seed=1)
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# both branches' artifacts present, namespaced by label
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assert "wan:video" in out.artifacts and "ltx:video" in out.artifacts
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wan_v = np.asarray(out.artifacts["wan:video"].frames)
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ltx_v = np.asarray(out.artifacts["ltx:video"].frames)
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assert wan_v.ndim == 4 and ltx_v.ndim == 4
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# two different models on the same prompt → different videos (genuine fan-out, not duplication)
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assert wan_v.shape != ltx_v.shape or not np.array_equal(wan_v, ltx_v)
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assert wf.requires == ["wan2.1-1.3b", "ltx2-2stage-distilled"]
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def _best_of_n(n=4):
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eng = build_default_engine()
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scorer = ServedRewardScorer(new_instance(build_reward_card(batch=2)))
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wf = BestOfNWorkflow("wan.best_of_n", WorkflowStage("wan2.1-1.3b", _t2v("wan2.1-1.3b")),
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scorer=scorer, n=n, score_key="latents")
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return eng, scorer, wf
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def test_best_of_n_returns_the_highest_scored_candidate():
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eng, scorer, wf = _best_of_n(n=4)
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out = wf.run(eng, prompt="a fox", seed=2)
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assert out.metrics["best_of_n"] == 4.0
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# re-score the n candidates independently and confirm the returned one is the argmax
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cands = [eng.run(make_request(TaskType.T2V, "wan2.1-1.3b", "a fox",
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diffusion=DiffusionParams(num_steps=4, seed=2 * 100 + i))) for i in range(4)]
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scores = scorer.score([np.asarray(c.artifacts["latents"].latent) for c in cands], ["a fox"] * 4)["avg"]
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assert out.metrics["best_score"] == float(np.max(scores))
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assert out.metrics["best_index"] == float(int(np.argmax(scores)))
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def test_best_of_n_is_deterministic():
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eng, _, wf = _best_of_n(n=3)
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a = wf.run(eng, prompt="a city", seed=5).metrics["best_index"]
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b = wf.run(eng, prompt="a city", seed=5).metrics["best_index"]
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assert a == b
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def test_best_of_n_requires_only_the_generator():
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_, _, wf = _best_of_n()
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assert wf.requires == ["wan2.1-1.3b"] # the reward scorer is a held instance, not a chained stage
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