Will Lin
1fe50c0092
The v2 top level had grown to ~27 dirs + 13 loose files — half of them
single-concept abstraction shells (memory/ 86 LOC, transport/ 222, parity/ 178,
extend/ 226) and half vendored fastvideo code sitting as peers to the actual v2
design. Regroup to mirror README section 3 "Planes & dependency order":
core/ enums+types, card, loop, program, parity, request, parallel
(the model-native contracts; no kernels)
runtime/ + folded-in substrate: cache, memory, transport, extend
(the import graph shows only runtime consumes them; compile/cudagraph
already lived here)
serving/ + deploy/ (products / fleet)
_vendor/ all copied fastvideo: models, layers, attention, configs, distributed,
platforms, api, hooks, logging_utils, third_party + fastvideo_args/
utils/logger/envs/forward_context — internal layout unchanged, still
mirrors upstream for diffing
28 dirs + 13 root files -> 8 dirs + 6 root files. Pure mechanical move: 947
absolute-import paths rewritten (v2.X -> v2.{core,runtime,serving,_vendor}.X),
boundary-anchored so platform/ (native dispatch) and platforms/ (vendored CUDA
detect) no longer collide and neither does hooks/ vs extend/. Deleted the empty
v2/loader/. README section 3 + 16 updated; stale test count corrected
(34 files/216 tests -> 22 files/143 tests).
Validated: `import v2` stays torch-free; `v2/run_tests.py` and `pytest v2/tests/`
-> 143 passed, 2 skipped on the numpy toy backend. (On a GPU box force the toy
backend with CUDA_VISIBLE_DEVICES="" or detect() picks cuda.) No external importer
changed — examples use the re-exported `from v2 import VideoGenerator`.
v2_examples/workflows — cross-model composition
Runnable examples of cross-model Workflows — chaining two distinct models, threading typed
artifacts between them (designv4 §9.6). A Program composes the loops of ONE resident model
(step-interleaved, parity-gated); a Workflow composes across model instances, above the engine — so
the per-step hot path is unchanged and each model keeps its own interleave-parity guarantee.
The shipped example is T2I → I2V (the realistic FLUX→Wan pipeline): a text-to-image model produces an image, which conditions an image-to-video model. Run from anywhere:
python3 v2_examples/workflows/01_t2i_then_i2v.py
| Script | Shows |
|---|---|
01_t2i_then_i2v.py |
run the cross-model workflow; the I2V stage provably consumes the generated image |
02_register_as_servable.py |
a workflow is a first-class servable — declared requires, validated, addressable by workflow_id like a model; the declarative catalog + WorkflowRegistry |