[perf] MiniMax-H3 VAE decode optimization: _compile_conditions for the video +
audio VAE decoders (makes enable_torch_compile_vae effective for H3),
torch.compile on _stitch_tiles/_project_decoder_tile, VAE attention through the
FastVideo selector (TORCH_SDPA/FLASH_ATTN), opt-in FASTVIDEO_NVTX_PROFILE
ranges, per-worker attention-backend receipt.
Clean textual merge; semantic overlaps verified by hand:
- minimax_h3_conditioning.py: 1732's rewritten _encode_fl2va/_encode_ref2va
kept their names, 1734's nvtx_range wrap composes over them (checked).
- minimax_h3.py: 1735 fusion routing + 1734 per-block nvtx_range coexist
(fusions at attention/mlp/modulate seams, nvtx at the block loop).
- component_loader.py: 1732 quant plumbing at load_model (~L369) vs 1734
backend receipt (~L1103) - disjoint.
- envs.py: FASTVIDEO_NVTX_PROFILE (1734) + FASTVIDEO_MINIMAX_H3_FUSIONS (1735)
are distinct additions.
- minimax_h3_video.py: 1734 was authored on a base that already contains the
merged #1703 (incl. pr1703-fixes content), so the 1734-vs-1703 conflict the
reviews predicted was pre-resolved by the author's rebase.
KNOWN CARRIED DEFECT at this point in the stack: review finding F1 of
pr1734.md - reduce-overhead CUDA-graph outputs of _stitch_tiles escape into
collect-then-cat consumers (_decode/_encode/_encode_pixels), crashing tiled
eager decode/encode on CUDA. Fixed in a follow-up commit on this branch.
Will Lin
aa0d98a6b8