Add parity test comparing FastVideo's SAAudioVAEModel against the official
daVinci-MagiHuman SAAudioFeatureExtractor.decode() path. The sibling
test_magi_human_sa_audio_parity.py validates against Diffusers
AutoencoderOobleck; this test validates against the upstream repo's custom
integration layer, which rebuilds AudioAutoencoder from model.pretransform.config
and filters pretransform.model.* weights.
Test passes at machine-eps (diff_max=0, diff_mean=0) in fp32, confirming
FV's SAAudioVAEModel is bit-identical to the official decode path. This
rules out the audio VAE as a contributor to OQ-6 (pipeline compounding).
Requires the daVinci-MagiHuman upstream clone and the gated
stabilityai/stable-audio-open-1.0 repo. Skips cleanly when either is absent.
Complete the magi-human negative prompt to match upstream's three-block
concatenation (video + audio-quality + speech-delivery negatives). FV's
preset previously included only the video-side block, leaving audio CFG
to amplify the missing-block delta 5x via `v = uncond + 5 * (cond - uncond)`.
This explains the audio-side amplification observed in the pipeline-trace
investigation (step 1 v_cond_audio: 4.6% drift; v_cfg_audio: 13.8%).
Upstream reference: daVinci-MagiHuman/inference/pipeline/video_generate.py
:222-224.
Also harden CFG path: missing negative embeds previously silently fell
back to zeros, which is a hidden CFG amplifier. Now raises ValueError
explicitly when CFG=2 is set without negative embeds. Tracks OQ-6
production fix in tests/local_tests/magi-human.md.
Document Wave 1-5 numerical-alignment investigation results in
tests/local_tests/magi-human.md (417 lines total):
- OQ-6: DiT bf16 noise-floor drift (diff_max=0.057 at atol=0.03);
pipeline compounding at 4 steps (18.85x ratio vs 1-step baseline);
root cause under investigation via _debug_magi_human_block_parity.py
- OQ-7: Wan VAE fp32 op-order drift (z*std+mean vs z/(1/std)+mean);
shared Wan-family bug, deferred pending upstream fix
Also records Wave 1-5 methodology: loader fix, per-side log emission,
tolerance tightening, scheduler split, and bisect confirmation that
the compounding bug predates Wave 1.
Surface known bf16 numerical alignment bugs by tightening parity bounds:
- DiT parity atol=0.1 -> atol=0.03 (test FAILs at observed diff_max=0.057;
bf16-noise-floor; tracked as OQ-6 root-cause investigation)
- Pipeline parity num_inference_steps=1 -> 4 (test FAILs at video
diff_max=15.10, diff_mean=1.30 = 18.85x compounding ratio vs 1-step
baseline 0.069; pre-existing compounding bug in original magi port,
NOT introduced by Wave 1 -- bisect confirmed; tracked as OQ-6)
- Wan VAE parity atol=5e-2 -> atol=1e-3 (Wan VAE shared fp32 op-order
drift, FV `z * std + mean` vs upstream `z / (1/std) + mean`; affects
all Wan-family pipelines, deferred per OQ-7)
Also split _build_schedulers into _build_fastvideo_schedulers (double-shift,
matching MagiHumanDenoisingStage production) and _build_upstream_schedulers
(single-shift, matching MagiEvaluator.eval_with_text) to faithfully mirror
each side's production scheduler init pattern.
These tests SHIP IN A FAILING STATE intentionally as a forcing function
for follow-up investigation. See OQ-6 + OQ-7 in magi-human.md.
Add _debug_magi_human_block_parity.py, a standalone script that runs
forward hooks on both the upstream DiTModel and FastVideo MagiHumanDiT,
then writes per-side layer activation logs to:
/tmp/opencode/magi_dit_up_layers.log
/tmp/opencode/magi_dit_fv_layers.log
The logs record (name, shape, abs_mean, sum, min, max) for every hooked
activation, sorted by layer order. This enables side-by-side diff via
`diff /tmp/opencode/magi_dit_up_layers.log /tmp/opencode/magi_dit_fv_layers.log`
to pinpoint the first block where numerical divergence appears — a key
diagnostic step for OQ-6 root-cause investigation.
Replace hf_hub_download (index-only canary) with snapshot_download using
allow_patterns=["base/*.safetensors", "base/model.safetensors.index.json"].
The old approach returned the parent of the index file, which could be a
symlink-resolved HF cache path that lacked the actual shard blobs. The new
approach verifies that at least one .safetensors shard is present before
returning the candidate directory, preventing false-positive skip decisions.
Applies to test_magi_human_parity.py, test_magi_human_pipeline_parity.py,
and the new _debug_magi_human_weight_diff.py debug script (which uses the
same loader pattern for weight-diff analysis).
Drop the magi-introduced 'encoder-style' Stable Audio VAE wrapper now
that main has merged a first-class Oobleck VAE port plus a shared
SAAudioVAEModel pipeline-glue lazy-loader (#1260). MagiHuman now
reuses that infrastructure instead of carrying duplicates:
- audio VAE config: fastvideo.configs.models.vaes.OobleckVAEConfig
- audio VAE wrapper: fastvideo.models.vaes.sa_audio.SAAudioVAEModel
Removes:
- fastvideo/configs/models/encoders/sa_audio.py (SAAudioVAEConfig)
- fastvideo/models/encoders/sa_audio.py (SAAudioVAEModel dup)
Updates:
- magi-human pipeline + config to construct OobleckVAEConfig and set
pretrained_path instead of arch_config.sa_audio_model_path.
- encoders/__init__.py drops the SAAudioVAEConfig export.
- parity test moves from tests/local_tests/encoders/ to .../vaes/
(matches main's classification) and switches to the shared wrapper;
explicit pretrained_dtype='float32' override keeps the fp32 ref
parity check intact (default is fp16 to match official
stable_audio_tools).
audio_decoding.py docstring still mentions 'sa_audio_vae_model' — main's
wrapper exposes that name as a back-compat alias for oobleck_vae, so
the existing comment is still accurate.
- Drop misleading "T2V" framing — base MagiHuman is a joint audio-visual
generator. Rename MagiHumanT2VConfig→MagiHumanBaseConfig,
MagiHumanDistillT2VConfig→MagiHumanDistillConfig, presets
magi_human_base_t2v→magi_human_base, magi_human_distill_t2v→
magi_human_distill. Update comments / docstrings / example output
filename. Keep workload_type="t2v" string (framework enum has no
T2AV variant yet — same placeholder Stable Audio uses for T2A).
- Pipeline parity test: tighten atol/rtol from 0.5/0.5 to 0.35/0.05.
atol absorbs the observed worst-element drift (~0.31 on signal abs_mean
~2.4); the tight rtol still flags gross structural bugs.
- Wan VAE parity: import FastVideo's AutoencoderKLWan from
fastvideo.models.vaes.wanvae instead of diffusers. The test now
actually validates the class MagiHumanBaseConfig.vae_config resolves
to in production.
- Pipeline parity scheduler init: split per-side so upstream mirrors
MagiEvaluator's single-shift pattern (fresh FlowUniPCMultistepScheduler
+ shift only in set_timesteps) and FastVideo mirrors
MagiHumanDenoisingStage's double-shift pattern (constructor + set_timesteps
both with shift). Surfaces a real production divergence between
FastVideo's magi denoise loop and the official one for N>1 steps.
Ports GAIR-NLP/daVinci-MagiHuman's 15B-param joint-AV DiT into FastVideo:
text + video + audio joint denoise in one flat token stream, 32-step
FlowUniPC w/ CFG=2, Wan 2.2 TI2V-5B video VAE, Stable Audio Open 1.0
audio VAE (first-class port at fastvideo/models/vaes/oobleck.py, no
runtime diffusers import), T5-Gemma 9B UL2 text encoder, auto-muxed
mp4 with h264 video + aac stereo audio.
Parity tests all pass on converted weights: DiT (diff_median=2.6e-3),
text encoder (exact), video VAE (8e-4), audio VAE (exact), pipeline
latent (5e-2).
See .agents/skills/add-model/REVIEW.md for porting procedure + open
review items.
SolitaryThinker