hao-ai-lab-FastVideo/tests/local_tests/flux

FLUX.1-dev Local Tests

Prerequisites

• CUDA GPU
• official_weights/FLUX.1-dev (Diffusers layout) or set FLUX_DEV_ROOT
• FASTVIDEO_ATTENTION_BACKEND=TORCH_SDPA for parity tests

Download weights:

huggingface-cli download black-forest-labs/FLUX.1-dev --local-dir official_weights/FLUX.1-dev

Component Loader Smoke Test

Verifies CLIP/T5 encoders, tokenizers, VAE, and FlowMatch scheduler all load from the Diffusers checkpoint layout.

pytest tests/local_tests/flux/test_flux_dev_component_loaders.py -vs

Status: requires weights — not run in CI.

Pipeline Smoke Test

Short denoise + decode (2 steps, 256×256) end-to-end.

FASTVIDEO_ATTENTION_BACKEND=TORCH_SDPA \
pytest tests/local_tests/pipelines/test_flux_dev_pipeline_smoke.py -vs

Status: requires weights — not run in CI.

Pipeline Parity Test

Compares FastVideo FluxPipeline decoded image output against Diffusers FluxPipeline under identical prompt, seed, and inference parameters (4 steps, 256×256, seed=42). Tolerance: atol=5e-2.

FASTVIDEO_ATTENTION_BACKEND=TORCH_SDPA \
pytest tests/local_tests/pipelines/test_flux_dev_pipeline_parity.py -vs

Status: PASS on A40 (2026-05-11) — requires weights; not run in CI.

DiT Parity Test

Single-forward comparison of FastVideo FluxTransformer2DModel against Diffusers FluxTransformer2DModel under identical random inputs.

FASTVIDEO_ATTENTION_BACKEND=TORCH_SDPA \
pytest fastvideo/tests/transformers/test_flux.py -vs

Status: requires weights — not run in CI. Pass evidence: PASS recorded in PORT_STATUS.md (A40, 2026-05-11).

SSIM Regression Test

Full-quality image generation compared against per-device reference images. Reference images must be seeded first via reference_videos_cli.py.

FASTVIDEO_ATTENTION_BACKEND=TORCH_SDPA \
FLUX_T2I_MODEL_DIR=official_weights/FLUX.1-dev \
pytest fastvideo/tests/ssim/test_flux_t2i_similarity.py -vs

Status: seeded reference images committed (TORCH_SDPA, A40, 2026-05-11) — see PORT_STATUS.md.