Files
hao-ai-lab-FastVideo/examples/inference/basic/basic_fasth3.py
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Davids048andClaude Fable 5.1 1ea7278c00 [refactor]: group model-family settings under pipeline.model
pipeline.model is a tagged union: a mapping with exactly one key, which
names the model family (ltx2, minimax_h3, longcat, or generic) and selects
that family's options class. The former sibling sections pipeline.ltx2,
pipeline.minimax_h3, and pipeline.longcat, and the DiT/VAE architecture
override dicts pipeline.dit and pipeline.vae, live inside the family block.
The parser implements tagged unions as a general mechanism (a dataclass
with a TAGS table); the family is readable as pipeline.model.family.

Resolution validates the tag against the family that the registry chose
for model_path (validate_model_family raises and names the registry class
and the right block) and fills the family's empty block when the input has
none (fill_model_family), so readers never see None. Family-only fills and
derivations (the MiniMax-H3 parallel-VAE environment variables, the LTX-2
tile-size derivation and refine preset copy, the LongCat BSA mirrors) run
only for their family.

Against the 3f6893a0 goldens every PipelineConfig is identical and no
other field differs beyond the allowed categories; family-only settings
are no longer decided on models of another family. LingBot-Video reads
its refiner switch from pipeline.preset_overrides.refine.enabled and loads
the refiner by default when the checkpoint has one, as at 3f6893a0.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01CbSuTKA9oX4YsECdcBPAsX
2026-10-05 06:04:17 +00:00

405 lines
18 KiB
Python

# SPDX-License-Identifier: Apache-2.0
"""Few-step video+audio generation with the DMD2-distilled MiniMax H3 preview.
The default ``all`` profile reproduces the fastest measured FastH3 Preview
recipe on four GB200 GPUs. It runs the checkpoint's native five-point sigma
grid (exactly four DiT forwards), trained VSA policy, Blackwell sparse kernel,
regional fullgraph DiT compile, compiled/parallel video VAE, and inference-only
H3 fusions. One compile warmup is excluded before three measured requests.
Both regional compile and the default fusions can change floating-point
operation order, so ``all`` is a report-only performance profile.
``--profile strict`` disables the H3 fusions but preserves regional compile;
combine it with ``--no-inference-torch-compile`` for the eager strict route.
"""
from __future__ import annotations
import argparse
import importlib.util
import os
import statistics
import time
from collections.abc import Sequence
from pathlib import Path
from fastvideo import VideoGenerator
from fastvideo.api import (
AttentionConfig,
CompileConfig,
ComponentConfig,
EngineConfig,
GenerationRequest,
GeneratorConfig,
MiniMaxH3Options,
OffloadConfig,
OutputConfig,
ParallelismConfig,
PipelineSelection,
SamplingConfig,
)
DEFAULT_MODEL = "FastVideo/FastVideo-Minimax-FastH3-Preview-v0.2"
def build_parser(description: str | None = None) -> argparse.ArgumentParser:
"""Build the shared FastH3 preview CLI used by full and LoRA checkpoints."""
parser = argparse.ArgumentParser(description=description or __doc__)
parser.add_argument("--model-path", default=DEFAULT_MODEL)
# The HF repo may require authentication while the MiniMax H3 Community
# License review completes. A local snapshot can be passed here instead.
parser.add_argument("--prompt", required=True)
parser.add_argument("--output", default="outputs/fasth3")
parser.add_argument("--lazy-module-load",
action=argparse.BooleanOptionalAction,
default=None,
help="load each heavy component on first use and free it after the last stage that "
"needs it, so peak memory is the largest overlapping set instead of the sum of every "
"component. Omit for auto (on for unified-memory devices such as GB10; off on discrete "
"GPUs). Costs a reload per generation; pass --no-lazy-module-load to keep every "
"component resident")
parser.add_argument("--profile",
choices=("all", "strict"),
default="all",
help="all enables the fastest measured, non-parity H3 fusions; strict disables only them")
parser.add_argument("--height", type=int, default=768)
parser.add_argument("--width", type=int, default=1344)
parser.add_argument("--num-frames", type=int, default=124)
# num_inference_steps counts sigma-GRID POINTS. The distilled schedule is
# t=1000,750,500,250 -> 0: five points and exactly four DiT forwards.
parser.add_argument("--steps",
type=int,
default=5,
help="sigma-grid points; N points run N-1 DiT forwards (the trained default is 5)")
parser.add_argument("--seed", type=int, default=1000, help="seed reused for every measured request")
parser.add_argument("--warmup-seed", type=int, default=999)
parser.add_argument("--repeats", type=int, default=3, help="number of measured requests after warmup")
parser.add_argument("--warmup",
action=argparse.BooleanOptionalAction,
default=True,
help="run one excluded request before timing")
parser.add_argument("--num-gpus", type=int, default=4)
parser.add_argument(
"--execution-backend",
choices=("mp", "ray"),
default=None,
help="mp for one node; ray for a Ray cluster (two DGX Sparks). "
"Default: ray when RAY_ADDRESS is set, otherwise mp",
)
parser.add_argument("--vsa-sparsity",
type=float,
default=0.9,
help="run-level VSA sparsity in [0, 1); 0.9 is the checkpoint's trained policy")
parser.add_argument("--vsa-tile-size",
type=int,
choices=(64, 256),
default=64,
help="VSA-H3 tile size; 64 is the checkpoint's trained and measured geometry")
parser.add_argument("--vsa-kernel",
choices=("triton", "sm100a"),
default="sm100a",
help="tile-64 sparse kernel; sm100a is the measured GB200 route and requires a compatible "
"fastvideo-kernel build")
parser.add_argument("--fa4",
action=argparse.BooleanOptionalAction,
default=True,
help="use FA4 for eligible non-VSA attention paths")
parser.add_argument("--h3-fusions",
action=argparse.BooleanOptionalAction,
default=None,
help="override the profile's H3 fusion policy (changes model numerics when enabled)")
parser.add_argument("--compile-vae",
action=argparse.BooleanOptionalAction,
default=True,
help="compile the video VAE decoder independently of the DiT")
parser.add_argument("--parallel-vae",
action=argparse.BooleanOptionalAction,
default=True,
help="round-robin VAE temporal chunks across sequence-parallel ranks")
parser.add_argument("--h3-sequential-load",
action=argparse.BooleanOptionalAction,
default=None,
help="encode with Qwen3-VL, release it, then load DiT/VAEs. Default auto: on for "
"unified-memory devices (GB10), off on discrete GPUs")
parser.add_argument("--video-decode-backend",
choices=("h3-vae", "taeh3"),
default="h3-vae",
help="h3-vae is the full MiniMax VAE; taeh3 is the fast approximate preview decoder")
parser.add_argument("--taeh3-checkpoint", default=None, help="local taeh3.safetensors; unset uses the pinned cache")
parser.add_argument("--replicated-dit",
action=argparse.BooleanOptionalAction,
default=True,
help="replicate DiT weights instead of FSDP-sharding them")
parser.add_argument("--pin-cpu-memory",
action=argparse.BooleanOptionalAction,
default=True,
help="pin CPU-offloaded text-encoder and VAE weights")
parser.add_argument("--torch-compile",
action=argparse.BooleanOptionalAction,
default=False,
help="compile the whole DiT path (off in the fastest FastH3 profile)")
parser.add_argument("--inference-torch-compile",
action=argparse.BooleanOptionalAction,
default=True,
help="regionally compile DiT blocks (enabled in the fastest FastH3 profile)")
parser.add_argument("--ulysses-a2a",
choices=("off", "auto"),
default="off",
help="sequence-parallel all-to-all route; off reproduces the fastest FastH3 profile, while "
"auto opts into the fused NVLink kernel when the installed kernel package supports it")
parser.add_argument("--compile-mode",
default=None,
help='whole-DiT torch.compile mode, e.g. "reduce-overhead"; requires '
"--no-inference-torch-compile")
return parser
def validate_args(parser: argparse.ArgumentParser, args: argparse.Namespace) -> argparse.Namespace:
if args.repeats < 1:
parser.error("--repeats must be at least 1")
if args.num_gpus < 1:
parser.error("--num-gpus must be at least 1")
if not 0.0 <= args.vsa_sparsity < 1.0:
parser.error("--vsa-sparsity must be in [0, 1)")
if args.compile_mode is not None and args.inference_torch_compile:
parser.error("--compile-mode cannot be combined with regional compile; pass --no-inference-torch-compile")
return args
def parse_args(argv: Sequence[str] | None = None) -> argparse.Namespace:
parser = build_parser()
return validate_args(parser, parser.parse_args(argv))
def _uses_vsa(args: argparse.Namespace) -> bool:
"""Full FastH3 checkpoints use VSA; LoRA previews may select dense attention."""
return bool(getattr(args, "vsa", True))
def _h3_fusions_enabled(args: argparse.Namespace) -> bool:
if args.h3_fusions is not None:
return bool(args.h3_fusions)
return args.profile == "all"
def profile_environment(args: argparse.Namespace) -> dict[str, str | None]:
"""Return the complete boot-time environment for this profile.
``None`` means the variable must be removed. Values are explicit even for
disabled features so a shell's inherited experiment settings cannot
silently change the advertised profile.
"""
use_vsa = _uses_vsa(args)
return {
"FASTVIDEO_ATTENTION_BACKEND": "VIDEO_SPARSE_ATTN_H3" if use_vsa else "FLASH_ATTN",
"FASTVIDEO_VSA_SM100A": "1" if use_vsa and args.vsa_kernel == "sm100a" else "0",
"FASTVIDEO_VSA_CUTEDSL": "0",
# A non-empty output path enables the diagnostic probe.
"FASTVIDEO_H3_VSA_PROBE": None,
"FASTVIDEO_DISABLE_ATTENTION_COMPILE": "0",
"FASTVIDEO_FA4": "1" if args.fa4 else "0",
"FASTVIDEO_NVFP4_FA4": "0",
"FASTVIDEO_MINIMAX_H3_FA4_PACKED_VARLEN": "0",
"FASTVIDEO_MINIMAX_H3_FUSIONS": "all" if _h3_fusions_enabled(args) else "0",
"FASTVIDEO_INFERENCE_TORCH_COMPILE": "1" if args.inference_torch_compile else "0",
"FASTVIDEO_VAE_PARALLEL_DECODE": "1" if args.parallel_vae else "0",
"FASTVIDEO_VAE_PARALLEL_ENCODE": "0",
"FASTVIDEO_VAE_PARALLEL_DECODE_STRATEGY": "gather",
"FASTVIDEO_ULYSSES_A2A": args.ulysses_a2a,
"FASTVIDEO_STAGE_LOGGING": "1",
}
def configure_environment(args: argparse.Namespace) -> dict[str, str | None]:
environment = profile_environment(args)
for name, value in environment.items():
if value is None:
os.environ.pop(name, None)
else:
os.environ[name] = value
return environment
def _fa4_is_installed() -> bool:
try:
return importlib.util.find_spec("flash_attn.cute") is not None
except (ImportError, ModuleNotFoundError):
return False
def _sm100a_kernel_is_installed() -> bool:
try:
from fastvideo_kernel import block_sparse_attn_sm100a
except ImportError:
return False
return bool(getattr(block_sparse_attn_sm100a, "_HAS_VSA_SM100A", False))
def validate_profile_dependencies(args: argparse.Namespace) -> None:
"""Fail before model loading when the selected measured route is absent."""
if args.fa4 and not _fa4_is_installed():
raise RuntimeError(
"FastH3's FA4 profile requires the pinned flash-attn-4 package. Install it with "
"`UV_TORCH_BACKEND=cu130 uv pip install -e \".[fasth3]\"`, or pass --no-fa4.")
if _uses_vsa(args) and args.vsa_kernel == "sm100a" and not _sm100a_kernel_is_installed():
raise RuntimeError(
"FastH3's sm100a profile requires fastvideo-kernel 0.3.4 built with the Blackwell VSA extension. "
"Install this checkout with `UV_TORCH_BACKEND=cu130 uv pip install -e \".[fasth3]\"` (or run "
"`cd fastvideo-kernel && ./build.sh`), or pass --vsa-kernel triton.")
def _execution_backend(args: argparse.Namespace) -> str:
if args.execution_backend is not None:
return args.execution_backend
return "ray" if os.environ.get("RAY_ADDRESS") else "mp"
def build_generator_config(args: argparse.Namespace) -> GeneratorConfig:
use_vsa = _uses_vsa(args)
return GeneratorConfig(
model_path=args.model_path,
pipeline=PipelineSelection(
components=ComponentConfig(
lora_path=getattr(args, "lora_path", None),
lora_strength=float(getattr(args, "lora_strength", 1.0)),
),
model=MiniMaxH3Options(
sequential_load=args.h3_sequential_load,
video_decode_backend=None if args.video_decode_backend == "h3-vae" else args.video_decode_backend,
taeh3_checkpoint=args.taeh3_checkpoint,
vae_parallel_decode=args.parallel_vae,
vae_parallel_decode_strategy="gather",
),
),
engine=EngineConfig(
num_gpus=args.num_gpus,
execution_backend=_execution_backend(args),
use_fsdp_inference=args.num_gpus > 1 and not args.replicated_dit,
parallelism=ParallelismConfig(tp_size=1, sp_size=args.num_gpus),
offload=OffloadConfig(
dit=False,
dit_layerwise=False,
text_encoder=True,
vae=True,
pin_cpu_memory=args.pin_cpu_memory,
lazy_module_load=args.lazy_module_load,
),
compile=CompileConfig(
enabled=args.torch_compile,
mode=args.compile_mode,
vae_enabled=args.compile_vae,
regional=args.inference_torch_compile,
),
attention=AttentionConfig(
backend="VIDEO_SPARSE_ATTN_H3" if use_vsa else "FLASH_ATTN",
vsa_sparsity=args.vsa_sparsity if use_vsa else None,
vsa_tile_size=args.vsa_tile_size if use_vsa else None,
),
),
)
def build_request(args: argparse.Namespace, output_path: Path, seed: int) -> GenerationRequest:
return GenerationRequest(
prompt=args.prompt,
negative_prompt="",
sampling=SamplingConfig(
height=args.height,
width=args.width,
num_frames=args.num_frames,
fps=24,
num_inference_steps=args.steps,
# MiniMax-H3 is guidance-distilled; FastH3 inherits that contract.
guidance_scale=1.0,
batch_cfg=False,
seed=seed,
),
output=OutputConfig(
output_path=str(output_path),
save_video=True,
return_frames=False,
),
)
def _actual_output_path(result: object, requested: Path) -> Path:
video_path = getattr(result, "video_path", None)
return Path(video_path) if video_path else requested
def _denoise_seconds(result: object) -> float | None:
stages = getattr(getattr(result, "logging_info", None), "stages", None)
if not stages:
return None
for stage_name, metrics in stages.items():
if "denois" not in stage_name.lower():
continue
execution_time = metrics.get("execution_time")
return float(execution_time) if execution_time is not None else None
return None
def run(args: argparse.Namespace) -> list[float]:
output_dir = Path(args.output)
output_dir.mkdir(parents=True, exist_ok=True)
environment = configure_environment(args)
validate_profile_dependencies(args)
print(f"Profile: {args.profile} ({'non-parity fusions' if _h3_fusions_enabled(args) else 'fusions off'})")
print(f"Output directory: {output_dir.resolve()}")
print("Denoising contract: 5 sigma points = 4 DiT forwards" if args.steps == 5 else
f"Denoising contract override: {args.steps} sigma points = {args.steps - 1} DiT forwards")
print("Profile environment: " + " ".join(f"{key}={value if value is not None else '<unset>'}"
for key, value in environment.items()))
print(f"Execution backend: {_execution_backend(args)}")
generator = VideoGenerator.from_config(build_generator_config(args))
measured_wall_times: list[float] = []
measured_denoise_times: list[float] = []
try:
if args.warmup:
warmup_path = output_dir / "_fasth3_warmup.mp4"
print(f"[warmup] generating (excluded from timing summary): {warmup_path}")
started = time.perf_counter()
warmup_result = generator.generate(build_request(args, warmup_path, args.warmup_seed))
warmup_wall = time.perf_counter() - started
actual_warmup_path = _actual_output_path(warmup_result, warmup_path)
print(f"[warmup] wall={warmup_wall:.3f}s (excluded)")
print(f"Warmup output written to: {actual_warmup_path}")
for index in range(1, args.repeats + 1):
requested_path = output_dir / f"fasth3_{args.profile}_run_{index:02d}.mp4"
print(f"[measured {index}/{args.repeats}] generating: {requested_path}")
started = time.perf_counter()
result = generator.generate(build_request(args, requested_path, args.seed))
wall = time.perf_counter() - started
measured_wall_times.append(wall)
actual_path = _actual_output_path(result, requested_path)
print(f"Output written to: {actual_path}")
print(f"E2E wall time: {wall:.3f}s")
generation_time = getattr(result, "generation_time", None)
if generation_time is not None:
print(f"Generation time: {float(generation_time):.3f}s")
denoise_time = _denoise_seconds(result)
if denoise_time is not None:
measured_denoise_times.append(denoise_time)
print(f"Denoising time: {denoise_time:.3f}s")
median = statistics.median(measured_wall_times)
print(f"Measured E2E wall times (n={len(measured_wall_times)}, warmup excluded): "
f"{[round(value, 3) for value in measured_wall_times]}")
print(f"Median E2E wall time: {median:.3f}s")
if measured_denoise_times:
print(f"Median denoising time: {statistics.median(measured_denoise_times):.3f}s")
return measured_wall_times
finally:
generator.shutdown()
def main() -> None:
run(parse_args())
if __name__ == "__main__":
main()