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hao-ai-lab-FastVideo/examples/inference/basic/basic_pika_h3_flex.py
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aryan5v 62fc354824 [feat]: wire NVFP4 decoder and text encoder into Pika H3 Flex
Expose the exported H3 NVFP4 VAE decoder through ComponentConfig and map it to FastVideoArgs, alongside the existing text-encoder weight override. Add example flags and docs for the 36L quality and 8L fast decoder tiers, including the 8L depth-cut and no-NVFP4-VAE-encoder caveats. Add compat translation tests.
2026-10-29 17:53:58 -07:00

194 lines
7.5 KiB
Python

# SPDX-License-Identifier: Apache-2.0
"""Generate synchronized video/audio with Pika H3 Flex.
Five task shapes share one model release:
``t2va`` text only
``i2va`` first image
``l2va`` last image
``fl2va`` first and last images
``ref2va`` ordered image/video/audio references
The six-forward ladder is part of the adapter contract; this script deliberately
does not expose a step-count flag. ``--lossless-accel`` turns on the existing
training-free FastVideo switches (bit-identical kernels, reference memo,
parallel VAE tiles) before the generator starts. ``--nvfp4-decoder`` and
``--nvfp4-text-encoder`` opt into the existing Blackwell FP4 weight paths;
they change weights, not the six-forward sampler. Kernel/VSA work is separate.
Examples:
python examples/inference/basic/basic_pika_h3_flex.py --task t2va \
--prompt "a paper boat drifting down a rainy street"
python examples/inference/basic/basic_pika_h3_flex.py --task fl2va \
--image first.png --last-image last.png --prompt "the flower opens"
python examples/inference/basic/basic_pika_h3_flex.py --task ref2va \
--reference image:person.png --reference video:dance.mp4 \
--reference audio:voice.wav --prompt "the person dances to the music"
"""
from __future__ import annotations
import argparse
import os
from pathlib import Path
from typing import Any
from fastvideo import VideoGenerator
from fastvideo.api import (
CompileConfig,
ComponentConfig,
EngineConfig,
GenerationRequest,
GeneratorConfig,
InputConfig,
OffloadConfig,
OutputConfig,
ParallelismConfig,
PipelineSelection,
SamplingConfig,
)
from fastvideo.models.vision_utils import load_image
from fastvideo.pipelines.basic.minimax_h3 import MiniMaxH3Reference
# Training-free switches FastVideo already exposes. Workers inherit the
# environment, so they must be set before VideoGenerator starts.
LOSSLESS_ACCEL_ENV = {
"FASTVIDEO_MINIMAX_H3_EXACT_KERNELS": "all",
"FASTVIDEO_H3_REF2VA_MEMO_ENTRIES": "16",
"FASTVIDEO_H3_VAE_TILE_PARALLEL": "1",
"FASTVIDEO_ULYSSES_A2A": "auto",
}
TASKS = ("t2va", "i2va", "l2va", "fl2va", "ref2va")
def _reference(value: str) -> MiniMaxH3Reference:
try:
media_type, source = value.split(":", 1)
except ValueError as error:
raise argparse.ArgumentTypeError("A reference must be image:PATH, video:PATH, or audio:PATH.") from error
if media_type not in ("image", "video", "audio"):
raise argparse.ArgumentTypeError(f"Unknown reference type {media_type!r}.")
return MiniMaxH3Reference(source=source, media_type=media_type)
def parse_args() -> argparse.Namespace:
parser = argparse.ArgumentParser(description=__doc__, formatter_class=argparse.RawDescriptionHelpFormatter)
parser.add_argument("--model-path", default="Pika-Labs/Pika-H3-Flex")
parser.add_argument("--task", choices=TASKS, default="t2va")
parser.add_argument("--prompt", required=True)
parser.add_argument("--image", help="first frame (i2va/fl2va)")
parser.add_argument("--last-image", help="last frame (l2va/fl2va)")
parser.add_argument("--reference",
action="append",
type=_reference,
default=[],
help="ordered reference (repeatable; ref2va)")
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)
parser.add_argument("--seed", type=int, default=0)
parser.add_argument("--num-gpus", type=int, default=1)
parser.add_argument("--compile", action="store_true", help="torch.compile the DiT")
parser.add_argument("--lossless-accel", action="store_true", help="enable bit-identical speed-ups")
parser.add_argument("--low-vram", action="store_true", help="stream the DiT layerwise")
parser.add_argument("--nvfp4-decoder",
help="Blackwell-only NVFP4 H3 decoder (quality-36L or fast-8L decoder-nvfp4.safetensors)")
parser.add_argument("--nvfp4-text-encoder",
help="Blackwell-only serialized NVFP4 Qwen3-VL text_encoder directory")
parser.add_argument("--output", default="outputs/pika_h3_flex")
args = parser.parse_args()
if args.task in ("i2va", "fl2va") and not args.image:
parser.error(f"--task {args.task} needs --image")
if args.task in ("l2va", "fl2va") and not args.last_image:
parser.error(f"--task {args.task} needs --last-image")
if args.task == "ref2va" and not args.reference:
parser.error("--task ref2va needs at least one --reference")
if args.task != "ref2va" and args.reference:
parser.error("--reference is only valid with --task ref2va")
return args
def _inputs(args: argparse.Namespace) -> InputConfig:
if args.task == "ref2va":
return InputConfig(references=args.reference)
# The request adapter copies image fields verbatim; the stage loads
# ``image_path`` itself but requires ``last_image`` to already be a PIL image.
last_image = load_image(args.last_image) if args.last_image else None
return InputConfig(image_path=args.image, last_image=last_image)
def _pipeline(args: argparse.Namespace) -> PipelineSelection:
components = ComponentConfig()
if args.task == "ref2va":
components.override_pipeline_cls_name = "PikaH3FlexRef2VAModularPipeline"
if args.nvfp4_decoder:
components.h3_vae_nvfp4_decoder = args.nvfp4_decoder
if args.nvfp4_text_encoder:
components.text_encoder_weights = args.nvfp4_text_encoder
return PipelineSelection(
workload_type="t2v" if args.task == "t2va" else "i2v",
components=components,
vae_tiling=True,
)
def main() -> None:
args = parse_args()
if args.lossless_accel:
for key, value in LOSSLESS_ACCEL_ENV.items():
os.environ.setdefault(key, value)
output_path = Path(args.output) / f"pika_h3_flex_{args.task}.mp4"
output_path.parent.mkdir(parents=True, exist_ok=True)
offload = OffloadConfig(
dit=False,
dit_layerwise=args.low_vram,
text_encoder=True,
vae=True,
pin_cpu_memory=not args.low_vram,
lazy_module_load=True,
)
generator = VideoGenerator.from_config(
GeneratorConfig(
model_path=args.model_path,
engine=EngineConfig(
num_gpus=args.num_gpus,
use_fsdp_inference=args.num_gpus > 1,
parallelism=ParallelismConfig(tp_size=1, sp_size=args.num_gpus),
offload=offload,
compile=CompileConfig(enabled=args.compile),
),
pipeline=_pipeline(args),
))
try:
result = generator.generate(
GenerationRequest(
prompt=args.prompt,
negative_prompt="",
inputs=_inputs(args),
sampling=SamplingConfig(
height=args.height,
width=args.width,
num_frames=args.num_frames,
fps=24,
num_inference_steps=6,
guidance_scale=1.0,
batch_cfg=False,
seed=args.seed,
),
output=OutputConfig(
output_path=str(output_path),
save_video=True,
return_frames=False,
),
))
print(f"Output written to: {result.video_path}")
finally:
generator.shutdown()
if __name__ == "__main__":
main()