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OpenGait/opengait/modeling/base_model_body.py
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Python

from __future__ import annotations
from typing import Any, Callable, cast
import numpy as np
import torch
from jaxtyping import Float, Int
from .base_model import BaseModel
from opengait.utils.common import list2var, np2var
class BaseModelBody(BaseModel):
"""Base model variant with a separate sequence-level body-prior input."""
def inputs_pretreament(
self,
inputs: tuple[list[np.ndarray], list[int], list[str], list[str], np.ndarray | None],
) -> Any:
seqs_batch, labs_batch, typs_batch, vies_batch, seqL_batch = inputs
seq_trfs = cast(
list[Callable[[Any], Any]],
self.trainer_trfs if self.training else self.evaluator_trfs,
)
if len(seqs_batch) != len(seq_trfs):
raise ValueError(
"The number of types of input data and transform should be same. "
f"But got {len(seqs_batch)} and {len(seq_trfs)}"
)
if len(seqs_batch) < 2:
raise ValueError("BaseModelBody expects one visual input and one body-prior input.")
requires_grad = bool(self.training)
visual_seqs = [
np2var(
np.asarray([trf(fra) for fra in seq]),
requires_grad=requires_grad,
).float()
for trf, seq in zip(seq_trfs[:-1], seqs_batch[:-1])
]
body_trf = seq_trfs[-1]
body_seq = np2var(
np.asarray([body_trf(fra) for fra in seqs_batch[-1]]),
requires_grad=requires_grad,
).float()
labs = list2var(labs_batch).long()
seqL = np2var(seqL_batch).int() if seqL_batch is not None else None
# Preserve a singleton modality axis so DRF can mirror the author stub's
# `squeeze(1)` behavior while still accepting the same sequence-level prior.
body_features = aggregate_body_features(body_seq, seqL).unsqueeze(1)
if seqL is not None:
seqL_sum = int(seqL.sum().data.cpu().numpy())
ipts = [_[:, :seqL_sum] for _ in visual_seqs]
else:
ipts = visual_seqs
return ipts, labs, typs_batch, vies_batch, seqL, body_features
def aggregate_body_features(
sequence_features: Float[torch.Tensor, "..."],
seqL: Int[torch.Tensor, "1 batch"] | None,
) -> Float[torch.Tensor, "batch pairs metrics"]:
"""Collapse a sampled body-prior sequence back to one vector per sequence."""
if seqL is None:
if sequence_features.ndim < 3:
raise ValueError(f"Expected body prior with >=3 dims, got shape {tuple(sequence_features.shape)}")
return sequence_features.mean(dim=1)
if sequence_features.ndim < 4:
raise ValueError(f"Expected packed body prior with >=4 dims, got shape {tuple(sequence_features.shape)}")
lengths = seqL[0].tolist()
flattened = sequence_features.squeeze(0)
aggregated: list[torch.Tensor] = []
start = 0
for length in lengths:
end = start + int(length)
aggregated.append(flattened[start:end].mean(dim=0))
start = end
return torch.stack(aggregated, dim=0)
# Match the symbol name used by the author-provided DRF stub.
BaseModel = BaseModelBody