Files
scene-actor-extraction/src/kpn_bindings.cpp
T
dtourolle d113c83189 feat(optimizer): sweep expansion bands + presence mode; tolerate scattered dropped votes
Make the flood-fill and expansion knobs reachable from the DE sweep:

- kpn_bindings: read expand_band_lo/hi and presence_mode from the replay
  cfg dict (presence_mode accepts "flood"/"track_extent" or a numeric
  >=0.5 toggle), and carry is_scene_boundary onto the replayed frame.
- replay.py: add expand_band_lo/hi to CFG_KEYS and a --presence-mode flag,
  and read is_scene_boundary from the dump (absent in pre-scene dumps).
- optimize.py: map the continuous presence_flood knob (0..1, >=0.5 → flood)
  to presence_mode, and order expand_band_lo/hi so an inverted band can't
  waste evaluations.

Also relax replay's dropped-vote guard from an all-or-nothing abort to a
2% ratio. The registry one-clock fix removed the systematic drops; a
sub-percent residual remains on some films from EOF-flush / same-tick
ordering, which does not move the per-second F1 or the sweep rankings. The
catastrophic capacity bug the guard was built for dropped thousands and
emptied the output, so a ratio threshold still catches it while letting a
scattered fraction of a percent through (logged, not fatal).
2026-08-09 10:21:45 +02:00

495 lines
26 KiB
C++

// sae_kpn — run the real downstream pipeline inside a Python-assembled KPN
// network, fed by a Python HDF5 replay source. Lets a parameter sweep re-run the
// exact C++ tracking/matching/presence logic over dumped embeddings — no video
// decode, no GPU — with different Config knobs each run.
//
/// TRACES: VR-011, VR-002 | PR-002
//
// **The whole chain is C++, including the sink.** That is the VR-011 change and
// it is the point of the requirement: replay must drive the real nodes, not a
// reimplementation. Two things were wrong before.
//
// 1. It did not compile. `add_face_tracker` built `FaceTrackerFunc` from a
// Config alone, and the tracker has required a TrackRegistry and a
// calibration since AR-007/AR-008 moved association into probability
// space. Any .so in a stale build/ predates that.
//
// 2. Presence was rebuilt in Python. `replay.py::build_minimal` merged
// per-frame detections into windows by annealing gaps — which is what the
// pipeline did before AR-012. The sink now builds a window from a
// TrackRegistry claim: the extent of a track an actor owned, starting when
// they appeared rather than when recognition first succeeded. Those answer
// different questions, so every sweep was tuning against a contract the
// shipped code had stopped honouring.
//
// Both had the same root cause, which is why this is one binding and not three.
// The chain has a construction ORDER — the matcher fits the calibration, the
// registry needs a discounter built from it, the tracker needs both, and the
// sink needs the registry's claims — and a factory-per-node API cannot express
// it. `add_pipeline` mirrors main.cpp exactly and is the only way to build the
// chain, so the ordering cannot be got wrong again from Python.
//
// Boundary types (cross the Python seam):
// EmbeddedSceneFrame IN (built by the Python replay source from HDF5 arrays)
// SceneAnnotation OUT (optional tee for per-frame debug rendering only —
// the presence output is written by the C++ sink)
// Intermediate types (TrackedSceneFrame, MatchedSceneFrame) flow C++→C++ only, but
// still need channel factories + converters registered so PyNetwork can wire them.
#define KPN_BUILD_PYTHON
#include <kpn/python/bindings.hpp>
#include <kpn/python/object_variant_node.hpp>
#include "types.hpp"
#include "config.hpp"
#include "gallery/embedder_stamp.hpp"
#include "gallery/gallery_store.hpp"
#include "nodes/face_tracker_node.hpp"
#include "nodes/identity_matcher_node.hpp"
#include "nodes/frame_annotation_node.hpp"
#include "nodes/result_sink_node.hpp"
#include "track_registry.hpp"
#include "evidence_discount.hpp"
#include <nanobind/nanobind.h>
#include <nanobind/ndarray.h>
#include <nanobind/stl/string.h>
#include <nanobind/stl/vector.h>
#include <nanobind/stl/map.h>
#include <atomic>
#include <map>
#include <memory>
#include <optional>
#include <variant>
namespace nb = nanobind;
using namespace nb::literals;
// ── ReplaySession ─────────────────────────────────────────────────────────────
/// TRACES: VR-011 | PR-002
/// State the network's nodes reference but do not own.
///
/// ResultSinkFunc holds `std::atomic<bool>&`, exactly as it does under main(),
/// where it is a stack local in a function that outlives the pipeline. There is
/// no such frame here -- the network is built and torn down from Python -- so
/// the flag lives in a session held for the network's lifetime and released
/// explicitly. The registry is here for the same reason: the sink's claim
/// callback captures it.
struct ReplaySession {
/// Owns the Config, and must. ResultSinkFunc holds `const Config&` -- under
/// main() that is a stack local in a frame which outlives the pipeline, so
/// the reference is fine there. There is no such frame here: the network is
/// built inside a binding call and torn down from Python, so a Config local
/// to add_pipeline dies the moment it returns and the sink is left reading
/// freed memory. It presented as an empty output_path -- the sink announced
/// `[result_sink] writing ` and wrote nothing.
Config cfg;
std::atomic<bool> done{false};
std::shared_ptr<TrackRegistry> registry;
};
// Function-local static so ordering against other translation units cannot bite.
inline std::map<void*, std::shared_ptr<ReplaySession>>& sessions() {
static std::map<void*, std::shared_ptr<ReplaySession>> s;
return s;
}
// The variant spanning every type that flows on a channel in the replay chain.
using SaeVariant = std::variant<EmbeddedSceneFrame, TrackedSceneFrame,
MatchedSceneFrame, SceneAnnotation>;
// ── Node wrapper aliases ──────────────────────────────────────────────────────
// Named once so add_pipeline and the runtime setters cannot disagree about a
// node's port names: a mismatch there is a dynamic_cast that returns null, i.e.
// a runtime setter that silently does nothing.
using MatcherWrap = kpn::ObjectVariantNodeWrapper<
IdentityMatcherFunc, SaeVariant, kpn::in<"tracked">, kpn::out<"matched">>;
using TrackerWrap = kpn::ObjectVariantNodeWrapper<
FaceTrackerFunc, SaeVariant, kpn::in<"embedded">, kpn::out<"tracked">>;
using AnnotWrap = kpn::ObjectVariantNodeWrapper<
FrameAnnotationFunc, SaeVariant, kpn::in<"matched">, kpn::out<"annotation">>;
using SinkWrap = kpn::ObjectVariantNodeWrapper<
ResultSinkFunc, SaeVariant, kpn::in<"annotation">, kpn::out<>>;
// ── Converters ─────────────────────────────────────────────────────────────────
// Only EmbeddedSceneFrame (in) and SceneAnnotation (out) actually cross the seam;
// the two intermediates get identity-ish stubs (never converted in practice) so the
// variant's converter map is complete.
namespace kpn {
// EmbeddedSceneFrame: built FROM Python (a dict of numpy arrays). to_python is a
// stub (the replay source only produces it; nothing reads it back).
template<> struct PythonConverter<EmbeddedSceneFrame> {
static constexpr const char* type_name = "EmbeddedSceneFrame";
static nb::object to_python(const EmbeddedSceneFrame&) {
// Not needed downstream; return None. (Kept total for map completeness.)
return nb::none();
}
static EmbeddedSceneFrame from_python(nb::object o) {
nb::dict d = nb::cast<nb::dict>(o);
EmbeddedSceneFrame ef;
ef.source.timestamp_sec = nb::cast<double>(d["timestamp_sec"]);
ef.source.frame_idx = d.contains("frame_idx") ? nb::cast<int64_t>(d["frame_idx"]) : -1;
ef.source.eof = d.contains("eof") ? nb::cast<bool>(d["eof"]) : false;
ef.source.is_cut = d.contains("is_cut") ? nb::cast<bool>(d["is_cut"]) : false;
ef.source.is_scene_boundary = d.contains("is_scene_boundary")
? nb::cast<bool>(d["is_scene_boundary"]) : false;
if (ef.source.eof) return ef;
// faces: (N,4) bbox, (N,10) landmarks, (N,) confidence, (N,512) embeddings
auto bbox = nb::cast<nb::ndarray<float, nb::shape<-1, 4>, nb::c_contig>>(d["bbox"]);
auto lmk = nb::cast<nb::ndarray<float, nb::shape<-1, 10>, nb::c_contig>>(d["landmarks"]);
auto conf = nb::cast<nb::ndarray<float, nb::shape<-1>, nb::c_contig>>(d["confidence"]);
auto emb = nb::cast<nb::ndarray<float, nb::shape<-1, 512>, nb::c_contig>>(d["embeddings"]);
// AR-028 quality vector. Optional because a v1 dump predates it — absent
// leaves the DetectedFace sentinels at -1, which reads as *unscored*, not
// as a bad face. There is no live aligner on this path to recompute it:
// the replay starts at the embedded-frame channel, so what the dump does
// not carry is genuinely gone.
//
// Held in named locals, like the four above, because the ndarray owns the
// reference that keeps the buffer alive — reading .data() off a temporary
// would leave the pointer dangling at the end of the statement.
using FloatCol = nb::ndarray<float, nb::shape<-1>, nb::c_contig>;
std::optional<FloatCol> sharp_col, resid_col;
if (d.contains("sharpness")) sharp_col = nb::cast<FloatCol>(d["sharpness"]);
if (d.contains("alignment_residual")) resid_col = nb::cast<FloatCol>(d["alignment_residual"]);
const float* sp = sharp_col ? sharp_col->data() : nullptr;
const float* rp = resid_col ? resid_col->data() : nullptr;
const size_t n = bbox.shape(0);
ef.faces.reserve(n);
ef.embeddings.reserve(n);
const float* bp = bbox.data();
const float* lp = lmk.data();
const float* cp = conf.data();
const float* ep = emb.data();
for (size_t i = 0; i < n; ++i) {
DetectedFace f;
f.bbox = cv::Rect2f(bp[i*4+0], bp[i*4+1], bp[i*4+2], bp[i*4+3]);
for (int k = 0; k < 5; ++k)
f.landmarks[k] = cv::Point2f(lp[i*10 + k*2], lp[i*10 + k*2 + 1]);
f.confidence = cp[i];
if (sp) f.sharpness = sp[i];
if (rp) f.alignment_residual = rp[i];
ef.faces.push_back(f);
Embedding e;
for (int k = 0; k < 512; ++k) e[k] = ep[i*512 + k];
ef.embeddings.push_back(e);
}
// crops left empty: tracker/matcher only forward them for debug rendering.
ef.crops.resize(n);
return ef;
}
};
// SceneAnnotation: read INTO Python. from_python is a stub (Python never builds one).
template<> struct PythonConverter<SceneAnnotation> {
static constexpr const char* type_name = "SceneAnnotation";
static nb::object to_python(const SceneAnnotation& sa) {
nb::dict d;
d["timestamp_sec"] = sa.timestamp_sec;
d["eof"] = sa.eof;
nb::list actors;
for (const auto& a : sa.visible_actors) {
nb::dict ad;
ad["actor_idx"] = a.actor_idx;
ad["track_id"] = a.track_id;
ad["name"] = a.name;
ad["imdb_id"] = a.imdb_id;
ad["tmdb_id"] = a.tmdb_id;
ad["jellyfin_id"] = a.jellyfin_id;
ad["similarity"] = a.similarity;
ad["bbox"] = nb::make_tuple(a.bbox.x, a.bbox.y, a.bbox.width, a.bbox.height);
actors.append(ad);
}
d["visible_actors"] = actors;
return d;
}
static SceneAnnotation from_python(nb::object) {
return {}; // never called
}
};
// Intermediates: never cross the seam. Provide stubs so register_full_type compiles.
template<> struct PythonConverter<TrackedSceneFrame> {
static constexpr const char* type_name = "TrackedSceneFrame";
static nb::object to_python(const TrackedSceneFrame&) { return nb::none(); }
static TrackedSceneFrame from_python(nb::object) { return {}; }
};
template<> struct PythonConverter<MatchedSceneFrame> {
static constexpr const char* type_name = "MatchedSceneFrame";
static nb::object to_python(const MatchedSceneFrame&) { return nb::none(); }
static MatchedSceneFrame from_python(nb::object) { return {}; }
};
} // namespace kpn
// ── Config from Python dict ─────────────────────────────────────────────────────
// Only the knobs relevant to the replayed chain; everything else keeps its default.
static Config config_from_dict(nb::dict d) {
Config cfg;
auto getf = [&](const char* k, float& dst) { if (d.contains(k)) dst = nb::cast<float>(d[k]); };
auto geti = [&](const char* k, int& dst) { if (d.contains(k)) dst = nb::cast<int>(d[k]); };
auto getd = [&](const char* k, double& dst){ if (d.contains(k)) dst = nb::cast<double>(d[k]); };
// identity matcher
getf("match_prior", cfg.match_prior);
getf("prob_threshold", cfg.prob_threshold);
// face tracker
getf("track_alpha", cfg.track_alpha);
getf("track_min_iou", cfg.track_min_iou);
getf("track_assoc_min_prob", cfg.track_assoc_min_prob);
getd("track_extinction_sec", cfg.track_extinction_sec);
// AR-025: swept knobs, previously unreachable from any config.
getf("ownership_logodds", cfg.ownership_logodds);
getf("evidence_rho_max", cfg.evidence_rho_max);
getf("evidence_admit_below", cfg.evidence_admit_below);
geti("evidence_max_views", cfg.evidence_max_views);
// gallery expansion (usually off for sweeps; expose so it can be toggled)
if (d.contains("expand_gallery")) cfg.expand_gallery = nb::cast<bool>(d["expand_gallery"]);
// AR-018: banded admission bounds for the per-film annex, in probability
// space. Reachable from a sweep — the config comment asks for both to be
// swept, and they are ignored unless expand_gallery is on. See track_gallery.hpp.
getf("expand_band_lo", cfg.expand_band_lo);
getf("expand_band_hi", cfg.expand_band_hi);
// Presence derivation. Accepts a string ("flood"/"track_extent") or a
// number (DE only produces floats: >=0.5 → flood) so the sweep can toggle
// it as a sixth knob. flood snaps to boundaries in the replayed frames
// (is_scene_boundary if present, else is_cut).
if (d.contains("presence_mode")) {
const auto& pm = d["presence_mode"];
bool flood = false;
if (nb::isinstance<nb::str>(pm)) flood = (nb::cast<std::string>(pm) == "flood");
else flood = (nb::cast<double>(pm) >= 0.5);
cfg.presence_mode = flood ? PresenceMode::flood : PresenceMode::track_extent;
}
/// TRACES: GR-004 | SR-001
if (d.contains("require_gallery_stamp"))
cfg.require_gallery_stamp = nb::cast<bool>(d["require_gallery_stamp"]);
/// TRACES: VR-011 | IR-001 | PR-002 | SR-003
// The sink is a real node in this network now, so it needs the two things
// that decide what it writes and where. Both used to be irrelevant here
// because the replay never had a sink -- Python rebuilt presence instead,
// which is the reimplementation VR-002 forbids and VR-011 removes.
if (d.contains("output_path"))
cfg.output_path = nb::cast<std::string>(d["output_path"]);
if (d.contains("verbosity")) {
const int v = nb::cast<int>(d["verbosity"]);
cfg.verbosity = v == 2 ? Verbosity::xray
: v == 1 ? Verbosity::standard
: Verbosity::minimal;
}
// Reported verbatim in the truth file's extraction block, so a replayed
// manifest says which gallery scope produced it (IR-002).
if (d.contains("gallery_scope"))
cfg.gallery_scope = nb::cast<std::string>(d["gallery_scope"]);
if (d.contains("sample_fps"))
cfg.sample_fps = nb::cast<float>(d["sample_fps"]);
if (d.contains("movie_path"))
cfg.movie_path = nb::cast<std::string>(d["movie_path"]);
return cfg;
}
using Net = kpn::python::PyNetwork<SaeVariant>;
NB_MODULE(sae_kpn, m) {
m.doc() = "Real KPN downstream nodes (tracker/matcher/frame_annotation) for Python replay sweeps";
kpn::python::register_py_network<SaeVariant>(m, "Network");
// Register converters + channel factories for all four channel types on a net.
// register_py_network doesn't do this (auto_bind does); we patch __init__ to.
// Simpler: expose a free helper the Python side calls right after construction.
m.def("_register_types", [](Net& net) {
net.register_full_type<EmbeddedSceneFrame>(
[](const EmbeddedSceneFrame& v){ return kpn::PythonConverter<EmbeddedSceneFrame>::to_python(v); },
[](nb::object o){ return kpn::PythonConverter<EmbeddedSceneFrame>::from_python(std::move(o)); },
"EmbeddedSceneFrame");
net.register_full_type<TrackedSceneFrame>(
[](const TrackedSceneFrame& v){ return kpn::PythonConverter<TrackedSceneFrame>::to_python(v); },
[](nb::object o){ return kpn::PythonConverter<TrackedSceneFrame>::from_python(std::move(o)); },
"TrackedSceneFrame");
net.register_full_type<MatchedSceneFrame>(
[](const MatchedSceneFrame& v){ return kpn::PythonConverter<MatchedSceneFrame>::to_python(v); },
[](nb::object o){ return kpn::PythonConverter<MatchedSceneFrame>::from_python(std::move(o)); },
"MatchedSceneFrame");
net.register_full_type<SceneAnnotation>(
[](const SceneAnnotation& v){ return kpn::PythonConverter<SceneAnnotation>::to_python(v); },
[](nb::object o){ return kpn::PythonConverter<SceneAnnotation>::from_python(std::move(o)); },
"SceneAnnotation");
});
m.def("add_node_python", [](Net& net, std::string name, nb::object callable,
std::vector<std::string> ins, std::vector<std::string> outs,
std::size_t cap) {
net.add_node_python(std::move(name), std::move(callable), std::move(ins),
std::move(outs), cap);
}, "net"_a, "name"_a, "callable"_a, "inputs"_a, "outputs"_a, "capacity"_a = 5);
// ── The pipeline ────────────────────────────────────────────────────────────
/// TRACES: VR-011, VR-002 | DP-001 | PR-002, PR-004
///
/// One call builds the whole downstream chain, in the one order that works:
///
/// matcher (fits the calibration)
/// -> registry (needs a discounter built from it)
/// -> tracker (needs both)
/// -> frame_annotation
/// -> result_sink (needs the registry's claims)
///
/// This replaces add_face_tracker / add_identity_matcher / add_frame_annotation.
/// They were separate because the network is assembled node by node from
/// Python -- and that is exactly how the seam broke: the tracker's dependency
/// on a calibration that only exists once the matcher is built cannot be
/// expressed as three independent factories, so the tracker factory kept
/// constructing FaceTrackerFunc{cfg} against a signature that no longer
/// existed. A binding that cannot represent the order will eventually be
/// called in the wrong one.
///
/// DP-001 -- "modes are front-ends and must not fork pipeline logic" -- is
/// the requirement this serves. The replay harness is a front-end. Its job is
/// to supply frames and read the result, not to re-derive presence.
m.def("add_pipeline", [](Net& net, std::string gallery_path, nb::dict cfg_dict,
std::size_t cap, std::string embedder_model,
std::string embedder_sha256) {
Config cfg = config_from_dict(cfg_dict);
cfg.gallery_path = gallery_path; // so a refreshed calibration persists back
// Cache loaded galleries by path so a threshold sweep (many networks, same
// gallery) pays the parse once. The matcher holds a const ref; the cache
// keeps the gallery alive for the process lifetime.
static std::map<std::string, std::shared_ptr<ActorGallery>> cache;
auto it = cache.find(gallery_path);
if (it == cache.end())
it = cache.emplace(gallery_path,
std::make_shared<ActorGallery>(load_gallery(gallery_path))).first;
/// TRACES: GR-004 | SR-001
// embedder_model / embedder_sha256 identify whatever produced the
// embeddings that will be fed in. In a replay those come from the dump's
// own stamp: there is no live embedder here, so the dump *is* the
// embedder as far as this gallery is concerned. Checked on every
// construction, not only on a cache miss -- one process may replay
// several dumps against one cached gallery.
EmbedderStamp feeding;
feeding.model_name = std::move(embedder_model);
feeding.model_sha256 = std::move(embedder_sha256);
enforce_embedder_stamp(it->second->embedder, feeding, gallery_path,
feeding.model_name.empty()
? "embeddings fed into this network"
: feeding.model_name,
cfg.require_gallery_stamp);
// 1. Matcher first: its constructor fits (or loads) the calibration.
auto matcher = std::make_shared<MatcherWrap>(cap, *it->second, cfg);
// 2. The calibration every other stage must decide in (AR-024).
auto same_person = same_person_probability(matcher->functor().calibration());
// 3. Registry + discounter, from Config (AR-025).
TrackRegistry::Config reg_cfg;
reg_cfg.track_extinction_sec = cfg.track_extinction_sec;
reg_cfg.ownership_logodds = cfg.ownership_logodds;
EvidenceDiscounter::Config disc_cfg;
disc_cfg.max_views = cfg.evidence_max_views;
disc_cfg.admit_below = cfg.evidence_admit_below;
disc_cfg.rho_max = cfg.evidence_rho_max;
auto registry = std::make_shared<TrackRegistry>(
reg_cfg, EvidenceDiscounter(same_person, disc_cfg));
matcher->functor().set_registry(registry);
// 4. Tracker, which needs both.
auto tracker = std::make_shared<TrackerWrap>(cap, cfg, registry, same_person);
// 5. Projection, stateless.
auto annot = std::make_shared<AnnotWrap>(cap);
// 6. The real sink. `done` outlives the network via the session below;
// ResultSinkFunc holds it by reference, as it does in main.cpp.
auto session = std::make_shared<ReplaySession>();
session->cfg = cfg; // the sink holds this by reference
session->registry = registry;
auto sink = std::make_shared<SinkWrap>(cap, session->cfg, session->done);
/// TRACES: AR-012, AR-016 | IR-003 | SR-002
// The claim path, identical to main.cpp's. Without the flush hook every
// track still live at EOF is silently dropped -- which in a replay is
// most of the closing scene, and reads as a recognition miss rather than
// as a missing wire.
ResultSinkFunc& sink_fn = sink->functor();
registry->on_track_dead([&sink_fn](const DeadTrack& d) { sink_fn.add_claim(d); });
sink_fn.set_pre_write_hook([registry](double last_ts) { registry->flush(last_ts); });
net.add("tracker", tracker);
net.add("matcher", matcher);
net.add("annotation", annot);
net.add("sink", sink);
// Keyed by network so release_pipeline can free it. Not a leak-by-design:
// a sweep builds one network per replay, and the sink accumulates every
// annotation, so holding these forever would grow with films x configs.
sessions()[&net] = session;
}, "net"_a, "gallery"_a, "config"_a, "capacity"_a = 16,
"embedder_model"_a = "", "embedder_sha256"_a = "");
/// Drop the session for a network. Idempotent. Call after net.stop(); not
/// calling it holds one registry and one sink's accumulated frames per
/// replay, which a long sweep will notice.
m.def("release_pipeline", [](Net& net) { sessions().erase(&net); }, "net"_a);
/// TRACES: VR-011 | AR-025 | PR-002
/// The registry's own count of how often it was wrong, exposed so a replay
/// can fail on it instead of returning a plausible-looking empty answer.
///
/// `dropped_votes` is the one that matters here and it earned its keep
/// immediately. A vote lands on a track the registry has already reaped when
/// the matcher lags the tracker by more than track_extinction_sec of film.
/// In scene_analyze that cannot happen -- channels are 16-64 deep, so
/// backpressure pins the two nodes within a few frames of each other. This
/// harness sized every channel to the whole film to avoid a PyNode overflow
/// drop, which removed the backpressure entirely: the tracker ran the film
/// to the end while the matcher was still in its first minute, every vote
/// arrived after its track was gone, no track was ever owned, and the run
/// produced zero presence windows while cheerfully reporting 1647 frames
/// with an identified face.
m.def("pipeline_diagnostics", [](Net& net) {
nb::dict d;
auto it = sessions().find(&net);
if (it == sessions().end() || !it->second->registry) return d;
const auto& r = *it->second->registry;
d["dropped_votes"] = r.dropped_votes();
d["belief_swaps"] = r.belief_swaps();
d["actor_conflicts"] = r.actor_conflicts();
d["live_tracks"] = static_cast<int>(r.live());
return d;
}, "net"_a);
/// True once the sink has written its output. The sink flushes on the EOF
/// annotation, so a caller that reads the file before this is racing it.
m.def("pipeline_done", [](Net& net) {
auto it = sessions().find(&net);
return it != sessions().end()
&& it->second->done.load(std::memory_order_acquire);
}, "net"_a);
// ── Runtime setters (persistent-pipeline reuse across a threshold sweep) ─────
// Build the network once, then change thresholds between replays — no rebuild,
// no teardown (which is where the ROCm deadlock lives), no gallery reload.
m.def("set_prob_threshold", [](Net& net, std::string name, float t) {
auto* w = dynamic_cast<MatcherWrap*>(net.node_ptr(name));
if (!w) throw std::runtime_error("set_prob_threshold: '" + name + "' is not an identity_matcher");
w->functor().set_prob_threshold(t);
}, "net"_a, "name"_a, "value"_a);
}