chore: import upstream snapshot with attribution

2026-07-13 12:06:04 +08:00
commit 86c9b1c39f
7743 changed files with 3316339 additions and 0 deletions
@@ -0,0 +1,112 @@
+#ifndef OPENCV_GAPI_PIPELINE_MODELING_TOOL_DUMMY_SOURCE_HPP
+#define OPENCV_GAPI_PIPELINE_MODELING_TOOL_DUMMY_SOURCE_HPP
+
+#include <thread>
+#include <memory>
+#include <chrono>
+
+#include <opencv2/gapi.hpp>
+#include <opencv2/gapi/streaming/cap.hpp> // cv::gapi::wip::IStreamSource
+
+#include "utils.hpp"
+
+class DummySource final: public cv::gapi::wip::IStreamSource {
+public:
+    using WaitStrategy = std::function<void(std::chrono::microseconds)>;
+    using Ptr = std::shared_ptr<DummySource>;
+    using ts_t = std::chrono::microseconds;
+
+    template <typename DurationT>
+    DummySource(const DurationT    latency,
+                const OutputDescr& output,
+                const bool         drop_frames,
+                WaitStrategy&&     wait);
+
+    bool pull(cv::gapi::wip::Data& data) override;
+    cv::GMetaArg descr_of() const override;
+
+private:
+    int64_t       m_latency;
+    cv::Mat       m_mat;
+    bool          m_drop_frames;
+    int64_t       m_next_tick_ts = -1;
+    int64_t       m_curr_seq_id  = 0;
+    WaitStrategy  m_wait;
+};
+
+template <typename DurationT>
+DummySource::DummySource(const DurationT    latency,
+                         const OutputDescr& output,
+                         const bool         drop_frames,
+                         WaitStrategy&&     wait)
+    : m_latency(std::chrono::duration_cast<ts_t>(latency).count()),
+      m_drop_frames(drop_frames),
+      m_wait(std::move(wait)) {
+    utils::createNDMat(m_mat, output.dims, output.precision);
+    utils::generateRandom(m_mat);
+}
+
+bool DummySource::pull(cv::gapi::wip::Data& data) {
+    using namespace std::chrono;
+    using namespace cv::gapi::streaming;
+
+    // NB: Wait m_latency before return the first frame.
+    if (m_next_tick_ts == -1) {
+        m_next_tick_ts = utils::timestamp<ts_t>() + m_latency;
+    }
+
+    int64_t curr_ts = utils::timestamp<ts_t>();
+    if (curr_ts < m_next_tick_ts) {
+        /*
+         *            curr_ts
+         *               |
+         *    ------|----*-----|------->
+         *                     ^
+         *               m_next_tick_ts
+         *
+         *
+         * NB: New frame will be produced at the m_next_tick_ts point.
+         */
+        m_wait(ts_t{m_next_tick_ts - curr_ts});
+    } else if (m_latency != 0) {
+        /*
+         *                                       curr_ts
+         *                         +1         +2    |
+         *    |----------|----------|----------|----*-----|------->
+         *               ^                     ^
+         *         m_next_tick_ts ------------->
+         *
+         */
+
+        // NB: Count how many frames have been produced since last pull (m_next_tick_ts).
+        int64_t num_frames =
+            static_cast<int64_t>((curr_ts - m_next_tick_ts) / m_latency);
+        // NB: Shift m_next_tick_ts to the nearest tick before curr_ts.
+        m_next_tick_ts += num_frames * m_latency;
+        // NB: if drop_frames is enabled, update current seq_id and wait for the next tick, otherwise
+        // return last written frame (+2 at the picture above) immediately.
+        if (m_drop_frames) {
+            // NB: Shift tick to the next frame.
+            m_next_tick_ts += m_latency;
+            // NB: Wait for the next frame.
+            m_wait(ts_t{m_next_tick_ts - curr_ts});
+            // NB: Drop already produced frames + update seq_id for the current.
+            m_curr_seq_id += num_frames + 1;
+        }
+    }
+    // NB: Just increase reference counter not to release mat memory
+    // after assigning it to the data.
+    cv::Mat mat = m_mat;
+    data.meta[meta_tag::timestamp] = utils::timestamp<ts_t>();
+    data.meta[meta_tag::seq_id] = m_curr_seq_id++;
+    data = mat;
+    m_next_tick_ts += m_latency;
+
+    return true;
+}
+
+cv::GMetaArg DummySource::descr_of() const {
+    return cv::GMetaArg{cv::descr_of(m_mat)};
+}
+
+#endif // OPENCV_GAPI_PIPELINE_MODELING_TOOL_DUMMY_SOURCE_HPP