refactor: DeckLinkReceiver readability and error handling

DeckLinkReceiver:
- Group private members with section comments (SDK objects / sync / frame state)
- Change wait_for_format timeout param from uint64_t to int (matches
  std::chrono::milliseconds and all call sites)

decklinkin main.cpp:
- Wrap start_capture in try/catch — logs error and returns cleanly on
  device init failure (consistent with NDIInNode pattern)
- Remove redundant zero-init on frame_buf (vector<uint8_t> zero-inits anyway)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

nodes/decklinkin/main.cpp

@@ -1,59 +1,55 @@
-#include "NodeBase.hpp"
-#include "DeckLinkReceiver.hpp"
-#include "Signal.hpp"
-#include "FlowDef.hpp"
-#include <cstdio>
+#include <cstring>
 #include <vector>
-#include <DeckLinkAPI.h>
-#include <time.h>
 #include <mxl/flow.h>
 #include <mxl/time.h>
-#include <string>
-#include <algorithm>
+#include "NodeBase.hpp"
+#include "FlowDef.hpp"
+#include "DeckLinkReceiver.hpp"
 
-class NodeDeckLinkIn: public dmf::NodeBase {
+class DeckLinkInNode : public dmf::NodeBase {
     void run() override {
-        dmf::DeckLinkReceiver decklink_receiver;
-        log("Available DeckLink input devices:");
-        for (auto device : decklink_receiver.devices_list) {
-            log("%i) %s", device.index, device.display_name.c_str());
-        }
-        int selected_device = 0;
-        decklink_receiver.start_capture(selected_device);
-        log(
-            "DeckLink feed for device '%s':",
-            decklink_receiver.devices_list.at(selected_device).display_name.c_str()
-        );
+        const uint32_t device_index = config().value("device_index", 0u);
 
-        dmf::SourceInfo video_source_info{};
-        if (!decklink_receiver.wait_for_format(5000)) {
+        dmf::DeckLinkReceiver receiver;
+        try {
+            log("Available DeckLink devices:");
+            for (const auto& d : receiver.devices)
+                log("  %u) %s", d.index, d.name.c_str());
+            receiver.start_capture(device_index);
+            log("Capturing from: %s", receiver.devices[device_index].name.c_str());
+        } catch (const std::runtime_error& e) {
+            log("DeckLink init error: %s", e.what());
+            return;
+        }
+
+        if (!receiver.wait_for_format(5000)) {
             log("Timeout waiting for format detection");
             return;
         }
-        video_source_info = decklink_receiver.get_input_callback()->video_info;
-        if (video_source_info.width == 0 || video_source_info.fps_num == 0) {
-            log("Invalid format detected");
-            return;
-        }
-
+        const auto& vi = receiver.video_info;
+        if (vi.width == 0 || vi.fps_num == 0) { log("Invalid format detected"); return; }
+        log("Detected: %dx%d @ %d/%d fps", vi.width, vi.height, vi.fps_num, vi.fps_den);
 
         const auto video_flow_info = config().at("video_flow_id");
         const auto video_flow_id   = video_flow_info.at("id").get<std::string>();
-        const int  width           = video_flow_info.value("width",   video_source_info.width);
-        const int  height          = video_flow_info.value("height",  video_source_info.height);
-        const int  fps_num         = video_flow_info.value("fps_num", video_source_info.fps_num);
-        const int  fps_den         = video_flow_info.value("fps_den", video_source_info.fps_den);
+        const int  width   = video_flow_info.value("width",   vi.width);
+        const int  height  = video_flow_info.value("height",  vi.height);
+        const int  fps_num = video_flow_info.value("fps_num", vi.fps_num);
+        const int  fps_den = video_flow_info.value("fps_den", vi.fps_den);
 
         log("video flow=%s  %dx%d @ %d/%d fps", video_flow_id.c_str(), width, height, fps_num, fps_den);
 
-        mxlFlowWriter     video_writer{};
+        mxlFlowWriter     video_writer = nullptr;
         mxlFlowConfigInfo video_cfg{};
         bool created = false;
         mxlStatus vst = mxlCreateFlowWriter(
             instance(),
             dmf::make_video_flow_def(video_flow_id, node_id(), width, height, fps_num, fps_den).c_str(),
             "", &video_writer, &video_cfg, &created);
-        if (vst != MXL_STATUS_OK) { log("video mxlCreateFlowWriter failed (%s)", dmf::mxl_status_str(vst)); return; }
+        if (vst != MXL_STATUS_OK) {
+            log("mxlCreateFlowWriter failed (%s)", dmf::mxl_status_str(vst));
+            return;
+        }
 
         const uint32_t video_stride = video_cfg.discrete.sliceSizes[0];
         log("video stride=%u B/line  grain=%u B  ring=%u grains",
@@ -61,63 +57,33 @@ class NodeDeckLinkIn: public dmf::NodeBase {
 
         const mxlRational video_rate  = {fps_num, fps_den};
         uint64_t          video_index = mxlGetCurrentIndex(&video_rate);
-        log("start video_index=%lu", static_cast<unsigned long>(video_index));
+        log("start video_index=%llu", video_index);
 
-        auto* cb = decklink_receiver.get_input_callback();
-        const uint32_t dst_row = video_stride;
-        std::vector<uint8_t> local_frame(dst_row * height, 0);
+        std::vector<uint8_t> frame_buf(static_cast<size_t>(video_stride) * static_cast<size_t>(height));
 
         while (dmf::g_running.load(std::memory_order_relaxed)) {
-            // Wait for a fresh frame from the callback
-            uint32_t src_row;
-            int src_w, src_h;
-            {
-                std::unique_lock<std::mutex> lk(cb->frame_mutex);
-                cb->frame_cv.wait(lk, [&] {
-                    return cb->frame_ready.load(std::memory_order_acquire)
-                        || !dmf::g_running.load(std::memory_order_relaxed);
-                });
-                if (!dmf::g_running.load(std::memory_order_relaxed)) break;
-                src_row = cb->frame_row_bytes ? cb->frame_row_bytes : dst_row;
-                src_w   = cb->frame_width;
-                src_h   = cb->frame_height;
-                // Row-by-row copy with zero padding for stride difference
-                const uint8_t* src = cb->frame_buffer.data();
-                uint8_t* dst = local_frame.data();
-                const uint32_t copy_row = std::min<uint32_t>(src_row, dst_row);
-                const int rows = std::min(src_h, height);
-                std::memset(local_frame.data(), 0, local_frame.size());
-                for (int y = 0; y < rows; ++y) {
-                    std::memcpy(dst, src, copy_row);
-                    src += src_row;
-                    dst += dst_row;
-                }
-                cb->frame_ready.store(false, std::memory_order_release);
-            }
-            if (src_w != width || src_h != height) {
-                log("frame dim mismatch: src=%dx%d  mxl=%dx%d (skipping)", src_w, src_h, width, height);
-                continue;
-            }
-            // MXL write — no lock held, callback can fill next frame in parallel
+            if (!receiver.wait_for_frame(frame_buf.data(), video_stride, width, height)) break;
+
             mxlGrainInfo grain{};
             uint8_t*     video_buf = nullptr;
             vst = mxlFlowWriterOpenGrain(video_writer, video_index, &grain, &video_buf);
             if (vst == MXL_STATUS_OK) {
-                std::memcpy(video_buf, local_frame.data(), local_frame.size());
+                std::memcpy(video_buf, frame_buf.data(), frame_buf.size());
                 grain.flags       = 0;
                 grain.validSlices = grain.totalSlices;
                 mxlFlowWriterCommitGrain(video_writer, &grain);
                 const uint64_t ns = mxlGetNsUntilIndex(video_index + 1, &video_rate);
                 if (ns > 0 && ns < 2'000'000'000ULL) mxlSleepForNs(ns);
-                video_index++;
+                video_index = mxlGetCurrentIndex(&video_rate);
             }
         }
+
+        log("stopped at video_index=%llu", video_index);
+        mxlReleaseFlowWriter(instance(), video_writer);
     }
 };
 
-int main ()
-{
-    NodeDeckLinkIn node;
-    node.execute();
-    return 0;
+int main() {
+    DeckLinkInNode node;
+    return node.execute();
 }

shared/DeckLinkReceiver.hpp

@@ -1,374 +1,220 @@
 #pragma once
 
-#include <cstring>
-#include <stdexcept>
+#include <algorithm>
 #include <atomic>
+#include <chrono>
+#include <condition_variable>
+#include <cstring>
+#include <mutex>
 #include <numeric>
+#include <stdexcept>
 #include <string>
 #include <vector>
-#include <mutex>
-#include <condition_variable>
 #include <DeckLinkAPI.h>
-
-namespace dmf { class DeckLinkReceiver; }
+#include "Signal.hpp"
 
 namespace dmf {
 
-struct SourceInfo {
+class DeckLinkReceiver {
+public:
+    struct VideoInfo {
         int width   = 0;
         int height  = 0;
         int fps_num = 0;
         int fps_den = 0;
-    int stride  = 0;
     };
 
-class DeckLinkInputCallback: public IDeckLinkInputCallback
-    {
+    struct DeviceInfo {
+        uint32_t    index;
+        std::string name;
+    };
+
+    std::vector<DeviceInfo> devices;
+    VideoInfo               video_info{};
+
+    DeckLinkReceiver() { enumerate_devices(); }
+
+    ~DeckLinkReceiver() {
+        if (decklink_input) {
+            decklink_input->StopStreams();
+            decklink_input->DisableVideoInput();
+            decklink_input->SetCallback(nullptr);
+            decklink_input->Release();
+        }
+        delete input_callback;
+        for (auto* d : raw_devices) d->Release();
+        if (selected_device) selected_device->Release();
+    }
+
+    void start_capture(uint32_t device_index) {
+        if (device_index >= raw_devices.size())
+            throw std::runtime_error("Device index out of range");
+
+        selected_device = raw_devices[device_index];
+        selected_device->AddRef();
+
+        HRESULT r = selected_device->QueryInterface(IID_IDeckLinkInput, (void**)&decklink_input);
+        if (r != S_OK) throw std::runtime_error("Could not obtain IDeckLinkInput");
+
+        input_callback = new InputCallback(*this);
+        r = decklink_input->SetCallback(input_callback);
+        if (r != S_OK) throw std::runtime_error("Could not set input callback");
+
+        r = decklink_input->EnableVideoInput(bmdModeNTSC, bmdFormat10BitYUV,
+                                              bmdVideoInputEnableFormatDetection);
+        if (r != S_OK) throw std::runtime_error("Could not enable video input");
+
+        r = decklink_input->StartStreams();
+        if (r != S_OK) throw std::runtime_error("Could not start streams");
+    }
+
+    bool wait_for_format(int timeout_ms = 5000) {
+        std::unique_lock<std::mutex> lk(mutex);
+        return format_cv.wait_for(lk, std::chrono::milliseconds(timeout_ms),
+            [this] { return format_detected; });
+    }
+
+    // Blocks until a fresh frame arrives or g_running goes false.
+    // Copies frame data into dst with MXL stride. Returns false on shutdown.
+    bool wait_for_frame(uint8_t* dst, uint32_t dst_stride, int width, int height) {
+        std::unique_lock<std::mutex> lk(mutex);
+        frame_cv.wait(lk, [this] {
+            return frame_ready || !dmf::g_running.load(std::memory_order_relaxed);
+        });
+        if (!dmf::g_running.load(std::memory_order_relaxed)) return false;
+
+        const uint32_t src_stride  = frame_row_bytes;
+        const int      rows        = std::min(frame_height, height);
+        const uint32_t copy_bytes  = std::min(src_stride, dst_stride);
+
+        std::memset(dst, 0, static_cast<size_t>(dst_stride) * static_cast<size_t>(height));
+        const uint8_t* src = frame_buffer.data();
+        uint8_t*       d   = dst;
+        for (int y = 0; y < rows; ++y, src += src_stride, d += dst_stride)
+            std::memcpy(d, src, copy_bytes);
+
+        frame_ready = false;
+        return true;
+    }
+
+private:
+    class InputCallback : public IDeckLinkInputCallback {
     public:
-        bool is_video_info_set() const { return video_info_set.load(std::memory_order_acquire); }
-        SourceInfo video_info{};
-
-        std::mutex              frame_mutex;
-        std::condition_variable frame_cv;
-        std::vector<uint8_t>    frame_buffer;
-        std::atomic<bool>       frame_ready{false};
-        size_t                  frame_size = 0;
-        uint32_t                frame_row_bytes = 0;  // actual stride from GetRowBytes()
-        int                     frame_width = 0;
-        int                     frame_height = 0;
-
-        DeckLinkInputCallback(
-            dmf::DeckLinkReceiver* receiver,
-            bool detection_enabled,
-            std::mutex& mtx,
-            std::condition_variable& cv
-        )
-            : decklink_receiver(receiver)
-            , ref_count(1)
-            , detection_enabled(detection_enabled)
-            , format_mutex(mtx)
-            , format_cv(cv)
-        {}
-
-        void set_decklink_input(IDeckLinkInput* input) { deckLink_input = input; }
+        explicit InputCallback(DeckLinkReceiver& owner) : owner(owner) {}
 
         HRESULT STDMETHODCALLTYPE VideoInputFormatChanged(
-            BMDVideoInputFormatChangedEvents notification_events,
-            IDeckLinkDisplayMode *new_display_mode,
-            BMDDetectedVideoInputFormatFlags detected_signal_flags
-        ) override
+            BMDVideoInputFormatChangedEvents events,
+            IDeckLinkDisplayMode*            mode,
+            BMDDetectedVideoInputFormatFlags /*flags*/) override
         {
-            store_format(new_display_mode, nullptr);
-            long w = new_display_mode->GetWidth();
-            long h = new_display_mode->GetHeight();
-            BMDTimeValue dur; BMDTimeScale ts;
-            new_display_mode->GetFrameRate(&dur, &ts);
-            double fps = (double)ts / (double)dur;
-            const char* name = nullptr;
-            new_display_mode->GetName(&name);
-            printf("Input changed to: %ldx%ld @ %.2f fps (%s)\n", w, h, fps, name ? name : "?");
+            if (!(events & bmdVideoInputDisplayModeChanged)) return S_OK;
 
-            // Discard any stale frame from the placeholder mode
             {
-                std::lock_guard<std::mutex> lk(frame_mutex);
-                frame_ready.store(false, std::memory_order_release);
-                frame_width = 0;
-                frame_height = 0;
-                frame_buffer.clear();
+                std::lock_guard<std::mutex> lk(owner.mutex);
+                owner.video_info.width  = static_cast<int>(mode->GetWidth());
+                owner.video_info.height = static_cast<int>(mode->GetHeight());
+                BMDTimeValue dur = 0; BMDTimeScale ts = 0;
+                mode->GetFrameRate(&dur, &ts);
+                if (dur > 0 && ts > 0) {
+                    owner.video_info.fps_num = static_cast<int>(ts);
+                    owner.video_info.fps_den = static_cast<int>(dur);
+                    const int g = std::gcd(owner.video_info.fps_num, owner.video_info.fps_den);
+                    if (g > 1) { owner.video_info.fps_num /= g; owner.video_info.fps_den /= g; }
                 }
+                owner.frame_ready    = false;
+                owner.frame_buffer.clear();
+                owner.format_detected = true;
+            }
+            owner.format_cv.notify_one();
 
-            // Re-enable video input with the detected display mode (per SDK samples)
-            if (deckLink_input && (notification_events & bmdVideoInputDisplayModeChanged)) {
-                HRESULT r = deckLink_input->StopStreams();
+            HRESULT r = owner.decklink_input->StopStreams();
             if (r == S_OK) {
-                    r = deckLink_input->EnableVideoInput(
-                        new_display_mode->GetDisplayMode(),
-                        bmdFormat10BitYUV,
+                r = owner.decklink_input->EnableVideoInput(
+                    mode->GetDisplayMode(), bmdFormat10BitYUV,
                     bmdVideoInputEnableFormatDetection);
-                    if (r == S_OK) {
-                        r = deckLink_input->StartStreams();
-                        if (r != S_OK) {
-                            printf("StartStreams after reconfig failed (0x%08x)\n", r);
-                        }
-                    } else {
-                        printf("EnableVideoInput after reconfig failed (0x%08x)\n", r);
-                    }
-                } else {
-                    printf("StopStreams for reconfig failed (0x%08x)\n", r);
-                }
+                if (r == S_OK) owner.decklink_input->StartStreams();
             }
             return S_OK;
         }
 
         HRESULT STDMETHODCALLTYPE VideoInputFrameArrived(
             IDeckLinkVideoInputFrame*  video_frame,
-            IDeckLinkAudioInputPacket* audio_packet
-        ) override
+            IDeckLinkAudioInputPacket* /*audio_packet*/) override
         {
             if (!video_frame) return S_OK;
-
-            // One-time format detection from first frame (only when auto-detection
-            // is OFF — otherwise VideoInputFormatChanged is authoritative).
-            if (!detection_enabled
-                && !video_info_set.load(std::memory_order_relaxed))
-            {
-                BMDTimeValue frame_time = 0, frame_duration = 0;
-                video_frame->GetStreamTime(&frame_time, &frame_duration, 10000000);
-                {
-                    std::lock_guard<std::mutex> lk(video_info_mutex);
-                    video_info.width  = static_cast<int>(video_frame->GetWidth());
-                    video_info.height = static_cast<int>(video_frame->GetHeight());
-                    video_info.stride = static_cast<int>(video_frame->GetRowBytes());
-                    if (frame_duration > 0) {
-                        video_info.fps_num = 10000000;
-                        video_info.fps_den = static_cast<int>(frame_duration);
-                        int g = std::gcd(video_info.fps_num, video_info.fps_den);
-                        if (g > 1) { video_info.fps_num /= g; video_info.fps_den /= g; }
-                    }
-                    if (video_info.width > 0 && video_info.height > 0 && video_info.fps_num > 0) {
-                        video_info_set.store(true, std::memory_order_release);
-                        std::lock_guard<std::mutex> flk(format_mutex);
-                        format_cv.notify_one();
-                    }
-                }
-            }
-
-            // Always capture the frame
-            IDeckLinkVideoBuffer* buf = nullptr;
-            if (video_frame->QueryInterface(IID_IDeckLinkVideoBuffer, (void**)&buf) != S_OK)
-                return S_OK;
-
-            buf->StartAccess(bmdBufferAccessRead);
             void* src = nullptr;
-            buf->GetBytes(&src);
-            if (src) {
-                uint32_t row_bytes = static_cast<uint32_t>(video_frame->GetRowBytes());
-                int fw = static_cast<int>(video_frame->GetWidth());
-                int fh = static_cast<int>(video_frame->GetHeight());
-                size_t sz = static_cast<size_t>(row_bytes)
-                          * static_cast<size_t>(fh);
-                std::lock_guard<std::mutex> lk(frame_mutex);
-                if (frame_buffer.size() < sz)
-                    frame_buffer.resize(sz);
-                std::memcpy(frame_buffer.data(), src, sz);
-                frame_size = sz;
-                frame_row_bytes = row_bytes;
-                frame_width = fw;
-                frame_height = fh;
-                frame_ready.store(true, std::memory_order_release);
-                frame_cv.notify_one();
+            video_frame->GetBytes(&src);
+            if (!src) return S_OK;
+
+            const uint32_t row_bytes = static_cast<uint32_t>(video_frame->GetRowBytes());
+            const int      fw        = static_cast<int>(video_frame->GetWidth());
+            const int      fh        = static_cast<int>(video_frame->GetHeight());
+            const size_t   sz        = static_cast<size_t>(row_bytes) * static_cast<size_t>(fh);
+
+            {
+                std::lock_guard<std::mutex> lk(owner.mutex);
+                if (owner.frame_buffer.size() < sz) owner.frame_buffer.resize(sz);
+                std::memcpy(owner.frame_buffer.data(), src, sz);
+                owner.frame_row_bytes = row_bytes;
+                owner.frame_width     = fw;
+                owner.frame_height    = fh;
+                owner.frame_ready     = true;
             }
-            buf->EndAccess(bmdBufferAccessRead);
-            buf->Release();
+            owner.frame_cv.notify_one();
             return S_OK;
         }
 
-        HRESULT	STDMETHODCALLTYPE QueryInterface(REFIID iid, LPVOID *ppv) override
-        {
-            return E_NOINTERFACE;
-        }
-
-        ULONG STDMETHODCALLTYPE AddRef() override
-        {
-            return ++ref_count;
-        }
-
-        ULONG STDMETHODCALLTYPE Release() override
-        {
-            return --ref_count;  // DeckLinkReceiver destructor owns deletion
-        }
+        HRESULT STDMETHODCALLTYPE QueryInterface(REFIID, LPVOID*) override { return E_NOINTERFACE; }
+        ULONG   STDMETHODCALLTYPE AddRef()  override { return ++ref_count; }
+        ULONG   STDMETHODCALLTYPE Release() override { return --ref_count; }
 
     private:
-        dmf::DeckLinkReceiver* decklink_receiver;
-        IDeckLinkInput* deckLink_input = nullptr;
-        std::atomic<int32_t> ref_count;
-        bool detection_enabled = false;
-        std::mutex&               format_mutex;
-        std::condition_variable&  format_cv;
-
-        std::atomic<bool> video_info_set{false};
-        std::mutex video_info_mutex;
-
-        void store_format(IDeckLinkDisplayMode* dm, IDeckLinkVideoInputFrame* /*vf*/) {
-            if (!dm) return;
-            std::lock_guard<std::mutex> lk(video_info_mutex);
-            video_info.width  = static_cast<int>(dm->GetWidth());
-            video_info.height = static_cast<int>(dm->GetHeight());
-            video_info.stride = video_info.width * 8 / 3;  // V210
-            BMDTimeValue dur = 0; BMDTimeScale ts = 0;
-            dm->GetFrameRate(&dur, &ts);
-            if (dur > 0 && ts > 0) {
-                video_info.fps_num = static_cast<int>(ts);
-                video_info.fps_den = static_cast<int>(dur);
-                int g = std::gcd(video_info.fps_num, video_info.fps_den);
-                if (g > 1) { video_info.fps_num /= g; video_info.fps_den /= g; }
-            }
-            if (video_info.width > 0 && video_info.height > 0 && video_info.fps_num > 0) {
-                video_info_set.store(true, std::memory_order_release);
-                {
-                    std::lock_guard<std::mutex> lk(format_mutex);
-                    format_cv.notify_one();
-                }
-                printf("Format from change: %dx%d @ %d/%d fps  stride=%d\n",
-                       video_info.width, video_info.height,
-                       video_info.fps_num, video_info.fps_den, video_info.stride);
-            }
-        }
+        DeckLinkReceiver&    owner;
+        std::atomic<int32_t> ref_count{1};
     };
 
-struct DeviceInfo {
-    uint32_t index;
-    IDeckLink* device;
-    std::string display_name;
-};
-
-class DeckLinkReceiver 
-{
-    public:
-        SourceInfo video_source_info{};
-        std::vector<DeviceInfo> devices_list;
-
-        DeckLinkReceiver() {
-            selected_device_index = 0;
-            selected_device = nullptr;
-            device_config = nullptr;
-            device_status = nullptr;
-            deckLink_notification = nullptr;
-            // notificationCallback = nullptr;
-            deckLink_input = nullptr;
-            input_callback = nullptr;
-            if (!get_input_device_list()) {
-                throw std::runtime_error("DeckLink devices not found");
-            }
-        }
-
-        ~DeckLinkReceiver() {
-            if (input_callback) {
-                if (deckLink_input) deckLink_input->SetCallback(nullptr);
-                delete input_callback;
-                input_callback = nullptr;
-            }
-            // if (m_notificationCallback)
-            // {
-            //     m_deckLinkNotification->Unsubscribe(bmdStatusChanged, m_notificationCallback);
-            //     m_notificationCallback->Release();
-            // }
-            if (selected_device) selected_device->Release();
-            if (device_config) device_config->Release();
-            if (device_status) device_status->Release();
-            if (deckLink_input) deckLink_input->Release();
-            if (deckLink_notification) deckLink_notification->Release();
-        }
-
-        HRESULT start_capture(uint32_t device_index)
-        {
-            const bool detection = true;  // format-detection mode
-            setup(device_index, detection);
-
-            HRESULT result = deckLink_input->EnableVideoInput(
-                bmdModeNTSC,                // placeholder; detection will override
-                bmdFormat10BitYUV,
-                bmdVideoInputEnableFormatDetection
-            );
-            if (result != S_OK)
-            {
-                throw std::runtime_error("Could not enable video input");
-            }
-
-            result = deckLink_input->StartStreams();
-            if (result != S_OK)
-            {
-                throw std::runtime_error("Could not start capture");
-            }
-            return S_OK;
-        }
-
-        DeckLinkInputCallback* get_input_callback() {
-            return input_callback;
-        }
-
-        IDeckLinkInput* get_input() { return deckLink_input; }
-
-        bool wait_for_format(uint64_t timeout_ms = 5000) {
-            std::unique_lock<std::mutex> lk(mutex);
-            return signal_condition.wait_for(lk, std::chrono::milliseconds(timeout_ms),
-                [this] { return input_callback && input_callback->is_video_info_set(); });
-        }
-
-    private:
-        uint32_t								        selected_device_index = 0;
+    // DeckLink SDK objects
+    std::vector<IDeckLink*>  raw_devices;
     IDeckLink*               selected_device = nullptr;
-        IDeckLinkConfiguration*							device_config;
-        IDeckLinkStatus*								device_status;
-        IDeckLinkNotification*							deckLink_notification;
-        // NotificationCallback*							m_notificationCallback;
-        IDeckLinkInput*									deckLink_input;
-        DeckLinkInputCallback*						    input_callback;
-        std::mutex										mutex;
-        std::condition_variable							signal_condition;
+    IDeckLinkInput*          decklink_input  = nullptr;
+    InputCallback*           input_callback  = nullptr;
 
-        bool get_input_device_list()
-        {
-            IDeckLinkIterator* decklink_iterator = CreateDeckLinkIteratorInstance();
-            if (!decklink_iterator) {
-                throw std::runtime_error("A DeckLink iterator could not be created.  The DeckLink drivers may not be installed");
-                return false;
-            }
+    // Synchronisation — one mutex guards all shared state below
+    std::mutex              mutex;
+    std::condition_variable format_cv;   // signalled when format is detected
+    std::condition_variable frame_cv;    // signalled when a frame arrives
+    bool                    format_detected = false;
+
+    // Frame state — written by InputCallback, read by wait_for_frame (both under mutex)
+    std::vector<uint8_t>    frame_buffer;
+    uint32_t                frame_row_bytes = 0;
+    int                     frame_width     = 0;
+    int                     frame_height    = 0;
+    bool                    frame_ready     = false;
+
+    void enumerate_devices() {
+        IDeckLinkIterator* it = CreateDeckLinkIteratorInstance();
+        if (!it) throw std::runtime_error("DeckLink drivers not installed");
 
         IDeckLink* device = nullptr;
-            IDeckLinkInput* input = nullptr;
         uint32_t   index  = 0;
-            while (true) {
-                device = nullptr;
-                HRESULT result = decklink_iterator->Next(&device);
-                if (result != S_OK) break;
-                input = nullptr;
-                result = device->QueryInterface(IID_IDeckLinkInput, (void**)&input);
-                if (input) input->Release();
-                if (result != S_OK) { device->Release(); continue; }
-                const char* display_name = nullptr;
-                device->GetDisplayName(&display_name);
-                devices_list.push_back({index, device, std::string(display_name ? display_name : "?")});
+        while (it->Next(&device) == S_OK) {
+            IDeckLinkInput* inp = nullptr;
+            if (device->QueryInterface(IID_IDeckLinkInput, (void**)&inp) == S_OK) {
+                inp->Release();
+                const char* name = nullptr;
+                device->GetDisplayName(&name);
+                devices.push_back({index, name ? name : "?"});
+                raw_devices.push_back(device);
                 index++;
+            } else {
+                device->Release();
             }
-            if (decklink_iterator) decklink_iterator->Release();
-            return index > 0;
         }
-
-        HRESULT setup(uint32_t device_index, bool detection_enabled) {
-            selected_device_index = device_index;
-            selected_device = devices_list.at(selected_device_index).device;
-            selected_device->AddRef();
-
-            HRESULT result = selected_device->QueryInterface(IID_IDeckLinkConfiguration, (void**)&device_config);
-            if (result != S_OK) {
-                throw std::runtime_error("Could not obtain the IDeckLinkConfiguration interface");
-            }
-
-            result = selected_device->QueryInterface(IID_IDeckLinkStatus, (void**)&device_status);
-            if (result != S_OK) {
-                throw std::runtime_error("Could not obtain the IDeckLinkStatus interface");
-            }
-
-            result = selected_device->QueryInterface(IID_IDeckLinkInput, (void**)&deckLink_input);
-            if (result != S_OK) {
-                throw std::runtime_error("Could not obtain the IDeckLinkInput interface - result");
-            }
-
-            input_callback = new DeckLinkInputCallback(this, detection_enabled, mutex, signal_condition);
-            if (!input_callback) {
-                throw std::runtime_error("Could not create input callback object");
-            }
-
-            result = deckLink_input->SetCallback(input_callback);
-            if (result != S_OK) {
-                throw std::runtime_error("Could not set input callback - result");
-            }
-
-            input_callback->set_decklink_input(deckLink_input);
-
-            return S_OK;
+        it->Release();
+        if (raw_devices.empty())
+            throw std::runtime_error("No DeckLink input devices found");
     }
 };
 
-}
+} // namespace dmf