refactor: NDIHelper → NDIReceiver with cleaner API and naming

NDIReceiver (shared/NDIReceiver.hpp):
- Rename class NDIHelper → NDIReceiver, file NDIHelper.hpp → NDIReceiver.hpp
- Add SourceInfo struct (width, height, fps_num, fps_den, stride, fourcc)
  replacing raw public member variables (xres, yres, frame_N, frame_D, stride)
- find_sources() now returns std::vector<std::string> instead of output pointer
- select_source() + get_source_info() → connect() + probe() (cleaner sequence,
  probe() returns SourceInfo and stores it internally for capture_v210)
- getV210_video_frame() → capture_v210() — removes unused source_num parameter
- get_bytes_per_pixel, fourCCtoStr → private static bytes_per_pixel, fourcc_str
- u_int32_t → uint32_t; (uint32_t) casts → static_cast
- probe() checks g_running to avoid hanging if source never sends video

ndiin/main.cpp:
- Update to new NDIReceiver API
- malloc/free latest_buffer → std::vector<uint8_t> latest_frame
- Remove unused #include <Processing.NDI.Lib.h> and V210.hpp
- memcpy uses latest_frame.size() instead of separate frame_bytes variable

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

nodes/ndiin/main.cpp

@@ -1,26 +1,25 @@
+#include <cstring>
 #include <string>
+#include <vector>
 #include <mxl/flow.h>
 #include <mxl/time.h>
 #include "NodeBase.hpp"
 #include "FlowDef.hpp"
-#include "V210.hpp"
+#include "NDIReceiver.hpp"
-#include "NDIHelper.hpp"
-#include <Processing.NDI.Lib.h>
-#include <cstring>
 
 class NDIInNode : public dmf::NodeBase {
     void run() override {
-        const uint32_t source_num = config().value("source_num", 0);
+        const auto source_num = static_cast<uint32_t>(config().value("source_num", 0));
 
-        dmf::NDIHelper ndi_helper;
+        dmf::NDIReceiver ndi;
+        dmf::NDIReceiver::SourceInfo src;
         try {
-            std::vector<std::string> ndi_sources;
+            auto sources = ndi.find_sources(5000);
-            ndi_helper.find_sources(&ndi_sources, 5000);
             log("Available NDI sources:");
-            for (const auto& source_name : ndi_sources)
+            for (const auto& name : sources)
-                log("  %s", source_name.c_str());
+                log("  %s", name.c_str());
-            ndi_helper.select_source(source_num);
+            ndi.connect(source_num);
-            ndi_helper.get_source_info(source_num);
+            src = ndi.probe();
         } catch (const std::runtime_error& e) {
             log("Error: %s", e.what());
             return;
@@ -28,10 +27,10 @@ class NDIInNode : public dmf::NodeBase {
 
         const auto flow_info = config().at("flow_id");
         const auto flow_id   = flow_info.at("id").get<std::string>();
-        const int  width     = flow_info.value("width",   ndi_helper.xres);
+        const int  width     = flow_info.value("width",   src.width);
-        const int  height    = flow_info.value("height",  ndi_helper.yres);
+        const int  height    = flow_info.value("height",  src.height);
-        const int  fps_num   = flow_info.value("fps_num", ndi_helper.frame_N);
+        const int  fps_num   = flow_info.value("fps_num", src.fps_num);
-        const int  fps_den   = flow_info.value("fps_den", ndi_helper.frame_D);
+        const int  fps_den   = flow_info.value("fps_den", src.fps_den);
 
         log("flow=%s  %dx%d @ %d/%d fps", flow_id.c_str(), width, height, fps_num, fps_den);
 
@@ -57,22 +56,21 @@ class NDIInNode : public dmf::NodeBase {
         uint64_t          index = mxlGetCurrentIndex(&rate);
         log("start index=%llu", index);
 
-        // because NDI can drop to 1 FPS for static frames, even if source is 29.97p
+        // NDI can drop to 1fps for static content — hold last valid frame
-        const size_t frame_bytes = stride * height;
+        std::vector<uint8_t> latest_frame(stride * height);
-        uint8_t* latest_buffer = (uint8_t*)malloc(frame_bytes);
+        bool have_frame = false;
-        bool last_ndi_frame_valid = false;
 
         while (dmf::g_running.load(std::memory_order_relaxed)) {
             try {
-                if (ndi_helper.getV210_video_frame(source_num, latest_buffer, stride))
+                if (ndi.capture_v210(latest_frame.data(), stride))
-                    last_ndi_frame_valid = true;
+                    have_frame = true;
             } catch (const std::runtime_error& e) {
                 log("NDI error: %s — stopping", e.what());
                 break;
             }
 
-            uint8_t* buf = nullptr;
             mxlGrainInfo grain{};
+            uint8_t*     buf = nullptr;
 
             st = mxlFlowWriterOpenGrain(writer, index, &grain, &buf);
             if (st != MXL_STATUS_OK) {
@@ -81,14 +79,14 @@ class NDIInNode : public dmf::NodeBase {
                 continue;
             }
 
-            if (last_ndi_frame_valid) {
+            if (have_frame) {
-                std::memcpy(buf, latest_buffer, frame_bytes);
+                std::memcpy(buf, latest_frame.data(), latest_frame.size());
                 grain.flags = 0;
             } else {
                 grain.flags = MXL_GRAIN_FLAG_INVALID;
             }
 
-            grain.validSlices = grain.totalSlices;  // mark grain complete so readers can consume it
+            grain.validSlices = grain.totalSlices;
             mxlFlowWriterCommitGrain(writer, &grain);
 
             const uint64_t ns = mxlGetNsUntilIndex(index + 1, &rate);
@@ -97,13 +95,11 @@ class NDIInNode : public dmf::NodeBase {
         }
 
         log("stopped at index=%llu", index);
-        free(latest_buffer);
         mxlReleaseFlowWriter(instance(), writer);
     }
 };
 
-int main()
+int main() {
-{
     NDIInNode node;
     return node.execute();
 }

shared/NDIHelper.hpp

@@ -1,206 +0,0 @@
-#include <stdexcept>
-#include <vector>
-#include <string>
-#include <Processing.NDI.Lib.h>
-#include "Signal.hpp"
-#include "V210.hpp"
-
-namespace dmf {
-class NDIHelper {
-    public:
-
-        int xres = 0, yres = 0, frame_D = 0, frame_N = 0, stride = 0;
-
-        NDIHelper() {
-            if (!NDIlib_is_supported_CPU()) {
-                throw std::runtime_error("CPU is not sufficient for NDI");
-            }
-            if (!NDIlib_initialize()) {
-                throw std::runtime_error("NDI lib init failed");
-            }
-        }
-
-        ~NDIHelper() {
-            if (pNDI_recv) NDIlib_recv_destroy(pNDI_recv);
-            if (pNDI_find) NDIlib_find_destroy(pNDI_find);
-            NDIlib_destroy();
-        }
-
-        void find_sources(std::vector<std::string>* sources, u_int32_t timeout_ms) {
-            pNDI_find = NDIlib_find_create_v2();
-            if (!pNDI_find) {
-                throw std::runtime_error("Cannot create NDI finder");
-            }
-
-            const int max_attempts = 10;
-            uint32_t sources_amount = 0;
-            const NDIlib_source_t* p_sources = nullptr;
-            for (int attempt = 0; !sources_amount && attempt < max_attempts; ++attempt) {
-                if (!dmf::g_running.load(std::memory_order_relaxed)) {
-                    NDIlib_find_destroy(pNDI_find);
-                    pNDI_find = nullptr;
-                    throw std::runtime_error("Interrupted while searching for NDI sources");
-                }
-                NDIlib_find_wait_for_sources(pNDI_find, timeout_ms);
-                p_sources = NDIlib_find_get_current_sources(pNDI_find, &sources_amount);
-            }
-            if (!sources_amount) {
-                NDIlib_find_destroy(pNDI_find);
-                pNDI_find = nullptr;
-                throw std::runtime_error("No NDI sources found after timeout");
-            }
-
-            // Copy while finder is alive: p_sources points into finder-owned memory
-            for (uint32_t i = 0; i < sources_amount; ++i) {
-                sources->push_back(p_sources[i].p_ndi_name);
-                cached_names.emplace_back(p_sources[i].p_ndi_name);
-                cached_urls.emplace_back(p_sources[i].p_url_address);
-            }
-            cached_sources.reserve(cached_names.size());
-            for (uint32_t i = 0; i < cached_names.size(); ++i) {
-                cached_sources.push_back({cached_names[i].c_str(), cached_urls[i].c_str()});
-            }
-
-            NDIlib_find_destroy(pNDI_find);
-            pNDI_find = nullptr;
-        }
-
-        void select_source(uint32_t source_num) {
-            if (cached_sources.empty()) {
-                throw std::runtime_error("0 sources found");
-            } else if (source_num >= cached_sources.size()) {
-                throw std::runtime_error("Source_num bigger that sources amount");
-            }
-
-            pNDI_recv = NDIlib_recv_create_v3();
-            if (!pNDI_recv) {
-                throw std::runtime_error("Cannot create NDI receive instance");
-            }
-            NDIlib_recv_connect(pNDI_recv, &cached_sources[source_num]);
-        }
-
-        void get_source_info(uint32_t source_num) {
-            NDIlib_video_frame_v2_t video_frame;
-            NDIlib_frame_type_e frame_type;
-            bool is_got_info = false;
-            while(!is_got_info)
-            {
-                frame_type = NDIlib_recv_capture_v3(pNDI_recv, &video_frame, nullptr, nullptr, 1000);
-                switch(frame_type)
-                {
-                    case NDIlib_frame_type_video:
-                        is_got_info = true;
-                        xres = video_frame.xres;
-                        yres = video_frame.yres;
-                        frame_D = video_frame.frame_rate_D;
-                        frame_N = video_frame.frame_rate_N;
-                        fourCC = video_frame.FourCC;
-                        stride = video_frame.line_stride_in_bytes;
-                        if (stride == 0) {
-                            stride = xres * get_bytes_per_pixel(fourCC);
-                        }
-                        break;
-                    case NDIlib_frame_type_error:
-                        is_got_info = true;
-                        throw std::runtime_error("Selected NDI source is lost");
-                        break;
-                }
-            }
-            NDIlib_recv_free_video_v2(pNDI_recv, &video_frame);
-        }
-
-        int get_bytes_per_pixel(NDIlib_FourCC_video_type_e fourCC) {
-            switch (fourCC) {
-                case NDIlib_FourCC_video_type_UYVY: // Standard 8-bit YUV 4:2:2
-                case NDIlib_FourCC_video_type_YV12: // 8-bit YUV 4:2:0
-                case NDIlib_FourCC_video_type_I420: // 8-bit YUV 4:2:0
-                case NDIlib_FourCC_video_type_NV12: // 8-bit YUV 4:2:0
-                    // These are 4:2:2 or 4:2:0 formats. 
-                    // On average, they use 2 bytes (16 bits) per pixel across the macroblock.
-                    return 2; 
-
-                case NDIlib_FourCC_video_type_BGRA: // 8-bit RGB with Alpha
-                case NDIlib_FourCC_video_type_RGBA: // 8-bit RGB with Alpha
-                    // 4 channels (Red, Green, Blue, Alpha) * 1 byte each
-                    return 4; 
-
-                case NDIlib_FourCC_video_type_BGRX: // 8-bit RGB (Padding)
-                case NDIlib_FourCC_video_type_RGBX: // 8-bit RGB (Padding)
-                    // 4 channels (Red, Green, Blue, Empty) * 1 byte each
-                    return 4; 
-
-                case NDIlib_FourCC_video_type_UYVA: // 8-bit YUV 4:2:2 + Alpha channel
-                    // 2 bytes for YUV + 1 byte for Alpha split
-                    return 3;
-
-                case NDIlib_FourCC_video_type_P216: // 16-bit YUV 4:2:2 (High bit depth)
-                    // 2 channels packed at 2 bytes (16-bits) per sample = 4 bytes per pixel
-                    return 4;
-
-                case NDIlib_FourCC_video_type_PA16: // 16-bit YUV 4:2:2 + 16-bit Alpha
-                    return 6;
-
-                default:
-                    return 2; // Safe NDI default fallback
-            }
-        }
-
-        std::string fourCCtoStr() {
-            char fourcc_str[5];
-            uint32_t fourcc = (uint32_t)fourCC;
-            fourcc_str[0] = (fourcc >> 0)  & 0xFF;
-            fourcc_str[1] = (fourcc >> 8)  & 0xFF;
-            fourcc_str[2] = (fourcc >> 16) & 0xFF;
-            fourcc_str[3] = (fourcc >> 24) & 0xFF;
-            fourcc_str[4] = '\0';
-            return std::string(fourcc_str);
-        }
-
-        bool getV210_video_frame(uint32_t source_num, uint8_t* frame_buffer, uint32_t frame_stride) {
-            NDIlib_video_frame_v2_t video_frame;
-            NDIlib_frame_type_e frame_type;
-            frame_type = NDIlib_recv_capture_v3(pNDI_recv, &video_frame, nullptr, nullptr, 5);
-
-            if (frame_type == NDIlib_frame_type_error)
-                throw std::runtime_error("NDI source lost");
-
-            if (frame_type == NDIlib_frame_type_status_change) {
-                // Source changed resolution or framerate — refresh internal info, repeat last frame
-                get_source_info(source_num);
-                return false;
-            }
-
-            if (frame_type != NDIlib_frame_type_video)
-                return false;
-
-            switch (fourCC) {
-                case NDIlib_FourCC_type_UYVY:
-                    v210::UYVYtoV210(video_frame.p_data, frame_buffer, xres, yres, stride, frame_stride);
-                    break;
-                case NDIlib_FourCC_type_P216: {
-                    // P216→V210: write directly into caller's buffer via a wrapper frame
-                    NDIlib_video_frame_v2_t dst{};
-                    dst.p_data = frame_buffer;
-                    dst.line_stride_in_bytes = frame_stride;
-                    NDIlib_util_P216_to_V210(&video_frame, &dst);
-                    break;
-                }
-                default:
-                    NDIlib_recv_free_video_v2(pNDI_recv, &video_frame);
-                    throw std::runtime_error("Unsupported NDI color format: " + fourCCtoStr());
-            }
-            NDIlib_recv_free_video_v2(pNDI_recv, &video_frame);
-            return true;
-        }
-
-    private:
-        // receive
-        NDIlib_find_instance_t pNDI_find = nullptr;
-        NDIlib_recv_instance_t pNDI_recv = nullptr;
-        NDIlib_FourCC_type_e fourCC;
-        // owned copies so finder can be destroyed early
-        std::vector<std::string>    cached_names;
-        std::vector<std::string>    cached_urls;
-        std::vector<NDIlib_source_t> cached_sources;
-};
-}

shared/NDIReceiver.hpp

@@ -0,0 +1,191 @@
+#pragma once
+
+#include <stdexcept>
+#include <string>
+#include <vector>
+#include <Processing.NDI.Lib.h>
+#include "Signal.hpp"
+#include "V210.hpp"
+
+namespace dmf {
+
+class NDIReceiver {
+public:
+    struct SourceInfo {
+        int width   = 0;
+        int height  = 0;
+        int fps_num = 0;
+        int fps_den = 0;
+        int stride  = 0;
+        NDIlib_FourCC_type_e fourcc{};
+    };
+
+    NDIReceiver() {
+        if (!NDIlib_is_supported_CPU())
+            throw std::runtime_error("CPU is not sufficient for NDI");
+        if (!NDIlib_initialize())
+            throw std::runtime_error("NDI lib init failed");
+    }
+
+    ~NDIReceiver() {
+        if (recv_) NDIlib_recv_destroy(recv_);
+        if (find_) NDIlib_find_destroy(find_);
+        NDIlib_destroy();
+    }
+
+    // Discovers NDI sources on the network. Polls up to max_attempts times,
+    // each waiting timeout_ms milliseconds. Respects g_running.
+    std::vector<std::string> find_sources(uint32_t timeout_ms, int max_attempts = 10) {
+        find_ = NDIlib_find_create_v2();
+        if (!find_)
+            throw std::runtime_error("Cannot create NDI finder");
+
+        uint32_t count = 0;
+        const NDIlib_source_t* p_sources = nullptr;
+        for (int i = 0; !count && i < max_attempts; ++i) {
+            if (!dmf::g_running.load(std::memory_order_relaxed)) {
+                NDIlib_find_destroy(find_);
+                find_ = nullptr;
+                throw std::runtime_error("Interrupted while searching for NDI sources");
+            }
+            NDIlib_find_wait_for_sources(find_, timeout_ms);
+            p_sources = NDIlib_find_get_current_sources(find_, &count);
+        }
+        if (!count) {
+            NDIlib_find_destroy(find_);
+            find_ = nullptr;
+            throw std::runtime_error("No NDI sources found after timeout");
+        }
+
+        // Copy while finder is alive: p_sources points into finder-owned memory
+        std::vector<std::string> names;
+        for (uint32_t i = 0; i < count; ++i) {
+            names.emplace_back(p_sources[i].p_ndi_name);
+            source_names_.emplace_back(p_sources[i].p_ndi_name);
+            source_urls_.emplace_back(p_sources[i].p_url_address);
+        }
+        sources_.reserve(source_names_.size());
+        for (size_t i = 0; i < source_names_.size(); ++i)
+            sources_.push_back({source_names_[i].c_str(), source_urls_[i].c_str()});
+
+        NDIlib_find_destroy(find_);
+        find_ = nullptr;
+        return names;
+    }
+
+    // Connects to a discovered source by index.
+    void connect(uint32_t source_num) {
+        if (sources_.empty())
+            throw std::runtime_error("No sources available — call find_sources() first");
+        if (source_num >= static_cast<uint32_t>(sources_.size()))
+            throw std::runtime_error("source_num exceeds available source count");
+
+        recv_ = NDIlib_recv_create_v3();
+        if (!recv_)
+            throw std::runtime_error("Cannot create NDI receive instance");
+        NDIlib_recv_connect(recv_, &sources_[source_num]);
+    }
+
+    // Captures the first video frame to determine resolution, frame rate, and format.
+    // Stores the result internally for use by capture_v210(). Respects g_running.
+    SourceInfo probe() {
+        while (dmf::g_running.load(std::memory_order_relaxed)) {
+            NDIlib_video_frame_v2_t frame;
+            auto type = NDIlib_recv_capture_v3(recv_, &frame, nullptr, nullptr, 1000);
+            if (type == NDIlib_frame_type_error)
+                throw std::runtime_error("NDI source lost during probe");
+            if (type != NDIlib_frame_type_video)
+                continue;
+
+            info_.width   = frame.xres;
+            info_.height  = frame.yres;
+            info_.fps_num = frame.frame_rate_N;
+            info_.fps_den = frame.frame_rate_D;
+            info_.fourcc  = static_cast<NDIlib_FourCC_type_e>(frame.FourCC);
+            info_.stride  = frame.line_stride_in_bytes;
+            if (info_.stride == 0)
+                info_.stride = info_.width * bytes_per_pixel(info_.fourcc);
+
+            NDIlib_recv_free_video_v2(recv_, &frame);
+            return info_;
+        }
+        throw std::runtime_error("Interrupted during probe");
+    }
+
+    // Captures one video frame and converts it to V210 in frame_buffer.
+    // Returns false if no frame was available this tick (caller should repeat last frame).
+    // Throws on source lost or unsupported format.
+    bool capture_v210(uint8_t* frame_buffer, uint32_t frame_stride) {
+        NDIlib_video_frame_v2_t frame;
+        auto type = NDIlib_recv_capture_v3(recv_, &frame, nullptr, nullptr, 5);
+
+        if (type == NDIlib_frame_type_error)
+            throw std::runtime_error("NDI source lost");
+
+        if (type == NDIlib_frame_type_status_change) {
+            info_ = probe();  // source changed resolution or framerate — refresh
+            return false;
+        }
+
+        if (type != NDIlib_frame_type_video)
+            return false;
+
+        switch (info_.fourcc) {
+            case NDIlib_FourCC_type_UYVY:
+                v210::UYVYtoV210(frame.p_data, frame_buffer,
+                                 info_.width, info_.height, info_.stride, frame_stride);
+                break;
+            case NDIlib_FourCC_type_P216: {
+                NDIlib_video_frame_v2_t dst{};
+                dst.p_data = frame_buffer;
+                dst.line_stride_in_bytes = frame_stride;
+                NDIlib_util_P216_to_V210(&frame, &dst);
+                break;
+            }
+            default:
+                NDIlib_recv_free_video_v2(recv_, &frame);
+                throw std::runtime_error("Unsupported NDI color format: " + fourcc_str(info_.fourcc));
+        }
+        NDIlib_recv_free_video_v2(recv_, &frame);
+        return true;
+    }
+
+private:
+    NDIlib_find_instance_t       find_ = nullptr;
+    NDIlib_recv_instance_t       recv_ = nullptr;
+    SourceInfo                   info_;
+    std::vector<std::string>     source_names_;
+    std::vector<std::string>     source_urls_;
+    std::vector<NDIlib_source_t> sources_;
+
+    static int bytes_per_pixel(NDIlib_FourCC_type_e fc) {
+        switch (fc) {
+            case NDIlib_FourCC_video_type_UYVY:
+            case NDIlib_FourCC_video_type_YV12:
+            case NDIlib_FourCC_video_type_I420:
+            case NDIlib_FourCC_video_type_NV12:  return 2;
+            case NDIlib_FourCC_video_type_BGRA:
+            case NDIlib_FourCC_video_type_RGBA:
+            case NDIlib_FourCC_video_type_BGRX:
+            case NDIlib_FourCC_video_type_RGBX:  return 4;
+            case NDIlib_FourCC_video_type_UYVA:  return 3;
+            case NDIlib_FourCC_video_type_P216:  return 4;
+            case NDIlib_FourCC_video_type_PA16:  return 6;
+            default:                              return 2;
+        }
+    }
+
+    static std::string fourcc_str(NDIlib_FourCC_type_e fc) {
+        uint32_t v = static_cast<uint32_t>(fc);
+        char s[5] = {
+            static_cast<char>((v >>  0) & 0xFF),
+            static_cast<char>((v >>  8) & 0xFF),
+            static_cast<char>((v >> 16) & 0xFF),
+            static_cast<char>((v >> 24) & 0xFF),
+            '\0'
+        };
+        return s;
+    }
+};
+
+} // namespace dmf