From 8f28b2f76821fa0fcee844d9e2a7fe2684223d43 Mon Sep 17 00:00:00 2001
From: itten <mrjitten@protonmail.com>
Date: Thu, 9 Jul 2026 20:39:41 +0300
Subject: [PATCH] gaindb node

---
 CMakeLists.txt              |  1 +
 gain-check.json             | 24 +++++++++++++++
 nodes/gaindb/CMakeLists.txt |  4 +++
 nodes/gaindb/main.cpp       | 58 +++++++++++++++++++++++++++++++++++++
 4 files changed, 87 insertions(+)
 create mode 100644 gain-check.json
 create mode 100644 nodes/gaindb/CMakeLists.txt
 create mode 100644 nodes/gaindb/main.cpp

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 7fc7eb0..ecc4e80 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -114,6 +114,7 @@ endif()
 
 add_subdirectory(nodes/videoin)
 add_subdirectory(nodes/pip)
+add_subdirectory(nodes/gaindb)
 
 # ── Asio standalone (needed by Crow; no Boost) ───────────────────────────────
 FetchContent_Declare(asio_fc
diff --git a/gain-check.json b/gain-check.json
new file mode 100644
index 0000000..831cb32
--- /dev/null
+++ b/gain-check.json
@@ -0,0 +1,24 @@
+{
+  "nodes": [
+    { "id": "testpattern", "type": "testpattern", "params": { "pattern": "bars" } },
+    { "id": "gaindb",      "type": "gaindb",      "params": {} },
+    { "id": "ndiout",      "type": "ndiout",      "params": {} }
+  ],
+  "edges": [
+    {
+      "from": "testpattern", "from_port": "video_flow_id",
+      "to":   "ndiout",      "to_port":   "video_flow_id",
+      "format": { "kind": "video", "width": 1920, "height": 1080, "fps_num": 25, "fps_den": 1 }
+    },
+    {
+      "from": "testpattern", "from_port": "audio_flow_id",
+      "to":   "gaindb",      "to_port":   "audio_in_flow_id",
+      "format": { "kind": "audio", "sample_rate": 48000, "channels": 2, "bit_depth": 32 }
+    },
+    {
+      "from": "gaindb", "from_port": "audio_out_flow_id",
+      "to":   "ndiout", "to_port":   "audio_flow_id",
+      "format": { "kind": "audio", "sample_rate": 48000, "channels": 2, "bit_depth": 32 }
+    }
+  ]
+}
diff --git a/nodes/gaindb/CMakeLists.txt b/nodes/gaindb/CMakeLists.txt
new file mode 100644
index 0000000..2063b5a
--- /dev/null
+++ b/nodes/gaindb/CMakeLists.txt
@@ -0,0 +1,4 @@
+add_executable(dmf-node-gaindb main.cpp)
+target_compile_features(dmf-node-gaindb PRIVATE cxx_std_20)
+target_link_libraries(dmf-node-gaindb PRIVATE dmf-shared)
+install(TARGETS dmf-node-gaindb RUNTIME DESTINATION bin)
diff --git a/nodes/gaindb/main.cpp b/nodes/gaindb/main.cpp
new file mode 100644
index 0000000..6dc8db1
--- /dev/null
+++ b/nodes/gaindb/main.cpp
@@ -0,0 +1,58 @@
+#include <string>
+#include "NodeBase.hpp"
+#include "FlowDef.hpp"
+#include <mxl/flow.h>
+#include <mxl/time.h>
+
+namespace dmf {
+class GainDbNode: public dmf::NodeBase {
+    void run() override {
+        if (!config().contains("audio_in_flow_id") || !config().contains("audio_out_flow_id")) {
+            log("no audio connected to in or out");
+            return;
+        }
+        const std::string in_flow_id = config().at("audio_in_flow_id").at("id").get<std::string>();
+        dmf::AudioFlowInfo in_flow_info = dmf::read_audio_flow_info(domain(), in_flow_id);
+        int gain = 0;
+        if (config().contains("gain")) {
+            gain = config().at("gain").get<int>(); 
+        }
+        // create writer
+        int sample_rate = in_flow_info.sample_rate;
+        const std::string out_flow_id = config().at("audio_out_flow_id").at("id").get<std::string>();
+        std::string flow_def = dmf::make_audio_flow_def(
+            out_flow_id,
+            node_id(),
+            sample_rate,
+            in_flow_info.channels,
+            32,
+            sample_rate,
+            in_flow_info.samples_per_grain
+        );
+        mxlFlowWriter writer{};
+        mxlFlowConfigInfo cfg{};
+        bool created = false;
+        mxlStatus st = mxlCreateFlowWriter(instance(), flow_def.c_str(), nullptr, &writer, &cfg, &created);
+        if (st != MXL_STATUS_OK) {
+            log("audio mxlCreateFlowWriter failed (%s) — continuing without audio", dmf::mxl_status_str(st));
+        } else {
+            log("audio channels=%u  buffer=%u samples",
+                cfg.continuous.channelCount, cfg.continuous.bufferLength);
+        }
+
+        const mxlRational rate = {sample_rate, 1};
+        uint64_t index = mxlGetCurrentIndex(&rate);
+        while (dmf::g_running.load(std::memory_order_relaxed)) {
+            mxlMutableBufferSlice slice{};
+            uint8_t* buf = nullptr;
+
+        }
+        mxlReleaseFlowWriter(instance(), writer);
+    }        
+};
+}
+
+int main() {
+    dmf::GainDbNode node;
+    return node.execute();
+}
\ No newline at end of file