From c95c7b18af2fa58fb5f977e0c55fecdafd83f52e Mon Sep 17 00:00:00 2001
From: AlexandreRouma <alexandre.rouma@gmail.com>
Date: Tue, 27 Sep 2022 15:43:33 +0200
Subject: [PATCH] added invert iq option

---
 core/src/core.cpp                    |  1 +
 core/src/gui/menus/source.cpp        | 10 ++++++++++
 core/src/signal_path/iq_frontend.cpp |  6 ++++++
 core/src/signal_path/iq_frontend.h   |  3 +++
 4 files changed, 20 insertions(+)

diff --git a/core/src/core.cpp b/core/src/core.cpp
index 0c661c9e..58fe0e62 100644
--- a/core/src/core.cpp
+++ b/core/src/core.cpp
@@ -214,6 +214,7 @@ int sdrpp_main(int argc, char* argv[]) {
     defConfig["source"] = "";
     defConfig["decimationPower"] = 0;
     defConfig["iqCorrection"] = false;
+    defConfig["invertIQ"] = false;
 
     defConfig["streams"]["Radio"]["muted"] = false;
     defConfig["streams"]["Radio"]["sink"] = "Audio";
diff --git a/core/src/gui/menus/source.cpp b/core/src/gui/menus/source.cpp
index 94f14f81..27f362c0 100644
--- a/core/src/gui/menus/source.cpp
+++ b/core/src/gui/menus/source.cpp
@@ -13,6 +13,7 @@ namespace sourcemenu {
     double effectiveOffset = 0.0;
     int decimationPower = 0;
     bool iqCorrection = false;
+    bool invertIQ = false;
 
     EventHandler<std::string> sourceRegisteredHandler;
     EventHandler<std::string> sourceUnregisterHandler;
@@ -138,7 +139,9 @@ namespace sourcemenu {
         offsetMode = core::configManager.conf["offsetMode"];
         decimationPower = core::configManager.conf["decimationPower"];
         iqCorrection = core::configManager.conf["iqCorrection"];
+        invertIQ = core::configManager.conf["invertIQ"];
         sigpath::iqFrontEnd.setDCBlocking(iqCorrection);
+        sigpath::iqFrontEnd.setInvertIQ(invertIQ);
         updateOffset();
 
         refreshSources();
@@ -180,6 +183,13 @@ namespace sourcemenu {
             core::configManager.release(true);
         }
 
+        if (ImGui::Checkbox("Invert IQ##_sdrpp_inv_iq", &invertIQ)) {
+            sigpath::iqFrontEnd.setInvertIQ(invertIQ);
+            core::configManager.acquire();
+            core::configManager.conf["invertIQ"] = invertIQ;
+            core::configManager.release(true);
+        }
+
         ImGui::LeftLabel("Offset mode");
         ImGui::SetNextItemWidth(itemWidth - ImGui::GetCursorPosX());
         if (ImGui::Combo("##_sdrpp_offset_mode", &offsetMode, offsetModesTxt)) {
diff --git a/core/src/signal_path/iq_frontend.cpp b/core/src/signal_path/iq_frontend.cpp
index c77ce160..2aa3f458 100644
--- a/core/src/signal_path/iq_frontend.cpp
+++ b/core/src/signal_path/iq_frontend.cpp
@@ -31,10 +31,12 @@ void IQFrontEnd::init(dsp::stream<dsp::complex_t>* in, double sampleRate, bool b
 
     decim.init(NULL, _decimRatio);
     dcBlock.init(NULL, genDCBlockRate(effectiveSr));
+    conjugate.init(NULL);
 
     preproc.init(&inBuf.out);
     preproc.addBlock(&decim, _decimRatio > 1);
     preproc.addBlock(&dcBlock, dcBlocking);
+    preproc.addBlock(&conjugate, false); // TODO: Replace by parameter
 
     split.init(preproc.out);
 
@@ -123,6 +125,10 @@ void IQFrontEnd::setDCBlocking(bool enabled) {
     preproc.setBlockEnabled(&dcBlock, enabled, [=](dsp::stream<dsp::complex_t>* out){ split.setInput(out); });
 }
 
+void IQFrontEnd::setInvertIQ(bool enabled) {
+    preproc.setBlockEnabled(&conjugate, enabled, [=](dsp::stream<dsp::complex_t>* out){ split.setInput(out); });
+}
+
 void IQFrontEnd::bindIQStream(dsp::stream<dsp::complex_t>* stream) {
     split.bindStream(stream);
 }
diff --git a/core/src/signal_path/iq_frontend.h b/core/src/signal_path/iq_frontend.h
index a3dda529..0fbafdf8 100644
--- a/core/src/signal_path/iq_frontend.h
+++ b/core/src/signal_path/iq_frontend.h
@@ -7,6 +7,7 @@
 #include "../dsp/routing/splitter.h"
 #include "../dsp/channel/rx_vfo.h"
 #include "../dsp/sink/handler_sink.h"
+#include "../dsp/math/conjugate.h"
 #include <fftw3.h>
 
 class IQFrontEnd {
@@ -27,6 +28,7 @@ public:
 
     void setBuffering(bool enabled);
     void setDecimation(int ratio);
+    void setInvertIQ(bool enabled);
     void setDCBlocking(bool enabled);
 
     void bindIQStream(dsp::stream<dsp::complex_t>* stream);
@@ -65,6 +67,7 @@ protected:
 
     // Pre-processing chain
     dsp::multirate::PowerDecimator<dsp::complex_t> decim;
+    dsp::math::Conjugate conjugate;
     dsp::correction::DCBlocker<dsp::complex_t> dcBlock;
     dsp::chain<dsp::complex_t> preproc;