Remote sink: fixed chanel frequency shift calculation and access

plugins/channelrx/remotesink/remotesink.cpp

@@ -38,6 +38,7 @@
 #include "dsp/threadedbasebandsamplesink.h"
 #include "dsp/downchannelizer.h"
 #include "dsp/dspcommands.h"
+#include "dsp/hbfilterchainconverter.h"
 #include "device/devicesourceapi.h"
 
 #include "../remotesink/remotesinkthread.h"
@@ -61,6 +62,7 @@ RemoteSink::RemoteSink(DeviceSourceAPI *deviceAPI) :
         m_centerFrequency(0),
         m_frequencyOffset(0),
         m_sampleRate(48000),
+        m_deviceSampleRate(48000),
         m_nbBlocksFEC(0),
         m_txDelay(35),
         m_dataAddress("127.0.0.1"),
@@ -273,7 +275,6 @@ bool RemoteSink::handleMessage(const Message& cmd)
         }
 
         setTxDelay(m_settings.m_txDelay, m_settings.m_nbFECBlocks);
-        m_frequencyOffset = notif.getFrequencyOffset();
 
 		return true;
 	}
@@ -286,6 +287,8 @@ bool RemoteSink::handleMessage(const Message& cmd)
                 << " centerFrequency: " << notif.getCenterFrequency();
 
         setCenterFrequency(notif.getCenterFrequency());
+        m_deviceSampleRate = notif.getSampleRate();
+        calculateFrequencyOffset(); // This is when device sample rate changes
 
         // Redo the channelizer stuff with the new sample rate to re-synchronize everything
         m_channelizer->set(m_channelizer->getInputMessageQueue(),
@@ -322,6 +325,8 @@ bool RemoteSink::handleMessage(const Message& cmd)
             m_settings.m_log2Decim,
             m_settings.m_filterChainHash);
 
+        calculateFrequencyOffset(); // This is when decimation or filter chain changes
+
         return true;
     }
     else
@@ -413,6 +418,12 @@ void RemoteSink::validateFilterChainHash(RemoteSinkSettings& settings)
     settings.m_filterChainHash = settings.m_filterChainHash >= s ? s-1 : settings.m_filterChainHash;
 }
 
+void RemoteSink::calculateFrequencyOffset()
+{
+    double shiftFactor = HBFilterChainConverter::getShiftFactor(m_settings.m_log2Decim, m_settings.m_filterChainHash);
+    m_frequencyOffset = m_deviceSampleRate * shiftFactor;
+}
+
 int RemoteSink::webapiSettingsGet(
         SWGSDRangel::SWGChannelSettings& response,
         QString& errorMessage)

plugins/channelrx/remotesink/remotesink.h

@@ -120,7 +120,7 @@ public:
 
     virtual void getIdentifier(QString& id) { id = objectName(); }
     virtual void getTitle(QString& title) { title = "Remote Sink"; }
-    virtual qint64 getCenterFrequency() const { return 0; }
+    virtual qint64 getCenterFrequency() const { return m_frequencyOffset; }
 
     virtual QByteArray serialize() const;
     virtual bool deserialize(const QByteArray& data);
@@ -173,6 +173,7 @@ private:
     uint64_t m_centerFrequency;
     int64_t m_frequencyOffset;
     uint32_t m_sampleRate;
+    uint32_t m_deviceSampleRate;
     int m_nbBlocksFEC;
     int m_txDelay;
     QString m_dataAddress;
@@ -182,6 +183,7 @@ private:
 
     void applySettings(const RemoteSinkSettings& settings, bool force = false);
     void validateFilterChainHash(RemoteSinkSettings& settings);
+    void calculateFrequencyOffset();
     void webapiFormatChannelSettings(SWGSDRangel::SWGChannelSettings& response, const RemoteSinkSettings& settings);
     void webapiReverseSendSettings(QList<QString>& channelSettingsKeys, const RemoteSinkSettings& settings, bool force);
 

sdrbase/dsp/hbfilterchainconverter.cpp

@@ -28,13 +28,10 @@ double HBFilterChainConverter::convertToIndexes(unsigned int log2, unsigned int
     }
 
     unsigned int s = 1;
-    unsigned int d = 1;
     unsigned int u = chainHash;
 
-    for (unsigned int i = 0; i < log2; i++)
-    {
+    for (unsigned int i = 0; i < log2; i++) {
         s *= 3;
-        d *= 2;
     }
 
     u %= s; // scale
@@ -73,14 +70,11 @@ double HBFilterChainConverter::convertToString(unsigned int log2, unsigned int c
     }
 
     unsigned int s = 1;
-    unsigned int d = 1;
     unsigned int u = chainHash;
     chainString = "";
 
-    for (unsigned int i = 0; i < log2; i++)
-    {
+    for (unsigned int i = 0; i < log2; i++) {
         s *= 3;
-        d *= 2;
     }
 
     u %= s; // scale
@@ -115,5 +109,44 @@ double HBFilterChainConverter::convertToString(unsigned int log2, unsigned int c
         shift_stage *= 2;
     }
 
+    return shift;
+}
+
+double HBFilterChainConverter::getShiftFactor(unsigned int log2, unsigned int chainHash)
+{
+    if (log2 == 0)
+    {
+        return 0.0;
+    }
+
+    unsigned int s = 1;
+    unsigned int u = chainHash;
+
+    for (unsigned int i = 0; i < log2; i++) {
+        s *= 3;
+    }
+
+    u %= s; // scale
+    unsigned int ix = log2;
+    double shift = 0.0;
+    double shift_stage = 1.0 / (1<<(log2+1));
+
+    // base3 conversion
+    do
+    {
+        int r = u % 3;
+        shift += (r-1)*shift_stage;
+        shift_stage *= 2;
+        u /= 3;
+        ix--;
+    } while (u);
+
+    // continue shift with leading zeroes. ix has the number of leading zeroes.
+    for (unsigned int i = 0; i < ix; i++)
+    {
+        shift -= shift_stage;
+        shift_stage *= 2;
+    }
+
     return shift;
 }

sdrbase/dsp/hbfilterchainconverter.h

@@ -34,6 +34,8 @@ public:
     static double convertToIndexes(unsigned int log2, unsigned int chainHash, std::vector<unsigned int>& chainIndexes);
     // Same but used only for display giving a string representation of the filter chain
     static double convertToString(unsigned int log2, unsigned int chainHash, QString& chainString);
+    // Just calculate the frequency shift factor relative to sample rate
+    static double getShiftFactor(unsigned int log2, unsigned int chainHash);
 };
 
 #endif // SDRBASE_DSP_HBFILTERCHAINCONVERTER_H