LimeSDR output: used fixed time length with minimum length for sample FIFO

devices/limesdr/devicelimesdrshared.cpp

@@ -18,3 +18,6 @@
 
 MESSAGE_CLASS_DEFINITION(DeviceLimeSDRShared::MsgCrossReportToGUI, Message)
 MESSAGE_CLASS_DEFINITION(DeviceLimeSDRShared::MsgReportDeviceInfo, Message)
+
+const float  DeviceLimeSDRShared::m_sampleFifoLengthInSeconds = 0.25;
+const int    DeviceLimeSDRShared::m_sampleFifoMinSize = 48000;

devices/limesdr/devicelimesdrshared.h

@@ -82,6 +82,9 @@ public:
     uint64_t            m_centerFrequency;
     uint32_t            m_log2Soft;
 
+    static const float  m_sampleFifoLengthInSeconds;
+    static const int    m_sampleFifoMinSize;
+
     DeviceLimeSDRShared() :
         m_deviceParams(0),
         m_channel(-1),

plugins/samplesink/limesdroutput/limesdroutput.cpp

@@ -505,7 +505,8 @@ bool LimeSDROutput::applySettings(const LimeSDROutputSettings& settings, bool fo
         (m_settings.m_lpfFIRBW != settings.m_lpfFIRBW) ||
         (m_settings.m_lpfFIREnable != settings.m_lpfFIREnable) ||
         (m_settings.m_ncoEnable != settings.m_ncoEnable) ||
-        (m_settings.m_ncoFrequency != settings.m_ncoFrequency) || force)
+        (m_settings.m_ncoFrequency != settings.m_ncoFrequency) ||
+        (m_settings.m_log2SoftInterp != settings.m_log2SoftInterp) || force)
     {
         suspendOwnThread = true;
     }
@@ -618,6 +619,15 @@ bool LimeSDROutput::applySettings(const LimeSDROutputSettings& settings, bool fo
         }
     }
 
+    if ((m_settings.m_devSampleRate != settings.m_devSampleRate)
+       || (m_settings.m_log2SoftInterp != settings.m_log2SoftInterp) || force)
+    {
+        int fifoSize = std::max(
+                (int) ((settings.m_devSampleRate/(1<<settings.m_log2SoftInterp)) * DeviceLimeSDRShared::m_sampleFifoLengthInSeconds),
+                DeviceLimeSDRShared::m_sampleFifoMinSize);
+        m_sampleSourceFifo.resize(fifoSize);
+    }
+
     if ((m_settings.m_lpfBW != settings.m_lpfBW) || force)
     {
         if (m_deviceShared.m_deviceParams->getDevice() != 0)