diff --git a/sdrbase/audio/audiofilter.cpp b/sdrbase/audio/audiofilter.cpp
index 980df959a..1f61569eb 100644
--- a/sdrbase/audio/audiofilter.cpp
+++ b/sdrbase/audio/audiofilter.cpp
@@ -14,6 +14,7 @@
 // along with this program. If not, see <http://www.gnu.org/licenses/>.          //
 ///////////////////////////////////////////////////////////////////////////////////
 
+#define _USE_MATH_DEFINES
 #include <math.h>
 #include <algorithm>
 #include <QDebug>
diff --git a/sdrbase/audio/audiog722.h b/sdrbase/audio/audiog722.h
index ee88e264c..59e199913 100644
--- a/sdrbase/audio/audiog722.h
+++ b/sdrbase/audio/audiog722.h
@@ -71,7 +71,7 @@ private:
         void init(int rate, int options);
     };
 
-    __inline__ int16_t saturate(int32_t amp)
+    int16_t saturate(int32_t amp)
     {
         int16_t amp16;
 
diff --git a/sdrbase/sdrbase.pro b/sdrbase/sdrbase.pro
index e06c4b82a..0a295936d 100644
--- a/sdrbase/sdrbase.pro
+++ b/sdrbase/sdrbase.pro
@@ -37,6 +37,7 @@ CONFIG(ANDROID):INCLUDEPATH += /opt/softs/boost_1_60_0
 CONFIG(MINGW32):INCLUDEPATH += "C:\softs\boost_1_66_0"
 CONFIG(MINGW64):INCLUDEPATH += "C:\softs\boost_1_66_0"
 CONFIG(MSVC):INCLUDEPATH += "C:\softs\boost_1_66_0"
+CONFIG(MSVC):INCLUDEPATH += "C:\softs\libopus_v1.3_msvc15\include"
 
 CONFIG(MINGW32):INCLUDEPATH += "C:\softs\serialDV"
 CONFIG(MINGW64):INCLUDEPATH += "C:\softs\serialDV"
@@ -58,6 +59,7 @@ SOURCES += audio/audiodevicemanager.cpp\
         audio/audiofifo.cpp\
         audio/audiofilter.cpp\
         audio/audiog722.cpp\
+        audio/audioopus.cpp\
         audio/audiooutput.cpp\
         audio/audioinput.cpp\
         audio/audionetsink.cpp\
@@ -138,6 +140,7 @@ HEADERS  += audio/audiodevicemanager.h\
         audio/audiofifo.h\
         audio/audiofilter.h\
         audio/audiog722.h\        
+        audio/audioopus.h\
         audio/audiooutput.h\
         audio/audioinput.h\
         audio/audionetsink.h\
@@ -231,6 +234,9 @@ HEADERS  += audio/audiodevicemanager.h\
         webapi/webapiserver.h\
         mainparser.h
 
+MSVC {
+    LIBS += -LC:\softs\libopus_v1.3_msvc15\lib\x64 -lopus
+}
 MINGW32 || MINGW64 || MSVC {
     LIBS += -L../serialdv/$${build_subdir} -lserialdv
 }