conference: fix switch input for conference

Change-Id: I9a4dbce6a574da439a627f99cb60e5aa0926bc7c

src/media/video/video_input.cpp

@@ -334,6 +334,14 @@ VideoInput::deleteDecoder()
     decoder_.reset();
 }
 
+
+void
+VideoInput::stopInput()
+{
+    clearOptions();
+    loop_.stop();
+}
+
 void VideoInput::clearOptions()
 {
     decOpts_ = {};

src/media/video/video_input.h

@@ -84,6 +84,8 @@ public:
      */
     void* obtainFrame(int length);
     void releaseFrame(void *frame);
+#else
+    void stopInput();
 #endif
 
 private:

src/media/video/video_mixer.cpp

@@ -91,10 +91,20 @@ VideoMixer::~VideoMixer()
 void
 VideoMixer::switchInput(const std::string& input)
 {
+    // Detach videoInput from mixer
+    videoLocal_->detach(this);
     if (auto local = videoLocal_) {
-        if (auto localInput = std::dynamic_pointer_cast<VideoInput>(local))
+        if (auto localInput = std::dynamic_pointer_cast<VideoInput>(local)) {
+#if !VIDEO_CLIENT_INPUT
+            // Stop old VideoInput
+            localInput->stopInput();
+#endif
+            // Start new VideoInput
             localInput->switchInput(input);
+        }
     }
+    // Re-attach videoInput to mixer
+    videoLocal_->attach(this);
 }
 
 void