Added load and save motion args into videostab sample

modules/videostab/include/opencv2/videostab/stabilizer.hpp

@@ -163,6 +163,9 @@ public:
     virtual void reset() { resetImpl(); }
     virtual Mat nextFrame();
 
+    // available after pre-pass, before it's empty
+    std::vector<Mat> motions() const;
+
 private:
     void resetImpl();
     void runPrePassIfNecessary();

modules/videostab/src/stabilizer.cpp

@@ -278,6 +278,16 @@ Mat TwoPassStabilizer::nextFrame()
 }
 
 
+vector<Mat> TwoPassStabilizer::motions() const
+{
+    if (frameCount_ == 0)
+        return vector<Mat>();
+    vector<Mat> res(frameCount_ - 1);
+    copy(motions_.begin(), motions_.begin() + frameCount_ - 1, res.begin());
+    return res;
+}
+
+
 void TwoPassStabilizer::resetImpl()
 {
     isPrePassDone_ = false;