diff --git a/base/include/H264EncoderV4L2.h b/base/include/H264EncoderV4L2.h
index 19c0319a7..694dcad1c 100644
--- a/base/include/H264EncoderV4L2.h
+++ b/base/include/H264EncoderV4L2.h
@@ -39,7 +39,6 @@ class H264EncoderV4L2 : public Module
 	std::shared_ptr<H264EncoderV4L2Helper> mHelper;
 
 	H264EncoderV4L2Props mProps;
-	framemetadata_sp mOutputMetadata;
 	std::string motionVectorFramePinId;
 	std::string h264FrameOutputPinId;
 };
diff --git a/base/include/H264EncoderV4L2Helper.h b/base/include/H264EncoderV4L2Helper.h
index d1d1ef776..71aa96868 100644
--- a/base/include/H264EncoderV4L2Helper.h
+++ b/base/include/H264EncoderV4L2Helper.h
@@ -4,7 +4,7 @@
 #include "ExtFrame.h"
 #include "AV4L2ElementPlane.h"
 #include "V4L2CUYUV420Converter.h"
-#include "v4l2_nv_extensions.h"
+#include <v4l2_nv_extensions.h>
 
 class H264EncoderV4L2Helper
 {
diff --git a/base/src/H264EncoderV4L2.cpp b/base/src/H264EncoderV4L2.cpp
index d2b941cd1..e22a248ca 100644
--- a/base/src/H264EncoderV4L2.cpp
+++ b/base/src/H264EncoderV4L2.cpp
@@ -10,7 +10,7 @@
 
 H264EncoderV4L2::H264EncoderV4L2(H264EncoderV4L2Props props) : Module(TRANSFORM, "H264EncoderV4L2", props), mProps(props)
 {
-	mOutputMetadata = framemetadata_sp(new H264Metadata(0, 0));
+	auto mOutputMetadata = framemetadata_sp(new H264Metadata(0, 0));
 	auto motionVectorOutputMetadata = framemetadata_sp(new FrameMetadata(FrameMetadata::OVERLAY_INFO_IMAGE));
 	h264FrameOutputPinId = addOutputPin(mOutputMetadata);
 	motionVectorFramePinId = addOutputPin(motionVectorOutputMetadata);
@@ -143,8 +143,6 @@ bool H264EncoderV4L2::processSOS(frame_sp &frame)
 	}
 
 	auto h264OutMetadata = framemetadata_sp(new H264Metadata(width, height));
-	auto h264Metadata = FrameMetadataFactory::downcast<H264Metadata>(h264OutMetadata);
-	h264Metadata->setData(*h264Metadata);
 	Module::setMetadata(h264FrameOutputPinId, h264OutMetadata);
 	
 	mHelper = H264EncoderV4L2Helper::create(v4l2MemType, pixelFormat, width, height, step, 1024 * mProps.targetKbps, mProps.enableMotionVectors, mProps.motionVectorThreshold, 30,h264FrameOutputPinId, motionVectorFramePinId, h264OutMetadata,
diff --git a/base/src/H264EncoderV4L2Helper.cpp b/base/src/H264EncoderV4L2Helper.cpp
index cf682a929..8be1256ab 100644
--- a/base/src/H264EncoderV4L2Helper.cpp
+++ b/base/src/H264EncoderV4L2Helper.cpp
@@ -275,26 +275,23 @@ void H264EncoderV4L2Helper::serializeMotionVectors(v4l2_ctrl_videoenc_outputbuf_
     std::vector<CircleOverlay> circleOverlays;
     CompositeOverlay compositeOverlay;
 
-    int totalMacroblockInRow = floor(mWidth / 16);
+    int totalMacroblockInRow = floor(mWidth / 16); // Tells about the total number of macro blocks in each row.
     auto motionVectorFrame = makeFrame(1024 * 1024 * 3, motionVectorFramePinId);
     uint32_t *frameBuffer = reinterpret_cast<uint32_t *>(motionVectorFrame->data());
     size_t mCount = 0;
-    for (uint32_t i = 0; i < numMVs; i++, pInfo++)
+    for (uint32_t i = 0; i < numMVs; i++, pInfo++) // numMVs is the total macroblock in the frame.
     {
 
         if (abs(pInfo->mv_x) > motionVectorThreshold || abs(pInfo->mv_y) > motionVectorThreshold)
         {
-            auto tempY = floor(i / totalMacroblockInRow);
-            auto y = tempY * 16 + 8;
+            auto tempY = floor(i / totalMacroblockInRow); // i represents current macroblock , To get the y offset of macroblock the current macroblock is divided by macroblock across width.
+            auto y = tempY * 16 + 8; // Here every macroblock is of 16x16 , So multiply it by 16. To get to the centre of the macroblock add it by 8.
             auto tempX = floor(i % totalMacroblockInRow);
             auto x = tempX * 16 + 8;
             CircleOverlay circleOverlay;
             circleOverlay.x1 = x;
             circleOverlay.y1 = y;
             circleOverlay.radius = 1;
-            frameBuffer[mCount] = static_cast<uint32_t>(x);
-            frameBuffer[mCount + 1] = static_cast<uint32_t>(y);
-            frameBuffer[mCount + 2] = 1;
             circleOverlays.push_back(circleOverlay);
         }
     }
diff --git a/base/test/h264encoderv4l2_tests.cpp b/base/test/h264encoderv4l2_tests.cpp
index 1698d5292..c0c609825 100755
--- a/base/test/h264encoderv4l2_tests.cpp
+++ b/base/test/h264encoderv4l2_tests.cpp
@@ -282,50 +282,4 @@ BOOST_AUTO_TEST_CASE(encode_and_extract_motion_vectors)
 		}
 	}
 }
-
-BOOST_AUTO_TEST_CASE(encode_and_extract_motion_vector_overlay,*boost::unit_test::disabled())
-{
-	// metadata is known
-	auto width = 640;
-	auto height = 360;
-
-	auto fileReader = boost::shared_ptr<FileReaderModule>(new FileReaderModule(FileReaderModuleProps("./data/Raw_YUV420_640x360/Image???_YUV420.raw")));
-	auto metadata = framemetadata_sp(new RawImagePlanarMetadata(width, height, ImageMetadata::ImageType::YUV420, size_t(0), CV_8U));
-	auto rawImagePin = fileReader->addOutputPin(metadata);
-
-	H264EncoderV4L2Props encoderProps;
-	encoderProps.targetKbps = 1024;
-	encoderProps.enableMotionVectors = true;
-	auto encoder = boost::shared_ptr<Module>(new H264EncoderV4L2(encoderProps));
-	fileReader->setNext(encoder);
-	
-	auto muxer = boost::shared_ptr<Module>(new FramesMuxer());
-	fileReader->setNext(muxer);
-	encoder->setNext(muxer);
-
-	auto overlay = boost::shared_ptr<OverlayModule>(new OverlayModule(OverlayModuleProps()));
-	muxer->setNext(overlay);
-
-	auto sink = boost::shared_ptr<ExternalSinkModule>(new ExternalSinkModule());
-	overlay->setNext(sink);
-
-	BOOST_TEST(fileReader->init());
-	BOOST_TEST(encoder->init());
-	BOOST_TEST(muxer->init());
-	BOOST_TEST(overlay->init());
-	BOOST_TEST(sink->init());
-
-	fileReader->play(true);
-
-	for (auto i = 0; i < 40; i++)
-	{
-		fileReader->step();
-		encoder->step();
-		muxer->step();
-		muxer->step();
-		overlay->step();
-		auto frames = sink->pop();
-	}
-}
-
 BOOST_AUTO_TEST_SUITE_END()