Add comment.

mediapipe/calculators/util/counting_vector_size_calculator.h

@@ -20,19 +20,28 @@
 
 namespace mediapipe {
 
-// A calculator that count input landmarksList size.
+// A calculator that counts the size of the input vector. It was created to 
+// aid in polling packets in the output stream synchronously. If there is 
+// a clock stream, it will output a value of 0 even if the input vector stream
+// is empty. If not, it will output some value only if there is an input vector.
+// The clock stream has the same time stamp as the input time stamp, and 
+// it must be a stream where packets must be transmitted during graph operation.
+// (e.g. Any input stream of graph)
 //
-// Count input landmark(std::vector<NormalizedLandmarkList>) and return this 
+// It is designed to be used like:
-// value to ouput_stream. Input IMAGE has no effect on calculation, but is used to
-// ensure that the calculator works even when the landmark is empty. And if the 
-// input landmark is empty, the number of faces found is zero.
 //
 // Example config:
 // node {
-//   calculator: "CountingVectorSizeCalculator"
+//   calculator: "CountingWithVectorSizeCalculator"
-//   input_stream: "IMAGE:input_image"
+//   input_stream: "CLOCK:triger_signal"
-//   input_stream: "LANDMARKS:multi_face_landmarks"
+//   input_stream: "VECTOR:input_vector"
-//   output_stream: "COUNT:face_count"
+//   output_stream: "COUNT:vector_count"
+// }
+//
+// node {
+//   calculator: "CountingWithVectorSizeCalculator"
+//   input_stream: "VECTOR:input_vector"
+//   output_stream: "COUNT:vector_count"
 // }
 
 template <typename VectorT>

mediapipe/examples/desktop/demo_run_graph_main.cc

@@ -27,7 +27,6 @@
 #include "mediapipe/framework/port/parse_text_proto.h"
 #include "mediapipe/framework/port/status.h"
 
-
 constexpr char kInputStream[] = "input_video";
 constexpr char kOutputImageStream[] = "output_video";
 constexpr char kOutputFaceCountStream[] = "face_count";

mediapipe/modules/face_landmark/face_landmark_front_cpu.pbtxt

@@ -191,6 +191,8 @@ node {
   output_stream: "ITERABLE:multi_face_landmarks"
 }
 
+# Counting a multi_faceLandmarks vector size. The image stream is only used to 
+# make the calculator work even when there is no input vector.
 node {
   calculator: "CountingNormalizedLandmarkListVectorSizeCalculator"
   input_stream: "CLOCK:image"
@@ -198,7 +200,6 @@ node {
   output_stream: "COUNT:face_count"
 }
 
-
 # Collects a NormalizedRect for each face into a vector. Upon receiving the
 # BATCH_END timestamp, outputs the vector of NormalizedRect at the BATCH_END
 # timestamp.

mediapipe/modules/face_landmark/face_landmark_front_gpu.pbtxt

@@ -191,6 +191,8 @@ node {
   output_stream: "ITERABLE:multi_face_landmarks"
 }
 
+# Counting a multi_faceLandmarks vector size. The image stream is only used to 
+# make the calculator work even when there is no input vector.
 node {
   calculator: "CountingNormalizedLandmarkListVectorSizeCalculator"
   input_stream: "CLOCK:image"