fix event metadata tag in av sample app (#1252)

Author: unicornss

samples/kvs_gstreamer_audio_video_sample.cpp

@@ -470,19 +470,6 @@ static GstFlowReturn on_new_sample(GstElement *sink, CustomData *data) {
         } else {
             if (key_frame_count % KEYFRAME_EVENT_INTERVAL == 0) {
                 key_frame_count = 0;
-                switch(gEvents) {
-                    case 1:
-                        data->kinesis_video_stream->putEventMetadata(STREAM_EVENT_TYPE_NOTIFICATION, NULL);
-                        break;
-                    case 2:
-                        data->kinesis_video_stream->putEventMetadata(STREAM_EVENT_TYPE_IMAGE_GENERATION, NULL);
-                        break;
-                    case 3:
-                        data->kinesis_video_stream->putEventMetadata(STREAM_EVENT_TYPE_NOTIFICATION | STREAM_EVENT_TYPE_IMAGE_GENERATION, NULL);
-                        break;
-                    default:
-                        break;
-                }
             }
             kinesis_video_flags = FRAME_FLAG_KEY_FRAME;
             key_frame_count++;
@@ -516,6 +503,29 @@ static GstFlowReturn on_new_sample(GstElement *sink, CustomData *data) {
 
     data->kinesis_video_stream->putFrame(frame);
 
+    // Sample to demonstrate how event metadata tags can be generated for fragment(s)
+    // Ref: https://docs.aws.amazon.com/kinesisvideostreams/latest/dg/notifications.html
+    //      https://docs.aws.amazon.com/kinesisvideostreams/latest/dg/images.html
+    if (CHECK_FRAME_FLAG_KEY_FRAME(frame.flags)) {
+        // Add event metadata after key frame
+        switch(gEvents) {
+            case 1:
+                DLOGI("Adding metadata for notification");
+                data->kinesis_video_stream->putEventMetadata(STREAM_EVENT_TYPE_NOTIFICATION, NULL);
+                break;
+            case 2:
+                DLOGI("Adding the metadata for image generation");
+                data->kinesis_video_stream->putEventMetadata(STREAM_EVENT_TYPE_IMAGE_GENERATION, NULL);
+                break;
+            case 3:
+                DLOGI("Adding the metadata for both notification and image generaion");
+                data->kinesis_video_stream->putEventMetadata(STREAM_EVENT_TYPE_NOTIFICATION | STREAM_EVENT_TYPE_IMAGE_GENERATION, NULL);
+                break;
+            default:
+                break;
+        }
+    }
+
 CleanUp:
 
     if (info.data != nullptr) {