diff --git a/README.md b/README.md
index d9de132a..0a1ae522 100644
--- a/README.md
+++ b/README.md
@@ -359,6 +359,7 @@ If you customize build with CMake GUI, darknet executable will be installed in y
     `./darknet detector test cfg/coco.data cfg/yolov4.cfg yolov4.weights -ext_output -dont_show -out result.json < data/train.txt`
 - To process a list of images `data/train.txt` and save results of detection to `result.txt` use:
     `./darknet detector test cfg/coco.data cfg/yolov4.cfg yolov4.weights -dont_show -ext_output < data/train.txt > result.txt`
+- To process a video and output results to a json file use: `darknet.exe detector demo cfg/coco.data cfg/yolov3.cfg yolov3.weights file.mp4 -dont_show -json_file_output results.json`
 - Pseudo-labelling - to process a list of images `data/new_train.txt` and save results of detection in Yolo training format for each image as label `<image_name>.txt` (in this way you can increase the amount of training data) use:
     `./darknet detector test cfg/coco.data cfg/yolov4.cfg yolov4.weights -thresh 0.25 -dont_show -save_labels < data/new_train.txt`
 - To calculate anchors: `./darknet detector calc_anchors data/obj.data -num_of_clusters 9 -width 416 -height 416`
diff --git a/src/coco.c b/src/coco.c
index 1ccb3bc8..8ad13834 100644
--- a/src/coco.c
+++ b/src/coco.c
@@ -398,6 +398,7 @@ void run_coco(int argc, char **argv)
     int cam_index = find_int_arg(argc, argv, "-c", 0);
     int frame_skip = find_int_arg(argc, argv, "-s", 0);
     int ext_output = find_arg(argc, argv, "-ext_output");
+    char *json_file_output = find_char_arg(argc, argv, "-json_file_output", 0);
 
     if(argc < 4){
         fprintf(stderr, "usage: %s %s [train/test/valid] [cfg] [weights (optional)]\n", argv[0], argv[1]);
@@ -412,5 +413,5 @@ void run_coco(int argc, char **argv)
     else if(0==strcmp(argv[2], "valid")) validate_coco(cfg, weights);
     else if(0==strcmp(argv[2], "recall")) validate_coco_recall(cfg, weights);
     else if(0==strcmp(argv[2], "demo")) demo(cfg, weights, thresh, hier_thresh, cam_index, filename, coco_classes, 80, 1, frame_skip,
-        prefix, out_filename, mjpeg_port, 0, json_port, dont_show, ext_output, 0, 0, 0, 0, 0);
+        prefix, out_filename, mjpeg_port, 0, json_port, dont_show, ext_output, 0, 0, 0, 0, 0, json_file_output);
 }
diff --git a/src/demo.c b/src/demo.c
index 7a258f3e..0e4d3d90 100644
--- a/src/demo.c
+++ b/src/demo.c
@@ -142,7 +142,7 @@ double get_wall_time()
 
 void demo(char *cfgfile, char *weightfile, float thresh, float hier_thresh, int cam_index, const char *filename, char **names, int classes, int avgframes,
     int frame_skip, char *prefix, char *out_filename, int mjpeg_port, int dontdraw_bbox, int json_port, int dont_show, int ext_output, int letter_box_in, int time_limit_sec, char *http_post_host,
-    int benchmark, int benchmark_layers)
+    int benchmark, int benchmark_layers, char *json_file_output)
 {
     if (avgframes < 1) avgframes = 1;
     avg_frames = avgframes;
@@ -157,6 +157,15 @@ void demo(char *cfgfile, char *weightfile, float thresh, float hier_thresh, int
     demo_thresh = thresh;
     demo_ext_output = ext_output;
     demo_json_port = json_port;
+    char *json_buf = NULL;
+    FILE* json_file = NULL;
+
+    if (json_file_output) {
+        json_file = fopen(json_file_output, "wb");
+        char *tmp = "[\n";
+        fwrite(tmp, sizeof(char), strlen(tmp), json_file);
+    }
+
     printf("Demo\n");
     net = parse_network_cfg_custom(cfgfile, 1, 1);    // set batch=1
     if(weightfile){
@@ -290,6 +299,16 @@ void demo(char *cfgfile, char *weightfile, float thresh, float hier_thresh, int
                 send_json(local_dets, local_nboxes, l.classes, demo_names, frame_id, demo_json_port, timeout);
             }
 
+            if (json_file_output) {
+                if (json_buf) {
+                    char *tmp = ", \n";
+                    fwrite(tmp, sizeof(char), strlen(tmp), json_file);
+                }
+                json_buf = detection_to_json(local_dets, local_nboxes, l.classes, demo_names, frame_id, NULL);
+                fwrite(json_buf, sizeof(char), strlen(json_buf), json_file);
+                free(json_buf);
+            }
+
             //char *http_post_server = "webhook.site/898bbd9b-0ddd-49cf-b81d-1f56be98d870";
             if (http_post_host && !send_http_post_once) {
                 int timeout = 3;            // 3 seconds
@@ -396,6 +415,11 @@ void demo(char *cfgfile, char *weightfile, float thresh, float hier_thresh, int
         printf("output_video_writer closed. \n");
     }
 
+    if (json_file_output) {
+        char *tmp = "\n]";
+        fwrite(tmp, sizeof(char), strlen(tmp), json_file);
+        fclose(json_file);
+    }
     this_thread_sleep_for(thread_wait_ms);
 
     custom_join(detect_thread, 0);
@@ -420,7 +444,7 @@ void demo(char *cfgfile, char *weightfile, float thresh, float hier_thresh, int
 #else
 void demo(char *cfgfile, char *weightfile, float thresh, float hier_thresh, int cam_index, const char *filename, char **names, int classes, int avgframes,
     int frame_skip, char *prefix, char *out_filename, int mjpeg_port, int dontdraw_bbox, int json_port, int dont_show, int ext_output, int letter_box_in, int time_limit_sec, char *http_post_host,
-    int benchmark, int benchmark_layers)
+    int benchmark, int benchmark_layers, char *json_file_output)
 {
     fprintf(stderr, "Demo needs OpenCV for webcam images.\n");
 }
diff --git a/src/demo.h b/src/demo.h
index 380b72fe..15f359dd 100644
--- a/src/demo.h
+++ b/src/demo.h
@@ -6,7 +6,7 @@
 extern "C" {
 #endif
 void demo(char *cfgfile, char *weightfile, float thresh, float hier_thresh, int cam_index, const char *filename, char **names, int classes, int avgframes,
-    int frame_skip, char *prefix, char *out_filename, int mjpeg_port, int dontdraw_bbox, int json_port, int dont_show, int ext_output, int letter_box_in, int time_limit_sec, char *http_post_host, int benchmark, int benchmark_layers);
+    int frame_skip, char *prefix, char *out_filename, int mjpeg_port, int dontdraw_bbox, int json_port, int dont_show, int ext_output, int letter_box_in, int time_limit_sec, char *http_post_host, int benchmark, int benchmark_layers, char *json_file_output);
 #ifdef __cplusplus
 }
 #endif
diff --git a/src/detector.c b/src/detector.c
index 5171ee86..8f3023d5 100644
--- a/src/detector.c
+++ b/src/detector.c
@@ -1975,6 +1975,7 @@ void run_detector(int argc, char **argv)
     char *http_post_host = find_char_arg(argc, argv, "-http_post_host", 0);
     int time_limit_sec = find_int_arg(argc, argv, "-time_limit_sec", 0);
     char *out_filename = find_char_arg(argc, argv, "-out_filename", 0);
+    char *json_file_output = find_char_arg(argc, argv, "-json_file_output", 0);
     char *outfile = find_char_arg(argc, argv, "-out", 0);
     char *prefix = find_char_arg(argc, argv, "-prefix", 0);
     float thresh = find_float_arg(argc, argv, "-thresh", .25);    // 0.24
@@ -2048,7 +2049,7 @@ void run_detector(int argc, char **argv)
             if (strlen(filename) > 0)
                 if (filename[strlen(filename) - 1] == 0x0d) filename[strlen(filename) - 1] = 0;
         demo(cfg, weights, thresh, hier_thresh, cam_index, filename, names, classes, avgframes, frame_skip, prefix, out_filename,
-            mjpeg_port, dontdraw_bbox, json_port, dont_show, ext_output, letter_box, time_limit_sec, http_post_host, benchmark, benchmark_layers);
+            mjpeg_port, dontdraw_bbox, json_port, dont_show, ext_output, letter_box, time_limit_sec, http_post_host, benchmark, benchmark_layers, json_file_output);
 
         free_list_contents_kvp(options);
         free_list(options);
diff --git a/src/yolo.c b/src/yolo.c
index dfd497df..ef68acab 100644
--- a/src/yolo.c
+++ b/src/yolo.c
@@ -353,6 +353,7 @@ void run_yolo(int argc, char **argv)
     int cam_index = find_int_arg(argc, argv, "-c", 0);
     int frame_skip = find_int_arg(argc, argv, "-s", 0);
     int ext_output = find_arg(argc, argv, "-ext_output");
+    char *json_file_output = find_char_arg(argc, argv, "-json_file_output", 0);
     if(argc < 4){
         fprintf(stderr, "usage: %s %s [train/test/valid] [cfg] [weights (optional)]\n", argv[0], argv[1]);
         return;
@@ -366,5 +367,5 @@ void run_yolo(int argc, char **argv)
     else if(0==strcmp(argv[2], "valid")) validate_yolo(cfg, weights);
     else if(0==strcmp(argv[2], "recall")) validate_yolo_recall(cfg, weights);
     else if(0==strcmp(argv[2], "demo")) demo(cfg, weights, thresh, hier_thresh, cam_index, filename, voc_names, 20, 1, frame_skip,
-        prefix, out_filename, mjpeg_port, 0, json_port, dont_show, ext_output, 0, 0, 0, 0, 0);
+        prefix, out_filename, mjpeg_port, 0, json_port, dont_show, ext_output, 0, 0, 0, 0, 0, json_file_output);
 }