feat: add rtmp support (ultralytics#1009)

* feat: add rtmp support

* Update detect.py

pass tuple to source.startswith()

Co-authored-by: ryan.fu <ryan.fu@aylaasia.com>
Co-authored-by: Glenn Jocher <glenn.jocher@ultralytics.com>

README.md

@@ -77,6 +77,7 @@ $ python detect.py --source 0  # webcam
                             path/  # directory
                             path/*.jpg  # glob
                             rtsp://170.93.143.139/rtplive/470011e600ef003a004ee33696235daa  # rtsp stream
+                            rtmp://192.168.1.105/live/test  # rtmp stream
                             http://112.50.243.8/PLTV/88888888/224/3221225900/1.m3u8  # http stream
 ```
 

detect.py

@@ -21,7 +21,7 @@
 def detect(save_img=False):
     out, source, weights, view_img, save_txt, imgsz = \
         opt.output, opt.source, opt.weights, opt.view_img, opt.save_txt, opt.img_size
-    webcam = source.isnumeric() or source.startswith('rtsp') or source.startswith('http') or source.endswith('.txt')
+    webcam = source.isnumeric() or source.startswith(('rtsp://', 'rtmp://', 'http://')) or source.endswith('.txt')
 
     # Initialize
     set_logging()