frame size specification for video sources in video.py

samples/python2/video.py

@@ -101,25 +101,32 @@ presets = dict(
 
 def create_capture(source = 0, fallback = presets['chess']):
     '''
-      source: <int> or '<int>' or '<filename>' or 'synth:<params>'
+      source: <int> or '<int>|<filename>|synth [:<param_name>=<value> [:...]]'
     '''
-    cap = None
+    source = str(source).strip()
+    chunks = source.split(':')
+    # hanlde drive letter ('c:', ...)
+    if len(chunks) > 1 and len(chunks[0]) == 1 and chunks[0].isalpha():
+        chunks[1] = chunks[0] + ':' + chunks[1]
+        del chunks[0]
+
+    source = chunks[0]
     try: source = int(source)
     except ValueError: pass
+    params = dict( s.split('=') for s in chunks[1:] )
+    
+    cap = None
+    if source == 'synth':
+        Class = classes.get(params.get('class', None), VideoSynthBase)
+        try: cap = Class(**params)
+        except: pass
     else:
         cap = cv2.VideoCapture(source)
-    if cap is None:
-        source = str(source).strip()
-        if source.startswith('synth'):
-            ss = filter(None, source.split(':'))
-            params = dict( s.split('=') for s in ss[1:] )
-            try: Class = classes[params['class']]
-            except: Class = VideoSynthBase
-            try: cap = Class(**params)
-            except: pass
-    if cap is None:
-        cap = cv2.VideoCapture(source)
-    if not cap.isOpened():
+        if 'size' in params:
+            w, h = map(int, params['size'].split('x'))
+            cap.set(cv2.cv.CV_CAP_PROP_FRAME_WIDTH, w)
+            cap.set(cv2.cv.CV_CAP_PROP_FRAME_HEIGHT, h)
+    if cap is None or not cap.isOpened():
         print 'Warning: unable to open video source: ', source
         if fallback is not None:
             return create_capture(fallback, None)