Issue #18 - got it working with videos

sksurgerydavinci/ui/sksurgerydavinci_demo.py

@@ -32,17 +32,31 @@ def run_demo(args):
         vtk_models = create_sample_model()
 
     num_of_input_sources = len(video_sources)
-
+    if video_sources[0].isdigit():
+        print('Video 0 will come from a camera')
+    else:
+        print('Video 0 will come from a file')
     if num_of_input_sources == 1:
-        viewer = MonoViewer(int(video_sources[0]))
-
+        if video_sources[0].isdigit():
+            viewer = MonoViewer(int(video_sources[0]))
+        else:
+            viewer = MonoViewer(video_sources[0])
     elif int(video_sources[1]) == -1:
-        viewer = MockStereoViewer(int(video_sources[0]))
+        if video_sources[0].isdigit():
+            viewer = MockStereoViewer(int(video_sources[0]))
+        else:
+            viewer = MockStereoViewer(video_sources[0])
         viewer.set_external_screens(output_screens)
 
     else:
-        left_source = int(video_sources[0])
-        right_source = int(video_sources[1])
+        if video_sources[0].isdigit():
+            left_source = int(video_sources[0])
+        else:
+            left_source = int(video_sources[0])
+        if video_sources[1].isdigit():
+            right_source = int(video_sources[1])
+        else:
+            right_source = video_sources[1]
 
         viewer = StereoViewer(left_source, right_source)
         viewer.set_external_screens(output_screens)