added video stream positioning in QTKit-based VideoCapture backend (patch #1420)

diff --git a/modules/highgui/src/cap_qtkit.mm b/modules/highgui/src/cap_qtkit.mm
index 3cbcb75..6efe4bd 100644 (file)
--- a/modules/highgui/src/cap_qtkit.mm
+++ b/modules/highgui/src/cap_qtkit.mm
@@ -864,6 +864,17 @@ bool CvCaptureFile::setProperty(int property_id, double value) {
                case CV_CAP_PROP_FPS:
                        //etval = currentFPS;  
                        break; 
+               case CV_CAP_PROP_FRAME_COUNT:
+                       {
+                       NSArray *videoTracks = [mCaptureSession tracksOfMediaType:QTMediaTypeVideo];
+                       if ([videoTracks count] > 0) {
+                               QTMedia *media = [[videoTracks objectAtIndex:0] media];
+                               retval = [[media attributeForKey:QTMediaSampleCountAttribute] longValue];
+                       } else {
+                               retval = 0;
+                       }
+                       }
+                       break; 
                case CV_CAP_PROP_FOURCC:
                default:
                        retval = false;