From 9618584c806c8f2ad972d7634f9587dc2ce5091b Mon Sep 17 00:00:00 2001
From: daniel watson <ozzloy@gmail.com>
Date: Sun, 10 Jul 2011 17:58:50 -0700
Subject: [PATCH] more fault tolerant of single frames and/or capture dying

---
 oble.cpp | 70 ++++++++++++++++++++++++++++++++++++--------------------
 oble.h   |  2 +-
 2 files changed, 46 insertions(+), 26 deletions(-)

diff --git a/oble.cpp b/oble.cpp
index 13a1021..ab5ca39 100644
--- a/oble.cpp
+++ b/oble.cpp
@@ -186,64 +186,84 @@ int parse_opts(int argc, char **argv)
   return 0;
 }
 
-void get_frames(CvCapture* capture, CvHaarClassifierCascade* cascade)
+int get_frames(CvCapture* capture, CvHaarClassifierCascade* cascade)
 {
+  int got_null_frame = 0;
   IplImage* frame = NULL;
   get_one_frame(capture, frame);
 
   IplImage* mirrored =
     cvCreateImage(cvGetSize(frame), frame->depth, frame->nChannels);
   // Show the image captured from the camera in the window and repeat
-  while(1) {
-    if(get_one_frame(capture, frame)) break;
-
-    //flip the image so displayed right/left corresponds to physical right/left
-    cvFlip(frame, mirrored, MIRROR);
+  while(!(got_null_frame = get_one_frame(capture, frame)))
+    {
+      //so displayed right/left corresponds to physical right/left:
+      cvFlip(frame, mirrored, MIRROR);
 
-    detect_and_draw_objects(mirrored, cascade, 1);
-    cvShowImage("mywindow", mirrored);
-    // Do not release the frame!
-    //screensave(t_current);
+      detect_and_draw_objects(mirrored, cascade, 1);
+      cvShowImage("mywindow", mirrored);
+      // Do not release the frame!
+      //screensave(t_current);
 
-    //If ESC key pressed, Key=0x10001B under OpenCV 0.9.7(linux version),
-    //remove higher bits using AND operator
-    if((cvWaitKey(100) & 255) == 27) break;
-  }
+      //If ESC key pressed, Key=0x10001B under OpenCV 0.9.7(linux version),
+      //remove higher bits using AND operator
+      if((cvWaitKey(100) & 255) == 27) break;
+    }
   cvReleaseImage(&mirrored);
+  return got_null_frame;
 }
 
 int do_capture()
 {
+  int got_null_capture = 0;
   CvHaarClassifierCascade* cascade =
     load_object_detector(cascade_filename.c_str());
 
   CvCapture* capture = cvCaptureFromCAM(CV_CAP_ANY);
   if(!capture) {
     cerr << "ERROR: capture is NULL " << endl;
-    getchar();
-    return -1;
+    return 1;
   }
 
   // Create a window in which the captured images will be presented
   cvNamedWindow("mywindow", CV_WINDOW_AUTOSIZE);
   t_current = time(NULL);
-  get_frames(capture, cascade);
+  while(get_frames(capture, cascade))
+    {
+      cerr << "resetting capture." << endl;
+      cvReleaseCapture( &capture );
+      capture = cvCaptureFromCAM( CV_CAP_ANY );
+      if(!capture)
+        {
+          got_null_capture = 1;
+          break;
+        }
+    }
 
   // Release the capture device housekeeping
-  cvReleaseCapture(&capture);
+  if(!got_null_capture)
+    {
+      cvReleaseCapture(&capture);
+    }
   cvDestroyWindow("mywindow");
-  return 0;
+  return got_null_capture;
 }
 
 int get_one_frame(CvCapture* capture, IplImage* &frame)
 {
+  int got_null_frame = 0;
   frame = cvQueryFrame(capture);
-  if(!frame) {
-    cerr << "ERROR: frame is null..." << endl;
-    getchar();
-    return 1;
-  }
-  return 0;
+  if(!frame)
+    {
+      cerr << "ERROR: frame is null..., trying again" << endl;
+      frame = cvQueryFrame(capture);
+      if(!frame)
+        {
+          cerr << "ERROR: frame is still null... maybe reset capture?" << endl;
+          got_null_frame = 1;
+        }
+    }
+  return got_null_frame;
 }
 
 // A Simple Camera Capture Framework.
diff --git a/oble.h b/oble.h
index cb4cd24..7fd6b6d 100644
--- a/oble.h
+++ b/oble.h
@@ -54,6 +54,6 @@ int do_capture();
 
 int get_one_frame(CvCapture* capture, IplImage* &frame);
 
-void get_frames(CvCapture* capture, CvHaarClassifierCascade* cascade);
+int get_frames(CvCapture* capture, CvHaarClassifierCascade* cascade);
 
 void update_idle(int faces_total);
-- 
2.30.2