* Throw appropriate exception in FrameGrabber.start() (issue #315)

bytedeco · Feb 1, 2016 · 6917026 · 6917026
1 parent 94d7973
commit 6917026
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diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -1,5 +1,6 @@
 
- * Fix swallowed `InterruptedException` ([issue #315](https://github.com/bytedeco/javacv/issues/315))
+ * Clean up `IPCameraFrameGrabber` ([pull #323](https://github.com/bytedeco/javacv/pull/323)
+ * Fix swallowed `InterruptedException` and throw appropriate exception in `FrameGrabber.start()` ([issue #315](https://github.com/bytedeco/javacv/issues/315))
  * Fix `IPCameraFrameGrabber.stop()` not checking for null ([pull #300](https://github.com/bytedeco/javacv/pull/300)
  * Upgrade dependencies for OpenCV 3.1.0, FFmpeg 2.8.4
  * Let users call `FFmpegFrameFilter.push(null)` to indicate EOF, as required by some filters like "palettegen" ([issue #287](https://github.com/bytedeco/javacv/issues/287))

diff --git a/src/main/java/org/bytedeco/javacv/DC1394FrameGrabber.java b/src/main/java/org/bytedeco/javacv/DC1394FrameGrabber.java
@@ -339,7 +339,9 @@ public void start(boolean tryReset, boolean try1394b) throws Exception {
                 } catch (InterruptedException ex) {
                     // reset interrupt to be nice
                     Thread.currentThread().interrupt();
-                    return;
+                }
+                if (!resetDone) {
+                    throw new Exception("dc1394_reset_bus() Error: Could not reset bus and try to start again.");
                 }
             } else {
                 throw e;

diff --git a/src/main/java/org/bytedeco/javacv/OpenCVFrameGrabber.java b/src/main/java/org/bytedeco/javacv/OpenCVFrameGrabber.java
@@ -197,19 +197,22 @@ public void start() throws Exception {
         }
         cvSetCaptureProperty(capture, CV_CAP_PROP_CONVERT_RGB, imageMode == ImageMode.COLOR ? 1 : 0);
 
+        IplImage frame = null;
         try {
             // Before cvRetrieveFrame() starts returning something else then null
             // QTKit sometimes requires some "warm-up" time for some reason...
             // The first frame on Linux is sometimes null as well,
             // so it's probably a good idea to run this for all platforms... ?
             int count = 0;
-            while (count++ < 100 && cvGrabFrame(capture) != 0 && cvRetrieveFrame(capture) == null) {
+            while (count++ < 100 && cvGrabFrame(capture) != 0 && (frame = cvRetrieveFrame(capture)) == null) {
                 Thread.sleep(100);
             }
         } catch (InterruptedException ex) {
             // reset interrupt to be nice
             Thread.currentThread().interrupt();
-            return;
+        }
+        if (frame == null) {
+            throw new Exception("cvRetrieveFrame() Error: Could not retrieve frame in start().");
         }
 
         if (!triggerMode) {