Merge pull request MasteringOpenCV#32 from SSteve/master

BloodAxe · BloodAxe · commit f3b69163eb85 · 2014-06-02T18:20:31.000+03:00
Check that the return value is nil before attempting to do anything with...
diff --git a/Chapter2_iPhoneAR/Example_MarkerBasedAR/Example_MarkerBasedAR/VideoSource.mm b/Chapter2_iPhoneAR/Example_MarkerBasedAR/Example_MarkerBasedAR/VideoSource.mm
@@ -146,7 +146,7 @@ - (bool) startWithDevicePosition:(AVCaptureDevicePosition)devicePosition
         AVCaptureDeviceInput *videoIn = [AVCaptureDeviceInput deviceInputWithDevice:videoDevice error:&error];
         self.deviceInput = videoIn;
         
-        if (!error)
+        if (nil != videoIn)
         {
             if ([[self captureSession] canAddInput:videoIn])
             {
@@ -160,7 +160,7 @@ - (bool) startWithDevicePosition:(AVCaptureDevicePosition)devicePosition
         }
         else
         {
-            NSLog(@"Couldn't create video input");
+    		NSLog(@"Couldn't create video input: %@", [error localizedDescription]);
             return FALSE;
         }
     }

Original file line number	Diff line number	Diff line change
`@@ -146,7 +146,7 @@ - (bool) startWithDevicePosition:(AVCaptureDevicePosition)devicePosition`
`146`	`146`	`AVCaptureDeviceInput *videoIn = [AVCaptureDeviceInput deviceInputWithDevice:videoDevice error:&error];`
`147`	`147`	`self.deviceInput = videoIn;`
`148`	`148`
`149`		`- if (!error)`
	`149`	`+ if (nil != videoIn)`
`150`	`150`	`{`
`151`	`151`	`if ([[self captureSession] canAddInput:videoIn])`
`152`	`152`	`{`
`@@ -160,7 +160,7 @@ - (bool) startWithDevicePosition:(AVCaptureDevicePosition)devicePosition`
`160`	`160`	`}`
`161`	`161`	`else`
`162`	`162`	`{`
`163`		`- NSLog(@"Couldn't create video input");`
	`163`	`+ NSLog(@"Couldn't create video input: %@", [error localizedDescription]);`
`164`	`164`	`return FALSE;`
`165`	`165`	`}`
`166`	`166`	`}`