Mac CameraPlugin: Add safety, only copying the minimum of the size of the c

framebuffer and the size of the input buffer.  Use "grabber" instead of "this"
as the variable name for each camera struct, since lldb refuses to allow this
to be used, assuming it is being used outside an object context.

Author: eliotmiranda

platforms/iOS/plugins/CameraPlugin/AVFoundationVideoGrabber.m

@@ -52,24 +52,19 @@ - (void)captureOutput:(AVCaptureOutput *)captureOutput
   didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer
   fromConnection:(AVCaptureConnection *)connection
 {
-  CVImageBufferRef imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);
-  if (firstTime) {
-	width = CVPixelBufferGetWidth(imageBuffer);
-	height = CVPixelBufferGetHeight(imageBuffer);
-
-    // We unlock the image buffer
-    CVPixelBufferUnlockBaseAddress(imageBuffer, 0);
-
-    pixels = malloc(width * height * 4);
-    firstTime = false;
-  }
-  else {
-    CVPixelBufferLockBaseAddress(imageBuffer, 0);
-    unsigned int *isrc4 = (unsigned int *)CVPixelBufferGetBaseAddress(imageBuffer);
-    memcpy(pixels, isrc4, height * width * 4);
-    CVPixelBufferUnlockBaseAddress(imageBuffer, 0);
-  }
-  frameCount++;
+	CVImageBufferRef imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);
+	if (firstTime) {
+		width = CVPixelBufferGetWidth(imageBuffer);
+		height = CVPixelBufferGetHeight(imageBuffer);
+		pixels = malloc(width * height * 4);
+	}
+	CVPixelBufferLockBaseAddress(imageBuffer, 0);
+	memcpy(	pixels,
+			CVPixelBufferGetBaseAddress(imageBuffer),
+			width * height * 4);
+	firstTime = false;
+	CVPixelBufferUnlockBaseAddress(imageBuffer, 0);
+	frameCount++;
 }
 
 // If desiredWidth == 0 && desiredHeight == 0 then initialize
@@ -84,9 +79,8 @@ -(SqueakVideoGrabber*)initCapture:(int)deviceNum
     }]];
 
   // NSLog(@"devices count %d\n", [devices count]);
-  if ([devices count] == 0) {
+  if ([devices count] == 0)
     return NULL;
-  }
 
   deviceID = deviceNum > ([devices count] - 1)
 				? ([devices count] - 1)
@@ -131,9 +125,8 @@ -(SqueakVideoGrabber*)initCapture:(int)deviceNum
   [captureOutput setVideoSettings: videoSettings];
 
   // And we create a capture session
-  if (captureSession) {
+  if (captureSession)
     captureSession = NULL;
-  }
   captureSession = [[AVCaptureSession alloc] init];
 #if IOS
   [captureSession autorelease];
@@ -169,17 +162,14 @@ -(SqueakVideoGrabber*)initCapture:(int)deviceNum
 
 #undef USEPRESETFOR
 
-  if (preset) {
+  if (preset)
     [captureSession setSessionPreset: preset];
-  }
 
   // We add input and output
-  if ([captureSession canAddInput: captureInput]) {
+  if ([captureSession canAddInput: captureInput])
     [captureSession addInput: captureInput];
-  }
-  if ([captureSession canAddOutput: captureOutput]) {
+  if ([captureSession canAddOutput: captureOutput])
     [captureSession addOutput: captureOutput];
-  }
 
   // We start the capture Session
   [captureSession commitConfiguration];
@@ -194,15 +184,15 @@ -(SqueakVideoGrabber*)initCapture:(int)deviceNum
 
 -(void)startCapture: (sqInt)cameraNum {
   if (!bInitCalled) {
-    [self initCapture: cameraNum-1 desiredWidth: 640 desiredHeight: 480];
+    (void)[self initCapture: cameraNum-1 desiredWidth: 640 desiredHeight: 480];
   }
-  [captureSession startRunning];
+  //[captureSession startRunning];
   [captureInput.device lockForConfiguration: nil];
 
-  //if ( [captureInput.device isExposureModeSupported:AVCaptureExposureModeAutoExpose] ) [captureInput.device setExposureMode:AVCaptureExposureModeAutoExpose ];
-  if ([captureInput.device isFocusModeSupported: AVCaptureFocusModeAutoFocus]) {
+  //if ( [captureInput.device isExposureModeSupported:AVCaptureExposureModeAutoExpose] )
+	[captureInput.device setExposureMode:AVCaptureExposureModeAutoExpose ];
+  if ([captureInput.device isFocusModeSupported: AVCaptureFocusModeAutoFocus])
     [captureInput.device setFocusMode: AVCaptureFocusModeAutoFocus];
-  }
 }
 
 -(void)stopCapture: (sqInt)cameraNum {
@@ -238,10 +228,10 @@ -(void)stopCapture: (sqInt)cameraNum {
 
 SqueakVideoGrabber *
 init(sqInt cameraNum, int desiredWidth, int desiredHeight) {
-  SqueakVideoGrabber *this = [SqueakVideoGrabber alloc];
-  return [this initCapture: cameraNum-1
-               desiredWidth: desiredWidth
-               desiredHeight: desiredHeight];
+  SqueakVideoGrabber *grabber = [SqueakVideoGrabber alloc];
+  return [grabber	initCapture: cameraNum-1
+					desiredWidth: desiredWidth
+					desiredHeight: desiredHeight];
 }
 
 void
@@ -264,56 +254,63 @@ -(void)stopCapture: (sqInt)cameraNum {
 
 sqInt
 CameraOpen(sqInt cameraNum, sqInt desiredWidth, sqInt desiredHeight) {
-  if (cameraNum<1 || cameraNum>8) return false;
-  SqueakVideoGrabber *this = grabbers[cameraNum-1];
+  if (cameraNum<1 || cameraNum>8)
+	return false;
+  SqueakVideoGrabber *grabber = grabbers[cameraNum-1];
 
-  if (this)
+  if (grabber)
 	return true;
 
-  this = init(cameraNum, desiredWidth, desiredHeight);
-  if (!this)
+  grabber = init(cameraNum, desiredWidth, desiredHeight);
+  if (!grabber)
 	return false;
-  [this startCapture: cameraNum];
+  [grabber startCapture: cameraNum];
   return true;
 }
 
 void 
 CameraClose(sqInt cameraNum)
 {
-  if (cameraNum<1 || cameraNum>8) return;
-  SqueakVideoGrabber *this = grabbers[cameraNum-1];
-  if (!this) return;
-  [this stopCapture: cameraNum];
+  if (cameraNum<1 || cameraNum>8)
+	return;
+  SqueakVideoGrabber *grabber = grabbers[cameraNum-1];
+  if (!grabber)
+	return;
+  [grabber stopCapture: cameraNum];
 }
 
 sqInt
 CameraExtent(sqInt cameraNum)
 {
-  SqueakVideoGrabber *this;
+  SqueakVideoGrabber *grabber;
 
   /* if the camera is already open answer its extent */
   if (cameraNum >= 1 && cameraNum <= 8
-	&& (this = grabbers[cameraNum-1]))
-	return this->width <<16 | this->height;
-  if (!getDeviceName(cameraNum)) return 0;
+	&& (grabber = grabbers[cameraNum-1]))
+	return grabber->width <<16 | grabber->height;
+  if (!getDeviceName(cameraNum))
+	return 0;
   /* if not yet open, open with default resolution and answer default extent */
-  this = grabbers[cameraNum-1];
-  if (!this)
-	this = init(cameraNum, 0, 0);
-  return this ? (this->width <<16 | this->height) : 0;
+  grabber = grabbers[cameraNum-1];
+  if (!grabber)
+	grabber = init(cameraNum, 0, 0);
+  return grabber ? (grabber->width <<16 | grabber->height) : 0;
 }
 
 sqInt
 CameraGetFrame(sqInt cameraNum, unsigned char *buf, sqInt pixelCount)
 {
-  if (cameraNum<1 || cameraNum>8) return -1;
-  SqueakVideoGrabber *this = grabbers[cameraNum-1];
-  if (!this)
+  if (cameraNum<1 || cameraNum>8)
+	return -1;
+  SqueakVideoGrabber *grabber = grabbers[cameraNum-1];
+  if (!grabber)
 	return -1;
-  if (!this->firstTime) {
-    int ourFrames = this->frameCount;
-    this->frameCount = 0;
-    memcpy(buf, this->pixels, pixelCount * 4);
+  if (!grabber->firstTime) {
+    int ourFrames = grabber->frameCount;
+#define min(a,b) ((a)<=(b)?(a):(b))
+	long actualPixelCount = grabber->width * grabber->height;
+    memcpy(buf, grabber->pixels, min(pixelCount,actualPixelCount) * 4);
+    grabber->frameCount = 0;
     return ourFrames;
   }
   return 0;