diff --git a/include/media/stagefright/YUVImage.h b/include/media/stagefright/YUVImage.h
index afeac3f..4e98618 100644
--- a/include/media/stagefright/YUVImage.h
+++ b/include/media/stagefright/YUVImage.h
@@ -67,18 +67,22 @@
     // memory.
     static size_t bufferSize(YUVFormat yuvFormat, int32_t width, int32_t height);
 
-    int32_t width() {return mWidth;}
-    int32_t height() {return mHeight;}
+    int32_t width() const {return mWidth;}
+    int32_t height() const {return mHeight;}
+
+    // Returns true if pixel is the range [0, width-1] x [0, height-1]
+    // and false otherwise.
+    bool validPixel(int32_t x, int32_t y) const;
 
     // Get the pixel YUV value at pixel (x,y).
     // Note that the range of x is [0, width-1] and the range of y is [0, height-1].
-    // Returns true if get was succesful and false otherwise.
+    // Returns true if get was successful and false otherwise.
     bool getPixelValue(int32_t x, int32_t y,
             uint8_t *yPtr, uint8_t *uPtr, uint8_t *vPtr) const;
 
     // Set the pixel YUV value at pixel (x,y).
     // Note that the range of x is [0, width-1] and the range of y is [0, height-1].
-    // Returns true if set was succesful and false otherwise.
+    // Returns true if set was successful and false otherwise.
     bool setPixelValue(int32_t x, int32_t y,
             uint8_t yValue, uint8_t uValue, uint8_t vValue);
 
diff --git a/media/libstagefright/yuv/YUVImage.cpp b/media/libstagefright/yuv/YUVImage.cpp
index 73e3297..b712062 100644
--- a/media/libstagefright/yuv/YUVImage.cpp
+++ b/media/libstagefright/yuv/YUVImage.cpp
@@ -155,8 +155,15 @@
     return true;
 }
 
+bool YUVImage::validPixel(int32_t x, int32_t y) const {
+    return (x >= 0 && x < mWidth &&
+            y >= 0 && y < mHeight);
+}
+
 bool YUVImage::getPixelValue(int32_t x, int32_t y,
         uint8_t *yPtr, uint8_t *uPtr, uint8_t *vPtr) const {
+    CHECK(validPixel(x, y));
+
     uint8_t *yAddr;
     uint8_t *uAddr;
     uint8_t *vAddr;
@@ -171,6 +178,8 @@
 
 bool YUVImage::setPixelValue(int32_t x, int32_t y,
         uint8_t yValue, uint8_t uValue, uint8_t vValue) {
+    CHECK(validPixel(x, y));
+
     uint8_t *yAddr;
     uint8_t *uAddr;
     uint8_t *vAddr;