Adding YUVImage and YUVCanvas.

YUVImage is a container class to hold YUV data and provide
various utilities, e.g. to set/get pixel values for different
YUV formats, fast copying routines, etc.
Currently supported YUV420 Planar and YUV420 Semi Planar.

YUVCanvas holds a reference to a YUVImage on which it can do various
drawing operations.

Change-Id: I052a57b7fbc834efe1626914f76c04c091996cac

5 files changed, 741 insertions, 0 deletions

diff --git a/include/media/stagefright/YUVCanvas.h b/include/media/stagefright/YUVCanvas.h
new file mode 100644
index 0000000..5e17046
--- /dev/null
+++ b/include/media/stagefright/YUVCanvas.h
@@ -0,0 +1,67 @@
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+// YUVCanvas holds a reference to a YUVImage on which it can do various
+// drawing operations. It provides various utility functions for filling,
+// cropping, etc.
+
+
+#ifndef YUV_CANVAS_H_
+
+#define YUV_CANVAS_H_
+
+#include <stdint.h>
+
+namespace android {
+
+class YUVImage;
+class Rect;
+
+class YUVCanvas {
+public:
+
+    // Constructor takes in reference to a yuvImage on which it can do
+    // various drawing opreations.
+    YUVCanvas(YUVImage &yuvImage);
+    ~YUVCanvas();
+
+    // Fills the entire image with the given YUV values.
+    void FillYUV(uint8_t yValue, uint8_t uValue, uint8_t vValue);
+
+    // Fills the rectangular region [startX,endX]x[startY,endY] with the given YUV values.
+    void FillYUVRectangle(const Rect& rect,
+            uint8_t yValue, uint8_t uValue, uint8_t vValue);
+
+    // Copies the region [startX,endX]x[startY,endY] from srcImage into the
+    // canvas' target image (mYUVImage) starting at
+    // (destinationStartX,destinationStartY).
+    // Note that undefined behavior may occur if srcImage is same as the canvas'
+    // target image.
+    void CopyImageRect(
+            const Rect& srcRect,
+            int32_t destStartX, int32_t destStartY,
+            const YUVImage &srcImage);
+
+private:
+    YUVImage& mYUVImage;
+
+    YUVCanvas(const YUVCanvas &);
+    YUVCanvas &operator=(const YUVCanvas &);
+};
+
+}  // namespace android
+
+#endif  // YUV_CANVAS_H_
diff --git a/include/media/stagefright/YUVImage.h b/include/media/stagefright/YUVImage.h
new file mode 100644
index 0000000..afeac3f
--- /dev/null
+++ b/include/media/stagefright/YUVImage.h
@@ -0,0 +1,174 @@
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+// A container class to hold YUV data and provide various utilities,
+// e.g. to set/get pixel values.
+// Supported formats:
+//  - YUV420 Planar
+//  - YUV420 Semi Planar
+//
+//  Currently does not support variable strides.
+//
+//  Implementation: Two simple abstractions are done to simplify access
+//  to YUV channels for different formats:
+//  - initializeYUVPointers() sets up pointers (mYdata, mUdata, mVdata) to
+//  point to the right start locations of the different channel data depending
+//  on the format.
+//  - getOffsets() returns the correct offset for the different channels
+//  depending on the format.
+//  Location of any pixel's YUV channels can then be easily computed using these.
+//
+
+#ifndef YUV_IMAGE_H_
+
+#define YUV_IMAGE_H_
+
+#include <stdint.h>
+#include <cstring>
+
+namespace android {
+
+class Rect;
+
+class YUVImage {
+public:
+    // Supported YUV formats
+    enum YUVFormat {
+        YUV420Planar,
+        YUV420SemiPlanar
+    };
+
+    // Constructs an image with the given size, format. Also allocates and owns
+    // the required memory.
+    YUVImage(YUVFormat yuvFormat, int32_t width, int32_t height);
+
+    // Constructs an image with the given size, format. The memory is provided
+    // by the caller and we don't own it.
+    YUVImage(YUVFormat yuvFormat, int32_t width, int32_t height, uint8_t *buffer);
+
+    // Destructor to delete the memory if it owns it.
+    ~YUVImage();
+
+    // Returns the size of the buffer required to store the YUV data for the given
+    // format and geometry. Useful when the caller wants to allocate the requisite
+    // memory.
+    static size_t bufferSize(YUVFormat yuvFormat, int32_t width, int32_t height);
+
+    int32_t width() {return mWidth;}
+    int32_t height() {return mHeight;}
+
+    // 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.
+    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.
+    bool setPixelValue(int32_t x, int32_t y,
+            uint8_t yValue, uint8_t uValue, uint8_t vValue);
+
+    // Uses memcpy to copy an entire row of data
+    static void fastCopyRectangle420Planar(
+            const Rect& srcRect,
+            int32_t destStartX, int32_t destStartY,
+            const YUVImage &srcImage, YUVImage &destImage);
+
+    // Uses memcpy to copy an entire row of data
+    static void fastCopyRectangle420SemiPlanar(
+            const Rect& srcRect,
+            int32_t destStartX, int32_t destStartY,
+            const YUVImage &srcImage, YUVImage &destImage);
+
+    // Tries to use memcopy to copy entire rows of data.
+    // Returns false if fast copy is not possible for the passed image formats.
+    static bool fastCopyRectangle(
+            const Rect& srcRect,
+            int32_t destStartX, int32_t destStartY,
+            const YUVImage &srcImage, YUVImage &destImage);
+
+    // Convert the given YUV value to RGB.
+    void yuv2rgb(uint8_t yValue, uint8_t uValue, uint8_t vValue,
+        uint8_t *r, uint8_t *g, uint8_t *b) const;
+
+    // Write the image to a human readable PPM file.
+    // Returns true if write was succesful and false otherwise.
+    bool writeToPPM(const char *filename) const;
+
+private:
+    // YUV Format of the image.
+    YUVFormat mYUVFormat;
+
+    int32_t mWidth;
+    int32_t mHeight;
+
+    // Pointer to the memory buffer.
+    uint8_t *mBuffer;
+
+    // Boolean telling whether we own the memory buffer.
+    bool mOwnBuffer;
+
+    // Pointer to start of the Y data plane.
+    uint8_t *mYdata;
+
+    // Pointer to start of the U data plane. Note that in case of interleaved formats like
+    // YUV420 semiplanar, mUdata points to the start of the U data in the UV plane.
+    uint8_t *mUdata;
+
+    // Pointer to start of the V data plane. Note that in case of interleaved formats like
+    // YUV420 semiplanar, mVdata points to the start of the V data in the UV plane.
+    uint8_t *mVdata;
+
+    // Initialize the pointers mYdata, mUdata, mVdata to point to the right locations for
+    // the given format and geometry.
+    // Returns true if initialize was succesful and false otherwise.
+    bool initializeYUVPointers();
+
+    // For the given pixel location, this returns the offset of the location of y, u and v
+    // data from the corresponding base pointers -- mYdata, mUdata, mVdata.
+    // Note that the range of x is [0, width-1] and the range of y is [0, height-1].
+    // Returns true if getting offsets was succesful and false otherwise.
+    bool getOffsets(int32_t x, int32_t y,
+        int32_t *yOffset, int32_t *uOffset, int32_t *vOffset) const;
+
+    // Returns the offset increments incurred in going from one data row to the next data row
+    // for the YUV channels. Note that this corresponds to data rows and not pixel rows.
+    // E.g. depending on formats, U/V channels may have only one data row corresponding
+    // to two pixel rows.
+    bool getOffsetIncrementsPerDataRow(
+        int32_t *yDataOffsetIncrement,
+        int32_t *uDataOffsetIncrement,
+        int32_t *vDataOffsetIncrement) const;
+
+    // Given the offset return the address of the corresponding channel's data.
+    uint8_t* getYAddress(int32_t offset) const;
+    uint8_t* getUAddress(int32_t offset) const;
+    uint8_t* getVAddress(int32_t offset) const;
+
+    // Given the pixel location, returns the address of the corresponding channel's data.
+    // Note that the range of x is [0, width-1] and the range of y is [0, height-1].
+    bool getYUVAddresses(int32_t x, int32_t y,
+        uint8_t **yAddr, uint8_t **uAddr, uint8_t **vAddr) const;
+
+    // Disallow implicit casting and copying.
+    YUVImage(const YUVImage &);
+    YUVImage &operator=(const YUVImage &);
+};
+
+}  // namespace android
+
+#endif  // YUV_IMAGE_H_
diff --git a/media/libstagefright/yuv/Android.mk b/media/libstagefright/yuv/Android.mk
new file mode 100644
index 0000000..0794ad1
--- /dev/null
+++ b/media/libstagefright/yuv/Android.mk
@@ -0,0 +1,13 @@
+LOCAL_PATH:= $(call my-dir)
+include $(CLEAR_VARS)
+
+LOCAL_SRC_FILES:=               \
+        YUVImage.cpp            \
+        YUVCanvas.cpp
+
+LOCAL_SHARED_LIBRARIES :=       \
+        libcutils
+
+LOCAL_MODULE:= libstagefright_yuv
+
+include $(BUILD_SHARED_LIBRARY)
diff --git a/media/libstagefright/yuv/YUVCanvas.cpp b/media/libstagefright/yuv/YUVCanvas.cpp
new file mode 100644
index 0000000..7ef652d
--- /dev/null
+++ b/media/libstagefright/yuv/YUVCanvas.cpp
@@ -0,0 +1,83 @@
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define LOG_NDEBUG 0
+#define LOG_TAG "YUVCanvas"
+
+#include <media/stagefright/YUVCanvas.h>
+#include <media/stagefright/YUVImage.h>
+#include <ui/Rect.h>
+
+namespace android {
+
+YUVCanvas::YUVCanvas(YUVImage &yuvImage)
+    : mYUVImage(yuvImage) {
+}
+
+YUVCanvas::~YUVCanvas() {
+}
+
+void YUVCanvas::FillYUV(uint8_t yValue, uint8_t uValue, uint8_t vValue) {
+    for (int32_t y = 0; y < mYUVImage.height(); ++y) {
+        for (int32_t x = 0; x < mYUVImage.width(); ++x) {
+            mYUVImage.setPixelValue(x, y, yValue, uValue, vValue);
+        }
+    }
+}
+
+void YUVCanvas::FillYUVRectangle(const Rect& rect,
+        uint8_t yValue, uint8_t uValue, uint8_t vValue) {
+    for (int32_t y = rect.top; y < rect.bottom; ++y) {
+        for (int32_t x = rect.left; x < rect.right; ++x) {
+            mYUVImage.setPixelValue(x, y, yValue, uValue, vValue);
+        }
+    }
+}
+
+void YUVCanvas::CopyImageRect(
+        const Rect& srcRect,
+        int32_t destStartX, int32_t destStartY,
+        const YUVImage &srcImage) {
+
+    // Try fast copy first
+    if (YUVImage::fastCopyRectangle(
+                srcRect,
+                destStartX, destStartY,
+                srcImage, mYUVImage)) {
+        return;
+    }
+
+    int32_t srcStartX = srcRect.left;
+    int32_t srcStartY = srcRect.top;
+    for (int32_t offsetY = 0; offsetY < srcRect.height(); ++offsetY) {
+        for (int32_t offsetX = 0; offsetX < srcRect.width(); ++offsetX) {
+            int32_t srcX = srcStartX + offsetX;
+            int32_t srcY = srcStartY + offsetY;
+
+            int32_t destX = destStartX + offsetX;
+            int32_t destY = destStartY + offsetY;
+
+            uint8_t yValue;
+            uint8_t uValue;
+            uint8_t vValue;
+
+            srcImage.getPixelValue(srcX, srcY, &yValue, &uValue, & vValue);
+            mYUVImage.setPixelValue(destX, destY, yValue, uValue, vValue);
+        }
+    }
+}
+
+}  // namespace android
diff --git a/media/libstagefright/yuv/YUVImage.cpp b/media/libstagefright/yuv/YUVImage.cpp
new file mode 100644
index 0000000..73e3297
--- /dev/null
+++ b/media/libstagefright/yuv/YUVImage.cpp
@@ -0,0 +1,404 @@
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define LOG_NDEBUG 0
+#define LOG_TAG "YUVImage"
+
+#include <media/stagefright/YUVImage.h>
+#include <ui/Rect.h>
+#include <media/stagefright/MediaDebug.h>
+
+namespace android {
+
+YUVImage::YUVImage(YUVFormat yuvFormat, int32_t width, int32_t height) {
+    mYUVFormat = yuvFormat;
+    mWidth = width;
+    mHeight = height;
+
+    size_t numberOfBytes = bufferSize(yuvFormat, width, height);
+    uint8_t *buffer = new uint8_t[numberOfBytes];
+    mBuffer = buffer;
+    mOwnBuffer = true;
+
+    initializeYUVPointers();
+}
+
+YUVImage::YUVImage(YUVFormat yuvFormat, int32_t width, int32_t height, uint8_t *buffer) {
+    mYUVFormat = yuvFormat;
+    mWidth = width;
+    mHeight = height;
+    mBuffer = buffer;
+    mOwnBuffer = false;
+
+    initializeYUVPointers();
+}
+
+//static
+size_t YUVImage::bufferSize(YUVFormat yuvFormat, int32_t width, int32_t height) {
+    int32_t numberOfPixels = width*height;
+    size_t numberOfBytes = 0;
+    if (yuvFormat == YUV420Planar || yuvFormat == YUV420SemiPlanar) {
+        // Y takes numberOfPixels bytes and U/V take numberOfPixels/4 bytes each.
+        numberOfBytes = (size_t)(numberOfPixels + (numberOfPixels >> 1));
+    } else {
+        LOGE("Format not supported");
+    }
+    return numberOfBytes;
+}
+
+bool YUVImage::initializeYUVPointers() {
+    int32_t numberOfPixels = mWidth * mHeight;
+
+    if (mYUVFormat == YUV420Planar) {
+        mYdata = (uint8_t *)mBuffer;
+        mUdata = mYdata + numberOfPixels;
+        mVdata = mUdata + (numberOfPixels >> 2);
+    } else if (mYUVFormat == YUV420SemiPlanar) {
+        // U and V channels are interleaved as VUVUVU.
+        // So V data starts at the end of Y channel and
+        // U data starts right after V's start.
+        mYdata = (uint8_t *)mBuffer;
+        mVdata = mYdata + numberOfPixels;
+        mUdata = mVdata + 1;
+    } else {
+        LOGE("Format not supported");
+        return false;
+    }
+    return true;
+}
+
+YUVImage::~YUVImage() {
+    if (mOwnBuffer) delete[] mBuffer;
+}
+
+bool YUVImage::getOffsets(int32_t x, int32_t y,
+        int32_t *yOffset, int32_t *uOffset, int32_t *vOffset) const {
+    *yOffset = y*mWidth + x;
+
+    int32_t uvOffset = (y >> 1) * (mWidth >> 1) + (x >> 1);
+    if (mYUVFormat == YUV420Planar) {
+        *uOffset = uvOffset;
+        *vOffset = uvOffset;
+    } else if (mYUVFormat == YUV420SemiPlanar) {
+        // Since U and V channels are interleaved, offsets need
+        // to be doubled.
+        *uOffset = 2*uvOffset;
+        *vOffset = 2*uvOffset;
+    } else {
+        LOGE("Format not supported");
+        return false;
+    }
+
+    return true;
+}
+
+bool YUVImage::getOffsetIncrementsPerDataRow(
+        int32_t *yDataOffsetIncrement,
+        int32_t *uDataOffsetIncrement,
+        int32_t *vDataOffsetIncrement) const {
+    *yDataOffsetIncrement = mWidth;
+
+    int32_t uvDataOffsetIncrement = mWidth >> 1;
+
+    if (mYUVFormat == YUV420Planar) {
+        *uDataOffsetIncrement = uvDataOffsetIncrement;
+        *vDataOffsetIncrement = uvDataOffsetIncrement;
+    } else if (mYUVFormat == YUV420SemiPlanar) {
+        // Since U and V channels are interleaved, offsets need
+        // to be doubled.
+        *uDataOffsetIncrement = 2*uvDataOffsetIncrement;
+        *vDataOffsetIncrement = 2*uvDataOffsetIncrement;
+    } else {
+        LOGE("Format not supported");
+        return false;
+    }
+
+    return true;
+}
+
+uint8_t* YUVImage::getYAddress(int32_t offset) const {
+    return mYdata + offset;
+}
+
+uint8_t* YUVImage::getUAddress(int32_t offset) const {
+    return mUdata + offset;
+}
+
+uint8_t* YUVImage::getVAddress(int32_t offset) const {
+    return mVdata + offset;
+}
+
+bool YUVImage::getYUVAddresses(int32_t x, int32_t y,
+        uint8_t **yAddr, uint8_t **uAddr, uint8_t **vAddr) const {
+    int32_t yOffset;
+    int32_t uOffset;
+    int32_t vOffset;
+    if (!getOffsets(x, y, &yOffset, &uOffset, &vOffset)) return false;
+
+    *yAddr = getYAddress(yOffset);
+    *uAddr = getUAddress(uOffset);
+    *vAddr = getVAddress(vOffset);
+
+    return true;
+}
+
+bool YUVImage::getPixelValue(int32_t x, int32_t y,
+        uint8_t *yPtr, uint8_t *uPtr, uint8_t *vPtr) const {
+    uint8_t *yAddr;
+    uint8_t *uAddr;
+    uint8_t *vAddr;
+    if (!getYUVAddresses(x, y, &yAddr, &uAddr, &vAddr)) return false;
+
+    *yPtr = *yAddr;
+    *uPtr = *uAddr;
+    *vPtr = *vAddr;
+
+    return true;
+}
+
+bool YUVImage::setPixelValue(int32_t x, int32_t y,
+        uint8_t yValue, uint8_t uValue, uint8_t vValue) {
+    uint8_t *yAddr;
+    uint8_t *uAddr;
+    uint8_t *vAddr;
+    if (!getYUVAddresses(x, y, &yAddr, &uAddr, &vAddr)) return false;
+
+    *yAddr = yValue;
+    *uAddr = uValue;
+    *vAddr = vValue;
+
+    return true;
+}
+
+void YUVImage::fastCopyRectangle420Planar(
+        const Rect& srcRect,
+        int32_t destStartX, int32_t destStartY,
+        const YUVImage &srcImage, YUVImage &destImage) {
+    CHECK(srcImage.mYUVFormat == YUV420Planar);
+    CHECK(destImage.mYUVFormat == YUV420Planar);
+
+    int32_t srcStartX = srcRect.left;
+    int32_t srcStartY = srcRect.top;
+    int32_t width = srcRect.width();
+    int32_t height = srcRect.height();
+
+    // Get source and destination start addresses
+    uint8_t *ySrcAddrBase;
+    uint8_t *uSrcAddrBase;
+    uint8_t *vSrcAddrBase;
+    srcImage.getYUVAddresses(srcStartX, srcStartY,
+            &ySrcAddrBase, &uSrcAddrBase, &vSrcAddrBase);
+
+    uint8_t *yDestAddrBase;
+    uint8_t *uDestAddrBase;
+    uint8_t *vDestAddrBase;
+    destImage.getYUVAddresses(destStartX, destStartY,
+            &yDestAddrBase, &uDestAddrBase, &vDestAddrBase);
+
+    // Get source and destination offset increments incurred in going
+    // from one data row to next.
+    int32_t ySrcOffsetIncrement;
+    int32_t uSrcOffsetIncrement;
+    int32_t vSrcOffsetIncrement;
+    srcImage.getOffsetIncrementsPerDataRow(
+            &ySrcOffsetIncrement, &uSrcOffsetIncrement, &vSrcOffsetIncrement);
+
+    int32_t yDestOffsetIncrement;
+    int32_t uDestOffsetIncrement;
+    int32_t vDestOffsetIncrement;
+    destImage.getOffsetIncrementsPerDataRow(
+            &yDestOffsetIncrement, &uDestOffsetIncrement, &vDestOffsetIncrement);
+
+    // Copy Y
+    {
+        size_t numberOfYBytesPerRow = (size_t) width;
+        uint8_t *ySrcAddr = ySrcAddrBase;
+        uint8_t *yDestAddr = yDestAddrBase;
+        for (int32_t offsetY = 0; offsetY < height; ++offsetY) {
+            memcpy(yDestAddr, ySrcAddr, numberOfYBytesPerRow);
+
+            ySrcAddr += ySrcOffsetIncrement;
+            yDestAddr += yDestOffsetIncrement;
+        }
+    }
+
+    // Copy U
+    {
+        size_t numberOfUBytesPerRow = (size_t) (width >> 1);
+        uint8_t *uSrcAddr = uSrcAddrBase;
+        uint8_t *uDestAddr = uDestAddrBase;
+        // Every other row has an entry for U/V channel values. Hence only
+        // go half the height.
+        for (int32_t offsetY = 0; offsetY < (height >> 1); ++offsetY) {
+            memcpy(uDestAddr, uSrcAddr, numberOfUBytesPerRow);
+
+            uSrcAddr += uSrcOffsetIncrement;
+            uDestAddr += uDestOffsetIncrement;
+        }
+    }
+
+    // Copy V
+    {
+        size_t numberOfVBytesPerRow = (size_t) (width >> 1);
+        uint8_t *vSrcAddr = vSrcAddrBase;
+        uint8_t *vDestAddr = vDestAddrBase;
+        // Every other pixel row has a U/V data row. Hence only go half the height.
+        for (int32_t offsetY = 0; offsetY < (height >> 1); ++offsetY) {
+            memcpy(vDestAddr, vSrcAddr, numberOfVBytesPerRow);
+
+            vSrcAddr += vSrcOffsetIncrement;
+            vDestAddr += vDestOffsetIncrement;
+        }
+    }
+}
+
+void YUVImage::fastCopyRectangle420SemiPlanar(
+        const Rect& srcRect,
+        int32_t destStartX, int32_t destStartY,
+        const YUVImage &srcImage, YUVImage &destImage) {
+    CHECK(srcImage.mYUVFormat == YUV420SemiPlanar);
+    CHECK(destImage.mYUVFormat == YUV420SemiPlanar);
+
+    int32_t srcStartX = srcRect.left;
+    int32_t srcStartY = srcRect.top;
+    int32_t width = srcRect.width();
+    int32_t height = srcRect.height();
+
+    // Get source and destination start addresses
+    uint8_t *ySrcAddrBase;
+    uint8_t *uSrcAddrBase;
+    uint8_t *vSrcAddrBase;
+    srcImage.getYUVAddresses(srcStartX, srcStartY,
+            &ySrcAddrBase, &uSrcAddrBase, &vSrcAddrBase);
+
+    uint8_t *yDestAddrBase;
+    uint8_t *uDestAddrBase;
+    uint8_t *vDestAddrBase;
+    destImage.getYUVAddresses(destStartX, destStartY,
+            &yDestAddrBase, &uDestAddrBase, &vDestAddrBase);
+
+    // Get source and destination offset increments incurred in going
+    // from one data row to next.
+    int32_t ySrcOffsetIncrement;
+    int32_t uSrcOffsetIncrement;
+    int32_t vSrcOffsetIncrement;
+    srcImage.getOffsetIncrementsPerDataRow(
+            &ySrcOffsetIncrement, &uSrcOffsetIncrement, &vSrcOffsetIncrement);
+
+    int32_t yDestOffsetIncrement;
+    int32_t uDestOffsetIncrement;
+    int32_t vDestOffsetIncrement;
+    destImage.getOffsetIncrementsPerDataRow(
+            &yDestOffsetIncrement, &uDestOffsetIncrement, &vDestOffsetIncrement);
+
+    // Copy Y
+    {
+        size_t numberOfYBytesPerRow = (size_t) width;
+        uint8_t *ySrcAddr = ySrcAddrBase;
+        uint8_t *yDestAddr = yDestAddrBase;
+        for (int32_t offsetY = 0; offsetY < height; ++offsetY) {
+            memcpy(yDestAddr, ySrcAddr, numberOfYBytesPerRow);
+
+            ySrcAddr = ySrcAddr + ySrcOffsetIncrement;
+            yDestAddr = yDestAddr + yDestOffsetIncrement;
+        }
+    }
+
+    // Copy UV
+    {
+        // UV are interleaved. So number of UV bytes per row is 2*(width/2).
+        size_t numberOfUVBytesPerRow = (size_t) width;
+        uint8_t *vSrcAddr = vSrcAddrBase;
+        uint8_t *vDestAddr = vDestAddrBase;
+        // Every other pixel row has a U/V data row. Hence only go half the height.
+        for (int32_t offsetY = 0; offsetY < (height >> 1); ++offsetY) {
+            memcpy(vDestAddr, vSrcAddr, numberOfUVBytesPerRow);
+
+            vSrcAddr += vSrcOffsetIncrement;
+            vDestAddr += vDestOffsetIncrement;
+        }
+    }
+}
+
+// static
+bool YUVImage::fastCopyRectangle(
+        const Rect& srcRect,
+        int32_t destStartX, int32_t destStartY,
+        const YUVImage &srcImage, YUVImage &destImage) {
+    if (srcImage.mYUVFormat == destImage.mYUVFormat) {
+        if (srcImage.mYUVFormat == YUV420Planar) {
+            fastCopyRectangle420Planar(
+                    srcRect,
+                    destStartX, destStartY,
+                    srcImage, destImage);
+        } else if (srcImage.mYUVFormat == YUV420SemiPlanar) {
+            fastCopyRectangle420SemiPlanar(
+                    srcRect,
+                    destStartX, destStartY,
+                    srcImage, destImage);
+        }
+        return true;
+    }
+    return false;
+}
+
+uint8_t clamp(uint8_t v, uint8_t minValue, uint8_t maxValue) {
+    CHECK(maxValue >= minValue);
+
+    if (v < minValue) return minValue;
+    else if (v > maxValue) return maxValue;
+    else return v;
+}
+
+void YUVImage::yuv2rgb(uint8_t yValue, uint8_t uValue, uint8_t vValue,
+        uint8_t *r, uint8_t *g, uint8_t *b) const {
+    *r = yValue + (1.370705 * (vValue-128));
+    *g = yValue - (0.698001 * (vValue-128)) - (0.337633 * (uValue-128));
+    *b = yValue + (1.732446 * (uValue-128));
+
+    *r = clamp(*r, 0, 255);
+    *g = clamp(*g, 0, 255);
+    *b = clamp(*b, 0, 255);
+}
+
+bool YUVImage::writeToPPM(const char *filename) const {
+    FILE *fp = fopen(filename, "w");
+    if (fp == NULL) {
+        return false;
+    }
+    fprintf(fp, "P3\n");
+    fprintf(fp, "%d %d\n", mWidth, mHeight);
+    fprintf(fp, "255\n");
+    for (int32_t y = 0; y < mHeight; ++y) {
+        for (int32_t x = 0; x < mWidth; ++x) {
+            uint8_t yValue;
+            uint8_t uValue;
+            uint8_t vValue;
+            getPixelValue(x, y, &yValue, &uValue, & vValue);
+
+            uint8_t rValue;
+            uint8_t gValue;
+            uint8_t bValue;
+            yuv2rgb(yValue, uValue, vValue, &rValue, &gValue, &bValue);
+
+            fprintf(fp, "%d %d %d\n", (int32_t)rValue, (int32_t)gValue, (int32_t)bValue);
+        }
+    }
+    fclose(fp);
+    return true;
+}
+
+}  // namespace android