diff -r 000000000000 -r 6474c204b198 gfx/layers/YCbCrImageDataSerializer.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gfx/layers/YCbCrImageDataSerializer.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,186 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef MOZILLA_LAYERS_BLOBYCBCRSURFACE_H
+#define MOZILLA_LAYERS_BLOBYCBCRSURFACE_H
+
+#include <stddef.h>                     // for size_t
+#include <stdint.h>                     // for uint8_t, uint32_t
+#include "ImageTypes.h"                 // for StereoMode
+#include "mozilla/Attributes.h"         // for MOZ_STACK_CLASS
+#include "mozilla/RefPtr.h"             // for TemporaryRef
+#include "mozilla/gfx/Point.h"          // for IntSize
+
+namespace mozilla {
+namespace gfx {
+class DataSourceSurface;
+}
+
+namespace layers {
+
+class Image;
+
+/**
+ * Convenience class to share code between YCbCrImageDataSerializer
+ * and YCbCrImageDataDeserializer.
+ * Do not use it.
+ */
+class YCbCrImageDataDeserializerBase
+{
+public:
+  bool IsValid() const { return mIsValid; }
+
+  /**
+   * Returns the Y channel data pointer.
+   */
+  uint8_t* GetYData();
+  /**
+   * Returns the Cb channel data pointer.
+   */
+  uint8_t* GetCbData();
+  /**
+   * Returns the Cr channel data pointer.
+   */
+  uint8_t* GetCrData();
+
+  /**
+   * Returns the Y channel stride.
+   */
+  uint32_t GetYStride();
+  /**
+   * Returns the stride of the Cb and Cr channels.
+   */
+  uint32_t GetCbCrStride();
+
+  /**
+   * Returns the dimensions of the Y Channel.
+   */
+  gfx::IntSize GetYSize();
+
+  /**
+   * Returns the dimensions of the Cb and Cr Channel.
+   */
+  gfx::IntSize GetCbCrSize();
+
+  /**
+   * Stereo mode for the image.
+   */
+  StereoMode GetStereoMode();
+
+  /**
+   * Return a pointer to the begining of the data buffer.
+   */
+  uint8_t* GetData();
+
+  /**
+   * This function is meant as a helper to know how much shared memory we need
+   * to allocate in a shmem in order to place a shared YCbCr image blob of
+   * given dimensions.
+   */
+  static size_t ComputeMinBufferSize(const gfx::IntSize& aYSize,
+                                     uint32_t aYStride,
+                                     const gfx::IntSize& aCbCrSize,
+                                     uint32_t aCbCrStride);
+  static size_t ComputeMinBufferSize(const gfx::IntSize& aYSize,
+                                     const gfx::IntSize& aCbCrSize);
+  static size_t ComputeMinBufferSize(uint32_t aSize);
+
+protected:
+  YCbCrImageDataDeserializerBase(uint8_t* aData, size_t aDataSize)
+    : mData (aData)
+    , mDataSize(aDataSize)
+    , mIsValid(false)
+  {}
+
+  void Validate();
+
+  uint8_t* mData;
+  size_t mDataSize;
+  bool mIsValid;
+};
+
+/**
+ * A view on a YCbCr image stored with its metadata in a blob of memory.
+ * It is only meant as a convenience to access the image data, and does not own
+ * the data. The instance can live on the stack and used as follows:
+ *
+ * const YCbCrImage& yuv = sharedImage.get_YCbCrImage();
+ * YCbCrImageDataDeserializer deserializer(yuv.data().get<uint8_t>());
+ * if (!deserializer.IsValid()) {
+ *   // handle error
+ * }
+ * size = deserializer.GetYSize(); // work with the data, etc...
+ */
+class MOZ_STACK_CLASS YCbCrImageDataSerializer : public YCbCrImageDataDeserializerBase
+{
+public:
+  YCbCrImageDataSerializer(uint8_t* aData, size_t aDataSize)
+    : YCbCrImageDataDeserializerBase(aData, aDataSize)
+  {
+    // a serializer needs to be usable before correct buffer info has been written to it
+    mIsValid = !!mData;
+  }
+
+  /**
+   * Write the image informations in the buffer for given dimensions.
+   * The provided pointer should point to the beginning of the (chunk of)
+   * buffer on which we want to store the image.
+   */
+  void InitializeBufferInfo(uint32_t aYOffset,
+                            uint32_t aCbOffset,
+                            uint32_t aCrOffset,
+                            uint32_t aYStride,
+                            uint32_t aCbCrStride,
+                            const gfx::IntSize& aYSize,
+                            const gfx::IntSize& aCbCrSize,
+                            StereoMode aStereoMode);
+  void InitializeBufferInfo(uint32_t aYStride,
+                            uint32_t aCbCrStride,
+                            const gfx::IntSize& aYSize,
+                            const gfx::IntSize& aCbCrSize,
+                            StereoMode aStereoMode);
+  void InitializeBufferInfo(const gfx::IntSize& aYSize,
+                            const gfx::IntSize& aCbCrSize,
+                            StereoMode aStereoMode);
+  bool CopyData(const uint8_t* aYData,
+                const uint8_t* aCbData, const uint8_t* aCrData,
+                gfx::IntSize aYSize, uint32_t aYStride,
+                gfx::IntSize aCbCrSize, uint32_t aCbCrStride,
+                uint32_t aYSkip, uint32_t aCbCrSkip);
+};
+
+/**
+ * A view on a YCbCr image stored with its metadata in a blob of memory.
+ * It is only meant as a convenience to access the image data, and does not own
+ * the data. The instance can live on the stack and used as follows:
+ *
+ * const YCbCrImage& yuv = sharedImage.get_YCbCrImage();
+ * YCbCrImageDataDeserializer deserializer(yuv.data().get<uint8_t>());
+ * if (!deserializer.IsValid()) {
+ *   // handle error
+ * }
+ * size = deserializer.GetYSize(); // work with the data, etc...
+ */
+class MOZ_STACK_CLASS YCbCrImageDataDeserializer : public YCbCrImageDataDeserializerBase
+{
+public:
+  YCbCrImageDataDeserializer(uint8_t* aData, size_t aDataSize)
+    : YCbCrImageDataDeserializerBase(aData, aDataSize)
+  {
+    Validate();
+  }
+
+  /**
+   * Convert the YCbCr data into RGB and return a DataSourceSurface.
+   * This is a costly operation, so use it only when YCbCr compositing is
+   * not supported.
+   */
+  TemporaryRef<gfx::DataSourceSurface> ToDataSourceSurface();
+};
+
+} // namespace
+} // namespace
+
+#endif