gecko-dev/gfx/layers/YCbCrImageDataSerializer.h

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/* -*- 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 already_AddRefed
#include "mozilla/gfx/Point.h" // for IntSize
namespace mozilla {
namespace gfx {
class DataSourceSurface;
} // namespace gfx
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.
*/
already_AddRefed<gfx::DataSourceSurface> ToDataSourceSurface();
};
} // namespace layers
} // namespace mozilla
#endif