Android2.3 surface&&overlay

Android surface&&overlay

类：

class LayerBuffer : public LayerBaseClient

内部类class OverlayChannel : public BnOverlay

class OverlayRef : public LightRefBase<OverlayRef>

sp<IOverlay> mOverlayChannel;//继承BpOverlay，从而访问LayerBuffer中的OverlayChannel

/*显示系统HAL初始化*/

SurfaceFlinger::readyToRun()

{

// initialize the main display

GraphicPlane& plane(graphicPlane(dpy));

DisplayHardware* const hw = new DisplayHardware(this, dpy);

plane.setDisplayHardware(hw);//mHw = hw;

}

DisplayHardware::DisplayHardware()

{

init()

}

/*获取overlay_control_device_t* mOverlayEngine*/

DisplayHardware::init(uint32_t dpy)

{

mNativeWindow = new FramebufferNativeWindow();

framebuffer_device_t const * fbDev = mNativeWindow->getDevice();

mDpiX = mNativeWindow->xdpi;

mDpiY = mNativeWindow->ydpi;

mRefreshRate = fbDev->fps;

mOverlayEngine = NULL;

hw_module_t const* module;

if (hw_get_module(OVERLAY_HARDWARE_MODULE_ID, &module) == 0) {

overlay_control_open(module, &mOverlayEngine);

}

《调用关系》

Overlay框架：

@1打开显示设备模块，overlay是叠加在framebuffer之上的视频显示层(Surfaceflinger.cpp)

SurfaceFlinger::readyToRun()

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new DisplayHardware(const sp<SurfaceFlinger>& flinger,uint32_t dpy)

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DisplayHardware::init

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new FramebufferNativeWindow()///打开framebuffer驱动设备

hw_get_module(OVERLAY_HARDWARE_MODULE_ID, &module)///打开overlay模块库

load-->/system/lib/hw/overlay/overlay.default.so /vendor/lib/hw/ %s/%s.default.so

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HMI-->HAL_MODULE_INFO_SYM-->overlay_module_methods-->open: overlay_device_open-->overlay_device_open-->OVERLAY_HARDWARE_CONTROL||OVERLAY_HARDWARE_DATA

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overlay_data_open(module, &mOverlayData)-->overlay_device_open&&OVERLAY_HARDWARE_DATA

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overlay_control_open(module, &mOverlayEngine)

@2获取overlay 打开overlay驱动(surfaceflinger.cpp)

ref = mISurface->createOverlay(mDecodedWidth, mDecodedHeight, OVERLAY_FORMAT_CbYCrY_422_I, 0);(TIHardwareRenderer)

BpSurface::createOverlay

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Binder

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LayerBaseClient::Surface::onTransact--BnSurface::onTransact--case CREATE_OVERLAY

LayerBuffer::SurfaceLayerBuffer::createOverlay

-->LayerBuffer::createOverlay

-->LayerBuffer::OverlaySource::OverlaySource

-->获取已打开的overlay硬件模块：overlay_control_device_t* overlay_dev = getFlinger()->getOverlayEngine()--SurfaceFlinger::getOverlayEngine()--GraphicPlane::displayHardware().getOverlayEngine()--mHw.getOverlayEngine--mOverlayEngine控制设备

-->创建对象overlay_object打开驱动设备：overlay_t* overlay = overlay_dev->createOverlay(overlay_dev, w, h, format);--overlay_createOverlay--create_shared_data--create_shared_data&&open&&overlay=new overlay_object

-->取句柄：mOverlayHandle = overlay->getHandleRef(overlay);--overlay_object::getHandleRef--return &(static_cast<overlay_object *>(overlay)->mHandle)--mHandle

-->设置层：sp<OverlayChannel> channel = new OverlayChannel(&layer)

-->*overlayRef = new OverlayRef(mOverlayHandle, channel,mWidth, mHeight, mFormat, mWidthStride, mHeightStride);

@3操作overlay

mOverlay = new Overlay(ref)(系统API:base/libs/ui/Overlay.cpp)

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hw_get_module(OVERLAY_HARDWARE_MODULE_ID, &module)(Hardware.c)

load-->/system/lib/hw/overlay/overlay.default.so /vendor/lib/hw/ %s/%s.default.so

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HMI-->HAL_MODULE_INFO_SYM-->overlay_module_methods-->open: overlay_device_open-->overlay_device_open-->OVERLAY_HARDWARE_CONTROL||OVERLAY_HARDWARE_DATA

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overlay_data_open(module, &mOverlayData)-->overlay_device_open&&OVERLAY_HARDWARE_DATA

@4overlay显示(cameraservice应用:base/libs/ui/Overlay.cpp)

overlay->dequeueBuffer(&buffer);-->overlay_dequeueBuffer

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void* address = overlay->getBufferAddress(buffer);-->overlay_getBufferAddress

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memcpy(address,"hello overlay",15)///错--这里应该是送入YUV数据

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overlay->queueBuffer(buffer);-->overlay_queueBuffer-->ioctl(ctx->ctl_fd, OVERLAY_QUEUE_BUFFER, &(ctx->phy_buffers[(int)buffer]))