À partir du 27 mars 2025, nous vous recommandons d'utiliser android-latest-release
au lieu de aosp-main
pour créer et contribuer à AOSP. Pour en savoir plus, consultez la section Modifications apportées à AOSP.
Service proxy d'affichage automobile
Restez organisé à l'aide des collections
Enregistrez et classez les contenus selon vos préférences.
Ce service de framework simple permet aux processus du fournisseur d'utiliser SurfaceFlinger/EGL dans les implémentations HAL, sans associer libgui. AOSP fournit l'implémentation par défaut de ce service, qui est entièrement fonctionnelle. Toutefois, le fournisseur doit également implémenter des API pour fournir ce service sur sa plate-forme.
package android.frameworks.automotive.display@1.0;
import android.hardware.graphics.bufferqueue@2.0::IGraphicBufferProducer;
interface IAutomotiveDisplayProxyService {
/**
* Gets an IGraphicBufferProducer instance from the service.
*
* @param id Target's stable display identifier
*
* @return igbp Returns an IGraphicBufferProducer object, that can be
* converted to an ANativeWindow object.
*/
getIGraphicBufferProducer(uint64_t id) generates (IGraphicBufferProducer igbp);
/**
* Sets the ANativeWindow, which is associated with the
* IGraphicBufferProducer, to be visible and to take over the display.
*
* @param id Target display ID
*
* @return success Returns true on success.
*/
showWindow(uint64_t id) generates (bool success);
/**
* Sets the ANativeWindow, which is associated with the
* IGraphicBufferProducer, to be invisible and to release the control
* over display.
*
* @param id Target display ID
*
* @return success Returns true on success.
*/
hideWindow(uint64_t id) generates (bool success);
/**
* Returns the stable identifiers of all available displays.
*
* @return ids A list of stable display identifiers.
*/
getDisplayIdList() generates (vec<uint64_t> ids);
/**
* Returns the descriptor of the target display.
*
* @param id Stable ID of a target display.
* @return cfg DisplayConfig of the active display.
* @return state Current state of the active display.
*/
getDisplayInfo(uint64_t id) generates (HwDisplayConfig cfg, HwDisplayState state);
}
Pour utiliser ce service:
- Récupérez
IAutomotiveDisplayProxyService
.
android::sp<IAutomotiveDisplayProxyService> windowProxyService =
IAutomotiveDisplayProxyService::getService("default");
if (windowProxyService == nullptr) {
LOG(ERROR) << "Cannot use AutomotiveDisplayProxyService. Exiting.";
return 1;
}
- Récupérez les informations d'affichage actives auprès du service pour déterminer la résolution.
// We use the first display in the list as the primary.
pWindowProxy->getDisplayInfo(displayId, [this](auto dpyConfig, auto dpyState) {
DisplayConfig *pConfig = (DisplayConfig*)dpyConfig.data();
mWidth = pConfig->resolution.getWidth();
mHeight = pConfig->resolution.getHeight();
ui::DisplayState* pState = (ui::DisplayState*)dpyState.data();
if (pState->orientation != ui::ROTATION_0 &&
pState->orientation != ui::ROTATION_180) {
// rotate
std::swap(mWidth, mHeight);
}
LOG(DEBUG) << "Display resolution is " << mWidth << " x " << mHeight;
});
- Récupérez un
IGraphicBufferProducer
matériel (ou un HGBP (GraphicBufferProducer) HIDL) à partir de IAutomotiveDisplayProxyService
:
mGfxBufferProducer = pWindowProxy->getIGraphicBufferProducer(displayId);
if (mGfxBufferProducer == nullptr) {
LOG(ERROR) << "Failed to get IGraphicBufferProducer from "
<< "IAutomotiveDisplayProxyService.";
return false;
}
- Obtenez un
SurfaceHolder
à partir d'un HGBP récupéré à l'aide de l'API libbufferqueueconverter
:
mSurfaceHolder = getSurfaceFromHGBP(mGfxBufferProducer);
if (mSurfaceHolder == nullptr) {
LOG(ERROR) << "Failed to get a Surface from HGBP.";
return false;
}
- Convertissez un
SurfaceHolder
en fenêtre native à l'aide de l'API libbufferqueueconverter
:
mWindow = getNativeWindow(mSurfaceHolder.get());
if (mWindow == nullptr) {
LOG(ERROR) << "Failed to get a native window from Surface.";
return false;
}
- Créez une surface de fenêtre EGL avec une fenêtre native, puis effectuez le rendu:
// Set up our OpenGL ES context associated with the default display
mDisplay = eglGetDisplay(EGL_DEFAULT_DISPLAY);
if (mDisplay == EGL_NO_DISPLAY) {
LOG(ERROR) << "Failed to get egl display";
return false;
}
...
// Create the EGL render target surface
mSurface = eglCreateWindowSurface(mDisplay, egl_config, mWindow, nullptr);
if (mSurface == EGL_NO_SURFACE) {
LOG(ERROR) << "eglCreateWindowSurface failed.";
return false;
}
...
- Appelez
IAutomotiveDisplayProxyService::showWindow()
pour afficher la vue affichée à l'écran. Ce service a la priorité la plus élevée et prend donc toujours le contrôle de l'écran auprès du propriétaire actuel:
mAutomotiveDisplayProxyService->showWindow();
Pour en savoir plus sur l'implémentation, consultez service.cpp
et GlWrapper.cpp
dans $ANDROID_BUILD_TOP/packages/services/Car/evs/sampleDriver/
.
Une implémentation de HAL EVS nécessite les bibliothèques supplémentaires affichées en gras ci-dessous.
cc_binary {
name: "android.hardware.automotive.evs@1.1-sample",
vendor: true,
srcs: [
...
],
shared_libs: [
...
"libbufferqueueconverter",
"android.hidl.token@1.0-utils",
"android.frameworks.automotive.display@1.0",
"android.hardware.graphics.bufferqueue@1.0",
"android.hardware.graphics.bufferqueue@2.0",
],
Compatibilité multi-écran
Comme pour l'énumération des appareils photo, le framework EVS fournit une méthode permettant d'énumérer les écrans disponibles. L'
identifiant d'affichage statique encode un identifiant de type long, les informations sur le port d'affichage dans l'octet inférieur et Extended Display IDentification
Data
dans les bits supérieurs.
IAutomotiveDisplayProxyService::getDisplayIdList()
renvoie une liste d'ID d'écrans d'écrans physiques locaux, qui sont disponibles pour le service EVS, et IEvsEnumerator::getDisplayIdList()
renvoie une liste des ports d'affichage auxquels les écrans détectés sont connectés. Le premier ID de la liste correspond toujours à l'écran principal.
interface IEvsEnumerator extends @1.0::IEvsEnumerator {
...
/**
* Returns a list of all EVS displays available to the system
*
* @return displayIds Identifiers of available displays.
*/
getDisplayIdList() generates (vec<uint8_t> displayIds);
};
Ouvrir l'appareil d'affichage cible
L'application EVS appelle IEvsEnumerator::openDisplay_1_1() avec un numéro de port d'affichage cible:
android::sp<IEvsDisplay> pDisplay = pEvs->openDisplay_1_1(displayId);
if (pDisplay.get() == nullptr) {
LOG(ERROR) << "EVS Display unavailable. Exiting.";
return 1;
}
Remarque:Un seul écran peut être utilisé à la fois, ce qui signifie que le client EVS actuel perd son écran lorsqu'un autre client EVS demande à l'ouvrir, même s'il ne s'agit pas du même écran.
Le contenu et les exemples de code de cette page sont soumis aux licences décrites dans la Licence de contenu. Java et OpenJDK sont des marques ou des marques déposées d'Oracle et/ou de ses sociétés affiliées.
Dernière mise à jour le 2025/08/08 (UTC).
[[["Facile à comprendre","easyToUnderstand","thumb-up"],["J'ai pu résoudre mon problème","solvedMyProblem","thumb-up"],["Autre","otherUp","thumb-up"]],[["Il n'y a pas l'information dont j'ai besoin","missingTheInformationINeed","thumb-down"],["Trop compliqué/Trop d'étapes","tooComplicatedTooManySteps","thumb-down"],["Obsolète","outOfDate","thumb-down"],["Problème de traduction","translationIssue","thumb-down"],["Mauvais exemple/Erreur de code","samplesCodeIssue","thumb-down"],["Autre","otherDown","thumb-down"]],["Dernière mise à jour le 2025/08/08 (UTC)."],[],[],null,["# Automotive display proxy service\n\nThis simple framework service lets vendor\nprocesses use SurfaceFlinger/EGL in HAL implementations, without linking\nlibgui. AOSP provides the default implementation of this service, which is fully\nfunctional. However, the vendor must also implement APIs to provide this service\non their platform. \n\n```python\npackage android.frameworks.automotive.display@1.0;\n\nimport android.hardware.graphics.bufferqueue@2.0::IGraphicBufferProducer;\n\ninterface IAutomotiveDisplayProxyService {\n /**\n * Gets an IGraphicBufferProducer instance from the service.\n *\n * @param id Target's stable display identifier\n *\n * @return igbp Returns an IGraphicBufferProducer object, that can be\n * converted to an ANativeWindow object.\n */\n getIGraphicBufferProducer(uint64_t id) generates (IGraphicBufferProducer igbp);\n\n /**\n * Sets the ANativeWindow, which is associated with the\n * IGraphicBufferProducer, to be visible and to take over the display.\n *\n * @param id Target display ID\n *\n * @return success Returns true on success.\n */\n showWindow(uint64_t id) generates (bool success);\n\n /**\n * Sets the ANativeWindow, which is associated with the\n * IGraphicBufferProducer, to be invisible and to release the control\n * over display.\n *\n * @param id Target display ID\n *\n * @return success Returns true on success.\n */\n hideWindow(uint64_t id) generates (bool success);\n\n /**\n * Returns the stable identifiers of all available displays.\n *\n * @return ids A list of stable display identifiers.\n */\n getDisplayIdList() generates (vec\u003cuint64_t\u003e ids);\n\n /**\n * Returns the descriptor of the target display.\n *\n * @param id Stable ID of a target display.\n * @return cfg DisplayConfig of the active display.\n * @return state Current state of the active display.\n */\n getDisplayInfo(uint64_t id) generates (HwDisplayConfig cfg, HwDisplayState state);\n}\n```\n\nTo use this service:\n\n1. Get `IAutomotiveDisplayProxyService`. \n\n ```css+lasso\n android::sp\u003cIAutomotiveDisplayProxyService\u003e windowProxyService =\n IAutomotiveDisplayProxyService::getService(\"default\");\n if (windowProxyService == nullptr) {\n LOG(ERROR) \u003c\u003c \"Cannot use AutomotiveDisplayProxyService. Exiting.\";\n return 1;\n }\n ```\n2. Retrieve an active display information from the service to determine the resolution. \n\n ```transact-sql\n // We use the first display in the list as the primary.\n pWindowProxy-\u003egetDisplayInfo(displayId, [this](auto dpyConfig, auto dpyState) {\n DisplayConfig *pConfig = (DisplayConfig*)dpyConfig.data();\n mWidth = pConfig-\u003eresolution.getWidth();\n mHeight = pConfig-\u003eresolution.getHeight();\n\n ui::DisplayState* pState = (ui::DisplayState*)dpyState.data();\n if (pState-\u003eorientation != ui::ROTATION_0 &&\n pState-\u003eorientation != ui::ROTATION_180) {\n // rotate\n std::swap(mWidth, mHeight);\n }\n\n LOG(DEBUG) \u003c\u003c \"Display resolution is \" \u003c\u003c mWidth \u003c\u003c \" x \" \u003c\u003c mHeight;\n });\n ```\n3. Retrieve a hardware `IGraphicBufferProducer` (or, HIDL GraphicBufferProducer (HGBP) from `IAutomotiveDisplayProxyService`: \n\n ```text\n mGfxBufferProducer = pWindowProxy-\u003egetIGraphicBufferProducer(displayId);\n if (mGfxBufferProducer == nullptr) {\n LOG(ERROR) \u003c\u003c \"Failed to get IGraphicBufferProducer from \"\n \u003c\u003c \"IAutomotiveDisplayProxyService.\";\n return false;\n }\n ```\n4. Get a `SurfaceHolder` from a retrieved HGBP, by using the API `libbufferqueueconverter`: \n\n ```text\n mSurfaceHolder = getSurfaceFromHGBP(mGfxBufferProducer);\n if (mSurfaceHolder == nullptr) {\n LOG(ERROR) \u003c\u003c \"Failed to get a Surface from HGBP.\";\n return false;\n }\n ```\n5. Convert a `SurfaceHolder` into a native window by using the API `libbufferqueueconverter`: \n\n ```text\n mWindow = getNativeWindow(mSurfaceHolder.get());\n if (mWindow == nullptr) {\n LOG(ERROR) \u003c\u003c \"Failed to get a native window from Surface.\";\n return false;\n }\n ```\n6. Create an EGL window surface with a native window and then render: \n\n ```scilab\n // Set up our OpenGL ES context associated with the default display\n mDisplay = eglGetDisplay(EGL_DEFAULT_DISPLAY);\n if (mDisplay == EGL_NO_DISPLAY) {\n LOG(ERROR) \u003c\u003c \"Failed to get egl display\";\n return false;\n }\n ...\n\n // Create the EGL render target surface\n mSurface = eglCreateWindowSurface(mDisplay, egl_config, mWindow, nullptr);\n if (mSurface == EGL_NO_SURFACE) {\n LOG(ERROR) \u003c\u003c \"eglCreateWindowSurface failed.\";\n return false;\n }\n ...\n ```\n7. Call `IAutomotiveDisplayProxyService::showWindow()` to display the rendered view on the screen. This service has the highest priority and, therefore, always takes control of the screen from the current owner: \n\n ```text\n mAutomotiveDisplayProxyService-\u003eshowWindow();\n ```\n\nSee `service.cpp` and `GlWrapper.cpp`\nin `$ANDROID_BUILD_TOP/packages/services/Car/evs/sampleDriver/` for\nmore implementation details.\n\nAn EVS HAL implementation requires the additional libraries displayed in\n**bold** below. \n\n```objective-c\ncc_binary {\n name: \"android.hardware.automotive.evs@1.1-sample\",\n\n vendor: true,\n\n srcs: [\n ...\n ],\n\n shared_libs: [\n ...\n \"libbufferqueueconverter\",\n \"android.hidl.token@1.0-utils\",\n \"android.frameworks.automotive.display@1.0\",\n \"android.hardware.graphics.bufferqueue@1.0\",\n \"android.hardware.graphics.bufferqueue@2.0\",\n ],\n```\n\nMulti-display support\n---------------------\n\n### Display device enumeration and retrieve display information\n\nLike the camera device enumeration, the EVS framework provides a method to\nenumerate the available displays. The [static display identifier](/devices/tech/display/multi_display/displays#static) encodes a type-long identifier, the display\nport information in the lower byte and `Extended Display IDentification\nData` in upper bits.\n`IAutomotiveDisplayProxyService::getDisplayIdList()` returns a list\nof display IDs of physical local displays, which are available to EVS service,\nand `IEvsEnumerator::getDisplayIdList()` returns a list of display\nports detected displays are connected to. The first ID in the list is always of\nthe primary display. \n\n```objective-c\ninterface IEvsEnumerator extends @1.0::IEvsEnumerator {\n ...\n /**\n * Returns a list of all EVS displays available to the system\n *\n * @return displayIds Identifiers of available displays.\n */\n getDisplayIdList() generates (vec\u003cuint8_t\u003e displayIds);\n};\n```\n\n### Open target display device\n\nEVS app calls IEvsEnumerator::openDisplay_1_1() with a target display\nport number: \n\n```css+lasso\nandroid::sp\u003cIEvsDisplay\u003e pDisplay = pEvs-\u003eopenDisplay_1_1(displayId);\nif (pDisplay.get() == nullptr) {\n LOG(ERROR) \u003c\u003c \"EVS Display unavailable. Exiting.\";\n return 1;\n}\n```\n\n**Note:** Only a single display can be in use at one time,\nwhich means the current EVS client loses its display when another EVS client\nrequests to open the display, even when they are not the same."]]