Shulou(Shulou.com)06/03 Report--

Overview

The boot screen of a smartphone is usually composed of a static picture or a group of static pictures. A group of dynamic pictures can achieve the effect of boot animation in the code. In order to enrich the form of the boot interface, the variable boot screen complements this demand.

It can not only play custom video on boot, but also be compatible with the function of playing static pictures on boot.

This function is mainly implemented by two bin services

Counter service belongs to the system bin service, located in / system/bin/counter, has system permissions, can read and write system file, and realizes the countdown function of boot screen and the display of boot static pictures.

Play service belongs to the system bin service, located in / system/bin/counter, has system permissions, can read and write system file, implements boot custom video function, and can support common video formats such as mp4,ts.

Counte-like implementation

Counter.cpp is an explicit countdown prompt that prompts the user for the number of seconds left on the custom boot video and boot screen, and if there is a still picture, the background shows the picture.

1. Counter is the system bin service. Create an instance through createSurface as a layer:

Status_t Counter::readyToRun () {

/ / obtain the built-in display device

Sp dtoken (SurfaceComposerClient::getBuiltInDisplay (

ISurfaceComposer::eDisplayIdMain))

DisplayInfo dinfo

/ / get the default Display object parameters

Status_t status = SurfaceComposerClient::getDisplayInfo (dtoken, & dinfo)

If (status)

Return-1

/ / create a native SurfaceView

Sp control = session ()-> createSurface (String8 ("Counter")

Dinfo.w, dinfo.h, PIXEL_FORMAT_RGBA_8888, 0)

/ / operate SurfaceComposeClient and set layer priority

SurfaceComposerClient::openGlobalTransaction ()

Control- > setLayer (0x40000002)

SurfaceComposerClient::closeGlobalTransaction ()

Sp s = control- > getSurface ()

/ / initialize opengl and egl engine parameters

Const EGLint attribs [] = {

EGL_RED_SIZE, 8

EGL_GREEN_SIZE, 8

EGL_BLUE_SIZE, 8

EGL_ALPHA_SIZE, 8

EGL_DEPTH_SIZE, 0

EGL_NONE

}

two。 Load the default UI resource of the system, decode the picture through decodeImage, and display it on SurfaceLayer.

Status_t Counter::initTexture (Texture* texture, AssetManager& assets

Const char* name) {

/ / declare bitmap object

SkBitmap bitmap

/ / decode the picture through the sk library function

SkImageDecoder::DecodeMemory (asset- > getBuffer (false), asset- > getLength ()

& bitmap, kUnknown_SkColorType, SkImageDecoder::kDecodePixels_Mode)

/ / assert object is closed to release resources

Asset- > close ()

Delete asset

……

}

Player.cpp-like implementation

Player.cpp checks whether there are video files in the data directory and plays the video by drawing surfaceview in the boot interface.

After the surfacelinger service initialization is complete, start the Player service, create the surface sample, and set the initialization view parameters. This part is the same as initializing the Counter process, you need to create the Native Surface.

After detecting the video files in the directory, call MediaPlayer to play the video, obtain the video duration and format, and set the countdown service until the playback ends and enters the system.

Code flow related to video playback:

Int main (int argc, char * * argv) {

Android::ProcessState::self ()-> startThreadPool ()

/ / initialize SurfaceComposerClient

Sp composerClient = new SurfaceComposerClient

/ / obtain the built-in display device

Sp display (SurfaceComposerClient::getBuiltInDisplay (

ISurfaceComposer::eDisplayIdMain))

/ / create Surface and initialize relevant parameters

Sp control =

ComposerClient- > createSurface (

String8 ("A Surface")

DisplayWidth

DisplayHeight

PIXEL_FORMAT_RGB_565

0)

SurfaceComposerClient::closeGlobalTransaction ()

/ / create a MediaPlayer instance

Sp player =

Service- > create (client, AUDIO_SESSION_ALLOCATE)

/ / set the playback source destination

If (player! = NULL & & player- > setDataSource (source) = = NO_ERROR) {

/ / set the SurfaceTexture for playing Video, which is used to display the playback video stream

Player- > setVideoSurfaceTexture (surface- > getIGraphicBufferProducer ())

/ / start playing the file

Player- > start ()

Client- > waitForEOS ()

/ / playback stops

Player- > stop ()

} else {

Fprintf (stderr, "failed to instantiate player.\ n")

}

/ / close composerClient

ComposerClient- > dispose ()

}

Playback custom video process

Counter and Player loading analysis:

Add counter and advert services to init.rc. The user permission is declared as root, and the initial startup is set to disabled, which needs to be actively invoked.

Service connter / system/bin/counter

Class core

User root

Group graphics audio

Disabled

Oneshot

Service player / system/bin/player

Class core

User root

Group graphics audio

Disabled

Oneshot

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.