HarmonyOS 开发实践——对各种图片编解码格式的支持

原创

小帅聊鸿蒙

发布于 2024-11-12 05:41:14

1550

场景一：展示系统原生支持的图片格式编解码的代码实现

// 获取resourceManager资源管理
const context : Context = getContext(this);
const resourceMgr : resourceManager.ResourceManager = context.resourceManager;
// 创建ImageSource
resourceMgr.getRawFileContent('test.jpg').then((fileData : Uint8Array) => {
  console.log("Succeeded in getting RawFileContent")
  // 获取图片的ArrayBuffer
  const buffer = fileData.buffer.slice(0);
  const imageSource : image.ImageSource = image.createImageSource(buffer);
}).catch((err : BusinessError) => {
  console.error("Failed to get RawFileContent")
});
// 创建PixelMap
imageSource.createPixelMap().then((pixelMap: image.PixelMap) => {
   console.log("Succeeded in creating PixelMap")
}).catch((err : BusinessError) => {
   console.error("Failed to creating PixelMap")
});

场景二：使用第三方库进行系统原生不支持的常用图片格式解码进行解码

avif 格式

2.1 将libavif库添加到工程中，

2.1.1 编译第三方库

下载本仓库

git clone https://gitee.com/openharmony-sig/tpc_c_cplusplus.git --depth=1

三方库目录结构

o    tpc_c_cplusplus/thirdparty/libavif   #三方库libavif的目录结构如下
o    ├── docs                               #三方库相关文档的文件夹
o    ├── HPKBUILD                           #构建脚本
o    ├── HPKCHECK                           #自动化测试脚本
o    ├── SHA512SUM                          #三方库校验文件
o    ├── README.OpenSource                  #说明三方库源码的下载地址，版本，license等信息
o    ├── README_zh.md                       #三方库说明文档
├── OAT.xml                            #开源扫描相关文件

在tpc_c_cplusplus/lycium目录下编译三方库

编译环境的搭建参考准备三方库构建环境

cd tpc_c_cplusplus/lycium
./build.sh libavif

三方库头文件及生成的库

在lycium目录下会生成usr目录，该目录下存在已编译完成的32位和64位三方库和头文件

libavif/arm64-v8a   libavif/armeabi-v7a

2.1.2 应用中使用第三方库

拷贝动态库到\entry\libs\${OHOS_ARCH}\目录：动态库需要在\entry\libs\${OHOS_ARCH}\目录，才能集成到hap包中，所以需要将对应的so文件拷贝到对应CPU架构的目录
在IDE的cpp目录下新增thirdparty目录，将编译生成的库拷贝到该目录下，如下图所示

在最外层（cpp目录下）CMakeLists.txt中添加如下语句

#将三方库加入工程中
target_link_libraries(entry PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/../../../libs/${OHOS_ARCH}/libaom.a
${CMAKE_CURRENT_SOURCE_DIR}/../../../libs/${OHOS_ARCH}/libavif.so.16
${CMAKE_CURRENT_SOURCE_DIR}/../../../libs/${OHOS_ARCH}/libgmock.a
${CMAKE_CURRENT_SOURCE_DIR}/../../../libs/${OHOS_ARCH}/libgmock_main.a
${CMAKE_CURRENT_SOURCE_DIR}/../../../libs/${OHOS_ARCH}/libgtest.a
${CMAKE_CURRENT_SOURCE_DIR}/../../../libs/${OHOS_ARCH}/libgtest_main.a
${CMAKE_CURRENT_SOURCE_DIR}/../../../libs/${OHOS_ARCH}/libjpeg.a
${CMAKE_CURRENT_SOURCE_DIR}/../../../libs/${OHOS_ARCH}/libpng.a
${CMAKE_CURRENT_SOURCE_DIR}/../../../libs/${OHOS_ARCH}/libpng16.a
${CMAKE_CURRENT_SOURCE_DIR}/../../../libs/${OHOS_ARCH}/libyuv.so
)
#将三方库的头文件加入工程中
target_include_directories(entry PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/thirdparty/libavif/${OHOS_ARCH}/include
${CMAKE_CURRENT_SOURCE_DIR}/thirdparty/libyuv/${OHOS_ARCH}/include
${CMAKE_CURRENT_SOURCE_DIR}/thirdparty/libaom/${OHOS_ARCH}/include
${CMAKE_CURRENT_SOURCE_DIR}/thirdparty/jpeg/${OHOS_ARCH}/include
${CMAKE_CURRENT_SOURCE_DIR}/thirdparty/libpng/${OHOS_ARCH}/include
${CMAKE_CURRENT_SOURCE_DIR}/thirdparty/googletest/${OHOS_ARCH}/include)

2.1.3 测试第三方库

三方库的测试使用原库自带的测试用例来做测试，准备三方库测试环境

进入到构建目录（arm64-v8a-build为构建64位的目录，armeabi-v7a-build为构建32位的目录）,执行如下操作步骤:

配置环境变量执行如下命令：

export LD_LIBRARY_PATH=${LYCIUM_ROOT}/usr/libyuv/${ARCH}/lib:${LYCIUM_ROOT}/usr/libavif/${ARCH}/lib:${LYCIUM_ROOT}/usr/jpeg/${ARCH}/lib:${LYCIUM_ROOT}/usr/libaom/${ARCH}/lib:${LYCIUM_ROOT}/usr/libpng/${ARCH}/lib:$LD_LIBRARY_PATH