Using Image_NativeModule to Decode Images

You can use the ImageSource class to create an image source, obtain the width and height of the PixelMap, and release ImageSource instances.

How to Develop

Adding a Link Library

Open the src/main/cpp/CMakeLists.txt file of the native project, add libimage_source.so and libhilog_ndk.z.so (on which the log APIs depend) to the target_link_libraries dependency.

target_link_libraries(entry PUBLIC libhilog_ndk.z.so libimage_source.so)

Calling the Native APIs

For details about the APIs, see Image_NativeModule.

Implement the C APIs in hello.cpp. Refer to the sample code below.

Example of Using the Decoding APIs

After creating an ImageSource instance, obtain and modify property values, create a PixelMap object by using decoding parameters, and obtain the number of image frames.

   #include <linux/kd.h>
   #include <string>

   #include <hilog/log.h>
   #include <multimedia/image_framework/image/image_source_native.h>

   #undef LOG_DOMAIN
   #undef LOG_TAG
   #define LOG_DOMAIN 0x3200
   #define LOG_TAG "MY_TAG"

   #define NUM_0 0
   #define NUM_1 1

   static napi_value sourceTest(napi_env env, napi_callback_info info)
   {
       napi_value argValue[NUM_1] = {0};
       size_t argCount = NUM_1;
       if (napi_get_cb_info(env, info, &argCount, argValue, nullptr, nullptr) != napi_ok || argCount < NUM_1 ||
           argValue[NUM_0] == nullptr) {
           OH_LOG_ERROR(LOG_APP, "ImageSourceNativeCTest sourceTest napi_get_cb_info failed, argCount: %{public}d.", argCount);
           return getJsResult(env, IMAGE_BAD_PARAMETER);
       }
       char name[1024];
       size_t nameSize = 1024;
       napi_get_value_string_utf8(env, argValue[NUM_0], name, 1024, &nameSize);

       // Create an ImageSource instance.
       OH_ImageSourceNative *source = nullptr;
       Image_ErrorCode errCode = OH_ImageSourceNative_CreateFromUri(name, nameSize, &source);
       if (errCode != IMAGE_SUCCESS) {
           OH_LOG_ERROR(LOG_APP, "ImageSourceNativeCTest sourceTest OH_ImageSourceNative_CreateFromUri failed, errCode: %{public}d.", errCode);
           return errCode;
       }

       // Create a structure object that defines the image information and obtain the image information.
       OH_ImageSource_Info *imageInfo;
       OH_ImageSourceInfo_Create(&imageInfo);
       errCode = OH_ImageSourceNative_GetImageInfo(source, 0, imageInfo);
       if (errCode != IMAGE_SUCCESS) {
           OH_LOG_ERROR(LOG_APP, "ImageSourceNativeCTest sourceTest OH_ImageSourceNative_GetImageInfo failed, errCode: %{public}d.", errCode);
           return errCode;
       }

       // Obtain the values of the specified properties.
       uint32_t width, height;
       OH_ImageSourceInfo_GetWidth(imageInfo, &width);
       OH_ImageSourceInfo_GetHeight(imageInfo, &height);
       OH_ImageSourceInfo_Release(imageInfo);
       OH_LOG_INFO(LOG_APP, "ImageSourceNativeCTest sourceTest OH_ImageSourceNative_GetImageInfo success, width: %{public}d, height: %{public}d.", width, height);
       Image_String getKey;
       const std::string PIXEL_X_DIMENSION = "PixelXDimension";
       getKey.data = (char *)PIXEL_X_DIMENSION.c_str();
       getKey.size = PIXEL_X_DIMENSION.length();
       Image_String getValue;
       errCode = OH_ImageSourceNative_GetImageProperty(source, &getKey, &getValue);
       if (errCode != IMAGE_SUCCESS) {
           OH_LOG_ERROR(LOG_APP, "ImageSourceNativeCTest sourceTest OH_ImageSourceNative_GetImageProperty failed, errCode: %{public}d.", errCode);
           return errCode;
       }

       // Modify the values of the specified properties.
       Image_String setKey;
       const std::string ORIENTATION = "Orientation";
       setKey.data = (char *)ORIENTATION.c_str();
       setKey.size = ORIENTATION.length();
       Image_String setValue;
       setValue.data = (char *)"4";
       setValue.size = 1;
       errCode = OH_ImageSourceNative_ModifyImageProperty(source, &setKey, &setValue);
       if (errCode != IMAGE_SUCCESS) {
           OH_LOG_ERROR(LOG_APP, "ImageSourceNativeCTest sourceTest OH_ImageSourceNative_ModifyImageProperty failed, errCode: %{public}d.", errCode);
           return errCode;
       }

       // Create a PixelMap object based on image decoding parameters.
       OH_DecodingOptions *ops = nullptr;
       OH_DecodingOptions_Create(&ops);
       // If IMAGE_DYNAMIC_RANGE_AUTO is passed in, decoding is performed based on the image format. If the image is an HDR resource, an HDR PixelMap is obtained after decoding.
       OH_DecodingOptions_SetDesiredDynamicRange(ops, IMAGE_DYNAMIC_RANGE_AUTO);
       OH_PixelmapNative *resPixMap = nullptr;

       // A null pointer cannot be passed in to ops. If ops does not need to be set, you do not need to create a PixelMap object.
       errCode = OH_ImageSourceNative_CreatePixelmap(source, ops, &resPixMap);
       OH_DecodingOptions_Release(ops);
       if (errCode != IMAGE_SUCCESS) {
           OH_LOG_ERROR(LOG_APP, "ImageSourceNativeCTest sourceTest OH_ImageSourceNative_CreatePixelmap failed, errCode: %{public}d.", errCode);
           return errCode;
       }

       // Check whether the PixelMap is the HDR content.
       OH_Pixelmap_ImageInfo *pixelmapImageInfo = nullptr;
       OH_PixelmapImageInfo_Create(&pixelmapImageInfo);
       OH_PixelmapNative_GetImageInfo(resPixMap, pixelmapImageInfo);
       bool pixelmapIsHdr;
       OH_PixelmapImageInfo_GetDynamicRange(pixelmapImageInfo, &pixelmapIsHdr);
       OH_PixelmapImageInfo_Release(pixelmapImageInfo);

       // Obtain the number of image frames.
       uint32_t frameCnt = 0;
       errCode = OH_ImageSourceNative_GetFrameCount(source, &frameCnt);
       if (errCode != IMAGE_SUCCESS) {
           OH_LOG_ERROR(LOG_APP, "ImageSourceNativeCTest sourceTest OH_ImageSourceNative_GetFrameCount failed, errCode: %{public}d.", errCode);
           return errCode;
       }

       // Create a PixelMap list based on image decoding parameters.
       OH_DecodingOptions *opts = nullptr;
       OH_DecodingOptions_Create(&opts);
       OH_PixelmapNative **resVecPixMap = new OH_PixelmapNative*[frameCnt];
       size_t outSize = frameCnt;
       errCode = OH_ImageSourceNative_CreatePixelmapList(source, opts, resVecPixMap, outSize);
       OH_DecodingOptions_Release(opts);
       delete[] resVecPixMap;
       if (errCode != IMAGE_SUCCESS) {
           OH_LOG_ERROR(LOG_APP, "ImageSourceNativeCTest sourceTest OH_ImageSourceNative_CreatePixelmapList failed, errCode: %{public}d.", errCode);
           return errCode;
       }

       // Obtain the image delay time list.
       int32_t *delayTimeList = new int32_t[frameCnt];
       size_t size = frameCnt;
       errCode = OH_ImageSourceNative_GetDelayTimeList(source, delayTimeList, size);
       delete[] delayTimeList;
       if (errCode != IMAGE_SUCCESS) {
           OH_LOG_ERROR(LOG_APP, "ImageSourceNativeCTest sourceTest OH_ImageSourceNative_GetDelayTimeList failed, errCode: %{public}d.", errCode);
           return errCode;
       }

       // Release the ImageSource instance.
       OH_ImageSourceNative_Release(source);
       OH_LOG_INFO(LOG_APP, "ImageSourceNativeCTest sourceTest success.");
       return IMAGE_SUCCESS;
   }