# An exercise in frustration **URL:** \ **Category:** Android/Java\ **Created:** [April 26, 2023, 5:07pm UTC](https://forum.opencv.org/t/an-exercise-in-frustration/12964 "2023-04-26T17:07:05Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![mtch](https://avatars.discourse-cdn.com/v4/letter/m/f14d63/32.png) [@mtch](https://forum.opencv.org/u/mtch)\ **Post date:** [April 26, 2023, 5:07pm UTC](https://forum.opencv.org/t/an-exercise-in-frustration/12964/1 "2023-04-26T17:07:05Z")
Hi guys, I have not been so frustrated in long time. After a full day, I am still unable to compile an hello world in Android. OpenCV for android 4.7.0 as downloaded Android Studio Flamingo | 2022.2.1 Installed multiple SDK version, SDK built tools, NDK, command line tools, platform tools + some irrelevant extras. Successfully tested a simple camera capture program using only android (not opencv). Followed the tutorial: > **[A Beginner’s Guide to Setting up OpenCV Android Library on Android Studio](https://medium.com/android-news/a-beginners-guide-to-setting-up-opencv-android-library-on-android-studio-19794e220f3c)** > > I recently started a project that involved working with OpenCV on Android. Most of the guides on setting up the library on Android were… However, I am unable to get it compiled: error: package org.opencv.engine does not exist import org.opencv.engine.OpenCVEngineInterface; I found hundred of “solutions” on the internet. NONE of them works. Ended up copying all the opencv java into the project, i have the whole org/opencv/ tree in main, i have added the jniLibs folder, fixed version inconsistencies in gradle files etc… Still, nothing works. I was assuming that maybe I need to compile the opencv sdk. Attempting to import the opencv/sdk in Android Studio to see if it compile. It does not: A problem occurred evaluating root project ‘sdk’. > Plugin with id ‘com.android.library’ not found. Questions: - The android packet is ready to go or need compiled ? - How to get OpenCV to compile in Android Studio, if this is the problem? - If no, any hints to alleviate a nerve-racking experience ? Tnx. ---
**Author:** ![HenryHao](https://avatars.discourse-cdn.com/v4/letter/h/43a26b/32.png) [@HenryHao](https://forum.opencv.org/u/HenryHao)\ **Post date:** [April 27, 2023, 9:35am UTC](https://forum.opencv.org/t/an-exercise-in-frustration/12964/2 "2023-04-27T09:35:47Z")
You could have a try to add “android.defaults.buildfeatures.aidl=true” to the gradle.properties. to enable the aidl buildfeature. ref: [BuildFeatures  |  Android Developers](https://developer.android.com/reference/tools/gradle-api/7.0/com/android/build/api/dsl/BuildFeatures) ---
**Author:** ![mtch](https://avatars.discourse-cdn.com/v4/letter/m/f14d63/32.png) [@mtch](https://forum.opencv.org/u/mtch)\ **Post date:** [April 27, 2023, 9:43pm UTC](https://forum.opencv.org/t/an-exercise-in-frustration/12964/3 "2023-04-27T21:43:33Z")
Thank you very much Henry. That is a very good piece of info. It fixedthat point, Now, I advanced to the next frustration 😁 error: cannot find symbol import org.opencv.BuildConfig; No advice found by Google helped so far either. ---
**Author:** ![mtch](https://avatars.discourse-cdn.com/v4/letter/m/f14d63/32.png) [@mtch](https://forum.opencv.org/u/mtch)\ **Post date:** [May 1, 2023, 12:12pm UTC](https://forum.opencv.org/t/an-exercise-in-frustration/12964/4 "2023-05-01T12:12:51Z")
Just in case somebody else have the org.opencv.BuildConfig; issue, I was able to pass that by adding: ``` buildFeatures { buildConfig true } ``` in build.gradle for opencv. Android is so frustrating … ☹ ---
**Author:** ![berak](https://avatars.discourse-cdn.com/v4/letter/b/85f322/32.png) [@berak](https://forum.opencv.org/u/berak)\ **Post date:** [May 4, 2023, 7:48am UTC](https://forum.opencv.org/t/an-exercise-in-frustration/12964/5 "2023-05-04T07:48:46Z")
recent updates, please take a look: > > > Hello, > > Android Gradle Plugin version 8.0 is asking for namespace. This is bec…ome mandatory and after I update my AGP to 8.0, I got this error > > > \`\`\` > Namespace not specified. Please specify a namespace in the module's build.gradle file like so: > > android { > namespace 'com.example.namespace' > } > > If the package attribute is specified in the source AndroidManifest.xml, it can be migrated automatically to the namespace value in the build.gradle file using the AGP Upgrade Assistant; please refer to https://developer.android.com/studio/build/agp-upgrade-assistant for more information. > \`\`\` > > This change fix this future releases. However I am not sure how opencv wants to user namespace I used "org.opencv" if there is a different namespace please let me know so I can changed that too. Also should I add namepsace into "opencv/modules/java/android\_sdk/android\_gradle\_lib/build.gradle" here ? > > > \### Sources > > Android developer link: https://developer.android.com/studio/preview/features#namespace-dsl > Issue Tracker Google: https://issuetracker.google.com/issues/191813691?pli=1#comment19 > > > > > > > \### Pull Request Readiness Checklist > > See details at https://github.com/opencv/opencv/wiki/How\_to\_contribute#making-a-good-pull-request > > \- \[x\] I agree to contribute to the project under Apache 2 License. > \- \[x\] To the best of my knowledge, the proposed patch is not based on a code under GPL or another license that is incompatible with OpenCV > \- \[x\] The PR is proposed to the proper branch > \- \[x\] There is a reference to the original bug report and related work > \- \[\] There is accuracy test, performance test and test data in opencv\_extra repository, if applicable > Patch to opencv\_extra has the same branch name. > \- \[\] The feature is well documented and sample code can be built with the project CMake ---
**Author:** ![YohannesTz](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.opencv.org/yohannestz/32/7835_2.png) [@YohannesTz](https://forum.opencv.org/u/YohannesTz)\ **Post date:** [May 7, 2023, 2:25pm UTC](https://forum.opencv.org/t/an-exercise-in-frustration/12964/6 "2023-05-07T14:25:44Z")
> [@mtch](#): > > ` buildConfig true` thank you so much. This saved me after 3 hours of searching all over. ---
**Author:** ![ankit\_sachan](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.opencv.org/ankit_sachan/32/8539_2.png) [@ankit\_sachan](https://forum.opencv.org/u/ankit_sachan)\ **Post date:** [August 14, 2023, 12:36pm UTC](https://forum.opencv.org/t/an-exercise-in-frustration/12964/7 "2023-08-14T12:36:29Z")
if somebody still needs help > **[Android Studio + Kotlin + Open CV](https://medium.com/@ankitsachan/android-studio-kotlin-open-cv-16d75f8d9969)** > > so this is if you are getting frustrated with how to integrate OpenCV 4.x.x with Android Studio. ---
**Author:** ![9dubs](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.opencv.org/9dubs/32/8725_2.png) [@9dubs](https://forum.opencv.org/u/9dubs)\ **Post date:** [October 23, 2023, 8:43pm UTC](https://forum.opencv.org/t/an-exercise-in-frustration/12964/8 "2023-10-23T20:43:06Z")
that was a life saver holy hell thank you guys ---
**Author:** ![rajmb](https://avatars.discourse-cdn.com/v4/letter/r/f14d63/32.png) [@rajmb](https://forum.opencv.org/u/rajmb)\ **Post date:** [November 25, 2023, 2:09pm UTC](https://forum.opencv.org/t/an-exercise-in-frustration/12964/9 "2023-11-25T14:09:41Z")
Thank you @ankit_sachan for documenting this. I followed the documentation and the build went smoothly. But when I try to run the app, I get an error that “OpenCV Manager” package not installed and it redirects me to Google Playstore. Any idea what needs to be done to tackle this? ---
**Author:** ![rajmb](https://avatars.discourse-cdn.com/v4/letter/r/f14d63/32.png) [@rajmb](https://forum.opencv.org/u/rajmb)\ **Post date:** [November 25, 2023, 3:42pm UTC](https://forum.opencv.org/t/an-exercise-in-frustration/12964/10 "2023-11-25T15:42:26Z")
OK, just after I posted this, I happened to look at the OpenCV build.gradle file that had this comment: ```auto // Load OpenCV native library before using: // // - avoid using of "OpenCVLoader.initAsync()" approach - it is deprecated // It may load library with different version (from OpenCV Android Manager, which is installed separatelly on device) // // - use "System.loadLibrary("opencv_java4")" or "OpenCVLoader.initDebug()" ``` So, now, I just have: ```auto static { System.loadLibrary("opencv_java4"); } @Override public View onCreateView( @NonNull LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState ) { binding = FragmentFirstBinding.inflate(inflater, container, false); Log.d(TAG, "OpenCV loaded: "+ OpenCVLoader.initDebug()); if (OpenCVLoader.initDebug()) { binding.mainCamera.setCameraIndex(CameraBridgeViewBase.CAMERA_ID_BACK); binding.mainCamera.setCameraPermissionGranted(); binding.mainCamera.enableView(); } return binding.getRoot(); } ``` And the preview pane opened 🙂 Only issue I now have is that the preview pane is in landscape mode. Any idea if I can get it to portrait mode? ---
**Author:** ![rajmb](https://avatars.discourse-cdn.com/v4/letter/r/f14d63/32.png) [@rajmb](https://forum.opencv.org/u/rajmb)\ **Post date:** [November 28, 2023, 5:58am UTC](https://forum.opencv.org/t/an-exercise-in-frustration/12964/11 "2023-11-28T05:58:49Z")
The code that I have used for portrait view: ```auto @Override public Mat onCameraFrame(CameraBridgeViewBase.CvCameraViewFrame inputFrame) { Imgproc.cvtColor(inputFrame.rgba(), rgb, Imgproc.COLOR_RGBA2RGB); /* --- Your logic // Do your processing before rotating the image so that the corner/pose estimations are not affected */ Mat localRGB; // Ref: https://stackoverflow.com/a/28601634 Core.rotate(rgb, localRGB, Core.ROTATE_90_CLOCKWISE); //ref: https://stackoverflow.com/a/37972813 Imgproc.resize(localRGB, rgb, rgb.size()); return rgb; } ```