th3or14 / opencv-with-ffmpeg-on-qt-for-android

How to compile native/C++ OpenCV with FFmpeg support and use it on Qt for Android

Building the OpenCV libraries

• Install Docker
• Supported architectures are listed in build-wrapper.sh, you are free to reduce the list there according to your needs
• Run ./build.sh

Running the sample application

• Qt kits and devices management is left on you, check out docker/Dockerfile for versions of JDK, Android SDK and Android NDK used to build
• Open sample/sample.pro in Qt Creator
• Change ARCHITECTURE to the corresponding architecture for your current build
• Set OPENCV_SRC_DIR=$PWD/opencv environment variable, where $PWD is a path to directory with this README.md
• Build and run
• In case of success the application generates a sample video

opencv-with-ffmpeg-on-qt-for-android's Issues

Hints for compile with CMake and Clang for Qt 5.12.3

Hello,

I am trying to build OpenCV 4.0.1 with FFmpeg 4.1 for Qt 5.12.3. New versions of Qt use Clang as a compiler for Android devices and NDK version 19r. Could you please give me some advise where should I change what in your brilliant scripts to make it work? New branch would be ideal. Thank you in advance for your help.

Can't open file?

I built this on a fresh install of lubuntu. It seems to compile ok. The sample seems to compile and run on my phone (Moto z4 running Android 9). But it can't open the VideoWriter file. If I replace the code starting with

cv::VideoWriter vw;

with a normal file open, write, close, I can write a text file so I don't think it's a permission issue. Otherwise I get "Can't open file for writing!" The only change I made is using android-ndk-r20b rather than android-ndk-r20.

v8a & 64x support

Hello @th3or14
Tried your script and seems compiling successfully without any issue. However, I need both v8a and 64x version. Is there any technical reason that you haven't included them? Also have you tried to use the VideoCapture with RTSP on android using your compiled libs?