khadas_android_hwdecode_library jni so is build by ndk-build command,so you need install NDK build environment
1) Download NDK
wget https://dl.google.com/android/repository/android-ndk-r17-linux-x86_64.zip
2) Unzip
unzip android-ndk-r17-linux-x86_64.zip
3) Configure NDK environment variables: open .bashrc and add the following two lines to the end of the file, Or add it to the /etc/profile file
export NDKROOT=/usr/ndk/android-ndk-r17
export PATH=$NDKROOT:$PATH
save and exit,update environment variables：source ~/.bashrc.
4) Check whether the NDK installation is completed:
enter the "ndk-build" command in the shell to check if your installation is successful, if not "ndk-build not found" is displayed.