You can use this library. You can implement it this way

Usage

1. Include the library as local library project.

allprojects {
    repositories {
        maven { url 'https://jitpack.io' }
    }
}
dependencies {
    implementation 'com.github.VRGsoftUA:VideoCrop:1.0'
}

2. In code you need to start Activityfor result like so:

startActivityForResult(VideoCropActivity.createIntent(this, inputPath, outputPath), CROP_REQUEST);

3. Then catch result in onActivityResult callback

    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        if(requestCode == CROP_REQUEST && resultCode == RESULT_OK){
            //crop successful
        }
    }