Stop adb screenrecord from java

Question

I'm using Selendroid in order to test my app. At the beginning of each test I run adb shell screenrecord with the following function:

public static Process startScreenRecord(String fileName) throws IOException{
    ProcessBuilder builder = new ProcessBuilder(
            "cmd.exe", "/c", "cd C:\\Users\\user\\Downloads\\adt-bundle-windows-x86_64-20140702\\adt-bundle-windows-x86_64-20140702\\sdk\\platform-tools\\ && adb shell screenrecord /sdcard/" + fileName);
    builder.redirectErrorStream(true);
    Process p = builder.start();
    return p;
}

The recording is starting and everything looks OK. At the end of each test I try to stop the record via the following code:

public static void stopScreenRecord(Process p) throws IOException{
    p.destroy();
}

And in the test I use the following structure:

    Process p = CmdHelper.startScreenRecord("e1.mp4");
    //TestCode
    CmdHelper.stopScreenRecord(p);

The problem is that the video recording doesn't stop. How can I stop the call recording at the end of each test?

Answer 1

The adb shell screenrecord --help documentation says that the two ways to terminate it are to set a time limit or to send it ctrl-C.

Assuming the time limit option doesn't work for you, the question would be how to send ctrl-C or its functional equivalent. If you get an output stream connected to ADB's stdin and keep it open, you might be able to send a ctrl-c down that (or you might end up interrupting ADB and not the remote).

A different option, which seems to work is to use the kill command to send SIGINT (which is what ctrl-C typically does) rather than the SIGTERM signal which kill normally sends. That should make the screenrecord process think you hit ctrl-c.

If you have found the process, id, the following seems to work and leave behind a video file:

adb shell kill -2 [pid number]

Where 2 is the usual number of SIGINT on Linux and thus Android.