[FIXED] Android adb shell command to play sound from the command line

Issue

I have a set of rooted android devices I can access through adb over tcp/ip. I am trying to identify a specific one by playing a sound from the command line (one of the .ogg files from /system/media/audio).

I know I could probably build an app for this but it feels like an overkill to use an APK, and I'm hoping there is a more native way. I already know how to start intents from the command line.

Things I have tried :

• Investigated using service call media.player but could not find any useful reference about the syntax. I can see with dumpsys media.player references about AwesomePlayer but couln't get anything going.
• Tried to find a compiled version of "/system/bin/media" from the android source code, as it is missing from the device, but without any luck so far.
• Tried to build a command line java app to call android.media.MediaPlayer with dalvikvm but my knowledge of Android and java is too limited (class compiled but complained about missing dependencies at runtime)

Any ideas?

Solution

After some trial and error, I will answer what is now working for me.

Based on other threads, I found the following java code to be the bare minimum to play some sound through the speaker. The MediaPlayer class seems the only one that will play with no user interaction, as others need a real activity context...

public class Beep {

    public static void main(String[] a) {

        MediaPlayer mp = new MediaPlayer();

        try {
            mp.setDataSource("/system/media/audio/alarms/Ticktac.ogg");
            mp.prepare();
            mp.start();
        }
        catch (IOException e) {
            Log.w("Beep", "IOException", e);
        }
}

(actual working example is here)

This must then be compiled as a dex file, linked to android.jar,
and can finally be run from the adb shell command line using app_process (not dalvikvm) :

export CLASSPATH=./Beep.dex
app_process /system/bin Beep /system/media/audio/ringtones/Beep-beep.ogg

It is not the one-liner I was hoping for but does what I needed...

Answered By - Benjamin
Answer Checked By - Katrina (JavaFixing Volunteer)