Yes, it is possible to detect when another app starts playing media on an Android device, but there are limitations and considerations depending on the Android version and the approach you use.

Possible Approaches

1. Using AudioManager and MediaSessionManager (API 21+)

• AudioManager: You can listen for changes in audio focus using OnAudioFocusChangeListener. This allows your app to detect when another app requests audio focus (e.g., to play music or video).
• MediaSessionManager: For Android 5.0 (API 21) and above, you can use MediaSessionManager to detect active media sessions. This requires the android.permission.MEDIA_CONTENT_CONTROL permission, which is only available to system apps or privileged apps (e.g., pre-installed apps or those with special permissions).

Limitation: Most third-party apps cannot access MediaSessionManager due to permission restrictions.

2. Using UsageStatsManager (API 22+)

• UsageStatsManager allows you to query app usage statistics, including foreground apps. You can check if a media app (e.g., Spotify, YouTube) is in the foreground and infer media playback.
• Requires: android.permission.PACKAGE_USAGE_STATS, which is a special permission that users must manually grant in settings.

Limitation: Users must explicitly enable this permission for your app in Settings > Apps > Special Access > Usage Access.

3. Using Accessibility Services

• You can create an Accessibility Service to detect when media apps open or when media playback controls (e.g., play/pause buttons) appear on the screen.
• Requires: android.permission.BIND_ACCESSIBILITY_SERVICE and user approval to enable the service.

Limitation: This approach is invasive and may not work reliably for all media apps. It also requires users to manually enable the service.

4. Using Notification Listener (API 18+)

• Some media apps (e.g., Spotify) show notifications when playing media. You can use a Notification Listener to detect these notifications.
• Requires: android.permission.BIND_NOTIFICATION_LISTENER_SERVICE and user approval.

Limitation: Not all media apps show notifications, and this method is not real-time (depends on notification updates).

5. Using Media3 or ExoPlayer (For Your Own App)

• If you want to detect media playback within your own app, you can use libraries like AndroidX Media3 or ExoPlayer to track playback state changes.

Limitation: This only works for media played by your app, not other apps.

Best Approach for Third-Party Apps

If you want to detect media playback from other apps in real-time:

1. Combine AudioManager and UsageStatsManager (if the user grants permissions).
2. Use Accessibility Services as a fallback (if the user enables it).
3. Request PACKAGE_USAGE_STATS permission and guide the user to enable it.

Example Code (Audio Focus Detection)

Here’s a simple example using AudioManager to detect audio focus changes:

AudioManager audioManager = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
AudioManager.OnAudioFocusChangeListener focusChangeListener =
    new AudioManager.OnAudioFocusChangeListener() {
        @Override
        public void onAudioFocusChange(int focusChange) {
            if (focusChange == AudioManager.AUDIOFOCUS_LOSS) {
                // Another app has taken audio focus (e.g., started playing media)
                Log.d("MediaDetection", "Another app is playing media!");
            }
        }
    };

// Request audio focus
audioManager.requestAudioFocus(
    focusChangeListener,
    AudioManager.STREAM_MUSIC,
    AudioManager.AUDIOFOCUS_GAIN
);

Key Challenges

• Permissions: Most reliable methods require special permissions that users must manually enable.
• Android Version: Newer Android versions (e.g., Android 10+) have stricter privacy restrictions.
• Battery Impact: Polling for app usage or notifications can drain battery.

Conclusion

Yes, it is possible, but not straightforward due to Android’s privacy and permission restrictions. The most reliable method for third-party apps is a combination of AudioManager and UsageStatsManager, but it requires user cooperation.

Would you like help implementing a specific approach?