On Android when you start recording video in your app there is a notification sound. Is there a reliable way to disable it?
For non-rooted devices, if the firmware allows muting that sound, you can mute it by using AudioManager.setStreamMute() on STREAM_MUSIC (or STREAM_SYSTEM on some devices) before recording and unmute when recording starts. It won't work if the firmware doesn't allow this. In this case, there is no way to disable it other than rooting it.