如何判断当前是否有音频输入

/**

* @return Whether isMusicActive is being played right now.

*/

boolean isMusicActive() {

final AudioManager am = (AudioManager) ContextUtil.getContext().getSystemService(Context.AUDIO_SERVICE);

boolean isMusicActive = false;

try {

if (am != null) {

Log.w(TAG, "isMusicActive: couldn't get AudioManager reference");

isMusicActive = am.isMusicActive();

}

} catch (Exception e) {

e.printStackTrace();

}

return isMusicActive;

}