As recommended by the doc, I’d like to use the setvolume()
method to control the volume of my MediaPlayer
, but I’m a bit confused about how to manage it.
I’m setting the volume using a SeekBar
, initialized to the current volume in the AudioManager.STREAM_MUSIC
stream.
This makes sense when the user does not modify the device volume control, but when he does, I’m not sure what I should do, and I have several doubts:
-
how is the
MediaPlayer
volume related to the device volume? Does the max value (1) set insetVolume()
correspond tomAudioManager.getStreamMaxVolume(AudioManager.STREAM_MUSIC)
-
if it’s the case, the progress value of the
SeekBar
should be reset every time the device volume control is set, but then, what’s the point of usingMediaPlayer.setVolume()
instead of AudioManager.setStreamVolume()? -
what’s the standard way of using
MediaPlayer.setVolume()
with aSeekBar
?
private final static int MAX_VOLUME = 100;
private AudioManager mAudioManager;
private SeekBar mVolumeControl;
mVolumeControl = (SeekBar) getActivity().findViewById(R.id.volume_control);
mAudioManager = (AudioManager) getActivity().getSystemService(Context.AUDIO_SERVICE);
mVolumeControl.setMax(MAX_VOLUME);
mVolumeControl.setProgress(MAX_VOLUME*mAudioManager.getStreamVolume(AudioManager.STREAM_MUSIC)/mAudioManager.getStreamMaxVolume(AudioManager.STREAM_MUSIC));
mVolumeControl.setOnSeekBarChangeListener(mVolumeControlChangeListener);
private SeekBar.OnSeekBarChangeListener mVolumeControlChangeListener = new SeekBar.OnSeekBarChangeListener() {
@Override
public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
float volume = (float) (1 - (Math.log(MAX_VOLUME - progress) / Math.log(MAX_VOLUME)));
mediaPlayer.setVolume(volume, volume);
}
@Override
public void onStartTrackingTouch(SeekBar seekBar) {}
@Override
public void onStopTrackingTouch(SeekBar seekBar) {
}
};
MediaPlayer.setVolume
sets the volume of that player as a percentage of the overall volume for that stream. It does not affect the stream volume. So if you want to set just that player’s volume, set it to something between 0 and 1 (a fractional value representing the percentage) and let the user control the system volume separately by using the hardware volume controls. To hook up a SeekBar
, you can scale it by a factor of 100 like you’ve done in your sample code, since SeekBar
doesn’t support fractional values. Oh, and one more thing for others’ benefit (since you’ve already figured it out): the docs say “UI controls should be scaled logarithmically”, which means that if you just set the volume without any scaling, the volume control will feel unnatural. Basically, halving the amplitude of the wave is NOT perceived by the human ear as “half the volume”, so you need to scale logarithmically to make it feel more natural to the human ear, like you’ve done in your sample code.
If you do want to set the system volume for the given stream (and not just for the given player), you can use AudioManager.setStreamVolume
with a value between 0 and the value returned by AudioManager.getStreamMaxVolume
. But keep in mind that that one is generally a low-resolution volume control – getMaxStreamVolume
usually returns a relatively low value – like 10 or 15, so you only have a few possible positions for the volume. This means that controlling the volume will not be as smooth as if you control the MediaPlayer
‘s volume directly. Also, obviously, setting the volume this way sets it for the entire system and affects all applications, which may not be what the user wants.
Answer:
Adding to TodorK’s answer.
What I did is I initially set the StreamVolume to Max, and let user control the SeekBar. Once they finished , I set the StreamVolume back to its original state.
This allows the user to control the MediaPlayer volume, and does not effect other applicaitons.
First set the Stream to your desired one & Initialize AudioManager
setVolumeControlStream(AudioManager.STREAM_MUSIC);
audioManager = (AudioManager) getActivity().getSystemService(Context.AUDIO_SERVICE);
Get the InitialVolume (so that you set it back to this once you’re done) and set it to MaxVolume
final int initVolume = audioManager.getStreamVolume(AudioManager.STREAM_MUSIC);
final int maxVolume = audioManager.getStreamMaxVolume(AudioManager.STREAM_MUSIC);
audioManager.setStreamVolume(AudioManager.STREAM_MUSIC,maxVolume, 0);
Do the AudioStuff in the onProgress part of the SeekBarChangedListener
@Override
public void onProgressChanged(SeekBar seekBar, int progress,boolean fromUser)
{
float volume = (float) (1 - (Math.log(100 - progress) / Math.log(100)));
mp.setVolume(volume, volume);
mp.start();
}
Once you’re done, set it back to the initialVolume, so that the User doesnt get pissed off (in my case,im using an AlertDialog, so its in the onDismiss thing
@Override
public void onDismiss(DialogInterface dialog)
{
audioManager.setStreamVolume(AudioManager.STREAM_MUSIC,initVolume, 0);
//Stop Playing the Song
stopSong();
}
Also notice, I did the log stuff in the onProgress part
Answer:
First make a seekBar in XML file. Then copy this code (seekBar2
is the Id for the seekBar):
private final static int MAX_VOLUME = 100;
SeekBar seekBar = (SeekBar) findViewById(R.id.seekBar2);
seekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
@Override
public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
float volume = (float) (1 - (Math.log(MAX_VOLUME - progress) / Math.log(MAX_VOLUME)));
mediaPlayer.setVolume(volume, volume);
}
@Override
public void onStartTrackingTouch(SeekBar seekBar) {
}
@Override
public void onStopTrackingTouch(SeekBar seekBar) {
}
});
Tags: androidandroid