Add volume management to CastPlayer

[MGaetan89]

This PR enables volume management in the CastPlayer. In particular, the following methods are now supported:

• setVolume()
• getVolume()
• isDeviceMuted()
• setDeviceMuted()

I've also updated the fetchDeviceInfo() method so now the max volume information is also provided.

---

Note: I didn't do anything for the setDeviceVolume(), increaseDeviceVolume() and decreaseDeviceVolume() methods. Let me know if something should be done there too.

Note 2: I don't have access to b/364580007 (the TODO I modified in CastPlayer). Maybe I'm missing some information or it needs to be updated.

[marcbaechinger]

Very nice change! Thank you very much!

setDeviceVolume(), increaseDeviceVolume()

I think this is fine. You are calling remoteMediaClient.setStreamVolume() which matches to setVolume(). Given there is no way to change the device volume with remoteMediaClient AFAIK, I think it's fine to not have the command for device volume changes and leave the methods as they are.

I don't have access to b/364580007 (

The bug is about setting the device info which is actually done. You can leave that with me.

I'm going to send this for internal review now. You may see some more commits being added as I make changes in response to review feedback. Please refrain from pushing any more substantive changes as it will complicate the internal review - thanks!

[AquilesCanta]

Very nice change! Thank you very much!

+1. Thanks for your PR.

Coincidentally I've been working on a similar fix for a while. But I hit the same issue as (seemingly) a bunch of other people out there. E.g.: https://stackoverflow.com/questions/39498516/remotemediaclient-setstreamvolume-doesnt-changing-cast-volume

As a result I changed my implementation to not use setStreamVolume, and instead use CastSession#setVolume. I was planning on merging this soon. Did setStreamVolume actually work for you? If so, can you share with me the model of the device that you used to test?

FWIW, my plan was to:

1. Implement setDeviceVolume using CastSession.setVolume (same for mute and CastSession#mute).
2. Fix RemoteMediaClient#setStreamVolume, or at least figure out internally what's going on there.
3. Implement, or figure out what to do with CastPlayer#setVolume() after dealing with 2.

[MGaetan89]

Hey @AquilesCanta,

To test my changes, I did a small change to the demo Cast application similar to the patch below/attached. If you think it is useful to include it, I can make it look a bit nicer and include it in this PR.

Basically, I added a slider to change the volume. When sliding ends, I call Player.setVolume() to update the remote volume. On my side, this seems to be working as expected. However, the physical volume buttons don't work.

The Cast device that I used for testing is a Chromecast with Google TV, running Android 14.
The casting device is a Google Pixel 7 Pro running Android 16.

Note that there's no visual feedback on the TV that the volume is changing.

diff --git a/demos/cast/src/main/java/androidx/media3/demo/cast/MainActivity.java b/demos/cast/src/main/java/androidx/media3/demo/cast/MainActivity.java
index ae49a6f45a..ab51c2a87c 100644
--- a/demos/cast/src/main/java/androidx/media3/demo/cast/MainActivity.java
+++ b/demos/cast/src/main/java/androidx/media3/demo/cast/MainActivity.java
@@ -25,6 +25,7 @@ import android.view.View.OnClickListener;
 import android.view.ViewGroup;
 import android.widget.ArrayAdapter;
 import android.widget.ListView;
+import android.widget.SeekBar;
 import android.widget.TextView;
 import android.widget.Toast;
 import androidx.annotation.Nullable;
@@ -85,6 +86,22 @@ public class MainActivity extends AppCompatActivity
     playerView = findViewById(R.id.player_view);
     playerView.requestFocus();
 
+    SeekBar volume = findViewById(R.id.volume_bar);
+    volume.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
+      @Override
+      public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
+      }
+
+      @Override
+      public void onStartTrackingTouch(SeekBar seekBar) {
+      }
+
+      @Override
+      public void onStopTrackingTouch(SeekBar seekBar) {
+        playerView.getPlayer().setVolume(seekBar.getProgress() / 100f);
+      }
+    });
+
     mediaQueueList = findViewById(R.id.sample_list);
     ItemTouchHelper helper = new ItemTouchHelper(new RecyclerViewCallback());
     helper.attachToRecyclerView(mediaQueueList);
diff --git a/demos/cast/src/main/res/layout/main_activity.xml b/demos/cast/src/main/res/layout/main_activity.xml
index 81320bb75b..5778e6a2e4 100644
--- a/demos/cast/src/main/res/layout/main_activity.xml
+++ b/demos/cast/src/main/res/layout/main_activity.xml
@@ -27,6 +27,12 @@
       android:background="@android:color/black"
       app:repeat_toggle_modes="all|one"/>
 
+  <SeekBar android:id="@+id/volume_bar"
+    android:layout_width="match_parent"
+    android:layout_height="48dp"
+    android:min="0"
+    android:max="100"/>
+
   <RelativeLayout android:layout_width="match_parent"
       android:layout_height="0dp"
       android:layout_weight="1">

demo_volume.patch

[AquilesCanta]

I appreciate the diff but it's not necessary. I already have a similar local setup. What I was interested in learning was about the receiver device.

It's strange I also tried with a chromecast running Android TV. Also tried with a Pixel tablet. And in both cases setStreamVolume didn't do anything. Let me dig a bit deeper.

[MGaetan89]

Hey @AquilesCanta,

I see that you pushed some changes related to volume management in the CastPlayer in 405365c.
Is there anything to keep from this PR, or can I close it?

[AquilesCanta]

So, even though I haven't managed to get RemoteMediaClient#setStreamVolume to work. I can confirm that CastSession#setVolume behaves as you'd expect for Player#setDeviceVolume. E.g. a UI slider shows up when I cast to a tablet and I call Player#setVolume. So I'm inclined to think RemoteMediaClient (when working properly) maps reasonably well to Player#setVolume. If you'd like to rebase your PR so that you only include the Player#setVolume (and family) method (and leave the #setDeviceVolume bit working as in the main tree) we can merge that part. Also, if you have any input on the solution using CastSession#setVolume, that'd be welcome.

E.g.

Note that there's no visual feedback on the TV that the volume is changing.

Using CastSession#setVolume, I'm getting a volume slider.

[MGaetan89]

Sure, I'll rebase my PR so it only includes Player#setVolume().
I'll test it a bit more before pushing my changes.

[MGaetan89]

@AquilesCanta I've updated my PR to fix the conflicts. It should be good for a second round of review now.

[AquilesCanta]

Thanks! I'm out of office for two weeks. I'll take a look as soon as I can after I'm back.

[MGaetan89]

I've played a bit more with the device volume feature in Cast player (introduced in 405365c), but I am not able to make it work.

Steps to reproduce

• Run the demo-cast application.
• Play one of the media.
• Cast it on a Chromecast (Chromecast with Google TV, running Android 14).
• Use the sender device's physical volume buttons (Google Pixel 7 Pro, running Android 16).

Actual result
The sender volume is changed.

Expected result
The receiver volume is changed.

Am I maybe missing something?

[AquilesCanta]

Hi, I'm now back, and will pick this back up soon.

I've played a bit more with the device volume feature in Cast player (introduced in 405365c), but I am not able to make it work.

mmm this is worrying, as that would mean that each approach (CastSession volume and RemoteMediaClient volume) works on different scenarios. Thanks for flagging. I'll let you know what I find.

[AquilesCanta]

Ok, so these are my findings. I've tested on the following receivers:

• Nest audio speaker
• Pixel tablet
• Chromecast running android TV

The conclusion is the following:

• CastSession.volume() controls the volume of the device.
• RemoteMediaClient.setStreamVolume controls the volume of the signal that the receiver app feeds to the device.

The only device that shows issues with session volume is the chromecast dongle, because it's not able to adjust the volume on the receiver device. For me, when I can setSessionVolume, I'll get a toast on the receiver device saying "please adjust using the device's remote control", or something along those lines.

The session volume is generally better, in that it provides the user with visual indication of the volume change (a volume slider on the tablet, and little lights on the nest audio speakers). The stream volume is silent in that sense.

I believe we want the merge this change as is, but keep the media session only associated with the session volume (which controls the device volume). I'll bring this up with the relevant audience internally, and see next steps. But at least you have visibility of what's going on on this front. For the time being I'll try to merge your pull request for which, once again, many thanks!

EDIT: Please avoid making any additional changes in this PR.