I have a camera activity that can record video. I think that some of the code for setting up the video recording possibility also runs some code (under the hood) for preventing the recording to be disturbed if a phone call or an alarm goes off. (However I need to stop the recording when an alarm goes off.)
I would like to add some kind of "receiver" (or something similar) that can register if something like a call or an alarm goes off, and was wondering if anyone knows how to know when an alarm goes off during a video recording.
Related
I have an audio recording service in my app which will record the sound continuously. So, it will always occupy the AudioRecord. It means no other app can use audio recorder as it is already occupied by the service. Is there any way to notify that other app is requesting for audio recorder(so that I can release it) and also when the app releases it(so that I can assign it back to the service)?
Maybe a possible way is to create a BroadcastReceiver which receives an event from the app which is requesting the control over the mic source. The onReceive() method should interact with the service and release the resource. When the other app is finishing it can revert the process to start the service again. If you can't get control over the behavior of the requesting app I think there's a slightly different problem. Anyway:
The problem is all about knowing when the resource is being requested, this can be done through AudioManager intent types.
Be sure to check Managing audio focus which talks about audio focus loss in TRANSIENT way!
As #Rekire mentioned, there is possibly no way to achieve this. Also, AudioManager provide no such broadcasts, so it is not possible for different apps. Maybe rooting the device is the only option.
This can be done with AudioManager.OnAudioFocusChangeListener callback. Just stop recording on AUDIOFOCUS_LOSS_TRANSIENT event and start again on AUDIOFOCUS_GAIN event.
This solution works well for Google Voice Search (Google Search widget, Google Chrome, etc).
But unfortunately it works poorly for other ordinary applications (for example HTC M7 Voice Recorder app is not able to start recording on first click on "Record" button, second click do the trick - it seems app should be ready to retry recording on failure several times).
I'm writing an Android music player, and is stuck on audio focus issue.
It seems like audio focus mainly affects media button receiving, but after reading the document I have no idea about when to gain and give up focus.
My music app will run in background, and need to detect play/pause button every time. That is, even when my app is not running, a user should be able to press headset's play button and start music.
It seems I should never give up audio focus, so why should I implement it?
Does anyone know practically how audio focus should be used? Thank you!
It seems like audio focus mainly affects media button receiving, but
after reading the document I have no idea about when to gain and give
up focus.
They both are separate functionalities, and thus have separate listeners. You may have audio focus taken away from you but you may still choose to respond to play pause hardware keys
That is, even when my app is not running, a user should be able to
press headset's play button and start music.
I am assuming that you meant by the above line is that you are still playing music but not showing an activity. To keep listening to hardware button press, dont unregister your media button receiver(dont call audioManager.unregisterMediaButtonEventReceiver(receiver) yet).
It seems I should never give up audio focus, so why should I implement
it?
you dont give up the focus , it gets taken from you. To handle that gracefully you have AudioFocus listener. For ex, consider an incoming phone call. Would you still like to continue playing your music?
Is there a way to know if the telephone is playing anything? for example a ringtone.
My phone doesn't work properly and I sometimes get a call without a ringtone. I mean, I can see the incoming call screen but nothing is heard (of course it is not in silence). It happens sometimes.
So I programmed something to detect incoming calls (a receiver) and play the default ringtone. It works pretty well when my phone fails, because I force it by playing it again.
The problem comes when my phone works! because in that case you can hear both at the same time (phone's and mine) and sounds terrible!
So I need to do one thing of these two:
-Either detect that the phone worked well (it is ringing) so I don't have to play anything.
-Or stop any current ringing (if any) and play it myself always.
Any help?
P.S.: I tried isMusicActive() and it doesn't work for the ringing.
You could try using the isMusicActive() method in AudioManager. I'm quite sure that it'll work system wide, but if you try it and it doesn't, do post back here.
This page gives a great description of how to manage audio focus.
You could implement onAudioFocusedChangedListener to get constant updates on what is playing.
And even the isMusicActive() method may also be helpful, as #raghav points out.
Right now my application lets the user start recording audio and puts an ongoing notification that can pause/restart recording on press using android.media.AudioRecord. All was fine and dandy until I realized that this blocks any other App from using an AudioRecorder (ie google voice search).
Is there a way I can set up a broadcast reciever to detect a call for an AudioRecorder from another app and pause my recording. Alternatively, is there another way to record audio that wont interfere with other Apps that use audio?
Cheers!
I have been looking into this very question for a while now. It seems that there is no clean way of achieving this as there is no broadcast that alerts when another app would like access to the mic.
The way that we have solved it (albeit not cleanly) is we poll what app is in the foreground and get its permissions; if that app has permission to use the mic, we terminate recording until there isn't an app in the foreground with the mic permission.
Although polling is a solution, I would be very interested if anyone has better!
I am trying to figure out what is the correct (new) approach for handling the Intent.ACTION_MEDIA_BUTTON in Froyo. In pre 2.2 days we had to register a BroadcastReceiver (either permanently or at run-time) and the Media Button events would arrive, as long as no other application intercepts them and aborts the broadcast.
Froyo seems to still somewhat support that model (at least for the wired headset), but it also introduces the registerMediaButtonEventReceiver, and unregisterMediaButtonEventReceiver methods that seem to control the "transport focus" between applications.
During my experiments, using registerMediaButtonEventReceiver does cause both the bluetooth and the wired headset button presses to be routed to the application's broadcast receiver (the app gets the "transport focus"), but it looks like any change in the audio routing (for example unplugging the headset) shits the focus back to the default media player.
What is the logic behind the implementation in Android 2.2? What is correct way to handle transport controls? Do we have to detect the change in the audio routing and try to re-gain the focus?
This is an issue that any 3rd party media player on the Android platform has to deal with, so I hope that somebody (probably a Google Engineer) can provide some guidelines that we can all follow. Having a standard approach may make headset button controls a bit more predictable for the end users.
Stefan
Google has a detailed blog post on implementing the newer 2.2 AudioManager media button event receiver while maintaining backwards compatibility with older devices.
http://android-developers.blogspot.com/2010/06/allowing-applications-to-play-nicer.html
After some experiments, I was able to get a working solution with the new transport and audio focus infrastructure in Android 2.2.
What I end up doing is requesting both the Audio Focus (using AudioManager.requestAudioFocus) and the Trasport Focus (using AudioManagter.registerMediaButtonEventReceiver) every time my application starts playback.
requestAudioFocus takes a callback that is called when the audio focus is taken away from you (for example the internal player starts a playback). In my case I just pause the playback in my application if the focus is taken permanently. Same callback also now tells you that the focus is taken only temporary (for example the Nav system is talking) so you can "duck" your playback - lower the volume or pause and resume after it is done talking.
The only issue remaining is that the built in Music Player takes the transport focus every time you connect a Bluetooth headset. This has the effect where the first press of the Play button on the headset after connecting it, always starts the playback in the default Music Player.
There is probably a way to detect the headset connection and "hijack" the transport focus. In my case, I decided to not "fight" the default player, and get the transport focus back when the user manually starts the playback in my application.
If somebody has more insight or knows of a better way of handling the transport/audio focus, please share it.
I also have this same issue with the media button registration.
Periodically the Android returns the media button registration to the default music player. I have not been able to figure out why. This can happen while may application is actively playing as well as while my application playback is paused.
After a number of users complained that their Bluetooth pause and play control buttons would periodically stop working to control my application, I implemented code that re-registers my application by calling registerMediaButtonEventReceiver every 2 seconds. This allows me to get the button registration back and for the most part avoids the time window where where the user presses a Bluetooth media button and the default media player ends up responding.
My application is holding the audio focus during this entire time period, but still loses the Bluetooth button events periodically while it has audio focus. My application always unregisters the media button event receiver if it is called with a notification that it is losing the audio focus, and then registers again if it is later called when a temporary audio focus loss returns the audio focus.
The work around to keep the 2 second timer running and re-registering has been working, but I would like to get rid of this 2 second timer if someone has found a work around for the media button registration periodically switching back to the default media player.