iOS Tutorial Background playback

This tutorial explains how you can play local audio files or stream audio while your app is in the background.
Standard applications are killed when moved to the background. However you can add the following attribute to your project to mark it as an application that plays audio in the background:

#Region  Project Attributes
   #ApplicationLabel: B4i Example
   #Version: 1.0.0
   'Orientation possible values: Portrait, LandscapeLeft, LandscapeRight and PortraitUpsideDown
   #iPhoneOrientations: Portrait, LandscapeLeft, LandscapeRight
   #iPadOrientations: Portrait, LandscapeLeft, LandscapeRight, PortraitUpsideDown
   #Target: iPhone, iPad
   #MinVersion: 8
#End Region
#PlistExtra: <key>UIBackgroundModes</key><array><string>audio</string></array>

Sub Process_Globals
    Public App As Application
    Public NavControl As NavigationController
    Private Page1 As Page
    Private NativeMe As NativeObject
    Private VideoPlayer1 As VideoPlayer
End Sub

Private Sub Application_Start (Nav As NavigationController)
    NativeMe = Me
    NavControl = Nav
    Page1.Initialize("Page1")
    Page1.RootPanel.LoadLayout("1")
    NavControl.ShowPage(Page1)
    NativeMe.RunMethod("setAudioSession", Null)
    VideoPlayer1.LoadVideoUrl("https://stream-dc1.radioparadise.com/mp3-32")
    VideoPlayer1.Play
   
    NativeMe.RunMethod("register", Null)
End Sub

Public Sub ControlEvent (Command As String)
    Select Command
        Case "play"
            VideoPlayer1.Play
        Case "pause"
            VideoPlayer1.Pause
    End Select
End Sub



#If OBJC
@import MediaPlayer;
#import <AVFoundation/AVFoundation.h>
#import <AudioToolbox/AudioToolbox.h>
- (void)setAudioSession {
  AVAudioSession *audioSession = [AVAudioSession sharedInstance];
  NSError *err = nil;
  BOOL success = [audioSession setCategory:AVAudioSessionCategoryPlayback error:&err];
  if (success) {
     success = [audioSession setActive:YES error:&err];
   success = [audioSession setPreferredSampleRate:4096 error:nil];
   [[UIApplication sharedApplication] beginReceivingRemoteControlEvents];
  }
  if (!success)
  [NSException raise:@"" format:@"Error setting audio session: %@", err];
}
- (void)register {
   MPRemoteCommandCenter* center = [MPRemoteCommandCenter sharedCommandCenter];
   center.playCommand.enabled = true;
   center.pauseCommand.enabled = true;
   [center.playCommand addTarget:self action:@selector(play)];
   [center.pauseCommand addTarget:self action:@selector(pause)];
}
- (MPRemoteCommandHandlerStatus) play {
   NSLog(@"test");
   [self.bi raiseEvent:nil event:@"controlevent:"  params:@[@"play"]];
   return MPRemoteCommandHandlerStatusSuccess;

}
- (MPRemoteCommandHandlerStatus) pause {
   [self.bi raiseEvent:nil event:@"controlevent:"  params:@[@"pause"]];
   return MPRemoteCommandHandlerStatusSuccess;
}

#end if

The above code will play the radio stream. You can leave your app and the streaming will continue.

With this code the user can play and pause the playback from the draggable control center.

 

[ilan]

this is great... just discovered this thread, did not knew its possible with b4i..

 

[yonson]

brilliant thank you so much for this, really essential for a lot of apps I'm srue

 

[susu]

How can I play online audio source with .m3u file?

 

[susu]

How can I play online audio source with .m3u file?

Sorry, .m3u file works fine for MP3, AAC codec not Ogg Vorbis.

 

[gudino jose luis]

Thank you so much for this...

 

[Erel]

Code in first post was updated to allow controlling the playback from the bottom drawer.

You can add more commands if you need: https://developer.apple.com/library...iaPlayer/Reference/MPRemoteCommandCenter_Ref/

 

[Daniel Uribe]

Greetings, here the next and previous buttons in background, result very efficient when you have a playlist.

Public Sub ControlEvent (Command AsString)
Select Command
         Case"play"
            vv.Play
         Case"pause"
            vv.Pause
        Case "nextTrack"
            Log("next")
        Case "previousTrack"
            Log("previous")
    End Select
End Sub



#If OBJC
@import MediaPlayer;
#import <AVFoundation/AVFoundation.h>
#import <AudioToolbox/AudioToolbox.h>
- (void)setAudioSession {
  AVAudioSession *audioSession = [AVAudioSession sharedInstance];
  NSError *err = nil;
  BOOL success = [audioSession setCategory:AVAudioSessionCategoryPlayback error:&err];
  if (success) {
  success = [audioSession setActive:YES error:&err];
  }
  if (!success)
  [NSException raise:@"" format:@"Error setting audio session: %@", err];
  [[UIApplication sharedApplication] beginReceivingRemoteControlEvents];
}
- (void)register {
   MPRemoteCommandCenter* center = [MPRemoteCommandCenter sharedCommandCenter];
   center.playCommand.enabled = true;
   center.pauseCommand.enabled = true;
   center.nextTrackCommand.enabled = true;
   center.previousTrackCommand.enabled = true;
   [center.playCommand addTarget:self action:@selector(play)];
   [center.pauseCommand addTarget:self action:@selector(pause)];
   [center.nextTrackCommand addTarget:self action:@selector(nextTrack)];
   [center.previousTrackCommand addTarget:self action:@selector(previousTrack)];
}
- (void) play {
   NSLog(@"test");
   [self.bi raiseEvent:nil event:@"controlevent:"  params:@[@"play"]];
}
- (void) pause {
   [self.bi raiseEvent:nil event:@"controlevent:"  params:@[@"pause"]];
}
- (void) nextTrack {
   [self.bi raiseEvent:nil event:@"controlevent:"  params:@[@"nextTrack"]];
}
- (void) previousTrack {
   [self.bi raiseEvent:nil event:@"controlevent:"  params:@[@"previousTrack"]];
}
- (void)remoteControlReceivedWithEvent:(UIEvent *)receivedEvent {
  if (receivedEvent.type == UIEventTypeRemoteControl) {
     [self.bi raiseEvent:nil event:@"remotecontrol_event:"
       params:@[@(receivedEvent.subtype)]];
   }
}

#end if

 

[cloner7801]

How can I add name and image to controll center music player ?

 

[Erel]

Are you using VideoView? What are you playing?

 

[cloner7801]

Are you using VideoView? What are you playing?

yes , I use videoView to stream mp3 file and play

 

[Erel]

1. Add this code to the OBJC block:

- (MPMediaItemArtwork*)createArtwork:(UIImage*) image {
   return [[MPMediaItemArtwork alloc] initWithBoundsSize:image.size requestHandler:^UIImage* _Nonnull(CGSize aSize) { return image; }];
}

2. Set title and artwork:

  Dim artwork As NativeObject = NativeMe.RunMethod("createArtwork:", Array(LoadBitmapResize(File.DirAssets, "b4i_128_128.png", 64, 64, True)))
   SetPlayingInfo(CreateMap("title": "Radio Paradise", "artwork": artwork))
End Sub

Sub SetPlayingInfo (info As Map)
   Dim NowPlayingInfoCenter As NativeObject
   NowPlayingInfoCenter = NowPlayingInfoCenter.Initialize("MPNowPlayingInfoCenter").RunMethod("defaultCenter", Null)
   Dim no As NativeObject = info
   NowPlayingInfoCenter.SetField("nowPlayingInfo", no.RunMethod("ToDictionary", Null))
End Sub

 

[cloner7801]

1. Add this code to the OBJC block:

- (MPMediaItemArtwork*)createArtwork:(UIImage*) image {
   return [[MPMediaItemArtwork alloc] initWithBoundsSize:image.size requestHandler:^UIImage* _Nonnull(CGSize aSize) { return image; }];
}

2. Set title and artwork:

  Dim artwork As NativeObject = NativeMe.RunMethod("createArtwork:", Array(LoadBitmapResize(File.DirAssets, "b4i_128_128.png", 64, 64, True)))
   SetPlayingInfo(CreateMap("title": "Radio Paradise", "artwork": artwork))
End Sub

Sub SetPlayingInfo (info As Map)
   Dim NowPlayingInfoCenter As NativeObject
   NowPlayingInfoCenter = NowPlayingInfoCenter.Initialize("MPNowPlayingInfoCenter").RunMethod("defaultCenter", Null)
   Dim no As NativeObject = info
   NowPlayingInfoCenter.SetField("nowPlayingInfo", no.RunMethod("ToDictionary", Null))
End Sub

How can I set playing info ? with SetPlayingInfo

can you post a example?
---
SOLVED !

 

[Erel]

Project was updated and is now based on VideoPlayer.