README.md

RxMusicPlayer

RxMusicPlayer is a wrapper of avplayer backed by RxSwift to make it easy for audio playbacks.

Features

• Following the Audio Guidelines for User-Controlled Playback and Recording Apps.
• Support for streaming both remote and local audio files.
• Functions to play, pause, stop, play next, play previous, skip forward/backward, prefetch metadata, repeat mode(repeat, repeat all), shuffle mode desired playback rate, seek to a certain second, and append/insert/remove an item into the playlist.
• Loading metadata, including title, album, artist, artwork, duration, and lyrics.
• Background mode integration with MPNowPlayingInfoCenter.
• Remote command control integration with MPRemoteCommandCenter.
• Interruption handling with AVAudioSession.interruptionNotification.
• Route change handling with AVAudioSession.routeChangeNotification.
• Including a fully working example project, one built on UIKit and the other built on SwiftUI.

Runtime Requirements

• iOS 10.0 or later

Installation

Swift Package Manager

With 2.0.1 and above.

Carthage

github "yoheimuta/RxMusicPlayer"

CocoaPods

pod "RxMusicPlayer"

Usage

For details, refer to the ExampleSwiftUI project or Example project. Plus, see also Users section below.

Example

You can implement your audio player with the custom frontend without any delegates, like below.

Based on SwiftUI

import SwiftUI
import Combine
import RxMusicPlayer
import RxSwift
import RxCocoa

final class PlayerModel: ObservableObject {
    private let disposeBag = DisposeBag()
    private let player: RxMusicPlayer
    private let commandRelay = PublishRelay<RxMusicPlayer.Command>()

    @Published var canPlay = true
    @Published var canPlayNext = true
    @Published var canPlayPrevious = true
    @Published var canSkipForward = true
    @Published var canSkipBackward = true
    @Published var title = "Not Playing"
    @Published var artwork: UIImage?
    @Published var restDuration = "--:--"
    @Published var duration = "--:--"
    @Published var shuffleMode = RxMusicPlayer.ShuffleMode.off
    @Published var repeatMode = RxMusicPlayer.RepeatMode.none
    @Published var remoteControl = RxMusicPlayer.RemoteControl.moveTrack

    @Published var sliderValue = Float(0)
    @Published var sliderMaximumValue = Float(0)
    @Published var sliderIsUserInteractionEnabled = false
    @Published var sliderPlayableProgress = Float(0)

    private var cancelBag = Set<AnyCancellable>()
    var sliderValueChanged = PassthroughSubject<Float, Never>()

    init() {
        // 1) Create a player
        let items = [
            URL(string: "https://storage.googleapis.com/great-dev/oss/musicplayer/tagmp3_1473200_1.mp3")!,
            URL(string: "https://storage.googleapis.com/great-dev/oss/musicplayer/tagmp3_2160166.mp3")!,
            URL(string: "https://storage.googleapis.com/great-dev/oss/musicplayer/tagmp3_4690995.mp3")!,
            Bundle.main.url(forResource: "tagmp3_9179181", withExtension: "mp3")!
        ]
        .map({ RxMusicPlayerItem(url: $0) })
        player = RxMusicPlayer(items: items)!

        // 2) Control views
        player.rx.canSendCommand(cmd: .play)
            .do(onNext: { [weak self] canPlay in
                self?.canPlay = canPlay
            })
            .drive()
            .disposed(by: disposeBag)

        player.rx.canSendCommand(cmd: .next)
            .do(onNext: { [weak self] canPlayNext in
                self?.canPlayNext = canPlayNext
            })
            .drive()
            .disposed(by: disposeBag)

        player.rx.canSendCommand(cmd: .previous)
            .do(onNext: { [weak self] canPlayPrevious in
                self?.canPlayPrevious = canPlayPrevious
            })
            .drive()
            .disposed(by: disposeBag)

        player.rx.canSendCommand(cmd: .seek(seconds: 0, shouldPlay: false))
            .do(onNext: { [weak self] canSeek in
                self?.sliderIsUserInteractionEnabled = canSeek
            })
            .drive()
            .disposed(by: disposeBag)

        player.rx.canSendCommand(cmd: .skip(seconds: 15))
            .do(onNext: { [weak self] canSkip in
                self?.canSkipForward = canSkip
            })
            .drive()
            .disposed(by: disposeBag)

        player.rx.canSendCommand(cmd: .skip(seconds: -15))
            .do(onNext: { [weak self] canSkip in
                self?.canSkipBackward = canSkip
            })
            .drive()
            .disposed(by: disposeBag)

        player.rx.currentItemDuration()
            .do(onNext: { [weak self] in
                self?.sliderMaximumValue = Float($0?.seconds ?? 0)
            })
            .drive()
            .disposed(by: disposeBag)

        player.rx.currentItemTime()
            .do(onNext: { [weak self] time in
                self?.sliderValue = Float(time?.seconds ?? 0)
            })
            .drive()
            .disposed(by: disposeBag)

        player.rx.currentItemLoadedProgressRate()
            .do(onNext: { [weak self] rate in
                self?.sliderPlayableProgress = rate ?? 0
            })
            .drive()
            .disposed(by: disposeBag)

        player.rx.currentItemTitle()
            .do(onNext: { [weak self] title in
                self?.title = title ?? ""
            })
            .drive()
            .disposed(by: disposeBag)

        player.rx.currentItemArtwork()
            .do(onNext: { [weak self] artwork in
                self?.artwork = artwork
            })
            .drive()
            .disposed(by: disposeBag)

        player.rx.currentItemRestDurationDisplay()
            .do(onNext: { [weak self] duration in
                self?.restDuration = duration ?? "--:--"
            })
            .drive()
            .disposed(by: disposeBag)

        player.rx.currentItemTimeDisplay()
            .do(onNext: { [weak self] duration in
                if duration == "00:00" {
                    self?.duration = "0:00"
                    return
                }
                self?.duration = duration ?? "--:--"
            })
            .drive()
            .disposed(by: disposeBag)

        player.rx.shuffleMode()
            .do(onNext: { [weak self] mode in
                self?.shuffleMode = mode
            })
            .drive()
            .disposed(by: disposeBag)

        player.rx.repeatMode()
            .do(onNext: { [weak self] mode in
                self?.repeatMode = mode
            })
            .drive()
            .disposed(by: disposeBag)

        player.rx.remoteControl()
            .do(onNext: { [weak self] control in
                self?.remoteControl = control
            })
            .drive()
            .disposed(by: disposeBag)

        // 3) Process the user's input
        player.run(cmd: commandRelay.asDriver(onErrorDriveWith: .empty()))
            .flatMap { status -> Driver<()> in
                switch status {
                case let RxMusicPlayer.Status.failed(err: err):
                    print(err)
                case let RxMusicPlayer.Status.critical(err: err):
                    print(err)
                default:
                    print(status)
                }
                return .just(())
            }
            .drive()
            .disposed(by: disposeBag)

        commandRelay.accept(.prefetch)

        sliderValueChanged
            .removeDuplicates()
            .sink { [weak self] value in
                self?.seek(value: value)
            }
            .store(in: &cancelBag)
    }

    func seek(value: Float?) {
        commandRelay.accept(.seek(seconds: Int(value ?? 0), shouldPlay: false))
    }

    func skip(second: Int) {
        commandRelay.accept(.skip(seconds: second))
    }

    func shuffle() {
        switch player.shuffleMode {
        case .off: player.shuffleMode = .songs
        case .songs: player.shuffleMode = .off
        }
    }

    func play() {
        commandRelay.accept(.play)
    }

    func pause() {
        commandRelay.accept(.pause)
    }

    func playNext() {
        commandRelay.accept(.next)
    }

    func playPrevious() {
        commandRelay.accept(.previous)
    }

    func doRepeat() {
        switch player.repeatMode {
        case .none: player.repeatMode = .one
        case .one: player.repeatMode = .all
        case .all: player.repeatMode = .none
        }
    }

    func toggleRemoteControl() {
        switch remoteControl {
        case .moveTrack:
            player.remoteControl = .skip(second: 15)
        case .skip:
            player.remoteControl = .moveTrack
        }
    }
}

struct PlayerView: View {
    @StateObject private var model = PlayerModel()

    var body: some View {
        ScrollView {
            VStack {
                Spacer()
                    .frame(width: 1, height: 49)

                if let artwork = model.artwork {
                    Image(uiImage: artwork)
                        .resizable()
                        .scaledToFit()
                        .frame(height: 276)
                } else {
                    Spacer()
                        .frame(width: 1, height: 276)
                }

                ProgressSliderView(value: $model.sliderValue,
                                   maximumValue: $model.sliderMaximumValue,
                                   isUserInteractionEnabled: $model.sliderIsUserInteractionEnabled,
                                   playableProgress: $model.sliderPlayableProgress) {
                    model.sliderValueChanged.send($0)
                }
                    .padding(.horizontal)

                HStack {
                    Text(model.duration)
                    Spacer()
                    Text(model.restDuration)
                }
                .padding(.horizontal)

                Spacer()
                    .frame(width: 1, height: 17)

                Text(model.title)

                Spacer()
                    .frame(width: 1, height: 19)

                HStack(spacing: 20.0) {
                    Button(action: {
                        model.shuffle()
                    }) {
                        Text(model.shuffleMode == .off ? "Shuffle" : "No Shuffle")
                    }

                    Button(action: {
                        model.playPrevious()
                    }) {
                        Text("Previous")
                    }
                    .disabled(!model.canPlayPrevious)

                    Button(action: {
                        model.canPlay ? model.play() : model.pause()
                    }) {
                        Text(model.canPlay ? "Play" : "Pause")
                    }

                    Button(action: {
                        model.playNext()
                    }) {
                        Text("Next")
                    }
                    .disabled(!model.canPlayNext)

                    Button(action: {
                        model.doRepeat()
                    }) {
                        Text({
                            switch model.repeatMode {
                            case .none: return "Repeat"
                            case .one: return "Repeat(All)"
                            case .all: return "No Repeat"
                            }
                        }() as String)
                    }
                }

                Group {
                    Spacer()
                        .frame(width: 1, height: 17)

                    HStack(spacing: 20.0) {
                        Button(action: {
                            model.skip(second: -15)
                        }) {
                            Text("SkipBackward")
                        }
                        .disabled(!model.canSkipBackward)

                        Button(action: {
                            model.skip(second: 15)
                        }) {
                            Text("SkipForward")
                        }
                        .disabled(!model.canSkipForward)
                    }
                }

                Group {
                    Spacer()
                        .frame(width: 1, height: 17)

                    HStack(spacing: 20.0) {
                        Button(action: {
                            model.toggleRemoteControl()
                        }) {
                            let control = model.remoteControl == .moveTrack ? "moveTrack" : "skip"
                            Text("RemoteControl: \(control)")
                        }
                    }
                }
            }
        }
    }
}

struct PlayerView_Previews: PreviewProvider {
    static var previews: some View {
        PlayerView()
    }
}

Based on UIKit

import RxCocoa
import RxMusicPlayer
import RxSwift
import UIKit

class TableViewController: UITableViewController {

    @IBOutlet private var playButton: UIButton!
    @IBOutlet private var nextButton: UIButton!
    @IBOutlet private var prevButton: UIButton!
    @IBOutlet private var titleLabel: UILabel!
    @IBOutlet private var artImageView: UIImageView!
    @IBOutlet private var lyricsLabel: UILabel!
    @IBOutlet private var seekBar: ProgressSlider!
    @IBOutlet private var seekDurationLabel: UILabel!
    @IBOutlet private var durationLabel: UILabel!
    @IBOutlet private var shuffleButton: UIButton!
    @IBOutlet private var repeatButton: UIButton!
    @IBOutlet private var rateButton: UIButton!
    @IBOutlet private var appendButton: UIButton!
    @IBOutlet private var changeButton: UIButton!

    private let disposeBag = DisposeBag()

    // swiftlint:disable cyclomatic_complexity
    override func viewDidLoad() {
        super.viewDidLoad()

        // 1) Create a player
        let items = [
            "https://storage.googleapis.com/great-dev/oss/musicplayer/tagmp3_1473200_1.mp3",
            "https://storage.googleapis.com/great-dev/oss/musicplayer/tagmp3_2160166.mp3",
            "https://storage.googleapis.com/great-dev/oss/musicplayer/tagmp3_4690995.mp3",
            "https://storage.googleapis.com/great-dev/oss/musicplayer/tagmp3_9179181.mp3",
            "https://storage.googleapis.com/great-dev/oss/musicplayer/bensound-extremeaction.mp3",
            "https://storage.googleapis.com/great-dev/oss/musicplayer/bensound-littleplanet.mp3",
        ]
        .map({ RxMusicPlayerItem(url: URL(string: $0)!) })
        let player = RxMusicPlayer(items: Array(items[0 ..< 4]))!

        // 2) Control views
        player.rx.canSendCommand(cmd: .play)
            .do(onNext: { [weak self] canPlay in
                self?.playButton.setTitle(canPlay ? "Play" : "Pause", for: .normal)
            })
            .drive()
            .disposed(by: disposeBag)

        player.rx.canSendCommand(cmd: .next)
            .drive(nextButton.rx.isEnabled)
            .disposed(by: disposeBag)

        player.rx.canSendCommand(cmd: .previous)
            .drive(prevButton.rx.isEnabled)
            .disposed(by: disposeBag)

        player.rx.canSendCommand(cmd: .seek(seconds: 0, shouldPlay: false))
            .drive(seekBar.rx.isUserInteractionEnabled)
            .disposed(by: disposeBag)

        player.rx.currentItemTitle()
            .drive(titleLabel.rx.text)
            .disposed(by: disposeBag)

        player.rx.currentItemArtwork()
            .drive(artImageView.rx.image)
            .disposed(by: disposeBag)

        player.rx.currentItemLyrics()
            .distinctUntilChanged()
            .do(onNext: { [weak self] _ in
                self?.tableView.reloadData()
            })
            .drive(lyricsLabel.rx.text)
            .disposed(by: disposeBag)

        player.rx.currentItemRestDurationDisplay()
            .map {
                guard let rest = $0 else { return "--:--" }
                return "-\(rest)"
            }
            .drive(durationLabel.rx.text)
            .disposed(by: disposeBag)

        player.rx.currentItemTimeDisplay()
            .drive(seekDurationLabel.rx.text)
            .disposed(by: disposeBag)

        player.rx.currentItemDuration()
            .map { Float($0?.seconds ?? 0) }
            .do(onNext: { [weak self] in
                self?.seekBar.maximumValue = $0
            })
            .drive()
            .disposed(by: disposeBag)

        let seekValuePass = BehaviorRelay<Bool>(value: true)
        player.rx.currentItemTime()
            .withLatestFrom(seekValuePass.asDriver()) { ($0, $1) }
            .filter { $0.1 }
            .map { Float($0.0?.seconds ?? 0) }
            .drive(seekBar.rx.value)
            .disposed(by: disposeBag)
        seekBar.rx.controlEvent(.touchDown)
            .do(onNext: {
                seekValuePass.accept(false)
            })
            .subscribe()
            .disposed(by: disposeBag)
        seekBar.rx.controlEvent(.touchUpInside)
            .do(onNext: {
                seekValuePass.accept(true)
            })
            .subscribe()
            .disposed(by: disposeBag)

        player.rx.currentItemLoadedProgressRate()
            .drive(seekBar.rx.playableProgress)
            .disposed(by: disposeBag)

        player.rx.shuffleMode()
            .do(onNext: { [weak self] mode in
                self?.shuffleButton.setTitle(mode == .off ? "Shuffle" : "No Shuffle", for: .normal)
            })
            .drive()
            .disposed(by: disposeBag)

        player.rx.repeatMode()
            .do(onNext: { [weak self] mode in
                var title = ""
                switch mode {
                case .none: title = "Repeat"
                case .one: title = "Repeat(All)"
                case .all: title = "No Repeat"
                }
                self?.repeatButton.setTitle(title, for: .normal)
            })
            .drive()
            .disposed(by: disposeBag)

        player.rx.playerIndex()
            .do(onNext: { index in
                if index == player.queuedItems.count - 1 {
                    // You can remove the comment-out below to confirm the append().
                    // player.append(items: items)
                }
            })
            .drive()
            .disposed(by: disposeBag)

        // 3) Process the user's input
        let cmd = Driver.merge(
            playButton.rx.tap.asDriver().map { [weak self] in
                if self?.playButton.currentTitle == "Play" {
                    return RxMusicPlayer.Command.play
                }
                return RxMusicPlayer.Command.pause
            },
            nextButton.rx.tap.asDriver().map { RxMusicPlayer.Command.next },
            prevButton.rx.tap.asDriver().map { RxMusicPlayer.Command.previous },
            seekBar.rx.controlEvent(.valueChanged).asDriver()
                .map { [weak self] _ in
                    RxMusicPlayer.Command.seek(seconds: Int(self?.seekBar.value ?? 0),
                                               shouldPlay: false)
                }
                .distinctUntilChanged()
        )
        .startWith(.prefetch)
        .debug()

        // You can remove the comment-out below to confirm changing the current index of music items.
        // Default is 0.
        // player.playIndex = 1

        player.run(cmd: cmd)
            .do(onNext: { status in
                UIApplication.shared.isNetworkActivityIndicatorVisible = status == .loading
            })
            .flatMap { [weak self] status -> Driver<()> in
                guard let weakSelf = self else { return .just(()) }

                switch status {
                case let RxMusicPlayer.Status.failed(err: err):
                    print(err)
                    return Wireframe.promptOKAlertFor(src: weakSelf,
                                                      title: "Error",
                                                      message: err.localizedDescription)

                case let RxMusicPlayer.Status.critical(err: err):
                    print(err)
                    return Wireframe.promptOKAlertFor(src: weakSelf,
                                                      title: "Critical Error",
                                                      message: err.localizedDescription)
                default:
                    print(status)
                }
                return .just(())
            }
            .drive()
            .disposed(by: disposeBag)

        shuffleButton.rx.tap.asDriver()
            .drive(onNext: {
                switch player.shuffleMode {
                case .off: player.shuffleMode = .songs
                case .songs: player.shuffleMode = .off
                }
            })
            .disposed(by: disposeBag)

        repeatButton.rx.tap.asDriver()
            .drive(onNext: {
                switch player.repeatMode {
                case .none: player.repeatMode = .one
                case .one: player.repeatMode = .all
                case .all: player.repeatMode = .none
                }
            })
            .disposed(by: disposeBag)

        rateButton.rx.tap.asDriver()
            .flatMapLatest { [weak self] _ -> Driver<()> in
                guard let weakSelf = self else { return .just(()) }

                return Wireframe.promptSimpleActionSheetFor(
                    src: weakSelf,
                    cancelAction: "Close",
                    actions: PlaybackRateAction.allCases.map {
                        ($0.rawValue, player.desiredPlaybackRate == $0.toFloat)
                })
                    .do(onNext: { [weak self] action in
                        if let rate = PlaybackRateAction(rawValue: action)?.toFloat {
                            player.desiredPlaybackRate = rate
                            self?.rateButton.setTitle(action, for: .normal)
                        }
                    })
                    .map { _ in }
            }
            .drive()
            .disposed(by: disposeBag)

        appendButton.rx.tap.asDriver()
            .do(onNext: {
                let newItems = Array(items[4 ..< 6])
                player.append(items: newItems)
            })
            .drive(onNext: { [weak self] _ in
                self?.appendButton.isEnabled = false
            })
            .disposed(by: disposeBag)

        changeButton.rx.tap.asObservable()
            .flatMapLatest { [weak self] _ -> Driver<()> in
                guard let weakSelf = self else { return .just(()) }

                return Wireframe.promptSimpleActionSheetFor(
                    src: weakSelf,
                    cancelAction: "Close",
                    actions: items.map {
                        ($0.url.lastPathComponent, player.queuedItems.contains($0))
                })
                    .asObservable()
                    .do(onNext: { action in
                        if let idx = player.queuedItems.map({ $0.url.lastPathComponent }).firstIndex(of: action) {
                            try player.remove(at: idx)
                        } else if let idx = items.map({ $0.url.lastPathComponent }).firstIndex(of: action) {
                            for i in (0 ... idx).reversed() {
                                if let prev = player.queuedItems.firstIndex(of: items[i]) {
                                    player.insert(items[idx], at: prev + 1)
                                    break
                                }
                                if i == 0 {
                                    player.insert(items[idx], at: 0)
                                }
                            }
                        }

                        self?.appendButton.isEnabled = !(player.queuedItems.contains(items[4])
                            || player.queuedItems.contains(items[5]))
                    })
                    .asDriver(onErrorJustReturn: "")
                    .map { _ in }
            }
            .asDriver(onErrorJustReturn: ())
            .drive()
            .disposed(by: disposeBag)
    }
}

Users

• AMMusicPlayerController
  • https://github.com/yoheimuta/AMMusicPlayerController

Contributing

• Fork it
• Run make bootstrap
• Create your feature branch: git checkout -b your-new-feature
• Commit changes: git commit -m 'Add your feature'
• Push to the branch: git push origin your-new-feature
• Submit a pull request

Release

• Create a new release on GitHub
• Publish a new podspec on Cocoapods
  • bundle exec pod trunk push RxMusicPlayer.podspec

Bug Report

While any bug reports are helpful, it's sometimes unable to pinpoint the cause without a reproducible project.

In particular, since RxMusicPlayer depends on RxSwift that is prone to your application program mistakes, it's more essential to decouple the problem.

Therefore, I highly recommend that you submit an issue with that project.

You can create it like the following steps.

• Fork it
• Create your feature branch: git checkout -b your-bug-name
• Add some changes under the Example directory to reproduce the bug
• Commit changes: git commit -m 'Add a reproducible feature'
• Push to the branch: git push origin your-bug-name
• (Optional) Submit a pull request
• Share it in your issue

The code should not be intertwined but concise, straightforward, and naive.

NOTE: If you can't prepare any reproducible code, you have to elaborate the detail precisely and clearly so that I can reproduce the problem.

License

The MIT License (MIT)

Acknowledgement

Thank you to the following projects and creators.

• Jukebox: https://github.com/teodorpatras/Jukebox
  • I inspired by this library for the interface and some implementation.
• RxAudioVisual: https://github.com/keitaoouchi/RxAudioVisual
  • I referred to some implementation instead of depending on it due to adaptation to the latest Swift compiler.
• Smith, J.O. Physical Audio Signal Processing: https://ccrma.stanford.edu/~jos/waveguide/Sound_Examples.html
  • This project is using these as sample mp3 files.
• file-examples.com: https://file-examples.com/index.php/sample-audio-files/sample-mp3-download/
  • This project is using one as a sample mp3 file.