SDK for Apple AVPlayer

This article details how to integrate CDN Mesh Delivery into your mobile app using Apple's AVPlayer on iOS.

Project setup

CocoaPods

To integrate StreamrootSDK into your Xcode project using CocoaPods, specify this in your Podfile:

use_frameworks!
target ' <Your Target Name >'
  pod 'StreamrootSDK', '~> 3.22.0'
end

Then, run the following command:

$ pod update

Finally, open the generated Workspace.

Carthage

Add the dependencies to the Cartfile:

binary "https://sdk.streamroot.io/ios/StreamrootSDK.json" ~> 3.22.0
github "daltoniam/Starscream" ~> 3.1.1
github "getsentry/sentry-cocoa" ~> 4.4.0
github "apple/swift-protobuf" ~> 1.7.0

Link the frameworks to your project:

Manually

1. Install dependencies

• daltoniam/Starscream
• getsentry/sentry-cocoa
• apple/swift-protobuf

Current dependencies versions can be found here.

2. Downloads Streamroot SDK

StreamrootSDK.framework: https://sdk.streamroot.io/ios/StreamrootSDK/3.22.0/StreamrootSDK.framework.zip

Copy script: http://sdk.streamroot.io/ios/copy_streamroot_sdk

3. Add StreamrootSDK.framework to your project

4. Link Binary With Libraries

Drag and drop StreamrootSDK.framework into your Xcode project. Make sure StreamrootSDK.framework has been added to your target's build phases under Link Binary With Libraries.

5. Copy the framework

There is no need for the script if using ARM version.

Create a new build phase (New Run Script Phase) to call the copy_streamroot_sdk script.

Add the folder containing the StreamrootSDK.framework in the Input Files field. It defaults to $(SRCROOT)/ if none input file is set.

Notes: Make sure to have all the dependencies installed in your project (ref above);

For Objective-C projects, set Always Embed Swift Standard Libraries to yes in your target's build settings.

Integrate Streamroot SDK

1. Import the SDK

import StreamrootSDK

#import <StreamrootSDK/StreamrootSDK.h>

2. Set the streamrootKey

In the Project Navigator, right click on the main target "Info.plist", and "Open as" → "Source Code".

Add the following lines with the values of the right parameters:

<key>Streamroot</key>
<dict>
  <key>Key</key>
  <string>streamrootKey</string>
</dict>

Here, <streamrootKey> refers to your Streamroot key that you will find in the Account section of the Streamroot Dashboard. If you don't have a Streamroot Key, you can register for a free trial account on our website.

3. Declare the Mesh Delivery Client as an Instance Variable

var dnaClient: DNAClient?

@property (nonatomic, strong) DNAClient *dnaClient;

4. Build and start the Mesh Delivery Client

do {
    dnaClient = try DNAClient.builder()
        .dnaClientDelegate(self)
        .latency(30)
        .streamrootKey(<#streamrootKey#>)
        .start(manifestUrl)
} catch let error {
    print("\(error)")
}

NSError *error;
self.dnaClient = [[[[DNAClient.builder dnaClientDelegate: self] latency: 30] streamrootKey:@"your-streamroot"] start:manifestUrl error: &error];
if (error || !self.dnaClient) {
  NSLog(@"error: %@", error);
}

Other Mesh Delivery options can be called in the builder. Please refer to this article to learn more about them.

5. Play the stream

guard let localPath = self.dnaClient?.manifestLocalURLPath,
  let localUrl = URL(string: localPath) else  {
  print("Could not generate localPath, please check your network")
  return
  }
 
let playerItem = AVPlayerItem(asset: AVURLAsset(url: localUrl))
if let bufferTarget = dnaClient?.bufferTarget {
  if #available(iOS 10.0, tvOS 10.2, *) {
    playerItem.preferredForwardBufferDuration = bufferTarget
  }
}

player = AVPlayer(playerItem: playerItem)
player?.play()

NSURL *url = [[NSURL alloc] initWithString: self.dnaClient.manifestLocalURLPath];
AVPlayerItem *playerItem =[[AVPlayerItem alloc] initWithURL: url];
  if (@available(iOS 10.0, tvOS 10.2, *)) {
    playerItem.preferredForwardBufferDuration = self.dnaClient.bufferTarget;
  }
self.player = [[AVPlayer alloc] initWithPlayerItem: playerItem];
[self.player play];
[self.view setNeedsLayout];
[self.view layoutIfNeeded];
[self.dnaClient displayStatsOnView: self.contentOverlayView];

localUrl refers to the HLS .m3u8 master playlist URL that will be passed to the player.

In order to improve the DNA traffic offload for Live streaming, we highly recommend setting different buffer levels for each player.

Here, at player instantiation, we will distribute the buffer target between 10 and the latency set above (30s recommended).

The maximum buffer target will then dynamically evolve for greater DNA delivery efficiency (Only from SDK 3.9.0).

6. Implement DNAClientDelegate

extension CurrentPlayerViewController: DNAClientDelegate {

  func playbackTime() -> Double {
    if let player = self.player {
       return CMTimeGetSeconds(player.currentTime())
     }
    return 0
  }

  func loadedTimeRanges() -> [NSValue] {
    guard let player = self.player else {
      return []
    }

    let timeRanges = player.currentItem!.loadedTimeRanges
    return timeRanges.map { (value) -> NSValue in
      NSValue(timeRange: TimeRange(range: value.timeRangeValue))
    }
  }

  func updatePeakBitRate(_ bitRate: Double) {
    self.player?.currentItem?.preferredPeakBitRate = bitRate
  }
  
  public func bufferTarget() -> Double {
    if #available(iOS 10.0, tvOS 10.0, *) {
      return self.player?.currentItem?.preferredForwardBufferDuration ?? 0
    }
    return 0.0
  }
  
  public func setBufferTarget(_ target: Double) {
    if #available(iOS 10.0, tvOS 10.0, *) {
      self.player?.currentItem?.preferredForwardBufferDuration = target
    }
  }
}

- (double)playbackTime {
    return CMTimeGetSeconds([self.player currentTime]);
}

- (NSArray<NSValue *> *)loadedTimeRanges {
    if (self.player == nil) {
      return [NSArray array];
    }
    NSMutableArray *timeRanges = [NSMutableArray array];
    for (NSValue *value in [[self.player currentItem] loadedTimeRanges]) {
      TimeRange *timeRange = [[TimeRange alloc] initWithRange:[value CMTimeRangeValue]];
      [timeRanges addObject:[[NSValue alloc] initWithTimeRange:timeRange]];
    }
    return timeRanges;
}

- (void)updatePeakBitRate:(double)bitRate {
    self.player.currentItem.preferredPeakBitRate = bitRate;
}

- (double) bufferTarget {
  return self.player.currentItem.preferredForwardBufferDuration;
}

- (void)setBufferTarget:(double)target {
  self.player.currentItem.preferredForwardBufferDuration = target;
}

7. Integrate the QoS module (optional)

This QoS module will allow you to link AVPlayer events to our SDK in order to get accurate metrics regarding the client session.

If this QoS module isn't implemented, a default module directly embedded in the SDK will be used instead.

let qosModule: QosModule = DNAQos.module(type: .plugin)

// call the method given the corresponding event
@objc public protocol QosModule {
  
  @objc func playerStateDidChange(_ state: PlaybackState)
  
  @objc func trackSwitchOccurred()
  
  @objc func updateDroppedFrameCount(_ count: Int)
  
  @objc func playbackErrorOccurred()
}

@objc public enum PlaybackState: Int {
  case idle
  case playing
  case paused
  case buffering
  case seeking
  case ended
}

It is then required to call the QosModule in the builder.

do {
  dnaClient = try DNAClient.builder().dnaClientDelegate(self)
                                          .latency(30)
                                          .streamrootKey(<#streamrootKey#>)
                                          .qosModule(qosModule)
                                          .start(manifestUrl)
                                          } catch let error {
                                            print("\(error)")
}

Stop the SDK

override func viewDidDisappear(_ animated: Bool) {
    dnaClient?.stop()
}

[self.dnaClient stop];

Disable App Transport security

In the Project Navigator, right click on "Info.plist", and "Open as" → "Source Code".

Add the following lines with the corresponding parameters values.

<key>NSAppTransportSecurity</key>
<dict> 
    <key>NSAllowsArbitraryLoads</key>
    <true/>
</dict>