iOS Streamer¶

Example of streamer for iOS¶

This streamer can be used to publish WebRTC video stream on Web Call Server.

On the screenshot below the example is displayed when a stream is being published. In the URL specified in the input field

192.168.2.107 is the address of the WCS server
testStream is the stream name

Two videos are played

left - video from the camera
right - the published video stream is played from the server

Analyzing the example code¶

To analyze the code, let's take Streamer example version, which is available here.

View class for the main view of the application: ViewController (header file ViewController.h; implementation file ViewController.m).

1. Import of API¶

code

#import <FPWCSApi2/FPWCSApi2.h>

2. Session creation¶

FPWCSApi2.createSession code

The options include:

URL of WCS server
appKey of internal server-side REST hook application (defaultApp)

FPWCSApi2SessionOptions *options = [[FPWCSApi2SessionOptions alloc] init];
NSURL *url =[[NSURL alloc] initWithString:_connectUrl.text];
options.urlServer = [NSString stringWithFormat:@"%@://%@:%@", url.scheme, url.host, url.port];
streamName = [url.path.stringByDeletingPathExtension stringByReplacingOccurrencesOfString: @"/" withString:@""];
options.appKey = @"defaultApp";
NSError *error;
session = [FPWCSApi2 createSession:options error:&error];

3. Connection to the server¶

FPWCSApi2Session.connect code

[session connect];

4. Receiving the event confirming successful connection¶

FPWCSApi2Session.onConnected code

On this event, ViewController.publishStream method is called to publish the stream

- (void)onConnected:(FPWCSApi2Session *)session {
    [_connectButton setTitle:@"STOP" forState:UIControlStateNormal];
   // [self changeViewState:_connectButton enabled:YES];
    [self publishStream];
}

5. Stream publishing¶

FPWCSApi2Session.createStream, FPWCSApi2Stream.publish code

Object with the following stream options is passed to createStream method:

stream name
view to display video
video constraints (picture resolution for iPad for example)

- (FPWCSApi2Stream *)publishStream {
    FPWCSApi2Session *session = [FPWCSApi2 getSessions][0];
    FPWCSApi2StreamOptions *options = [[FPWCSApi2StreamOptions alloc] init];
    options.name = streamName;
    options.display = _videoView.local;
    if ( UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad ) {
        options.constraints = [[FPWCSApi2MediaConstraints alloc] initWithAudio:YES videoWidth:640 videoHeight:480 videoFps:15];
    }
    NSError *error;
    publishStream = [session createStream:options error:&error];
    ...
    if(![publishStream publish:&error]) {
        UIAlertController * alert = [UIAlertController
                                     alertControllerWithTitle:@"Failed to publish"
                                     message:error.localizedDescription
                                     preferredStyle:UIAlertControllerStyleAlert];

        UIAlertAction* okButton = [UIAlertAction
                                    actionWithTitle:@"Ok"
                                    style:UIAlertActionStyleDefault
                                    handler:^(UIAlertAction * action) {
                                        [self onUnpublished];
                                    }];

        [alert addAction:okButton];
        [self presentViewController:alert animated:YES completion:nil];
    }
    return publishStream;
}

6. Receiving the event confirming successful stream publishing¶

FPWCSApi2Stream.onPublishing code

On this event, ViewController.playStream method is called to play published stream preview

- (void)onPublishing:(FPWCSApi2Stream *)stream {
    [self playStream];
}

7. Preview stream playback¶

FPWCSApi2Session.createStream, FPWCSApi2Stream.play code

Object with the following stream options is passed to createStream method:

stream name
view to display video

- (FPWCSApi2Stream *)playStream {
    FPWCSApi2Session *session = [FPWCSApi2 getSessions][0];
    FPWCSApi2StreamOptions *options = [[FPWCSApi2StreamOptions alloc] init];
    options.name = streamName;
    options.display = _videoView.remote;
    NSError *error;
    playStream = [session createStream:options error:nil];
    ...
    if(![playStream play:&error]) {
        UIAlertController * alert = [UIAlertController
                                     alertControllerWithTitle:@"Failed to play"
                                     message:error.localizedDescription
                                     preferredStyle:UIAlertControllerStyleAlert];

        UIAlertAction* okButton = [UIAlertAction
                                   actionWithTitle:@"Ok"
                                   style:UIAlertActionStyleDefault
                                   handler:^(UIAlertAction * action) {

                                   }];

        [alert addAction:okButton];
        [self presentViewController:alert animated:YES completion:nil];
    }
    return playStream;
}

8. Disconnection¶

FPWCSApi2Session.disconnect code

- (void)connectButton:(UIButton *)button {
    [self changeViewState:button enabled:NO];
    if ([button.titleLabel.text isEqualToString:@"STOP"]) {
        if ([FPWCSApi2 getSessions].count) {
            FPWCSApi2Session *session = [FPWCSApi2 getSessions][0];
            NSLog(@"Disconnect session with server %@", [session getServerUrl]);
            [session disconnect];
        } else {
            NSLog(@"Nothing to disconnect");
            [self onDisconnected];
        }
    } else {
        //todo check url is not empty
        [self changeViewState:_connectUrl enabled:NO];
        [self connect];
    }
}

9. Receiving the event confirming successful disconnection¶

ViewController.onDisconnected code

- (void)onDisconnected {
    [_connectButton setTitle:@"START" forState:UIControlStateNormal];
    [self changeViewState:_connectButton enabled:YES];
    [self changeViewState:_connectUrl enabled:YES];
    [self onUnpublished];
    [self onStopped];
}