iOS Two-way Streaming

Example of iOS application with player and streamer

This streamer can be used to publish WebRTC video stream and play any of the following types of streams on Web Call Server

• RTSP
• WebRTC
• RTMP

On the screenshot below the example is displayed when a stream is being published and another stream is being played. Input fields

• WCS URL, where 192.168.2.107 is the address of the WCS server
• Publish Stream - for the name of published stream
• Play Stream - for the name of played stream

Two videos are played

• left - video from the camera
• right - the played video stream

Analyzing the example code

To analyze the code, let's take TwoWayStreaming example, 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 and connecting to server

FPWCSApi2.createSession, FPWCSApi2Session.connect code

The options include:

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

- (FPWCSApi2Session *)connect {
    FPWCSApi2SessionOptions *options = [[FPWCSApi2SessionOptions alloc] init];
    options.urlServer = _connectUrl.text;
    options.appKey = @"defaultApp";
    NSError *error;
    FPWCSApi2Session *session = [FPWCSApi2 createSession:options error:&error];
    ...
    [session connect];
    return session;
}

3. 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 for iPad

- (FPWCSApi2Stream *)publishStream {
    FPWCSApi2Session *session = [FPWCSApi2 getSessions][0];
    FPWCSApi2StreamOptions *options = [[FPWCSApi2StreamOptions alloc] init];
    options.name = _localStreamName.text;
    options.display = _localDisplay;
    if ( UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad ) {
        options.constraints = [[FPWCSApi2MediaConstraints alloc] initWithAudio:YES videoWidth:640 videoHeight:480 videoFps:15];
    }
    NSError *error;
    FPWCSApi2Stream *stream = [session createStream:options error:&error];
    ...
    if(![stream 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 stream;
}

4. Switching camera while publishing stream

FPWCSApi2Stream.switchCamera code

- (void)switchCameraButton:(UIButton *)button {
    if ([FPWCSApi2 getSessions].count) {
        FPWCSApi2Session *session = [FPWCSApi2 getSessions][0];
        NSArray *streams = [session getStreams];
        for (FPWCSApi2Stream *stream in streams ) {
            if ([stream isPublished]) {
                NSLog(@"Found published stream, switching camera");
                [stream switchCamera];
            }
        }
    } else {
        NSLog(@"No active sessions found");
    }
}

5. 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 = _remoteStreamName.text;
    options.display = _remoteDisplay;
    NSError *error;
    FPWCSApi2Stream *stream = [session createStream:options error:nil];
    ...
    if(![stream 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 stream;
}

6. Stop of stream playback

FPWCSApi2Stream.stop code

- (void)playButton:(UIButton *)button {
    [self changeViewState:button enabled:NO];
    if ([button.titleLabel.text isEqualToString:@"STOP"]) {
        if ([FPWCSApi2 getSessions].count) {
            FPWCSApi2Stream *stream;
            for (FPWCSApi2Stream *s in [[FPWCSApi2 getSessions][0] getStreams]) {
                if ([[s getName] isEqualToString:_remoteStreamName.text]) {
                    stream = s;
                    break;
                }
            }
            if (!stream) {
                NSLog(@"Stop playing, nothing to stop");
                [self onStopped];
                return;
            }
            NSError *error;
            [stream stop:&error];
        } else {
            NSLog(@"Stop playing, no session");
            [self onStopped];
        }
        ...
    }
}

7. Stop of stream publishing

FPWCSApi2Stream.stop code

- (void)publishButton:(UIButton *)button {
    [self changeViewState:button enabled:NO];
    if ([button.titleLabel.text isEqualToString:@"STOP"]) {
        if ([FPWCSApi2 getSessions].count) {
            FPWCSApi2Stream *stream;
            for (FPWCSApi2Stream *s in [[FPWCSApi2 getSessions][0] getStreams]) {
                if ([[s getName] isEqualToString:_localStreamName.text]) {
                    stream = s;
                    break;
                }
            }
            if (!stream) {
                NSLog(@"Stop publishing, nothing to stop");
                [self onUnpublished];
                return;
            }
            NSError *error;
            [stream stop:&error];
        } else {
            NSLog(@"Stop publishing, no session");
            [self onUnpublished];
        }
        ...
    }
}

8. Disconnection

FPWCSApi2Session.disconnect code

- (void)connectButton:(UIButton *)button {
    [self changeViewState:button enabled:NO];
    if ([button.titleLabel.text isEqualToString:@"DISCONNECT"]) {
        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];
        }
        ...
    }
}