Specify Video Constraints for iOS v2.x

You can customize the properties of the video produced by a TVIVideoCapturer using TVIVideoConstraints. Constraints allow you to choose at runtime between one of the many TVIVideoFormats that are supported by the capturer. The included TVICameraCapturer class exposes formats based upon what your device's cameras are capable of.

Constraints allow you to filter by several criteria including size, frame rate, and aspect ratio. While constraints are used to resolve the actual capture format, the video sent to other Participants may be downscaled (temporally or spatially) in response to network and device conditions.

In Swift

1// Create camera object
2let camera = TVICameraCapturer(source: .frontCamera)
3
4// Setup the video constraints
5let videoConstraints = TVIVideoConstraints { (constraints) in
6    constraints.maxSize = TVIVideoConstraintsSize960x540
7    constraints.minSize = TVIVideoConstraintsSize960x540
8    constraints.maxFrameRate = TVIVideoConstraintsFrameRateNone
9    constraints.minFrameRate = TVIVideoConstraintsFrameRateNone
10}
11
12// Add local video track with camera and video constraints
13localVideoTrack = TVILocalVideoTrack(capturer: capturer,
14                                     enabled: true,
15                                     constraints: videoConstraints,
16                                     name: "Screen")
17
18// If the constraints are not satisfied, a nil track will be returned.
19if (localVideoTrack == nil) {
20    print ("Error: Failed to create a video track using the local camera.")
21}

In Objective-C

1// Create camera object
2TVICameraCapturer *camera = = [[TVICameraCapturer alloc] init];
3
4// Setup the video constraints
5TVIVideoConstraints *videoConstraints = [TVIVideoConstraints constraintsWithBlock:
6                              ^(TVIVideoConstraintsBuilder * _Nonnull builder) {
7    builder.maxSize = TVIVideoConstraintsSize960x540;
8    builder.minSize = TVIVideoConstraintsSize960x540;
9    builder.maxFrameRate = TVIVideoConstraintsFrameRateNone;
10    builder.minFrameRate = TVIVideoConstraintsFrameRateNone;
11}];
12
13// Add local video track with camera and video constraints
14TVIVideoTrack *localVideoTrack = [TVILocalVideoTrack trackWithCapturer:camera
15                                                               enabled:YES
16                                                           constraints:videoConstraints
17                                                                  name:@"Camera"];
18
19// If the constraints are not satisfied, a nil track will be returned.
20if (localVideoTrack == nil) {
21    NSLog(@"Error: Failed to create a video track using the local camera.");
22}