CompositionSettings

class CompositionSettings

Composition settings for dual concurrent camera. It includes alpha value for blending, offset in x, y coordinates, scale of width and height. The offset, and scale of width and height are specified in normalized device coordinates(NDCs). The offset is applied after scale. The origin of normalized device coordinates is at the center of the viewing volume. The positive X-axis extends to the right, the positive Y-axis extends upwards.The x, y values range from -1 to 1. E.g. scale with (0.5f, 0.5f) and offset with (0.5f, 0.5f) is the bottom-right quadrant of the output device.

Composited dual camera frames preview and recording can be supported using CompositionSettings and SingleCameraConfig. The z-order of composition is determined by the order of camera configs to bind. Currently the background color will be black by default. The resolution of camera frames for preview and recording will be determined by resolution selection strategy configured for each use case and the scale of width and height set in CompositionSettings, so it is recommended to use 16:9 aspect ratio strategy for preview if 16:9 quality selector is configured for video capture. The mirroring and rotation of the camera frame will be applied after composition because both cameras are using the same use cases.

The following code snippet demonstrates how to display in Picture-in-Picture mode:

      
        ResolutionSelector resolutionSelector = new ResolutionSelector.Builder()
                .setAspectRatioStrategy(
                        AspectRatioStrategy.RATIO_16_9_FALLBACK_AUTO_STRATEGY)
                .build();
        Preview preview = new Preview.Builder()
                .setResolutionSelector(resolutionSelector)
                .build();
        preview.setSurfaceProvider(mSinglePreviewView.getSurfaceProvider());
        UseCaseGroup useCaseGroup = new UseCaseGroup.Builder()
                .addUseCase(preview)
                .addUseCase(mVideoCapture)
                .build();
        SingleCameraConfig primary = new SingleCameraConfig(
                cameraSelectorPrimary,
                useCaseGroup,
                new CompositionSettings.Builder()
                        .setAlpha(1.0f)
                        .setOffset(0.0f, 0.0f)
                        .setScale(1.0f, 1.0f)
                        .build(),
                lifecycleOwner);
        SingleCameraConfig secondary = new SingleCameraConfig(
                cameraSelectorSecondary,
                useCaseGroup,
                new CompositionSettings.Builder()
                        .setAlpha(1.0f)
                        .setOffset(-0.3f, -0.4f)
                        .setScale(0.3f, 0.3f)
                        .build(),
                lifecycleOwner);
        cameraProvider.bindToLifecycle(ImmutableList.of(primary, secondary));

}

Summary

const val DEFAULT: CompositionSettings!

fun getAlpha(): Float

fun getOffset(): Pair<Float!, Float!>

fun getScale(): Pair<Float!, Float!>