Export Media

Image Exports

The below example demonstrates exporting to a UIImage:

if let image = session.image {
    ImageExporter.shared.export(image: image, completion: { (error, uiImage) in
        if let error = error {
            print("Unable to export image: \(error)")
            return
        }

        print("Finished image export with UIImage: \(uiImage!)")
    })
}

In addition to exporting as a UIImage, the exported image is saved to file as a JPEG at the image.exportedImageURL variable. After the export has completed, you may use, move or copy this file. Once you are finished with the file, you should call session.destroy() in order to remove the image from the users drafts and delete its associated files.

Video Exports

The below example demonstrates exporting a video to an mp4 file:

if let video = session.video {
    VideoExporter.shared.export(video: video, progress: { progress in
        print("Export progress: \(progress)")
    }, completion: { error in
        if let error = error {
            print("Unable to export video: \(error)")
            return
        }

        print("Finished video export at URL: \(video.exportedVideoURL)")
    })
}

After the export has completed, you should use, move or copy the file found at the video.exportedVideoURL. Once you are finished with the file, you should call session.destroy() in order to remove the video from the users drafts and delete its associated files.

Frame rate can be customized by setting the video.frameDuration variable before exporting the video.

You can also change video.renderSize but we recommend you instead set the PreviewCropController aspectRatio and CameraController aspectRatio. See the square content example. These properties allow you to preserve video quality by delaying any upscaling or downscaling until a later point in your video processing logic. If you plan on converting your video to HLS on a server that encoder should handle any upscaling or downscaling.

Encoding Settings

If you do not customize the video and audio encoding settings, the default settings will be an mp4 file with H.264 video encoding and stereo AAC audio encoding:

import PixelSDK
import AVFoundation

var acl = AudioChannelLayout()
memset(&acl, 0, MemoryLayout<AudioChannelLayout>.size)
acl.mChannelLayoutTag = kAudioChannelLayoutTag_Stereo

let audioEncodingSettings: [String: Any] = [
    AVFormatIDKey: kAudioFormatMPEG4AAC,
    AVNumberOfChannelsKey: 2,
    AVSampleRateKey: AVAudioSession.sharedInstance().sampleRate,
    AVChannelLayoutKey: NSData(bytes:&acl, length:MemoryLayout<AudioChannelLayout>.size),
    AVEncoderBitRateKey: 96000
]

let videoEncodingSettings: [String: Any] = [
    AVVideoCompressionPropertiesKey: [
        AVVideoProfileLevelKey: AVVideoProfileLevelH264HighAutoLevel,
        AVVideoH264EntropyModeKey: AVVideoH264EntropyModeCABAC],
    AVVideoCodecKey: AVVideoCodecType.h264
]

VideoExporter.shared.export(video: session.video!,
                            fileType: .mp4,
                            videoEncodingSettings: videoEncodingSettings,
                            audioEncodingSettings: audioEncodingSettings,
                            progress: nil,
                            completion: { error in
})

There are many combinations of encoding settings you can provide. They must conform to the specifications set forth in AVFoundations AVVideoSettings.h and AVAudioSettings.h headers. There is also a list of available codecs. Keep in mind each codec may have different requirements for the settings you provide.

Below is an example of HEVC video encoding settings:

import PixelSDK
import AVFoundation
import VideoToolbox

let videoEncodingSettings: [String: Any] = [
    AVVideoCompressionPropertiesKey: [
        AVVideoProfileLevelKey: kVTProfileLevel_HEVC_Main_AutoLevel],
    AVVideoCodecKey: AVVideoCodecType.hevc
]