VideoExporter

@objcMembers
public class VideoExporter

The VideoExporter is responsible for exporting SessionVideo and SessionVideoSegment objects to video files.

For example, you can export a video to an mp4 file with the following:

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 exportedVideoURL. Once you are finished with the file, you should call destroy() on the session in order to remove the video from the users drafts and delete its associated files.

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

You can also change 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.

Default Encoding Settings

If you do not provide a fileType, videoEncodingSettings, or audioEncodingSettings the default settings will be an mp4 file with H.264 video encoding and stereo AAC audio encoding:

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.

HEVC Encoding Settings

Below is an example of HEVC encoding settings:

import AVFoundation
import VideoToolbox

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

If you do not provide an API key or it is invalid, exported videos will include a watermark.