Crop video swift - ios

Question

I am recording a video in a square UIView but when I export the video is full screen 1080x1920 now I am wondering how I can reduce the video from being full screen to being square ratio 1:1...
Here is how I am setting my Video Camera up :
session = AVCaptureSession()
for device in AVCaptureDevice.devices() {
if let device = device as? AVCaptureDevice , device.position == AVCaptureDevicePosition.back {
self.device = device
}
}
for device in AVCaptureDevice.devices(withMediaType: AVMediaTypeAudio) {
let device = device as? AVCaptureDevice
let audioInput = try! AVCaptureDeviceInput(device: device)
session?.addInput(audioInput)
}
do {
if let session = session {
videoInput = try AVCaptureDeviceInput(device: device)
session.addInput(videoInput)
videoOutput = AVCaptureMovieFileOutput()
let totalSeconds = 60.0 //Total Seconds of capture time
let timeScale: Int32 = 30 //FPS
let maxDuration = CMTimeMakeWithSeconds(totalSeconds, timeScale)
videoOutput?.maxRecordedDuration = maxDuration
videoOutput?.minFreeDiskSpaceLimit = 1024 * 1024//SET MIN FREE SPACE IN BYTES FOR RECORDING TO CONTINUE ON A VOLUME
if session.canAddOutput(videoOutput) {
session.addOutput(videoOutput)
}
let videoLayer = AVCaptureVideoPreviewLayer(session: session)
videoLayer?.frame = self.videoPreview.bounds
videoLayer?.videoGravity = AVLayerVideoGravityResizeAspectFill
self.videoPreview.layer.addSublayer(videoLayer!)
session.startRunning()
I have seen several other posts but not found them very helpfull, and most of them are in Obj C...
If anyone can help me or put me in the correct direction it's much appreciated!

Answer 1

Firstly you need to make use of the AVCaptureFileOutputRecordingDelegate.
You specifically use the func capture( _ captureOutput: AVCaptureFileOutput!, didFinishRecordingToOutputFileAt outputFileURL: URL!, fromConnections connections: [Any]!, error: Error! ) method to perform the cropping process, once the video has finished recording.
Here is an example of a cropping function I once implemented. You need to pass in the URL of the video that was recorded and a callback that is used to return the new URL of the cropped video once the cropping process is finished.
func cropVideo( _ outputFileUrl: URL, callback: #escaping ( _ newUrl: URL ) -> () )
{
// Get input clip
let videoAsset: AVAsset = AVAsset( url: outputFileUrl )
let clipVideoTrack = videoAsset.tracks( withMediaType: AVMediaTypeVideo ).first! as AVAssetTrack
// Make video to square
let videoComposition = AVMutableVideoComposition()
videoComposition.renderSize = CGSize( width: clipVideoTrack.naturalSize.height, height: clipVideoTrack.naturalSize.height )
videoComposition.frameDuration = CMTimeMake( 1, self.framesPerSecond )
// Rotate to portrait
let transformer = AVMutableVideoCompositionLayerInstruction( assetTrack: clipVideoTrack )
let transform1 = CGAffineTransform( translationX: clipVideoTrack.naturalSize.height, y: -( clipVideoTrack.naturalSize.width - clipVideoTrack.naturalSize.height ) / 2 )
let transform2 = transform1.rotated(by: CGFloat( M_PI_2 ) )
transformer.setTransform( transform2, at: kCMTimeZero)
let instruction = AVMutableVideoCompositionInstruction()
instruction.timeRange = CMTimeRangeMake(kCMTimeZero, CMTimeMakeWithSeconds( self.intendedVideoLength, self.framesPerSecond ) )
instruction.layerInstructions = [transformer]
videoComposition.instructions = [instruction]
// Export
let croppedOutputFileUrl = URL( fileURLWithPath: FileManager.getOutputPath( String.random() ) )
let exporter = AVAssetExportSession(asset: videoAsset, presetName: AVAssetExportPresetHighestQuality)!
exporter.videoComposition = videoComposition
exporter.outputURL = croppedOutputFileUrl
exporter.outputFileType = AVFileTypeQuickTimeMovie
exporter.exportAsynchronously( completionHandler: { () -> Void in
DispatchQueue.main.async(execute: {
callback( croppedOutputFileUrl )
})
})
}
Also, here is the implementation of my getOutputPath method:
func getOutputPath( _ name: String ) -> String
{
let documentPath = NSSearchPathForDirectoriesInDomains( .documentDirectory, .userDomainMask, true )[ 0 ] as NSString
let outputPath = "\(documentPath)/\(name).mov"
return outputPath
}
Hope this helps.

Answer 2

func cropFrame(videoAsset:AVAsset, animation:Bool) -> Void {
var insertTime = kCMTimeZero
var arrayLayerInstructions:[AVMutableVideoCompositionLayerInstruction] = []
var outputSize = CGSize.init(width: 0, height: 0)
// Determine video output size
let videoTrack = videoAsset.tracks(withMediaType: AVMediaType.video)[0]
let assetInfo = orientationFromTransform(transform: videoTrack.preferredTransform)
var videoSize = videoTrack.naturalSize
if assetInfo.isPortrait == true {
videoSize.width = videoTrack.naturalSize.height
videoSize.height = videoTrack.naturalSize.width
}
if videoSize.height > outputSize.height {
outputSize = videoSize
}
let defaultSize = CGSize(width: 1920, height: 1080) // Default video size
if outputSize.width == 0 || outputSize.height == 0 {
outputSize = defaultSize
}
// Silence sound (in case of video has no sound track)
let silenceURL = Bundle.main.url(forResource: "silence", withExtension: "mp3")
let silenceAsset = AVAsset(url:silenceURL!)
let silenceSoundTrack = silenceAsset.tracks(withMediaType: AVMediaType.audio).first
// Init composition
let mixComposition = AVMutableComposition.init()
// Get audio track
var audioTrack:AVAssetTrack?
if videoAsset.tracks(withMediaType: AVMediaType.audio).count > 0 {
audioTrack = videoAsset.tracks(withMediaType: AVMediaType.audio).first
}
else {
audioTrack = silenceSoundTrack
}
// Init video & audio composition track
let videoCompositionTrack = mixComposition.addMutableTrack(withMediaType: AVMediaType.video,
preferredTrackID: Int32(kCMPersistentTrackID_Invalid))
let audioCompositionTrack = mixComposition.addMutableTrack(withMediaType: AVMediaType.audio,
preferredTrackID: Int32(kCMPersistentTrackID_Invalid))
do {
let startTime = kCMTimeZero
let duration = videoAsset.duration
// Add video track to video composition at specific time
try videoCompositionTrack?.insertTimeRange(CMTimeRangeMake(startTime, duration),
of: videoTrack,
at: insertTime)
// Add audio track to audio composition at specific time
if let audioTrack = audioTrack {
try audioCompositionTrack?.insertTimeRange(CMTimeRangeMake(startTime, duration),
of: audioTrack,
at: insertTime)
}
// Add instruction for video track
let layerInstruction = videoCompositionInstructionForTrack(track: videoCompositionTrack!,
asset: videoAsset,
standardSize: outputSize,
atTime: insertTime)
// Hide video track before changing to new track
let endTime = CMTimeAdd(insertTime, duration)
//let finalTimer = CMTimeAdd(CMTime(seconds: 5, preferredTimescale: videoAsset.duration.timescale), CMTime(seconds: 5, preferredTimescale: videoAsset.duration.timescale))
//Kalpesh crop video frames
if animation {
let timeScale = videoAsset.duration.timescale
let durationAnimation = CMTime.init(seconds: 1, preferredTimescale: timeScale)
layerInstruction.setOpacityRamp(fromStartOpacity: 1.0, toEndOpacity: 0.0, timeRange: CMTimeRange.init(start: endTime, duration: durationAnimation))
//**********======== CROP YOUR VIDEO FRAME HERE MANUALLY ========**********
layerInstruction.setCropRectangle(CGRect(x: 0, y: 0, width: videoTrack.naturalSize.width, height: 300.0), at: startTime)
} else {
layerInstruction.setOpacity(0, at: endTime)
}
arrayLayerInstructions.append(layerInstruction)
// Increase the insert time
insertTime = CMTimeAdd(insertTime, duration)
}
catch {
print("Load track error")
}
// Main video composition instruction
let mainInstruction = AVMutableVideoCompositionInstruction()
mainInstruction.timeRange = CMTimeRangeMake(kCMTimeZero, insertTime)
mainInstruction.layerInstructions = arrayLayerInstructions
// Main video composition
let mainComposition = AVMutableVideoComposition()
mainComposition.instructions = [mainInstruction]
mainComposition.frameDuration = CMTimeMake(1, 30)
mainComposition.renderSize = outputSize
// Export to file
let path = NSTemporaryDirectory().appending("mergedVideo.mp4")
let exportURL = URL.init(fileURLWithPath: path)
// Init exporter
let exporter = AVAssetExportSession.init(asset: mixComposition, presetName: AVAssetExportPresetHighestQuality)
exporter?.outputURL = exportURL
exporter?.outputFileType = AVFileType.mp4
exporter?.shouldOptimizeForNetworkUse = true
exporter?.videoComposition = mainComposition
// Do export
exporter?.exportAsynchronously(completionHandler: {
})
}
func videoCompositionInstructionForTrack(track: AVCompositionTrack, asset: AVAsset, standardSize:CGSize, atTime: CMTime) -> AVMutableVideoCompositionLayerInstruction {
let instruction = AVMutableVideoCompositionLayerInstruction(assetTrack: track)
let assetTrack = asset.tracks(withMediaType: AVMediaType.video)[0]
let transform = assetTrack.preferredTransform
let assetInfo = orientationFromTransform(transform: transform)
var aspectFillRatio:CGFloat = 1
if assetTrack.naturalSize.height < assetTrack.naturalSize.width {
aspectFillRatio = standardSize.height / assetTrack.naturalSize.height
}
else {
aspectFillRatio = standardSize.width / assetTrack.naturalSize.width
}
if assetInfo.isPortrait {
let scaleFactor = CGAffineTransform(scaleX: aspectFillRatio, y: aspectFillRatio)
let posX = standardSize.width/2 - (assetTrack.naturalSize.height * aspectFillRatio)/2
let posY = standardSize.height/2 - (assetTrack.naturalSize.width * aspectFillRatio)/2
let moveFactor = CGAffineTransform(translationX: posX, y: posY)
instruction.setTransform(assetTrack.preferredTransform.concatenating(scaleFactor).concatenating(moveFactor), at: atTime)
} else {
let scaleFactor = CGAffineTransform(scaleX: aspectFillRatio, y: aspectFillRatio)
let posX = standardSize.width/2 - (assetTrack.naturalSize.width * aspectFillRatio)/2
let posY = standardSize.height/2 - (assetTrack.naturalSize.height * aspectFillRatio)/2
let moveFactor = CGAffineTransform(translationX: posX, y: posY)
var concat = assetTrack.preferredTransform.concatenating(scaleFactor).concatenating(moveFactor)
if assetInfo.orientation == .down {
let fixUpsideDown = CGAffineTransform(rotationAngle: CGFloat(Double.pi))
concat = fixUpsideDown.concatenating(scaleFactor).concatenating(moveFactor)
}
instruction.setTransform(concat, at: atTime)
}
return instruction
}
func orientationFromTransform(transform: CGAffineTransform) -> (orientation: UIImageOrientation, isPortrait: Bool) {
var assetOrientation = UIImageOrientation.up
var isPortrait = false
if transform.a == 0 && transform.b == 1.0 && transform.c == -1.0 && transform.d == 0 {
assetOrientation = .right
isPortrait = true
} else if transform.a == 0 && transform.b == -1.0 && transform.c == 1.0 && transform.d == 0 {
assetOrientation = .left
isPortrait = true
} else if transform.a == 1.0 && transform.b == 0 && transform.c == 0 && transform.d == 1.0 {
assetOrientation = .up
} else if transform.a == -1.0 && transform.b == 0 && transform.c == 0 && transform.d == -1.0 {
assetOrientation = .down
}
return (assetOrientation, isPortrait)
}
Call this way:
let avssets = AVAsset(url: VideoURL)
self.cropFrame(videoAsset: avssets, animation: true)