Multi tool use

How to add a Fade In and Fade Out effect on Video AVAsset in Swift3 iOS

I am developing a Video application in Swift3. Where I have to convert any text to Video and then have to add a Fade In and Fade Out effect and post the Fade effect Video to server. I don't have to use any Third Party Library for Fade effect.

Video

Swift3

Video

Fade In and Fade Out

Fade effect Video

Third Party Library

Fade effect

I can able to convert my Text to a Video, My problem is how can I add Fade In and Fade Out on Video AVAsset.

Text

Video

Fade In and Fade Out

Video

AVAsset

Can anyone suggest me to achieve this. I cannot find any recent answers to this problem. Thanks for any help!

1 Answer
1

AVVideoCompositionLayerInstruction

An array of instances of AVVideoCompositionLayerInstruction that specify how video frames from source tracks should be layered and composed.

AVVideoCompositionLayerInstruction

AVMutableVideoCompositionInstruction

An AVVideoComposition object maintains an array of instructions to perform its composition.

AVVideoComposition

instructions

Example Swift4:
I merged videos with fade-in and fade-out effect and change sequence of audio

fade-in

fade-out

func doMerge(arrayVideos:[AVAsset], arrayAudios:[AVAsset], animation:Bool, completion:@escaping Completion) -> Void {

var insertTime = kCMTimeZero
var audioInsertTime = kCMTimeZero
var arrayLayerInstructions:[AVMutableVideoCompositionLayerInstruction] =
var outputSize = CGSize.init(width: 0, height: 0)

// Determine video output size
for videoAsset in arrayVideos {
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
}
outputSize = videoSize
}

// Init composition
let mixComposition = AVMutableComposition.init()

for index in 0..<arrayVideos.count {
// Get video track
guard let videoTrack = arrayVideos[index].tracks(withMediaType: AVMediaType.video).first else { continue }

// Get audio track
var audioTrack:AVAssetTrack?
if index < arrayAudios.count {
if arrayAudios[index].tracks(withMediaType: AVMediaType.audio).count > 0 {
audioTrack = arrayAudios[index].tracks(withMediaType: AVMediaType.audio).first
}
}
// 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 = arrayVideos[index].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
var audioDuration = kCMTimeZero
if index < arrayAudios.count {
audioDuration = arrayAudios[index].duration
}

if let audioTrack = audioTrack {
do {
try audioCompositionTrack?.insertTimeRange(CMTimeRangeMake(startTime, audioDuration), of: audioTrack, at: audioInsertTime)
}
catch {
print(error.localizedDescription)
}
}

// Add instruction for video track
let layerInstruction = videoCompositionInstructionForTrack(track: videoCompositionTrack!, asset: arrayVideos[index], standardSize: outputSize, atTime: insertTime)

// Hide video track before changing to new track
let endTime = CMTimeAdd(insertTime, duration)

if animation {
let timeScale = arrayVideos[index].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))
}
else {
layerInstruction.setOpacity(0, at: endTime)
}

arrayLayerInstructions.append(layerInstruction)

// Increase the insert time
audioInsertTime = CMTimeAdd(audioInsertTime, audioDuration)
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)

// Remove file if existed
FileManager.default.removeItemIfExisted(exportURL)

// 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: {
DispatchQueue.main.async {
self.exportDidFinish(exporter: exporter, videoURL: exportURL, completion: completion)
}
})

}


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