Swift Merge AVasset-Videos阵列 [英] Swift Merge AVasset-Videos array
问题描述
我想将AVAsset - arrayVideos
合并到一个视频中并将其保存在相机胶卷上。 Raywenderlich.com有一个很棒的教程,其中两个视频是合并成一个。我创建了以下代码,但是导出到相机胶卷后我获得的视频仅包含阵列中的第一个和最后一个视频(不包括 arrayVideos中间的其他视频
)。我在这里遗漏了什么吗?
I want to merge the AVAsset-arrayVideos
into one single video and save it on camera roll. Raywenderlich.com has a great tutorial where two videos are merged into one. I've created the following code, however the video that I get after exporting to camera roll includes only the first and the last video from the array (excluding the rest of the videos in the middle of arrayVideos
). Am I missing something here?
var arrayVideos = [AVAsset]() //Videos Array
var atTimeM: CMTime = CMTimeMake(0, 0)
var lastAsset: AVAsset!
var layerInstructionsArray = [AVVideoCompositionLayerInstruction]()
var completeTrackDuration: CMTime = CMTimeMake(0, 1)
var videoSize: CGSize = CGSize(width: 0.0, height: 0.0)
func mergeVideoArray(){
let mixComposition = AVMutableComposition()
for videoAsset in arrayVideos{
let videoTrack = mixComposition.addMutableTrack(withMediaType: AVMediaTypeVideo, preferredTrackID: Int32(kCMPersistentTrackID_Invalid))
do {
if videoAsset == arrayVideos.first{
atTimeM = kCMTimeZero
} else{
atTimeM = lastAsset!.duration
}
try videoTrack.insertTimeRange(CMTimeRangeMake(kCMTimeZero, videoAsset.duration), of: videoAsset.tracks(withMediaType: AVMediaTypeVideo)[0], at: atTimeM)
videoSize = videoTrack.naturalSize
} catch let error as NSError {
print("error: \(error)")
}
completeTrackDuration = CMTimeAdd(completeTrackDuration, videoAsset.duration)
let videoInstruction = AVMutableVideoCompositionLayerInstruction(assetTrack: videoTrack)
if videoAsset != arrayVideos.last{
videoInstruction.setOpacity(0.0, at: videoAsset.duration)
}
layerInstructionsArray.append(videoInstruction)
lastAsset = videoAsset
}
let mainInstruction = AVMutableVideoCompositionInstruction()
mainInstruction.timeRange = CMTimeRangeMake(kCMTimeZero, completeTrackDuration)
mainInstruction.layerInstructions = layerInstructionsArray
let mainComposition = AVMutableVideoComposition()
mainComposition.instructions = [mainInstruction]
mainComposition.frameDuration = CMTimeMake(1, 30)
mainComposition.renderSize = CGSize(width: videoSize.width, height: videoSize.height)
let documentDirectory = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0]
let dateFormatter = DateFormatter()
dateFormatter.dateStyle = .long
dateFormatter.timeStyle = .short
let date = dateFormatter.string(from: NSDate() as Date)
let savePath = (documentDirectory as NSString).appendingPathComponent("mergeVideo-\(date).mov")
let url = NSURL(fileURLWithPath: savePath)
let exporter = AVAssetExportSession(asset: mixComposition, presetName: AVAssetExportPresetHighestQuality)
exporter!.outputURL = url as URL
exporter!.outputFileType = AVFileTypeQuickTimeMovie
exporter!.shouldOptimizeForNetworkUse = true
exporter!.videoComposition = mainComposition
exporter!.exportAsynchronously {
PHPhotoLibrary.shared().performChanges({
PHAssetChangeRequest.creationRequestForAssetFromVideo(atFileURL: exporter!.outputURL!)
}) { saved, error in
if saved {
let alertController = UIAlertController(title: "Your video was successfully saved", message: nil, preferredStyle: .alert)
let defaultAction = UIAlertAction(title: "OK", style: .default, handler: nil)
alertController.addAction(defaultAction)
self.present(alertController, animated: true, completion: nil)
} else{
print("video erro: \(error)")
}
}
}
}
推荐答案
您需要跟踪所有资产的总时间并为每个资产进行更新视频。
You need to track the total time for all of the assets and update it for each video.
您问题中的代码是使用当前视频重写 atTimeM
。这就是为什么只包括第一个和最后一个。
The code in your question was rewriting the atTimeM
with the current video. That's why only the first and last got included.
它看起来像这样:
...
var totalTime : CMTime = CMTimeMake(0, 0)
func mergeVideoArray() {
let mixComposition = AVMutableComposition()
for videoAsset in arrayVideos {
let videoTrack =
mixComposition.addMutableTrack(withMediaType: AVMediaTypeVideo,
preferredTrackID: Int32(kCMPersistentTrackID_Invalid))
do {
if videoAsset == arrayVideos.first {
atTimeM = kCMTimeZero
} else {
atTimeM = totalTime // <-- Use the total time for all the videos seen so far.
}
try videoTrack.insertTimeRange(CMTimeRangeMake(kCMTimeZero, videoAsset.duration),
of: videoAsset.tracks(withMediaType: AVMediaTypeVideo)[0],
at: atTimeM)
videoSize = videoTrack.naturalSize
} catch let error as NSError {
print("error: \(error)")
}
totalTime += videoAsset.duration // <-- Update the total time for all videos.
...
您可以删除使用 lastAsset
。
这篇关于Swift Merge AVasset-Videos阵列的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!