IOS 视频压缩 Swift iOS 8 个损坏的视频文件
IOS Video Compression Swift iOS 8 corrupt video file
我正在尝试压缩用户相机从 UIImagePickerController 拍摄的视频（不是现有视频，而是动态视频）以上传到我的服务器并花费少量时间来完成，因此尺寸较小在较新质量的相机上是理想的，而不是 30-45 mb。
这是在 swift 中对 iOS 8 进行压缩的代码，它压缩得非常好，我很容易从 35 mb 下降到 2.1 mb。
func convertVideo(inputUrl: NSURL, outputURL: NSURL)
{
//setup video writer
var videoAsset = AVURLAsset(URL: inputUrl, options: nil) as AVAsset
var videoTrack = videoAsset.tracksWithMediaType(AVMediaTypeVideo)[0] as AVAssetTrack
var videoSize = videoTrack.naturalSize
var videoWriterCompressionSettings = Dictionary(dictionaryLiteral:(AVVideoAverageBitRateKey,NSNumber(integer:960000)))
var videoWriterSettings = Dictionary(dictionaryLiteral:(AVVideoCodecKey,AVVideoCodecH264),
(AVVideoCompressionPropertiesKey,videoWriterCompressionSettings),
(AVVideoWidthKey,videoSize.width),
(AVVideoHeightKey,videoSize.height))
var videoWriterInput = AVAssetWriterInput(mediaType: AVMediaTypeVideo, outputSettings: videoWriterSettings)
videoWriterInput.expectsMediaDataInRealTime = true
videoWriterInput.transform = videoTrack.preferredTransform
var videoWriter = AVAssetWriter(URL: outputURL, fileType: AVFileTypeQuickTimeMovie, error: nil)
videoWriter.addInput(videoWriterInput)
var videoReaderSettings: [String:AnyObject] = [kCVPixelBufferPixelFormatTypeKey:kCVPixelFormatType_420YpCbCr8BiPlanarVideoRange]
var videoReaderOutput = AVAssetReaderTrackOutput(track: videoTrack, outputSettings: videoReaderSettings)
var videoReader = AVAssetReader(asset: videoAsset, error: nil)
videoReader.addOutput(videoReaderOutput)
//setup audio writer
var audioWriterInput = AVAssetWriterInput(mediaType: AVMediaTypeAudio, outputSettings: nil)
audioWriterInput.expectsMediaDataInRealTime = false
videoWriter.addInput(audioWriterInput)
//setup audio reader
var audioTrack = videoAsset.tracksWithMediaType(AVMediaTypeAudio)[0] as AVAssetTrack
var audioReaderOutput = AVAssetReaderTrackOutput(track: audioTrack, outputSettings: nil) as AVAssetReaderOutput
var audioReader = AVAssetReader(asset: videoAsset, error: nil)
audioReader.addOutput(audioReaderOutput)
videoWriter.startWriting()
//start writing from video reader
videoReader.startReading()
videoWriter.startSessionAtSourceTime(kCMTimeZero)
//dispatch_queue_t processingQueue = dispatch_queue_create("processingQueue", nil)
var queue = dispatch_queue_create("processingQueue", nil)
videoWriterInput.requestMediaDataWhenReadyOnQueue(queue, usingBlock: { () -> Void in
println("Export starting")
while videoWriterInput.readyForMoreMediaData
{
var sampleBuffer:CMSampleBufferRef!
sampleBuffer = videoReaderOutput.copyNextSampleBuffer()
if (videoReader.status == AVAssetReaderStatus.Reading && sampleBuffer != nil)
{
videoWriterInput.appendSampleBuffer(sampleBuffer)
}
else
{
videoWriterInput.markAsFinished()
if videoReader.status == AVAssetReaderStatus.Completed
{
if audioReader.status == AVAssetReaderStatus.Reading || audioReader.status == AVAssetReaderStatus.Completed
{
}
else {
audioReader.startReading()
videoWriter.startSessionAtSourceTime(kCMTimeZero)
var queue2 = dispatch_queue_create("processingQueue2", nil)
audioWriterInput.requestMediaDataWhenReadyOnQueue(queue2, usingBlock: { () -> Void in
while audioWriterInput.readyForMoreMediaData
{
var sampleBuffer:CMSampleBufferRef!
sampleBuffer = audioReaderOutput.copyNextSampleBuffer()
println(sampleBuffer == nil)
if (audioReader.status == AVAssetReaderStatus.Reading && sampleBuffer != nil)
{
audioWriterInput.appendSampleBuffer(sampleBuffer)
}
else
{
audioWriterInput.markAsFinished()
if (audioReader.status == AVAssetReaderStatus.Completed)
{
videoWriter.finishWritingWithCompletionHandler({ () -> Void in
println("Finished writing video asset.")
self.videoUrl = outputURL
var data = NSData(contentsOfURL: outputURL)!
println("Byte Size After Compression: \(data.length / 1048576) mb")
println(videoAsset.playable)
//Networking().uploadVideo(data, fileName: "Test2")
self.dismissViewControllerAnimated(true, completion: nil)
})
break
}
}
}
})
break
}
}
}// Second if
}//first while
})// first block
// return
}
这是我的 UIImagePickerController 调用压缩方法的代码
func imagePickerController(picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [NSObject : AnyObject])
{
// Extract the media type from selection
let type = info[UIImagePickerControllerMediaType] as String
if (type == kUTTypeMovie)
{
self.videoUrl = info[UIImagePickerControllerMediaURL] as? NSURL
var uploadUrl = NSURL.fileURLWithPath(NSTemporaryDirectory().stringByAppendingPathComponent("captured").stringByAppendingString(".mov"))
var data = NSData(contentsOfURL: self.videoUrl!)!
println("Size Before Compression: \(data.length / 1048576) mb")
self.convertVideo(self.videoUrl!, outputURL: uploadUrl!)
// Get the video from the info and set it appropriately.
/*self.dismissViewControllerAnimated(true, completion: { () -> Void in
//self.next.enabled = true
})*/
}
}
正如我上面提到的，这可以减少文件大小，但是当我取回文件时（它仍然是 .mov 类型）quicktime 无法播放它。 Quicktime 最初确实尝试转换它但中途失败（打开文件后 1-2 秒。）我什至在 AVPlayerController 中测试了视频文件但它没有提供有关电影的任何信息，它只是一个播放按钮没有蚂蚁加载并且没有任何长度只是“--”，时间通常在播放器中。 IE 无法播放的损坏文件。
我确定这与写入资产的设置有关，无论是视频写入还是音频写入我都不确定。甚至可能是读取导致资产损坏的资产。我试过改变周围的变量并设置不同的读写键，但我没有找到正确的组合，这很糟糕，我可以压缩但从中得到一个损坏的文件。我完全不确定，如有任何帮助，我们将不胜感激。请放轻松。
您的转换方法是异步的，但没有完成块。那么您的代码如何知道文件何时准备就绪呢？也许您在文件完全写入之前正在使用它。
转换本身看起来也很奇怪 - 音频和视频通常是并行编写的，而不是串行的。
您神奇的压缩率可能表明您写出的帧数比您实际想象的要少。
想通了！
好的，所以有 2 个问题：1 个问题与 videoWriter.finishWritingWithCompletionHandler 函数调用有关。当这个完成块被执行时，它并不意味着视频编写器已经完成写入输出 url。所以我必须在上传实际视频文件之前检查状态是否已完成。这有点骇人听闻，但这就是我所做的
videoWriter.finishWritingWithCompletionHandler({() -> Void in
while true
{
if videoWriter.status == .Completed
{
var data = NSData(contentsOfURL: outputURL)!
println("Finished: Byte Size After Compression: \(data.length / 1048576) mb")
Networking().uploadVideo(data, fileName: "Video")
self.dismissViewControllerAnimated(true, completion: nil)
break
}
}
})
我遇到的第二个问题是失败状态，这是因为我一直写入同一个临时目录，如我的问题中 UIImagePickerController didFinishSelectingMediaWithInfo 方法的代码所示。所以我只是将当前日期用作目录名称，因此它是唯一的。
var uploadUrl = NSURL.fileURLWithPath(NSTemporaryDirectory().stringByAppendingPathComponent("\(NSDate())").stringByAppendingString(".mov"))
[编辑]：更好的解决方案
好的，经过大量试验和几个月后，我找到了一个该死的好且简单得多的解决方案，可以将视频从 45 mb 降低到 1.42 mb，并且质量非常好。
下面是要调用的函数，而不是原来的 convertVideo 函数。请注意，我必须编写自己的完成处理程序参数，该参数在异步导出完成后调用。我只是称它为处理程序。
func compressVideo(inputURL: NSURL, outputURL: NSURL, handler:(session: AVAssetExportSession)-> Void)
{
var urlAsset = AVURLAsset(URL: inputURL, options: nil)
var exportSession = AVAssetExportSession(asset: urlAsset, presetName: AVAssetExportPresetMediumQuality)
exportSession.outputURL = outputURL
exportSession.outputFileType = AVFileTypeQuickTimeMovie
exportSession.shouldOptimizeForNetworkUse = true
exportSession.exportAsynchronouslyWithCompletionHandler { () -> Void in
handler(session: exportSession)
}
}
这是 uiimagepickercontrollerDidFinisPickingMediaWithInfo 函数中的代码。
self.compressVideo(inputURL!, outputURL: uploadUrl!, handler: { (handler) -> Void in
if handler.status == AVAssetExportSessionStatus.Completed
{
var data = NSData(contentsOfURL: uploadUrl!)
println("File size after compression: \(Double(data!.length / 1048576)) mb")
self.picker.dismissViewControllerAnimated(true, completion: nil)
}
else if handler.status == AVAssetExportSessionStatus.Failed
{
let alert = UIAlertView(title: "Uh oh", message: " There was a problem compressing the video maybe you can try again later. Error: \(handler.error.localizedDescription)", delegate: nil, cancelButtonTitle: "Okay")
alert.show()
})
}
})
这个答案已经完全重写和注释以支持 Swift 4.0。请记住，更改 AVFileType 和 presetName 值允许您在大小和质量方面调整最终输出。
import AVFoundation
extension ViewController: AVCaptureFileOutputRecordingDelegate {
// Delegate function has been updated
func fileOutput(_ output: AVCaptureFileOutput, didFinishRecordingTo outputFileURL: URL, from connections: [AVCaptureConnection], error: Error?) {
// This code just exists for getting the before size. You can remove it from production code
do {
let data = try Data(contentsOf: outputFileURL)
print("File size before compression: \(Double(data.count / 1048576)) mb")
} catch {
print("Error: \(error)")
}
// This line creates a generic filename based on UUID, but you may want to use your own
// The extension must match with the AVFileType enum
let path = NSTemporaryDirectory() + UUID().uuidString + ".m4v"
let outputURL = URL.init(fileURLWithPath: path)
let urlAsset = AVURLAsset(url: outputURL)
// You can change the presetName value to obtain different results
if let exportSession = AVAssetExportSession(asset: urlAsset,
presetName: AVAssetExportPresetMediumQuality) {
exportSession.outputURL = outputURL
// Changing the AVFileType enum gives you different options with
// varying size and quality. Just ensure that the file extension
// aligns with your choice
exportSession.outputFileType = AVFileType.mov
exportSession.exportAsynchronously {
switch exportSession.status {
case .unknown: break
case .waiting: break
case .exporting: break
case .completed:
// This code only exists to provide the file size after compression. Should remove this from production code
do {
let data = try Data(contentsOf: outputFileURL)
print("File size after compression: \(Double(data.count / 1048576)) mb")
} catch {
print("Error: \(error)")
}
case .failed: break
case .cancelled: break
}
}
}
}
}
以下是为 Swift 3.0 编写的原始答案：
extension ViewController: AVCaptureFileOutputRecordingDelegate {
func capture(_ captureOutput: AVCaptureFileOutput!, didFinishRecordingToOutputFileAt outputFileURL: URL!, fromConnections connections: [Any]!, error: Error!) {
guard let data = NSData(contentsOf: outputFileURL as URL) else {
return
}
print("File size before compression: \(Double(data.length / 1048576)) mb")
let compressedURL = NSURL.fileURL(withPath: NSTemporaryDirectory() + NSUUID().uuidString + ".m4v")
compressVideo(inputURL: outputFileURL as URL, outputURL: compressedURL) { (exportSession) in
guard let session = exportSession else {
return
}
switch session.status {
case .unknown:
break
case .waiting:
break
case .exporting:
break
case .completed:
guard let compressedData = NSData(contentsOf: compressedURL) else {
return
}
print("File size after compression: \(Double(compressedData.length / 1048576)) mb")
case .failed:
break
case .cancelled:
break
}
}
}
func compressVideo(inputURL: URL, outputURL: URL, handler:@escaping (_ exportSession: AVAssetExportSession?)-> Void) {
let urlAsset = AVURLAsset(url: inputURL, options: nil)
guard let exportSession = AVAssetExportSession(asset: urlAsset, presetName: AVAssetExportPresetMediumQuality) else {
handler(nil)
return
}
exportSession.outputURL = outputURL
exportSession.outputFileType = AVFileTypeQuickTimeMovie
exportSession.shouldOptimizeForNetworkUse = true
exportSession.exportAsynchronously { () -> Void in
handler(exportSession)
}
}
}
这里是兼容Swift4.0的代码Compress video size before attach to an email in swift您还可以跟踪视频压缩的进度
我正在尝试压缩用户相机从 UIImagePickerController 拍摄的视频（不是现有视频，而是动态视频）以上传到我的服务器并花费少量时间来完成，因此尺寸较小在较新质量的相机上是理想的，而不是 30-45 mb。
这是在 swift 中对 iOS 8 进行压缩的代码，它压缩得非常好，我很容易从 35 mb 下降到 2.1 mb。
func convertVideo(inputUrl: NSURL, outputURL: NSURL)
{
//setup video writer
var videoAsset = AVURLAsset(URL: inputUrl, options: nil) as AVAsset
var videoTrack = videoAsset.tracksWithMediaType(AVMediaTypeVideo)[0] as AVAssetTrack
var videoSize = videoTrack.naturalSize
var videoWriterCompressionSettings = Dictionary(dictionaryLiteral:(AVVideoAverageBitRateKey,NSNumber(integer:960000)))
var videoWriterSettings = Dictionary(dictionaryLiteral:(AVVideoCodecKey,AVVideoCodecH264),
(AVVideoCompressionPropertiesKey,videoWriterCompressionSettings),
(AVVideoWidthKey,videoSize.width),
(AVVideoHeightKey,videoSize.height))
var videoWriterInput = AVAssetWriterInput(mediaType: AVMediaTypeVideo, outputSettings: videoWriterSettings)
videoWriterInput.expectsMediaDataInRealTime = true
videoWriterInput.transform = videoTrack.preferredTransform
var videoWriter = AVAssetWriter(URL: outputURL, fileType: AVFileTypeQuickTimeMovie, error: nil)
videoWriter.addInput(videoWriterInput)
var videoReaderSettings: [String:AnyObject] = [kCVPixelBufferPixelFormatTypeKey:kCVPixelFormatType_420YpCbCr8BiPlanarVideoRange]
var videoReaderOutput = AVAssetReaderTrackOutput(track: videoTrack, outputSettings: videoReaderSettings)
var videoReader = AVAssetReader(asset: videoAsset, error: nil)
videoReader.addOutput(videoReaderOutput)
//setup audio writer
var audioWriterInput = AVAssetWriterInput(mediaType: AVMediaTypeAudio, outputSettings: nil)
audioWriterInput.expectsMediaDataInRealTime = false
videoWriter.addInput(audioWriterInput)
//setup audio reader
var audioTrack = videoAsset.tracksWithMediaType(AVMediaTypeAudio)[0] as AVAssetTrack
var audioReaderOutput = AVAssetReaderTrackOutput(track: audioTrack, outputSettings: nil) as AVAssetReaderOutput
var audioReader = AVAssetReader(asset: videoAsset, error: nil)
audioReader.addOutput(audioReaderOutput)
videoWriter.startWriting()
//start writing from video reader
videoReader.startReading()
videoWriter.startSessionAtSourceTime(kCMTimeZero)
//dispatch_queue_t processingQueue = dispatch_queue_create("processingQueue", nil)
var queue = dispatch_queue_create("processingQueue", nil)
videoWriterInput.requestMediaDataWhenReadyOnQueue(queue, usingBlock: { () -> Void in
println("Export starting")
while videoWriterInput.readyForMoreMediaData
{
var sampleBuffer:CMSampleBufferRef!
sampleBuffer = videoReaderOutput.copyNextSampleBuffer()
if (videoReader.status == AVAssetReaderStatus.Reading && sampleBuffer != nil)
{
videoWriterInput.appendSampleBuffer(sampleBuffer)
}
else
{
videoWriterInput.markAsFinished()
if videoReader.status == AVAssetReaderStatus.Completed
{
if audioReader.status == AVAssetReaderStatus.Reading || audioReader.status == AVAssetReaderStatus.Completed
{
}
else {
audioReader.startReading()
videoWriter.startSessionAtSourceTime(kCMTimeZero)
var queue2 = dispatch_queue_create("processingQueue2", nil)
audioWriterInput.requestMediaDataWhenReadyOnQueue(queue2, usingBlock: { () -> Void in
while audioWriterInput.readyForMoreMediaData
{
var sampleBuffer:CMSampleBufferRef!
sampleBuffer = audioReaderOutput.copyNextSampleBuffer()
println(sampleBuffer == nil)
if (audioReader.status == AVAssetReaderStatus.Reading && sampleBuffer != nil)
{
audioWriterInput.appendSampleBuffer(sampleBuffer)
}
else
{
audioWriterInput.markAsFinished()
if (audioReader.status == AVAssetReaderStatus.Completed)
{
videoWriter.finishWritingWithCompletionHandler({ () -> Void in
println("Finished writing video asset.")
self.videoUrl = outputURL
var data = NSData(contentsOfURL: outputURL)!
println("Byte Size After Compression: \(data.length / 1048576) mb")
println(videoAsset.playable)
//Networking().uploadVideo(data, fileName: "Test2")
self.dismissViewControllerAnimated(true, completion: nil)
})
break
}
}
}
})
break
}
}
}// Second if
}//first while
})// first block
// return
}
这是我的 UIImagePickerController 调用压缩方法的代码
func imagePickerController(picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [NSObject : AnyObject])
{
// Extract the media type from selection
let type = info[UIImagePickerControllerMediaType] as String
if (type == kUTTypeMovie)
{
self.videoUrl = info[UIImagePickerControllerMediaURL] as? NSURL
var uploadUrl = NSURL.fileURLWithPath(NSTemporaryDirectory().stringByAppendingPathComponent("captured").stringByAppendingString(".mov"))
var data = NSData(contentsOfURL: self.videoUrl!)!
println("Size Before Compression: \(data.length / 1048576) mb")
self.convertVideo(self.videoUrl!, outputURL: uploadUrl!)
// Get the video from the info and set it appropriately.
/*self.dismissViewControllerAnimated(true, completion: { () -> Void in
//self.next.enabled = true
})*/
}
}
正如我上面提到的，这可以减少文件大小，但是当我取回文件时（它仍然是 .mov 类型）quicktime 无法播放它。 Quicktime 最初确实尝试转换它但中途失败（打开文件后 1-2 秒。）我什至在 AVPlayerController 中测试了视频文件但它没有提供有关电影的任何信息，它只是一个播放按钮没有蚂蚁加载并且没有任何长度只是“--”，时间通常在播放器中。 IE 无法播放的损坏文件。
我确定这与写入资产的设置有关，无论是视频写入还是音频写入我都不确定。甚至可能是读取导致资产损坏的资产。我试过改变周围的变量并设置不同的读写键，但我没有找到正确的组合，这很糟糕，我可以压缩但从中得到一个损坏的文件。我完全不确定，如有任何帮助，我们将不胜感激。请放轻松。
您的转换方法是异步的，但没有完成块。那么您的代码如何知道文件何时准备就绪呢？也许您在文件完全写入之前正在使用它。
转换本身看起来也很奇怪 - 音频和视频通常是并行编写的，而不是串行的。
您神奇的压缩率可能表明您写出的帧数比您实际想象的要少。
想通了！ 好的，所以有 2 个问题：1 个问题与 videoWriter.finishWritingWithCompletionHandler 函数调用有关。当这个完成块被执行时，它并不意味着视频编写器已经完成写入输出 url。所以我必须在上传实际视频文件之前检查状态是否已完成。这有点骇人听闻，但这就是我所做的
videoWriter.finishWritingWithCompletionHandler({() -> Void in
while true
{
if videoWriter.status == .Completed
{
var data = NSData(contentsOfURL: outputURL)!
println("Finished: Byte Size After Compression: \(data.length / 1048576) mb")
Networking().uploadVideo(data, fileName: "Video")
self.dismissViewControllerAnimated(true, completion: nil)
break
}
}
})
我遇到的第二个问题是失败状态，这是因为我一直写入同一个临时目录，如我的问题中 UIImagePickerController didFinishSelectingMediaWithInfo 方法的代码所示。所以我只是将当前日期用作目录名称，因此它是唯一的。
var uploadUrl = NSURL.fileURLWithPath(NSTemporaryDirectory().stringByAppendingPathComponent("\(NSDate())").stringByAppendingString(".mov"))
[编辑]：更好的解决方案
好的，经过大量试验和几个月后，我找到了一个该死的好且简单得多的解决方案，可以将视频从 45 mb 降低到 1.42 mb，并且质量非常好。
下面是要调用的函数，而不是原来的 convertVideo 函数。请注意，我必须编写自己的完成处理程序参数，该参数在异步导出完成后调用。我只是称它为处理程序。
func compressVideo(inputURL: NSURL, outputURL: NSURL, handler:(session: AVAssetExportSession)-> Void)
{
var urlAsset = AVURLAsset(URL: inputURL, options: nil)
var exportSession = AVAssetExportSession(asset: urlAsset, presetName: AVAssetExportPresetMediumQuality)
exportSession.outputURL = outputURL
exportSession.outputFileType = AVFileTypeQuickTimeMovie
exportSession.shouldOptimizeForNetworkUse = true
exportSession.exportAsynchronouslyWithCompletionHandler { () -> Void in
handler(session: exportSession)
}
}
这是 uiimagepickercontrollerDidFinisPickingMediaWithInfo 函数中的代码。
self.compressVideo(inputURL!, outputURL: uploadUrl!, handler: { (handler) -> Void in
if handler.status == AVAssetExportSessionStatus.Completed
{
var data = NSData(contentsOfURL: uploadUrl!)
println("File size after compression: \(Double(data!.length / 1048576)) mb")
self.picker.dismissViewControllerAnimated(true, completion: nil)
}
else if handler.status == AVAssetExportSessionStatus.Failed
{
let alert = UIAlertView(title: "Uh oh", message: " There was a problem compressing the video maybe you can try again later. Error: \(handler.error.localizedDescription)", delegate: nil, cancelButtonTitle: "Okay")
alert.show()
})
}
})
这个答案已经完全重写和注释以支持 Swift 4.0。请记住，更改 AVFileType 和 presetName 值允许您在大小和质量方面调整最终输出。
import AVFoundation
extension ViewController: AVCaptureFileOutputRecordingDelegate {
// Delegate function has been updated
func fileOutput(_ output: AVCaptureFileOutput, didFinishRecordingTo outputFileURL: URL, from connections: [AVCaptureConnection], error: Error?) {
// This code just exists for getting the before size. You can remove it from production code
do {
let data = try Data(contentsOf: outputFileURL)
print("File size before compression: \(Double(data.count / 1048576)) mb")
} catch {
print("Error: \(error)")
}
// This line creates a generic filename based on UUID, but you may want to use your own
// The extension must match with the AVFileType enum
let path = NSTemporaryDirectory() + UUID().uuidString + ".m4v"
let outputURL = URL.init(fileURLWithPath: path)
let urlAsset = AVURLAsset(url: outputURL)
// You can change the presetName value to obtain different results
if let exportSession = AVAssetExportSession(asset: urlAsset,
presetName: AVAssetExportPresetMediumQuality) {
exportSession.outputURL = outputURL
// Changing the AVFileType enum gives you different options with
// varying size and quality. Just ensure that the file extension
// aligns with your choice
exportSession.outputFileType = AVFileType.mov
exportSession.exportAsynchronously {
switch exportSession.status {
case .unknown: break
case .waiting: break
case .exporting: break
case .completed:
// This code only exists to provide the file size after compression. Should remove this from production code
do {
let data = try Data(contentsOf: outputFileURL)
print("File size after compression: \(Double(data.count / 1048576)) mb")
} catch {
print("Error: \(error)")
}
case .failed: break
case .cancelled: break
}
}
}
}
}
以下是为 Swift 3.0 编写的原始答案：
extension ViewController: AVCaptureFileOutputRecordingDelegate {
func capture(_ captureOutput: AVCaptureFileOutput!, didFinishRecordingToOutputFileAt outputFileURL: URL!, fromConnections connections: [Any]!, error: Error!) {
guard let data = NSData(contentsOf: outputFileURL as URL) else {
return
}
print("File size before compression: \(Double(data.length / 1048576)) mb")
let compressedURL = NSURL.fileURL(withPath: NSTemporaryDirectory() + NSUUID().uuidString + ".m4v")
compressVideo(inputURL: outputFileURL as URL, outputURL: compressedURL) { (exportSession) in
guard let session = exportSession else {
return
}
switch session.status {
case .unknown:
break
case .waiting:
break
case .exporting:
break
case .completed:
guard let compressedData = NSData(contentsOf: compressedURL) else {
return
}
print("File size after compression: \(Double(compressedData.length / 1048576)) mb")
case .failed:
break
case .cancelled:
break
}
}
}
func compressVideo(inputURL: URL, outputURL: URL, handler:@escaping (_ exportSession: AVAssetExportSession?)-> Void) {
let urlAsset = AVURLAsset(url: inputURL, options: nil)
guard let exportSession = AVAssetExportSession(asset: urlAsset, presetName: AVAssetExportPresetMediumQuality) else {
handler(nil)
return
}
exportSession.outputURL = outputURL
exportSession.outputFileType = AVFileTypeQuickTimeMovie
exportSession.shouldOptimizeForNetworkUse = true
exportSession.exportAsynchronously { () -> Void in
handler(exportSession)
}
}
}
这里是兼容Swift4.0的代码Compress video size before attach to an email in swift您还可以跟踪视频压缩的进度