IOS 视频压缩 Swift iOS 8 损坏的视频文件 [英] IOS Video Compression Swift iOS 8 corrupt video file
问题描述
我正在尝试压缩从 UIImagePickerController 使用用户相机拍摄的视频(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执行此操作，因此较小的尺寸是理想的选择在较新质量的相机上为 30-45 mb.
I am trying to compress video taken with the users camera from UIImagePickerController (Not an existing video but one on the fly) to upload to my server and take a small amount of time to do so, so a smaller size is ideal instead of 30-45 mb on newer quality cameras.
这是在 swift 中为 iOS 8 进行压缩的代码，它压缩得非常好，我很容易从 35 mb 减少到 2.1 mb.
Here is the code to do a compression in swift for iOS 8 and it compresses wonderfully, i go from 35 mb down to 2.1 mb easily.
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
Here is the code for my UIImagePickerController that calls the compress method
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，这在文件大小减小方面有效，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，但在中途失败(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 损坏的文件，无法播放.
As i mentioned above this works as far as file size reduction, but when i get the file back (it is still of type .mov) quicktime cannot play it. Quicktime does try to convert it initially but fails halfway through (1-2 seconds after opening the file.) I've even tested the video file in AVPlayerController but it doesn't give any info about the movie, its just a play button without ant loading and without any length just "--" where the time is usually in the player. IE a corrupt file that won't play.
我确定这与写入资产的设置有关，无论是视频写作还是音频写作，我都不确定.甚至可能是读取资产导致其损坏.我尝试更改变量并设置不同的读取和写入键，但我还没有找到正确的组合，这很糟糕，我可以压缩但从中获取损坏的文件.我完全不确定，任何帮助将不胜感激.Pleeeeeeeeeease.
Im sure it has something to do with the settings for writing the asset out wether it is the video writing or the audio writing I'm not sure at all. It could even be the reading of the asset that is causing it to be corrupt. I've tried changing the variables around and setting different keys for reading and writing but i haven't found the right combination and this sucks that i can compress but get a corrupt file out of it. I'm not sure at all and any help would be appreciated. Pleeeeeeeeease.
推荐答案
此答案已被完全重写和注释以支持 Swift 4.0.请记住，更改 AVFileType 和 presetName 值可以让您在大小和质量方面调整最终输出.
This answer has been completely rewritten and annotated to support Swift 4.0. Keep in mind that changing the AVFileType and presetName values allows you to tweak the final output in terms of size and quality.
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:
Below is the original answer as written for Swift 3.0:
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)
}
}
}
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