Apple正在使用新的视频编解码器hevc,我正在尝试使用hevc编解码器使用我的应用程序压缩视频。由于某种原因,应用程序崩溃并返回0 MB的文件大小。当我使用H264压缩它时,它可以工作,但是当我使用H265(HEVC)时,应用程序就会崩溃。这是我的代码。
我假设我输出文件的方式有问题。目前,我正在使用mov文件。我应该为特定的HEVC编解码器使用其他类型的文件扩展名吗?我不太清楚这里发生了什么。
func compressFile(urlToCompress: URL, completion:@escaping (URL)->Void){
//video file to make the asset
var audioFinished = false
var videoFinished = false
let asset = AVAsset(url: urlToCompress)
//create asset reader
do{
assetReader = try AVAssetReader(asset: asset)
} catch{
assetReader = nil
}
guard let reader = assetReader else{
fatalError("Could not initalize asset reader probably failed its try catch")
}
let videoTrack = asset.tracks(withMediaType: AVMediaType.video).first!
let audioTrack = asset.tracks(withMediaType: AVMediaType.audio).first!
let videoReaderSettings: [String:Any] = [kCVPixelBufferPixelFormatTypeKey as String!:kCVPixelFormatType_32ARGB]
// ADJUST BIT RATE OF VIDEO HERE
let videoSettings:[String:Any] = [
AVVideoCompressionPropertiesKey: [AVVideoAverageBitRateKey:self.bitrate],
AVVideoCodecKey: AVVideoCodecType.hevc,
AVVideoHeightKey: videoTrack.naturalSize.height,
AVVideoWidthKey: videoTrack.naturalSize.width
]
let assetReaderVideoOutput = AVAssetReaderTrackOutput(track: videoTrack, outputSettings: videoReaderSettings)
let assetReaderAudioOutput = AVAssetReaderTrackOutput(track: audioTrack, outputSettings: nil)
if reader.canAdd(assetReaderVideoOutput){
reader.add(assetReaderVideoOutput)
}else{
fatalError("Couldn't add video output reader")
}
if reader.canAdd(assetReaderAudioOutput){
reader.add(assetReaderAudioOutput)
}else{
fatalError("Couldn't add audio output reader")
}
let audioInput = AVAssetWriterInput(mediaType: AVMediaType.audio, outputSettings: nil)
let videoInput = AVAssetWriterInput(mediaType: AVMediaType.video, outputSettings: videoSettings)
videoInput.transform = videoTrack.preferredTransform
//we need to add samples to the video input
let videoInputQueue = DispatchQueue(label: "videoQueue")
let audioInputQueue = DispatchQueue(label: "audioQueue")
let formatter = DateFormatter()
formatter.dateFormat = "yyyy'-'MM'-'dd'T'HH':'mm':'ss'Z'"
let date = Date()
let documentsPath = NSTemporaryDirectory()
let outputPath = "\(documentsPath)/\(formatter.string(from: date)).mov"
let newOutputUrl = URL(fileURLWithPath: outputPath)
do{
assetWriter = try AVAssetWriter(outputURL: newOutputUrl, fileType: AVFileType.mov)
}catch{
assetWriter = nil
}
guard let writer = assetWriter else{
fatalError("assetWriter was nil")
}
writer.shouldOptimizeForNetworkUse = true
writer.add(videoInput)
writer.add(audioInput)
writer.startWriting()
reader.startReading()
writer.startSession(atSourceTime: kCMTimeZero)
let closeWriter:()->Void = {
if (audioFinished && videoFinished){
self.assetWriter?.finishWriting(completionHandler: {
self.checkFileSize(sizeUrl: (self.assetWriter?.outputURL)!, message: "The file size of the compressed file is: ")
completion((self.assetWriter?.outputURL)!)
print("Completed 1")
})
self.assetReader?.cancelReading()
}
}
audioInput.requestMediaDataWhenReady(on: audioInputQueue) {
while(audioInput.isReadyForMoreMediaData){
let sample = assetReaderAudioOutput.copyNextSampleBuffer()
if (sample != nil){
audioInput.append(sample!)
}else{
audioInput.markAsFinished()
DispatchQueue.main.async {
audioFinished = true
closeWriter()
print("Completed 2")
}
break;
}
}
}
videoInput.requestMediaDataWhenReady(on: videoInputQueue) {
//request data here
while(videoInput.isReadyForMoreMediaData){
let sample = assetReaderVideoOutput.copyNextSampleBuffer()
if (sample != nil){
videoInput.append(sample!)
}else{
videoInput.markAsFinished()
DispatchQueue.main.async {
videoFinished = true
print("Completed 3")
closeWriter()
}
break;
}
}
}
}
func checkFileSize(sizeUrl: URL, message:String){
let data = NSData(contentsOf: sizeUrl)!
print(message, (Double(data.length) / 1048576.0), " mb")
}