问题
I am planning to build an NSOpenGLView for an OS X app using SWIFT which can be used to apply Core Image Filter and effects to a video, so far I have worked on the code for the video Controller to add video playback, but I am not sure how to apply the filter to the video:
class VideoMediaViewController: NSViewController {
weak var mainView : DTMainViewController?
@IBOutlet weak var aVPlayerView: AVPlayerView!
var url:NSURL?{
didSet{
// this is the setter
}
}
var observer:AnyObject?
var player:AVPlayer?
var videoOutput:AVPlayerItemVideoOutput?
var ciContext:CIContext?
var loadStatus:NSNumber?
override func viewDidLoad() {
aVPlayerView.controlsStyle = AVPlayerViewControlsStyle.None
}
func loadMedia() {
unloadMedia()
//Create AVPlayerItem
player = AVPlayer.playerWithURL(url) as? AVPlayer
//Create VideoOutput
videoOutput = AVPlayerItemVideoOutput(pixelBufferAttributes: [kCVPixelBufferPixelFormatTypeKey:kCVPixelFormatType_32ARGB])
//Get notifications for status
player?.addObserver(self, forKeyPath: "status", options:.New, context: nil)
//looping logic start
player?.actionAtItemEnd = AVPlayerActionAtItemEnd.None
NSNotificationCenter.defaultCenter().addObserver(self,
selector: "playerItemDidReachEnd:",
name: AVPlayerItemDidPlayToEndTimeNotification,
object: player?.currentItem)
//looping logic end
observer = player?.addPeriodicTimeObserverForInterval(CMTimeMake(150, 600),
queue: dispatch_get_main_queue(),
usingBlock: {[unowned self](CMTime) in
self.updateSliderProgress()
self.updateStartAndEndTimes()
})
//Set videoOutput to player
player?.currentItem.addOutput(videoOutput)
aVPlayerView.player = player
aVPlayerView.player.play()
}
func playerItemDidReachEnd(notification: NSNotification) {
let aVPlayerItem: AVPlayerItem = notification.object as! AVPlayerItem
aVPlayerItem.seekToTime(kCMTimeZero)
}
func scrubberSliderChanged(sender: AnyObject){
var duration:Float64 = CMTimeGetSeconds(player!.currentItem.duration)
var sliderValue:Float64 = Float64(mainView!.scrubberSlider!.floatValue)
var seekToTime = CMTimeMakeWithSeconds(((sliderValue * duration)/100.00), 1)
player?.seekToTime(seekToTime, completionHandler: { (Bool) -> Void in
})
}
func secondsToHoursMinutesSeconds (seconds : Int) -> (Int, Int, Int) {
return (seconds / 3600, (seconds % 3600) / 60, (seconds % 3600) % 60)
}
func getStringFromHoursMinutesSeconds(h:Int, m:Int, s:Int) -> (String){
let formatter = NSNumberFormatter()
formatter.minimumIntegerDigits = 2
let hours = formatter.stringFromNumber(h) //"00"
let minutes = formatter.stringFromNumber(m) //"01"
let seconds = formatter.stringFromNumber(s) //"10"
var timerString = hours! + ":" + minutes! + ":" + seconds!
return timerString
}
func updateStartAndEndTimes(){
var time = CMTimeGetSeconds(player!.currentItem.duration) - CMTimeGetSeconds(player!.currentItem.currentTime())
var (hours,minutes,seconds) = secondsToHoursMinutesSeconds(Int(time))
let timeRemainingString = getStringFromHoursMinutesSeconds(hours, m: minutes, s: seconds)
mainView!.videoTimeRemaing.stringValue = timeRemainingString
time = CMTimeGetSeconds(player!.currentItem.currentTime())
(hours,minutes,seconds) = secondsToHoursMinutesSeconds(Int(time))
let timePassedString = getStringFromHoursMinutesSeconds(hours, m: minutes, s: seconds)
mainView?.videoTimePassed.stringValue = timePassedString
// mainView!.videoTimeRemaing.stringValue = "\(CMTimeGetSeconds(player!.currentItem.duration) - CMTimeGetSeconds(player!.currentItem.currentTime()))!"
// mainView?.videoTimePassed.stringValue = "\(CMTimeGetSeconds(player!.currentItem.currentTime()))!"
}
func updateSliderProgress(){
var currentTime = CMTimeGetSeconds(player!.currentItem.currentTime())
var duration = CMTimeGetSeconds(player!.currentItem.duration)
var progress = currentTime/duration*100
mainView!.scrubberSlider!.doubleValue = progress
}
func unloadMedia() {
//Cancel Prerolls and Notifications
player?.cancelPendingPrerolls
player?.removeTimeObserver(observer)
player?.removeObserver(self, forKeyPath: "status")
NSNotificationCenter.defaultCenter().removeObserver(self, name: AVPlayerItemDidPlayToEndTimeNotification, object: nil)
//dispose of assets and players, etc
//...
}
override func viewWillDisappear() {
unloadMedia()
}
//Get Status updates and log success or failure
override func observeValueForKeyPath(keyPath: String, ofObject object: AnyObject, change: [NSObject : AnyObject], context: UnsafeMutablePointer<Void>) {
if ( (object as! NSObject) == player && keyPath == "status") {
if (player?.status == .ReadyToPlay) {
NSLog("Status - Loaded")
} else if (player?.status == .Failed) {
NSLog("Status - Failed")
} else {
NSLog("Status - Unknown")
}
}
}
but I can't understand where and how to apply a Core Image Filter to it. I have searched online but haven't been able to find a complete example to do that.
Any help will be greatly appreciated, God willing, I can figure it out soon :)
回答1:
Actually I figured it out.. This is a solution that requires OS X El Capitan or later..
let url = NSBundle.mainBundle().URLForResource("skies", withExtension: "mp4”)!
let avAsset = AVAsset(URL: url)
let vidComp = AVVideoComposition(asset: avAsset,
applyingCIFiltersWithHandler: {
request in
self.image = request.sourceImage.imageByClampingToExtent();
self.image = (self.image!.imageByApplyingFilter("CIGaussianBlur”, withInputParameters: [kCIInputRadiusKey: self.blurTestSlider.integerValue])
self.image = self.image!.imageByCroppingToRect(request.sourceImage.extent)
request.finishWithImage(self.image!, context: self.context)
})
let playerItem = AVPlayerItem(asset: avAsset)
playerItem.videoComposition = vidComp
player = AVPlayer(playerItem: playerItem)
dTMediaViewControllerA?.player = player
dTMediaViewControllerA?.player.play()
来源：https://stackoverflow.com/questions/30519481/apply-core-image-filter-to-video-on-os-x-using-swift