1
Мне интересно, почему мой сеанс захвата начинается медленно, когда приложение запускается. Это происходит не каждый раз, когда я запускаю приложение, поэтому я не уверен, что это просто другие переменные реального телефона или что-то еще. Я не очень хороший параллельный/параллельный программист, поэтому более чем вероятно мое дрянное кодирование :(Capture Session Starts Up Slow
Я бы ВЕЛИКОЕ оценил это, если бы кто-то мог определить, что мешает иногда. Я прочитал, что все звонки с захват сессии может быть заблокирован, поэтому я попытался изо всех сил отправить эти вызовы в другую очередь без каких-либо условий гонки. Я узнал о том, как сделать кодирование таким образом в быстрой форме. here
Вот мой код, где i инициализировать и запустить все: мои очереди - это очередные очереди
/**************************************************************************
VIEW DID LOAD
***************************************************************************/
override func viewDidLoad() {
super.viewDidLoad()
println("Initializing the cameraCaptureDevice with MediaTypeVideo")
//------INIT CAMERA CAPTURE DEVICE TO BEGIN WITH------
self.cameraCaptureDevice = AVCaptureDevice.defaultDeviceWithMediaType(AVMediaTypeVideo)
println("Done initializing camera")
var error1: NSError? = nil
println("Getting array of available capture devices")
//------GRAB ALL OF THE DEVICES------
let devices = AVCaptureDevice.devices()
//------FIND THE CAMERA MATCHING THE POSITION------
for device in devices {
if device.position == self.cameraCapturePosition {
self.cameraCaptureDevice = device as? AVCaptureDevice
println("Back camera has been added")
self.usingBackCamera = true
}
}
//------ INIT MOVIE FILE OUTPUT ------
self.movieFileOutput = AVCaptureMovieFileOutput()
//------SET UP PREVIEW LAYER-----
self.videoPreviewLayer = AVCaptureVideoPreviewLayer(session: self.session)
if let preview = self.videoPreviewLayer {
println("Video Preview Layer set")
preview.videoGravity = AVLayerVideoGravityResizeAspectFill
}
else {
println("Video Preview Layer is nil!!! Could not set AVLayerVideoGravityResizeAspectFill")
}
println("Camera successully can display")
//------SET JPEG OUTPUT------
println("Setting JPEG Output")
self.stillImageOutput = AVCaptureStillImageOutput()
let outputSettings = [ AVVideoCodecKey : AVVideoCodecJPEG ]
if let imageOutput = self.stillImageOutput {
imageOutput.outputSettings = outputSettings
}
else {
println("still image output is nil, could notset output settings")
}
println("Successfully configured JPEG Ouput")
//------SET MOVIE FILE OUPUT MAX DURATION AND MIN FREE DISK SPACE------
println("Setting Movie File Max Duration")
let maxDuration:CMTime = CMTimeMakeWithSeconds(self.totalTime, self.preferredTimeScale)
if let movieOutput = self.movieFileOutput {
movieOutput.maxRecordedDuration = maxDuration
println("Successully set movie file max duration")
println("Setting movie file minimun byte space")
movieOutput.minFreeDiskSpaceLimit = self.minFreeSpace
println("Successfully added minium free space")
}
else {
println("Movie file output is nil, could not set maximum recording duration or minimum free space")
}
//------ GRAB THE DEVICE'S SUPPORTED FRAME RATE RANGES ------
if let device = self.cameraCaptureDevice {
println("Setting frame rates")
let supportedFrameRateRanges = device.activeFormat.videoSupportedFrameRateRanges
for range in supportedFrameRateRanges {
// Workaround until finding a better way
// frame rate should be 1 - 30
if (range.minFrameRate >= 1 || range.minFrameRate <= 30) == true && (range.maxFrameRate <= 30 || range.maxFrameRate >= 1) == true {
println("Frame rate is supported")
self.frameRateSupported = true
}
else {
println("Frame rate is not supported")
self.frameRateSupported = false
}
}
var error: NSError?
if frameRateSupported && device.lockForConfiguration(&error) {
device.activeVideoMaxFrameDuration = self.frameDuration
device.activeVideoMinFrameDuration = self.frameDuration
device.unlockForConfiguration()
println("SUCCESS")
}
else {
println("frame rate is not supported or there was an error")
if let err = error {
println("There was an error setting framerate: \(err.description)")
}
else {
println("Frame rate is not supported")
}
}
}
else {
println("camera capture device is nil, could not set frame rate")
}
//------ INIT AUDIO CAPTURE DEVICE ------
self.audioCaptureDevice = AVCaptureDevice.defaultDeviceWithMediaType(AVMediaTypeAudio)
var error2: NSError? = nil
let audioDeviceInput = AVCaptureDeviceInput(device: self.audioCaptureDevice, error: &error2)
//------ADD CAMERA CAPTURE DEVICE TO CAPTURE SESSION INPUT------
if let captureDevice = self.cameraCaptureDevice {
if error1 == nil {
println("Trying to add video input")
self.videoDeviceInput = AVCaptureDeviceInput(device: captureDevice, error: &error1)
}
else {
println("Could not create video input")
}
}
else {
println("Could not create camera capture device")
}
//------ ADD INPUTS AND OUTPUTS AS WELL AS OTHER SESSION CONFIGURATIONS------
dispatch_async(self.sessionQueue) {
println("Trying to add audio output")
if let input = audioDeviceInput {
self.session.addInput(audioDeviceInput)
println("Successfully added audio output")
}
else {
println("Could not create audio input")
}
if self.session.canAddInput(self.videoDeviceInput) {
self.session.addInput(self.videoDeviceInput)
println("Successfully added video input")
}
else {
println("Could not add video input")
}
println("initializing video capture session")
//----- SET THE IMAGE QUALITY/RESOLUTION -----
//Options:
// AVCaptureSessionPresetHigh - Highest recording quality (varies per device)
// AVCaptureSessionPresetMedium - Suitable for WiFi sharing (actual values may change)
// AVCaptureSessionPresetLow - Suitable for 3G sharing (actual values may change)
// AVCaptureSessionPreset640x480 - 640x480 VGA (check its supported before setting it)
// AVCaptureSessionPreset1280x720 - 1280x720 720p HD (check its supported before setting it)
// AVCaptureSessionPresetPhoto - Full photo resolution (not supported for video output)
if self.session.canSetSessionPreset(AVCaptureSessionPresetHigh) {
println("Capture Session preset is set to High Quality")
self.session.sessionPreset = AVCaptureSessionPresetHigh
}
else {
println("Capture Session preset is set to Medium Quality")
self.session.sessionPreset = AVCaptureSessionPresetMedium
}
//------ADD JPEG OUTPUT AND MOVIE FILE OUTPUT TO SESSION OUTPUT------
println("Adding still image and movie file output")
if self.session.canAddOutput(self.stillImageOutput) && self.session.canAddOutput(self.movieFileOutput) {
self.session.addOutput(self.stillImageOutput)
self.session.addOutput(self.movieFileOutput)
println("Successfully added outputs")
}
else {
//------ IF OUTPUTS COULD NOT BE ADDED, THEN APP SHOULD NOT RUN ON DEVICE!!!!! ------
println("Could Not Add still image and movie file output")
}
//------WE CALL A METHOD AS IT ALSO HAS TO BE DONE AFTER CHANGING CAMERA------
self.setCameraOutputProperties()
//------DISPLAY PREVIEW LAYER------
if let videoLayer = self.videoPreviewLayer {
self.videoPreviewView.layer.addSublayer(self.videoPreviewLayer)
println("Video Preview Layer Added as sublayer")
self.videoPreviewLayer!.frame = self.videoPreviewView.layer.frame
println("Video Preview frame set")
}
else {
println("videoPreviewLayer is nil, could not add sublayer or set frame")
}
self.view.sendSubviewToBack(self.videoPreviewView)
}
}
/**************************************************************************
VIEW DID APPEAR
***************************************************************************/
override func viewDidAppear(animated: Bool) {
println("About to start the capture session")
//------INITIALIZE THE CAMERA------
dispatch_async(self.startSessionQueue) {
if self.beenHereBefore == false {
println("Have not seen this view before.... starting the session")
//------ START THE PREVIEW SESSION ------
self.startSession()
/*
CHECK TO MAKE SURE THAT THIS CODE IS REALLY NEEDED FOR AUTHORIZATION
*/
// ----- SET MEDIA TYPE ------
var mediaTypeVideo = AVMediaTypeVideo
AVCaptureDevice.requestAccessForMediaType(mediaTypeVideo, completionHandler: { (granted) -> Void in
//------ GRANTED ACCESS TO MEDIATYPE ------
if granted {
self.deviceAuthorized = AVAuthorizationStatus.Authorized
}
//------ NOT GRANTED ACCESS TO MEDIATYPE ------
else {
dispatch_async(dispatch_get_main_queue()) {
UIAlertView(title: "CopWatch", message: "CopWatch does not have permission to use the camera, please change your privacy settings.", delegate: self, cancelButtonTitle: "OK")
self.deviceAuthorized = AVAuthorizationStatus.Denied
dispatch_resume(dispatch_get_main_queue())
}
}
})
}
else {
println("Been Here Before")
self.session.startRunning()
}
self.weAreRecording = false
}
}
и он re - метод, который запускает предварительный просмотр видео
/**************************************************************************
START SESSION
**************************************************************************/
func startSession() {
println("Checking to see if the session is already running before starting the session")
//------ START SESSION IF IT IS NOT ALREADY RUNNING------
if !self.session.running {
//------START CAMERA------
println("Session is not already running, starting the session now")
self.session.startRunning()
self.isSessionRunning = true
println("Capture Session initiated")
}
else {
println("Session is already running, no need to start it again")
}
}