show record timer while making video

Question

I had implemented the concept of AVCaptureSession for recording video.

-(void)startRecordingWithOrientation:(AVCaptureVideoOrientation)videoOrientation 
{

    AVCaptureConnection *videoConnection = [AVCamUtilities   
                                           connectionWithMediaType:AVMediaTypeVideo  
                                           fromConnections:[[self movieFileOutput] connections]];
    if ([videoConnection isVideoOrientationSupported])
        [videoConnection setVideoOrientation:videoOrientation];

    [[self movieFileOutput] startRecordingToOutputFileURL:[self outputFileURL]  
    recordingDelegate:self];
 } 

It is recording the video properly but the recording timer in not there on the screen. Anyone has an idea that how to show timer while making video.

Thanks in advance.

Answer 1

I use add a UILabel to the view where is presented the video while is recording and I use this code to show the record time

@property (weak, nonatomic) IBOutlet UILabel *labelTime;

@property(nonatomic, strong) NSTimer *timer;
@property(nonatomic) int timeSec;
@property(nonatomic) int timeMin;

//Method to start recording

- (void)startRecord {
    self.timeMin = 0;
    self.timeSec = 0;

    //String format 00:00
    NSString* timeNow = [NSString stringWithFormat:@"%02d:%02d", self.timeMin, self.timeSec];
    //Display on your label
    //[timeLabel setStringValue:timeNow];
    self.labelTime.text= timeNow;

    self.timer = [NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(timerTick:) userInfo:nil repeats:YES];
    [[NSRunLoop currentRunLoop] addTimer:self.timer forMode:NSDefaultRunLoopMode];

    //Start recording
    [movieFileOutput startRecordingToOutputFileURL:outputURL recordingDelegate:self];

}


//Event called every time the NSTimer ticks.
- (void)timerTick:(NSTimer *)timer {
    self.timeSec++;
    if (self.timeSec == 60)
    {
        self.timeSec = 0;
        self.timeMin++;
    }
    //String format 00:00
    NSString* timeNow = [NSString stringWithFormat:@"%02d:%02d", self.timeMin, self.timeSec];
    //Display on your label
    self.labelTime.text= timeNow;
}

Answer 2

The accepted answer from @Fran Martin works great!

Since i was using it in Swift it took me about an hour to figure out the correct Timer() function. To help the next person who isn't fluent in Objective C here's the Swift version of the accepted answer with some extra functions to invalidate the timer, to reset the timer back to 00:00, when to use it in viewWillAppear, and when to invalidate it

ALWAYS invalidate the timer in viewWillDisappear or viewDidDisappear otherwise if it is a repeat timer and it’s running you can get a memory leak

I had an unforeseen problem where the timer kept running even though I would stop it and I found this SO Answer that said you have to stop it before starting it again and when you declare the timer use weak

@IBOutlet weak fileprivate var yourLabel: UILabel!

var timeMin = 0
var timeSec = 0
weak var timer: Timer?

override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)

    // if your presenting this vc yourLabel.txt will show 00:00
    yourLabel.txt = String(format: "%02d:%02d", timeMin, timeSec)
}

override func viewDidDisappear(_ animated: Bool) {
    super.viewDidDisappear(animated)

    resetTimerToZero()
}

// MARK:- recordButton
@IBAction fileprivate func recordButtonTapped(_ sender: UIButton) {

    startTimer()
    
    movieFileOutput.startRecording(to: videoUrl, recordingDelegate: self)
}

// MARK:- Timer Functions
fileprivate func startTimer(){
    
    // if you want the timer to reset to 0 every time the user presses record you can uncomment out either of these 2 lines

    // timeSec = 0
    // timeMin = 0

    // If you don't use the 2 lines above then the timer will continue from whatever time it was stopped at
    let timeNow = String(format: "%02d:%02d", timeMin, timeSec)
    yourLabel.txt = timeNow

    stopTimer() // stop it at it's current time before starting it again
    timer = Timer.scheduledTimer(withTimeInterval: 1.0, repeats: true) { [weak self] _ in
                self?.timerTick()
            }
}
    
@objc fileprivate func timerTick(){
     timeSec += 1
        
     if timeSec == 60{
         timeSec = 0
         timeMin += 1
     }
        
     let timeNow = String(format: "%02d:%02d", timeMin, timeSec)
        
     yourLabel.txt = timeNow
}

// resets both vars back to 0 and when the timer starts again it will start at 0
@objc fileprivate func resetTimerToZero(){
     timeSec = 0
     timeMin = 0
     stopTimer()
}

// if you need to reset the timer to 0 and yourLabel.txt back to 00:00
@objc fileprivate resetTimerAndLabel(){

     resetTimerToZero()
     yourLabel.txt = String(format: "%02d:%02d", timeMin, timeSec)
}

// stops the timer at it's current time
@objc fileprivate stopTimer(){

     timer?.invalidate()
     timer = nil
}

Answer 3

I am using Timer with swift5 and Xcode14.3.1

declare a var Timer and a count

var timer : Timer?
var count : Int = 0

call the following method when need to start the timer...

 func startTimer(){
        timer?.invalidate() 
        timer = Timer.scheduledTimer(withTimeInterval: 1.0, repeats: true) { [weak self] timer in
            //do something with your timer
            print("Timer fired! \(self?.runCount)")
            self?.runCount += 1            
        }
    }

Note: always invalidate old timers before initializing the new timer ...if you initialize a new timer before deinitializing the old one you gonna lost the reference of old timer and that's gonna be a huge problem so be careful

call the following line whenever you want to stop the timer

timer?.invalidate()

you can also add logic to stop it after particular seconds or do something like the following...

 func startTimer(){
        timer?.invalidate()
        timer = Timer.scheduledTimer(withTimeInterval: 1.0, repeats: true) { [weak self] timer in
            print("Timer fired! \(self?.runCount)")
            
            self?.runCount += 1
            if self?.runCount == 15 {
                timer.invalidate()
                timer = nil
                //do something 
            }
        }

Answer 4

Remember the time (NSTimeInterval) when you started recording, save it in an instance variable, then calculate the difference to the current time (NSDate timeIntervalSinceReferenceDate) in a timer that fires twice per second or so, and display the resulting time in a UITextView?

To avoid drift, set the "fire time" on the Timer after every display and set it to how long until the next full second (or half second or however often) is away. That way, if e.g. displaying the time takes 0.1 seconds, the next fire time is more likely to be on a full second or so.