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• OpenCV Threading Capture Loses Connection to IP Camera

  27 janvier 2021, par David López Díaz

  I have a surveillance program that opens 16 threads to check on to 16 different cameras with live video, but when after some time (20/30 seconds) cameras starts to lose frames and I need to reconnect them.

  


  The thing is that if I only open 10 streams at once it might lose a frame from time to time, but if I open 16 streams it begins to fail every 20 seconds or so.

  


  I've checked system params, and CPU doesnt go more than 50% and RAM is on 4GB, so this doesnt look like the problem.
Also I've checked the network and it's fine, no delay and no packet loss.

  


  Sometime I get error while decoding MB 8 7, bytestream -5

  


  This is the thread I use to get the streams.

  


      """
    Class that continuously gets frames from a VideoCapture object
    with a dedicated thread.
    """
    def __init__(self, idcam,ipcamara, user, passwd,resolucionh,resolucionw):
        self.id = idcam
        self.ip = ipcamara
        self.user = user
        self.passwd = passwd
        self.Q =[]
        self.scale_percent = 50
        self.i = 0

    def start(self):
        self.conectar()
        Thread(target=self.get, args=()).start()
        return self

    def get(self):

        while True:
            if(self.stream.isOpened() and self.online):
                (status, preFrame) = self.stream.read()
                if(status):
                    self.frame = (preFrame)
                else:
                    self.stream.release()
                    self.online = False
            else:
                graba_log('Camara '+str(self.id),'Desconexion')
                self.conectar()
                time.sleep(1)

    def conectar(self):
        print('Iniciando conexion con camara '+str(self.id))
        self.stream = cv2.VideoCapture("rtsp://"+self.user+":"+self.passwd+"@"+self.ip)
        self.online = True
    def recuperarFrame(self):
        return self.frame ```


  


• What is video timescale, timebase, or timestamp in ffmpeg ? [on hold]

  11 avril 2017, par Please Help

  There does not seem to be any explanation online as to what these are. People talk about them a lot. I just want to know what they are and why they are significant. Using -video_track_timescale, how would I determine a number for it ? Is it random ? Should it be 0 ?

• Bash script : Cycle script until ffmpeg command restarts successfully

  13 août 2023, par Bellacoda

  I have a IP Camera and the recordings are saved with ffmpeg RTSP into a raspberry pi.

  


  Sometimes, when the electricity shuts off and comes back on, the raspberry boots faster than the IP Camera and the ffmpeg command (saved on a crontab to run every reboot) fails to execute because it can't reach the IP Camera (that is still turning on).

  


  I tried to put a sleep command before the command but that doesn't work either.

  


  It also happened that when the IP Camera reboots, the raspberry closes the command, but when the camera comes back online, I have to manually lauch the command.

  


  Is there a way to make a script that waits to run the ffmpeg command until the camera is fully online (I assume with the $ ? variable for command exit status), and to wait to restart the ffmpeg command when the camera reboots ?

  


  The setup I have now is a crontab :
SHELL=/bin/bash
@reboot sleep 120s ; sudo ffmpeg ...