Estimating real-time delay of a video data stream

In an arrangement where a physical phenomenon affects a digital video camera and is measured or sensed by a sensor, a delay of a digital video stream from the digital video camera is estimated. The digital video stream is processed by a video processor for producing a signal that represents the changing over time of the effect of the physical phenomenon on the digital video camera. The signal is then compared with the sensor output signal, such as by using cross-correlation or cross-convolution, for estimating the time delay between the compared signals. The estimated time delay may be used for synchronizing when combining additional varied data to the digital video stream for low-error time alignment. The physical phenomenon may be based on mechanical position or motion, such as pitch, yaw, or roll. The time delay estimating may be performed once, upon user control, periodically, or continuously.