A synchronization process may include detecting successive horizontal synchronization
pulses of a video signal, and a phase comparison between the successive detected
pulses and the successive transitions of the reference signal for controlling the
oscillator of the phase-locked loop. The detection of each horizontal synchronization
pulse may include sampling the video signal, low-pass filtering the sampled signal,
thresholding the filtered signal for leaving pulses having a level below a threshold.
The synchronization process may also include selecting, as a function of predetermined
selection criteria, from among the residual pulses within an observation window
centered on a transition of the reference signal for the one which corresponds
to the horizontal synchronization pulse.