Abstract: A decoding system comprises a software-oriented implementation of the decoding process for extracting binary teletext and closed caption data from a signal. The decoder system according to one embodiment includes a processing unit which implements both a closed caption module and a teletext module. The decoder system calls the closed caption module to detect a clock synchronization signal associated with closed caption data. Upon finding the clock synchronization signal, the closed caption module synchronizes to the signal, identifies a framing code, and extracts the closed caption data. Similarly, the decoder system may call the teletext module for the teletext lines, which also synchronizes using a teletext clock synchronization signal. When the clock synchronization signal is detected, the teletext module interpolates the incoming data to reconstruct the data signal.