A system and method for block-code transcoding. An input signal is analyzed to determine if the input signal includes multiple control words, multiple data words and a single control word or only data words. If the input signal comprises multiple control words, the method includes, generating a control word location map and mapping the control codes and any data words to a block-code encoded transmission signal. If the input signal comprises a single control word and multiple data words, the method includes, generating a control word location address indicating a location of the single control word and mapping the control code and the multiple data words to a block-code encoded transmission signal. If the input signal comprises only data words, the method includes, mapping the data words sequentially into the block-code encoded transmission signal. Accordingly, the bandwidth efficiency of the transmission signal is improved by varying the encoding technique used dependent upon the contents of the input signal.