Abstract: A method of transmitting digital data includes the steps of multiplexing a plurality of compressed digital video or video and audio signal data to produce 8-bit word sequence data, combining an additional word data group including 8-bit word synchronous data allotted a predetermined specific code with the 8-bit word sequence data to produce composite 8-bit word sequence data in which the additional word data group is repeatedly inserted at predetermined word intervals, causing the composite 8-bit word sequence data to be subjected to 8B/10B conversion to produce composite 10-bit word sequence data having a portion formed based on the additional word data group including 10-bit word synchronous data provided with running disparity not neutral, converting the composite 10-bit word sequence data into serial data, and transmitting the serial data.

Abstract: In the case of transmitting upon converting the 8-bit word string data showing signal information to the 10-bit word string data consisting of word synchronous data, 8-bit word string data showing signal information is obtained and after inserting 2 each of the 8-bit word synchronous data and the 8-bit auxiliary word data to be converted to the 10-bit neutral word data, 8 to 10 bits conversion is conducted to the 10-bit word string data and transmitted; when converting the 8-bit word synchronous data to 10-bit word synchronous data, if the immediately preceding word data is the data having plus running disparity, it is converted to 10-bit word synchronous data having minus running disparity, and if the immediately preceding word data is the data having minus running disparity, it is converted to the 10-bit word synchronous data having plus running disparity. Thereby, in the case of reproducing the signal information at the receiving end, the necessary signal synchronization can be certainly obtained.