2025 Volume 12 Issue 2 Pages 97-105
Digital video signal processing for varieties of purposes including storage as well as transmission is currently playing a very important role in our daily life. NEC Corporation has been actively doing R&D on video coding since its dawn and incessantly making every effort for implementation of practical codecs, terminals, and systems. They include Delta Modulation for digitization, HO-DPCM for high quality TV transmission, and interframe coding for a broad spectrum of audiovisual services. The author believes it is quite beneficial to introduce a combined history of coding algorithm improvements and practical codecs based on them, since they will provide the overview of the technical history from theoretical and also practical aspects, and definitely there is no such review published so far. This survey paper consists of two parts and reviews the corporate R&D efforts with respect to video coding algorithm improvements and our contribution to progress in digital TV/video transmission services over the world for three decades since the mid-1960s. Part -1 (Chapter 1 and 2) mainly handles continued improvement of Delta Modulation and coding algorithms on intraframe and interframe prediction as well as entropy coding. Part - 2 (from Chapter 3 to 6) mainly shows effectiveness and significance of video coding through various application examples of codecs/terminals as well as standardization activities in which we were deeply involved. In addition, Part-2 includes a brief history of NEC’s CODECs in conjunction with continued algorithm improvements and several examples of practical use in businesses.
