Video disc system using variable bit rate

With the compact-sized optical disc for video applications, a recording time of two or more hours is required. However conventional recording and coding techniques have not successfully satisfied the requirement. On the other hand, most pictures are of too high quality in constant bit rate coding. The authors have applied a variable bit rate coding scheme to the disc, and evaluated encoding, recording, playback and decoding. The report mainly discusses a rate control method. They have used a provisional coding to set the target rates of pictures, and considered a non-linear conversion of the target rate for constant visual quality. It gives stable picture and recording of the full data to fit the disc capacity