Satoshi Itoi

High-density land/groove recording using PRML technology

High density land/groove recording, using partial response maximum likelihood (PRML) technology, which corrects errors in the readout signal for exploiting readout channel characteristics, has been developed. By this detection method, both land area and groove area can be used for data storage tracks without a crosstalk cancellation technique. Applying this method with a red laser, 8 times the storage capacity, compared with the conventional method, has been achieved.

Development of the HDTV optical video disk recorder

We developed the HDTV optical video disk recorder, which combines the HD-CODEC, compresses HD-TV signal to 94Mbps, and the VF-200 optical disk recorder, which can record noncompressed NTSC video data, 4-channel audio data, and user data to both sides of a 30cm(phi) magneto-optical disk in 32 minutes.

HDTV CODEC for Digital Recording

This paper describes a data compression technique used on the HDTV CODEC for digital video recorders. The compression technique is a combination of intraframe DCT and variable length coding, which is typical Run-Length/Huffman coding, and bit rate control. Video data is transformed into the frequency domain with 8 × 8 Discrete Cosine Transform. The transform coefficients are linear quantized and then converted to Variable Length Word at Variable Length Coder (VLC). Consequently, the compressed data rate is about 90Mbps, which is bit rate controlled in each frame. The novel two-stage bit rate control method can prevent frame buffer overflow and contribute to providing encoded data efficiently. Computer simulation results revealed that the picture quality is excellent, even after multiple copy procedure.