Chapter 3: Other Information

Glossary

Linear PCM (Pulse Code Modula-

tion): Audio signal format without using compression. In the DVD which has a very large disc capacity, the linear PCM signal using high sampling rate can be recorded.

Packed PCM : The packed PCM (P.PCM) signal is obtained by compressing the linear PCM signal featuring large data amount and high sampling rate. With this compres- sion, the signal before compression can be restored perfectly.

Sampling rate: Sampling refers to converting an analog signal into digital signal by slicing the analog signal into fine parts at a certain time interval and digitizing every sliced part. The sampling rate is the count of slicing per second. The original sound can be reproduced more faithfully when the sampling rate is higher.

Quantization bit: The quantization bit count refers to the number used in digitizing the sliced parts obtained by slicing the analog signal as described above. The quantization bit count is the number of bits used in

digitization per second. The original sound can be reproduced more faithfully when the quantization bit count is larger.

Bitstream (DVD): This is the generic name given for the flow of data based on a standard such as Dolby Digital, DTS, MPEG, etc.

Downmixing: Conversion of multi- channel audio signals of DVD or DTS-CD into 2-channel stereo sig- nals.

Downconversion: Conversion of PCM signal with high sampling rate such as 96 kHz and 192 kHz into a signal with a sampling rate of 48 kHz or 44.1 kHz.

Decoder: A device for restoring standard audio signal from audio data recorded based on coding into DVD data, etc. This processing is referred to as decoding.

Dolby Digital: A digital audio compression technology developed by Dolby Laboratories, Inc. It is compatible with 5.1-channel surround audio as

well as 2-channel stereo, and capable of recording a large amount of audio data efficiently in a disc.

DTS : Digital surround system developed by Digital Theater Systems, Inc.

MPEG (Moving Picture Expert

Group) (DVD, VCD): A digital video and audio compression and decompression system which is standardized as an international stan- dard.

Aspect ratio: The ratio between the horizontal and vertical sizes of picture displayed on a TV screen. The aspect ratio of ordinary TV is 4:3, and that of widescreen TV is 16:9.

Pan & scan (DVD): Method of displaying a horizontally-long picture recorded in 16:9 aspect ratio on a 4:3 TV screen by trimming part of picture. In general, the trimming positions for pan & scan are determined uniformly by the reproducing device. However, the pan & scan of DVD allows the software producer to specify the trimming positions to be used in playback.

Letterbox (DVD): Method of displaying a horizontally-long picture recorded in 16:9 aspect ratio on a 4:3 TV screen by attaching bands at the top and bottom of the screen and displaying the horizontally-long picture at the center of screen.

Frame (DVD, VCD): Each frame of a moving picture, that is displayed 30 times a second with NTSC and 25 times a second with PAL. These TV formats reproduce moving pictures by displaying still pictures sequen- tially.

Field (DVD, VCD): Part of a frame obtained by diving the video data of each frame by two. Each frame of ordinary TV is constitute by displaying the fields alternately.

Frame still/Field still (DVD, VCD):

Types of still pictures obtained by temporarily stopping a moving pic- ture. The frame still picture may produce blur in the picture because it displays two specific fields alter- nately, but the picture quality is higher. The field still picture has

Knowledge General

43