1-1 Features

1-1-1 Features of the DVW-A500/1, A500P/1, 500/1 and 500P/1

The DVW-A500/1, A500P/1, 500/1, and 500P/1 Digital Videocassette Recorders adopt the Digital Betacam format, and are differentiated as follows:

•The DVW-A500/1 and DVW-A500P/1 are capable of playing back analog Betacam and Betacam SP format cassette tapes.

•The DVW-500/1 and DVW-500P/1 are not compatible with either the analog Betacam or Betacam SP formats.

The DVW-A500/1 and 500/1 can be used in the NTSC color system while the DVW-A500P/1 and 500P/1 can be used in the PAL color system, though they both adopt a component format.

Digital Betacam Format

The DVW-A500/1 series and DVW-500/1 series adopt the newly developed Digital Betacam format as an extension of the Betacam/Betacam SP format. The Digital Betacam format makes the most of the available recording area to achieve high-quality digital recording, while maintaining analog Betacam tape playback compatibility. The following have been developed for this purpose:

•Coefficient recording system

•Powerful error correction system

•High-quality precision heads and drum with DT® (Dynamic Tracking) heads

•New auto tracking system

Together, these allow 120 minutes or more of recording time on half-inch Digital Betacam (L-size) cassettes the same size as those for conventional Betacam and Betacam SP.

Overview of digial signal processing

Digital video signal processing is based on the 4:2:2 component digital D-1 format and CCIR 601 standard quantization. In addition, the data rate is compressed with the coefficient recording system. Digital audio signals are processed in full bits conforming to the AES/EBU format.

Input interface

The component serial digital interface, conforming to SMPTE 259M/EBU T.3267/CCIR 656-III standards, handles component video signals and 4-channel digital audio signals with a single BNC coaxial cable. Both

analog component signals and composite signals (with the BKDW-505/506) are digitized into CCIR 601 standard parallel data.

Audio data from the AES/EBU digital interface or A/D converted data from analog input can be selected for recording.

Bit rate reduction encoder

Video data are suppressed to about half by a newly developed coefficient recording system, whose key processes include field shuffling, blocking, DCT (Discrete Cosine Transform), quantizing, and variable length coding.

ECC encoder

The outer ECC (Error Correction Code) is added to the compressed video and audio data, followed by the inner ECC, ID data, and sync data. The Reed- Solomon code is employed in this error correction system.

Channel coding

Video and audio data with the ECC added are recorded in the form of serial data. The Digital Betacam format adopts a scrambled NRZI channel coding system that is superior in off-track and noise characteristics.

Playback signal processing

The playback digital data are equalized by auto EQ circuits and error-corrected by powerful inner and outer ECC, which can correct most data disturbed by noise and dropouts in the reproduced signal. Data that cannot be corrected further are compensated by error concealment circuits.

Output interface

Component video data are converted into serial data and multiplexed with audio data, then output in the serial digital interface format.

For analog output, component video data are D/A converted into an analog component signal, while they are encoded into composite digital, then D/A converted into analog composite signal.

For audio outputs, the AES/EBU digital interface and D/A converted analog audio are available.

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