Overview

1-1 Features

1-1-1 Features of the SRW-5000/ SRW-5500

The SRW-5000/SRW-5500 is a high-definition digital videocassette recorder using the HDCAM-SR format. It is a small and light unit incorporating LSIs for signal processing and is comparable to the HDCAM1) model HDW-F500 in size, weight and functionality.

The SRW-5500 only is a recorder supporting both the HDCAM-SR and HDCAM formats.

1) HDCAM is a trademark of Sony Corporation.

HDCAM-SR format

The HDCAM-SR format exploits technological advances in signal processing and magnetic recording, to provide functionality comparable to that of the HDCAM format, while offering HD digital recording and playback with high image and sound quality.

The technology incorporated in this unit includes the following.

Highly efficient and mild data compression using newly developed MPEG-4 Studio Profile

Powerful error-correcting codes

High-performance, high-accuracy heads and drum with dynamic tracking (DT ™), together with a new auto- tracking technique, yielding highly reliable narrow track

recording and playback.

These technologies allow 120 minutes of recording on an HDCAM-SR cassette (L type), the same size as the HDCAM cassette.

Digital signal processing

In this unit, 4:2:2 component video signals obtained by quantization according to ITU-R709, SMPTE 274M and BTA S-002B (SMPTE 260M) are compressed using MPEG-4 Studio Profile. Audio signals are processed uncompressed, according to the AES/EBU format.

Chapter 1

Input interface

The input interface is based on the HD SDI (HD Serial Digital Interface) format specified by BTA S-004B/005B/ 006B (SMPTE 291M/292M/299M) and ARIB STD-B4, allowing a single BNC coaxial cable to carry one component video signal, twelve digital audio channels, and time code in time division multiplex; this is separated for conversion to parallel data.

Audio recording can be switched between the digital audio signal multiplexed with the HD SDI signal and the audio signal from an AES/EBU digital interface.

Bit rate reduction encoder

The component video signal undergoes frame shuffling. It is then compressed by a process in which it is subjected to DCT (discrete cosine transform) or DPCM (differential pulse code modulation), quantization control, and variable length word encoding. This is the core of the newly developed MPEG-4 Studio Profile. Interlaced signals are compressed in fields and progressive signals are compressed in frames.

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. Reed-Solomon codes are employed in this error correction system.

Channel coding

Video and audio data with the ECC added is recorded in the form of serial data. The HDCAM-SR format adopts a scrambled i-NRZ channel coding system, giving consideration to off-track and noise characteristics.

Playback signal processing

The playback digital signal is equalized by an equalizer circuit. It then passes powerful inner and outer ECCs which can correct dropouts in the reproduced signal. It further goes through an error concealment circuit to have errors still remaining in the signal rectified.

Output interface

Component video data is converted into serial data and multiplexed with audio data and time code, then output in the HD SDI format.

Overview 1 Chapter

1-1 Features

9