Sony SRW-5500 User Manual

Page of 187
9
1-1 Features
Chapter
  Chapt
er 1  Ov
e
rv
ie
w
1
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 HDCAM
1) 
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.
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.