A-4. Signal Processing; A-4-1. Features Of Signal Processing; A-4-2. Outline Of Signal Processing - Sony DNW-A100 Maintenance Manual

A-4. Signal Processing

A-4. Signal Processing

A-4-1. Features of Signal Processing

In the Betacam SX format, MPEG2 4:2:2 Profile @Main
Level (omitted as MPEG2 4:2:2P@ML hereafter) is
employed as the compression system of a video signal.
In the MPEG2 4:2:2P@ML coder of this unit, video data is
compressed for each GOP (1GOP is two frames) by frame
correlation. As a result, video data can be compressed
efficiently. In the DNW-A100/A100P, the video data is
compressed to approximately 1/10.
This unit also uses an SDDI (serial digital data interface)
format for transmitting and processing the video data and
audio data inside equipment. Therefore, no data conver-
sion is required during transmission and reception of data
to and from the external equipment. This enables a high-
speed and non-deterioration dubbing.
The SDDI format can exchange system control data as well
as video data and audio data. Moreover, the conventional
external equipment (routing switcher provided with an SDI
interface) can be continuously used because the SDDI
format directly uses the data structure of an SDI (serial
digital interface: SMPTE 259M, CCIR656-III) format.
Analog
Playback
PB
Tape
Head
(Betacam/
Betacam SP)
A-6
Video
V
MPEG2 4:2:2P
Output
@ML Corder
A
Process
(Bit Reduction)
Interface
Audio
Audio Process
Output
Process
Interface
Fig. A-4-1

A-4-2. Outline of Signal Processing

Reproduction of the Betacam/Betacam SP Tape
The video and audio signals reproduced from the tape
based on a Betacam or Betacam SP format are converted
into a digital signal. After that, the output data is also sent
to the video and audio output terminals after gain adjust-
ment by output processor. The video data is compressed
using an MPEG2 4:2:2P@ML coder, integrated with the
audio data using an SDDI interface, and output to the hard
disk drive.
(Refer to Fig. A-4-1.)
Recording on the Hard Disk
The video data and audio data from each source (from tape
or external) are integrated into the data based on an SDDI
format using an SDDI interface. The resultant data is then
recorded on the hard disk via an SCSI interface.
V
SCSI
SDDI
Interface
Interface
A
SDI
Interface
SDDI Output
HDD
SCSI Terminal
SDI Output
Video Output
Audio Output
DNW-A100/A50/A45
DNW-A100P/A50P/A45P