A-7
DNW-A75/A75P
REC
Heads
Tape
(Betacam SX)
Analog Audio
Inputs
REC
Driver
ECC
Encoder
Composite
Decoder
MPEG 2
4:2:2P@ML
Coder
Bit
Reduction
Audio
Process
SDI
Interface
V
A
V
A
A/D
A/D
Analog Video
Input
(Composite)
Analog Video
Input
(Component)
Digital Audio
Inputs
(AES/EBU)
SDI Input
A/D
A-4. Signal Processing
External Input
Analog or digital video and audio input signals are con-
verted into parallel video data and serial audio data,
respectively. (Refer to Fig. A-4-2.)
Recording on the Tape (Betacam SX Format)
Codes are added to the compressed video data and record-
ing-level processed audio data for error correction using an
ECC encoder.
The video data and audio data are rearranged in the
recording format of the tape so as to add error correction
codes (Reed-Solomon product codes). At this time, the
shuffling is performed simultaneously. After that, outer
ECC data, sync data, ID data, and inner ECC data are
added sequentially. Lastly, channel-coded recording serial
data is sent to the head and recorded on the tape.
(Refer to Fig. A-4-2.)
Fig. A-4-2
The video data and audio data recorded on the tape are
gathered together for each GOP (1GOP is two frames) that
is a compression unit of video data. The video data and
audio data of 1GOP consist of ten tracks (525/60 system)
or 12 tracks (625/50 system) on the tape. An error occur-
ring during playback is corrected in this range. Therefore,
a higher error correction function can be obtained.
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