Sony DNW-A75 Maintenance Manual page 234

(3) Digital Signal Processing System
(DPR-118 board, DPR-119 board/BKNW-118, and DPR-150 board/BKNW-124)
Recording system
The external input video signals (SDI, component, and composite) that are sent from the SDI-41 board to
the DPR-118 board through the VPR-47 board are passed through a frame control block and pre-filter
block and SX-encoded (SX-compressed).
The SX encoding (SX compression) is constituted by the BRR (bit rate reduction) encode block and a
motion estimation block for motion detection.
The video data (bit stream data in units of GOP) that is SX-encoded by the BRR encode block is sent to
the ECC (error correction code) encode block.
The audio signal data for recording is directly sent from the audio processing block on the APR-40 board
to the ECC encode block on the DPR-118 board without being compressed.
In the ECC encode block, outer and inner error correction codes are added to the input video data and
audio signal data, respectively. Five-field audio control (in 525/60 mode only) and system data recording
control containing non-tracking control data are also performed in this case. Each recording data in video
and audio systems is multiplexed and sent to the REC driver on the EQ-75 board as REC data (A and B).
Playback system
Betacam SX PB data is sent from the EQ-75 board to the DPR-118 board and fed through the VAR x2
process block (1/2) to the outer ECC decode block.
In the VAR x2 process block (1/2), PB data is processed in the preceding stage during only VAR PB
operation.
In the outer ECC decode block, outer error correction is performed for audio and video data after non-
tracking processing (data rearrangement).
The video data after error correction is sent through the VAR x2 process block (2/2) to the BRR (bit rate
reduction) decode block. The audio data after error correction is sent through the VAR x2 process block
(2/2) to the DSP (digital signal process) block for audio processing.
In the VAR x2 process block (2/2), the data processing (decimation) for VAR playback is performed for
PB data in only the VAR PB mode.
In the BRR decode block, PB video data is SX-decoded to return to an eight-bit digital video signal. This
signal is input to the frame control block on the DPR-118 board, and simultaneously sent to the VPR-47
board as the Betacam SX PB video signal.
In the DSP block, five-field sequence processing (in 525/60 mode only) and JOG/VAR control are
performed.
The data output from the DSP block is sent to the audio processing block on the APR-40 board as serial
digital audio data.
When SDTI (SX) output option BKNW-118 (DPR-119 board) is installed, the video data output from the
outer ECC decode block and the audio data output from the VAR x2 process block (2/2) are sent for feed
PB output to the DPR-119 board.
When SDTI-CP output option BKNW-124 (DPR-150 board) is installed, the video data output from the
outer ECC decode block and the audio data output from the VAR x2 process block (2/2) are sent for feed
PB output to the DPR-150 board, and the compressed video data output from the BRR Encode block and
the audio data output from the audio process block (on the APR-40 board) are sent for the analog Beta-
cam PB or E-to-E output to the same board.
C-4
DNW-A75/A75P