Sony D8MM-01, Training Manual

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IC302 TFD
Channel Decoding
The incoming data stream now has the Sync, ID and ITI data removed
from it for processing. The interleaved video and audio data continue on
to the next stage. Data error is corrected using inner parity.
TBC
The incoming signal is time base corrected. The removes any jitter in the
data that may have been caused by the mechanical operation of the ser-
vos.
ECC
Outer parity errors are corrected at this stage.
Shuffling
The video data is shuffled again. Five DCT blocks at a time are selected
from different parts of the picture to form Macro blocks. This will keep the
activity level of the decompression circuit relatively equal throughout op-
erations.
IC301 SFD
DV In/Out Transformation
The interleaved audio, shuffled video data and subcode information from
the tape are output to IC303 LIP.
Audio Deinterleave
The audio signal data is separated from the video signal data.
Video signal Expansion
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Reverse Quantization and Variable Length Decoding (VLD)
The data is converted from its variable length code to a fixed length code.
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Inverse Discrete Cosine Transform (IDCT)
This section takes the one DC and 63 AC coefficients in a DCT block and
converts them to the original uncompressed data stream.
IC303 LIP
This IC contains the three layers needed for an IEEE1394 connection.
The three layers are the physical, link and transaction layers. See the
section on IEEE1394 for more details.
IC351 VFD
De-shuffling
Now that decompression is complete the data must be put back in its
original position. This operation is called de-shuffling. When we perform
this we reconstruct the ten bands that were read off of the tape. Each of
these bands represents a sub track on the tape.
Deblocking
The pixels are released from their blocks. We now have a full frame that
is not separated into blocks.
Video Encode
IC351 also contains a NTSC encoder so that it may send composite sig-
nals to the IR Out and Video Out, and component video to the viewfinder
and LCD if applicable.
IC643 AOI
The Y and C signals are output by IC351 VFD and input to IC643 AOI.
This IC outputs a composite video signal to IC644 IR Transmitter and to
the Line In/Out jack.
IC644 IR Transmit
IC644 IR transmitter modulates the audio and video signals it receives
and transmits them through the air, using the LEDs on the front of the
camcorder. Sircs data can also be transmitted if a TV input is selected in
the menu.