DVR-7000
3.2.4.2 Recording System
The basic flow of data with the DVR-7000 is similar to that with the
DVR-2000. Recordable media are DVD-R (Ver. 2.0) and DVD-
RW (Ver. 1.0/1.1), and recording application formats are Video
Recording Format (DVD-VR) and Video Mode Recording Format.
Only Video Mode Recording is possible with DVD-R discs, and
DVD-VR recording is possible with DVD-RW discs (Video Mode
Recording is also possible with Ver. 1.1 DVD-RW discs). The
available recording speed to discs is normal speed.
In DVD-VR recording, analog video and audio line input signals or
analog video and audio signals detected by the tuner are AD-
converted, input to the Graphics Engine LSI, processed with the
frame TBC and 3DNR, then encoded and multimplexed in real time.
In the video and audio encoding block, based on the set recording
length or recording bit rate, the most suitable encoding parameter is
determined, and MPEG video encoding is made by variable bit rate
(VBR). Compressed video stream and audio stream compressed by
DDCE (Dolby Digital Consumer Encoder) are then packed and
multiplexed, and are formed into a basic VOB (video object)
conforming to the Video Recording Format. In the video stream,
necessary information stipulated in the Video Recording Format,
such as RDI (Real-time Data Information) in a VOB, is described.
Everything up to this process is done by the MPEG Encoder LSI. A
stream sent from this MPEG Encoder LSI is temporarily stored in
the SDRAM (stream buffer) of the ATAPI interface LSI. The main
CPU controls transfer so that the downstream will not overflow,
and the temporarily stored stream is then transferred to the writer
block via the ATAPI bus. As actual recording to a disc is done
intermittently, a write command is issued when data reach certain
amount, and a mass of data are transferred simultaneously.
The data is formatted into the DVD physical format in the DVD-
ROM encoder of the writer block, then actually recorded on a disc
with the most suitable emission power of the laser diode and the
strategy. On the disc, data are recorded intermittently in blocks, and
these data blocks are linked with no linking loss.
In actual operation, one title is created by one sequence of a user's
starting recording through stopping recording. If recording is paused,
a chapter will be created. If the disc is removed from the unit, the
management information (file system and VR_MANGR.IFO, etc.),
which is managed by the main CPU and which is necessary to play
back the recorded video and audio signals, will be recorded on the
disc. Editing can be made on the originals and play lists. For editing
of a play list, only management information is updated and rewritten,
and VOBs are not rewritten. Thus, nondestructive editing is possible.
3.2.5 Playback System
3.2.5.1 DVD Playback
The path for transferring AV decoder data in the DVR-7000 has
largely been modified from that of the DVR-2000.
The path of DVD-video playback is the same as that of conventional
DVD-video playback: The RF signal read out from a disc is converted
into NRZI (non return to zero inverse) signal after passing through
the preamplifier, then is sent to the recorder block; There, the DVD
physical format is decoded. Then in the AV decoder, the signal is
decoded into digital video and audio data. This is basically the same
path as that the DVD-video player uses to play back a DVD-video
disc. The playback speed is normal speed.
During playback of a DVD-VR, the data-transfer path from the writer
block is the same as that in recording (via the ATAPI bus).
The RF signal read out from a disc is processed up to DVD physical
formatting in the writer block, transferred via the ATAPI bus, and is
temporarily stored in the SDRAM (stream buffer) of the ATAPI
interface LSI. Then, the data are transferred to the AV decoder and
decoded to video and audio digital data. Thus, for DVD-VR, the
same path is used for recording and playback during data transfer
from the recorder to the writer blocks. The playback speed of DVD-
VR is double normal speed (only for DVD-VR).
The AV-decoded data pass through the same path regardless of the
applications used. The digital video signal enters the Graphics Engine
LSI, where the overlay process with the GUI & OSD takes place. If
a disc-navigation display is called by the user, video capture and
multiscreen display processes are executed for the designated frame
(random designation possible) of each title. Then, the digital video
signal is processed with 3DNR in the NTSC Encode LSI to be output
as an analog video signal.
As to the audio signal, audio digital data to be output as an analog
signal are decoded in the AV decoder, and audio digital data to be
output as a digital signal are DIF-modulated after being decoded in
the AV decoder, then either signal goes to the AUDIO interface
LSI, where the signal to be output as a digital signal undergoes a
switching process, and for the signal to be output as an analog signal,
data are gathered for the level meter and switching process is
executed. The signal is then output through the DAC.
3.2.5.2 CD/Video-CD Playback
Playback of CD media is newly added for the DVR-7000. The basic
data flow is similar to that of a DVD-video player. Playback speed
of CD media is 4 times normal speed in CAV.
As to CD-DA playback, the RF signal read out from a disc is EFM-
demodulated in the writer block. Then the signal to be output as an
analog signal is sent to the recorder block as a 3-line serial signal of
IEC60958 format, and the signal to be output as a digital signal is
DIF-modulated in the writer block and then is sent to the recorder
block.
The signal to be output as an analog signal via the Audio interface
LSI enters the SRC, where the sampling rate is converted from 44.1
kHz to 48 kHz. Then, the signal enters the Audio interface LSI again,
and is finally output through the DAC. The signal to be output as a
digital signal also undergoes a switching process in the Audio
interface LSI, and then is output as DIF.
As to Video-CD playback, as with CD-DA playback, the RF signal
read out from a disc is EFM-demodulated in the writer block. Then
the CD-ROM data for Video-CD is then sent to the recorder block
as a 3-line serial signal of IEC60958 format, as with the signal to be
output as an analog signal. In the recorder block, the data are first
decoded then sent to the AV decoder, where the data are decoded
into video and audio digital data. Then, the data pass and are
processed in the same way as with DVD playback and are then
output.
