U.S. patent application number 11/598819 was filed with the patent office on 2007-05-31 for digital video signal recording/reproducing method and apparatus.
Invention is credited to Nobutaka Amada, Kyoichi Hosokawa, Hiroo Okamoto.
Application Number | 20070122122 11/598819 |
Document ID | / |
Family ID | 26438070 |
Filed Date | 2007-05-31 |
United States Patent
Application |
20070122122 |
Kind Code |
A1 |
Okamoto; Hiroo ; et
al. |
May 31, 2007 |
Digital video signal recording/reproducing method and apparatus
Abstract
A digital video signal recording method for recording on a
magnetic recording medium by using a rotary head, a first digital
compressed video signal having a predetermined number of bytes in a
packet format and a second digital compressed video signal having a
predetermined number of bytes in a packet format which is generated
from said first digital compressed video signal, including: adding
information representing a sequence of arrangement of said second
digital compressed video signal to said second digital compressed
video signal, said sequence representing information including at
least information indicating a sequence within a predetermined
region; and recording said second digital compressed video signal
thus added, on a predetermined region on said magnetic recording
medium.
Inventors: |
Okamoto; Hiroo;
(Yokohama-shi, JP) ; Amada; Nobutaka;
(Yokohama-shi, JP) ; Hosokawa; Kyoichi;
(Yokohama-shi, JP) |
Correspondence
Address: |
ANTONELLI, TERRY, STOUT & KRAUS, LLP
1300 NORTH SEVENTEENTH STREET
SUITE 1800
ARLINGTON
VA
22209-3873
US
|
Family ID: |
26438070 |
Appl. No.: |
11/598819 |
Filed: |
November 14, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10170703 |
Jun 14, 2002 |
|
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|
11598819 |
Nov 14, 2006 |
|
|
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09059355 |
Apr 14, 1998 |
6430362 |
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10170703 |
Jun 14, 2002 |
|
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Current U.S.
Class: |
386/316 ;
375/E7.198; 386/324; 386/357; G9B/27.002; G9B/27.039 |
Current CPC
Class: |
H04N 5/783 20130101;
H04N 5/78263 20130101; H04N 9/8227 20130101; H04N 9/8042 20130101;
H04N 5/775 20130101; H04N 19/40 20141101; H04N 9/8205 20130101;
G11B 27/005 20130101; H04N 9/8063 20130101; G11B 2220/91 20130101;
G11B 27/3081 20130101; H04N 9/7921 20130101 |
Class at
Publication: |
386/109 |
International
Class: |
H04N 7/26 20060101
H04N007/26 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 15, 1997 |
JP |
09-096915 |
Aug 20, 1997 |
JP |
09-223344 |
Claims
1. (canceled)
2. A digital video signal reproducing method for reproducing a
first digital video signal, which has been recorded on a recording
media, constituted by a picture signal compressed without using a
correlation between frames and another picture signal compressed by
using the correlation between the frames; and a second video
signal, which has been produced from said first digital video
signal constituted by a picture signal compressed without using a
correlation between frames, wherein: the digital video signal
reproducing method contains a first mode for reproducing the first
digital video signal and a second mode for reproducing the second
digital video signal; in the first mode, the reproduced first
digital signal is outputted at the same timing as an input timing
at the recording operation; in the second mode, the reproduced
second digital signal is outputted at predetermined timing
different from the input timing at the recording operation; and a
time reference of the output timing of the reproduced first and
second digital signals is different from that of input timing.
3. A digital video signal reproducing method as claimed in claim 2
wherein: said first and second digital video signals are packet
format signals which consist of preselected bytes.
4. A digital video signal reproducing method as claimed in claim 2
wherein: in said second mode, said reproduced second digital video
signal is outputted in unit of the picture.
5. A digital video signal reproducing method as claimed in claim 4
wherein: in said second mode in which said recording medium is
traveled along a direction reversed to the direction during the
recording operation, said second digital video signal reproduced
according to the reverse order with respect to that of the
recording operation is rearranged in unit of the picture along the
same order as in the recording operation, and then the rearranged
second digital video signal is outputted.
6. A digital video signal reproducing apparatus for reproducing a
first digital video signal, which has been recorded on a recording
media, constituted by a picture signal compressed without using a
correlation between frames and another picture signal compressed by
using the correlation between the frames; and a second video
signal, which has been produced from said first digital video
signal, constituted by a picture signal compressed without using a
correlation between frames, wherein: said digital video signal
reproducing apparatus complies; reproducing circuit including a
first mode for reproducing the first digital video signal and a
second mode for reproducing, the second digital video signal; and
output circuit for, in the first mode, the reproduced first digital
signal is outputted at the same timing as an input timing at the
recording operation; in the second mode, the reproduced second
digital signal is outputted at predetermined timing different from
the input timing at the recording operation; and a time reference
of the output timing of the reproduced first and second digital
signals is different from that of input timing.
7. A digital video signal reproducing apparatus as claimed in claim
6 wherein: said first and second digital video signals are packet
format signals which consist of preselected bytes.
8. A digital video signal reproducing apparatus as claimed in claim
6 wherein: in said second mode, said reproduced second digital
video signal is outputted in unit of the picture.
9. A digital video signal reproducing apparatus as claimed in claim
8 wherein: in said second mode in which said recording medium is
traveled along a direction reversed to the direction during the
recording operation, said second digital video signal reproduced
according to the reverse order with respect to that of the
recording operation is rearranged in unit of the picture along the
same order as in the recording operation, and then the rearranged
second digital video signal is outputted.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This is a continuation of U.S. application Ser. No.
10/170,703, filed Jun. 14, 2002, which is a continuation of U.S.
application Ser. No. 09/059,355, filed Apr. 14, 1998 (now U.S. Pat.
No. 6,430,362). This application relates to and claims priority
from Japanese Patent Application No. 09-096915, filed on Apr. 15,
1997 and No. 09-223344, filed on Aug. 20, 1997. The entirety of the
contents and subject matter of all of the above is incorporated
herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention generally relates to a digital video
signal recording and/or reproducing method, and a digital video
signal recording and/or reproducing apparatus for recording and/or
reproducing a digital video signal. More specifically, the present
invention is directed to a method and an apparatus capable of
recording and/or reproducing a digital compression video
signal.
[0004] 2. Description of the Related Art
[0005] The digital signal recording/reproducing apparatus for
recording the digital compression video signal on the magnetic tape
with employment of the rotary head is described in JP-A-8-273305.
In this digital signal recording/reproducing apparatus, the digital
compression video signal made in the packet format is subdivided
based on a preselected byte number, and each of these packets is
constructed of n bytes. Then, the sync (synchronization) signal,
the identification information, and the error detection/correction
code are added to the divided digital compression video signals to
thereby. constitute the block form. The digital signal recording
region is formed by a preselected number of blocks to be recorded
on the magnetic recording medium. Also, JP-A-8-273305 describes
that the signal used to reproduce in the trick play mode is
recorded as the digital compression video signal in this digital
signal recording/reproducing apparatus.
[0006] However, in the case of the digital compression video signal
by using a correlation between the frames, there are the following
problems. That is, the video signal can be hardly decoded by simply
deriving a portion of the data. Furthermore, the signal used to
reproduce in the trick play mode can be hardly produced by simply
deriving a portion of the data.
[0007] Also, since the head trace is not made coincident with the
recording track during the trick-play reproducing operation, there
is another problem. That is, it is practically difficult to
discriminate the signal used to reproduce in the trick play mode
from other digital video signals.
SUMMARY OF THE INVENTION
[0008] An object of the present invention is to provide a digital
signal recording method and a digital signal recording apparatus,
capable of readily producing a signal used to reproduce in a trick
play mode from a digital compression video signal.
[0009] Another object of the present invention is to provide a
digital signal recording method and a digital signal reproducing
apparatus, capable of easily discriminating a signal used to
reproduce in a trick play mode from other digital video
signals.
[0010] A further object is to provide a digital signal reproducing
method, a digital signal reproducing apparatus, and a digital
signal decoding apparatus, capable of switching the normal
reproducing operation and the trick-play reproducing operation.
[0011] The above-described object of the present invention may be
achieved by such a digital video signal recording method for
recording a first compression frame signal compressed without using
a correlation between frames, and a digital compression video
signal having preselected bytes of a packet format constituted by a
second compression frame signal compressed with using the
correlation between the frames, in which a third signal made of a
packet containing the first compression frame signal is produced,
and then is recorded in combination with the packet of the digital
compression signal.
[0012] Another object of the present invention may be achieved by
such a digital video signal recording method for recording on a
magnetic recording medium by using a rotary head, a first
compression frame signal constructed of a picture compressed
without using a correlation between frames; a digital compression
video signal having a preselected bytes of a packet format
constituted by a second compression frame signal made of a picture
compressed with using the correlation between the frames; and a
third signal made of a packet containing said first compression
frame signal; in which information indicative of an arrangement
condition of signals is added to the third signal, and the
resultant third signal is recorded on a predetermined region of a
track on the recording medium.
[0013] The further object of the present invention may be achieved
by such a digital video signal reproducing method for reproducing a
first digital video signal constituted by a picture signal which
has been recorded on a recording medium and compressed without
using a correlation between frames and by another picture signal
compressed by using the correlation between the frames; and a
second signal produced from a picture signal compressed without
using the correlation between the frames contained in the first
digital video signal, in which:
[0014] the digital video signal reproducing method contains a first
mode for reproducing the first digital video signal and a second
mode for reproducing the second signal; in the first mode, the
reproduced first digital video signal is outputted at the same
timing during the recording operation; and in the second mode, the
reproduced second signal is outputted at predetermined timing
different from that of the recording operation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] For a better understanding of the present invention,
reference is made of a detailed description to be read in
conjunction with the accompanying drawings, in which:
[0016] FIG. 1 schematically shows an arrangement diagram of a
digital signal recording/reproducing apparatus according to an
embodiment of the present invention;
[0017] FIG. 2 schematically indicates a structural diagram of a
digital broadcasting receiver connected to the digital signal
recording/reproducing apparatus of FIG. 1;
[0018] FIG. 3 shows a structural diagram of a packet of a digital
compression video signal;
[0019] FIG. 4 represents a structural diagram of a packet
header;
[0020] FIGS. 5A to 5C indicates a structural diagram of a
transmission signal used in the digital broadcasting system;
[0021] FIG. 6 illustratively shows a relationship between
intraframe data and interframe data of a digital compression video
signal;
[0022] FIG. 7 schematically indicates a structural diagram of 1
sequence of a digital compression video signal;
[0023] FIG. 8 schematically shows a recording pattern diagram of 1
track;
[0024] FIG. 9 schematically represents a block structural diagram
of a data recording region;
[0025] FIG. 10 schematically indicates a structural diagram of ID
information;
[0026] FIG. 11 schematically represents a data structural diagram
of 1 track in a data recording region;
[0027] FIG. 12 schematically shows a header structural diagram of
the data recording region;
[0028] FIG. 13 schematically indicates a structural diagram of a
block in the case that a digital compression video signal
transmitted in a 188-byte packet format is recorded on a data
recording region;
[0029] FIG. 14 schematically shows a structural diagram of a block
when a length of a packet is selected to be 140 bytes;
[0030] FIG. 15 schematically indicates another structural example
of a packet;
[0031] FIG. 16 schematically represents a structural diagram of
block information;
[0032] FIG. 17 schematically shows a structural diagram of
trick-play data information;
[0033] FIG. 18 schematically indicates a record example of data
information and a block number;
[0034] FIG. 19 is a schematic diagram for showing an arrangement of
first trick-play data;
[0035] FIG. 20 is a schematic diagram for indicating an arrangement
of trick-play data of 1 track;
[0036] FIG. 21 is a schematic diagram for representing an
arrangement of a track counter;
[0037] FIG. 22 is a schematic diagram for representing an
arrangement of a picture counter;
[0038] FIG. 23 is a schematic diagram for showing an arrangement of
second trick play data;
[0039] FIG. 24 schematically indicates another structural example
of a packet of trick play data;
[0040] FIG. 25 is a flow chart for describing a production of trick
play data from video signal packet data;
[0041] FIG. 26 is a flow chart for describing a production of trick
play data;
[0042] FIG. 27 illustratively shows a producing example of trick
play data;
[0043] FIG. 28 is a timing chart for extracting data of an
intraframe picture;
[0044] FIG. 29 is a timing chart for reproducing trick play data in
a trick-play reproducing mode;
[0045] FIG. 30 is a timing chart for reproducing trick play data in
a trick-play reproducing mode along a reverse direction;
[0046] FIG. 31 is a timing chart for stopping the trick play
reproducing operation;
[0047] FIG. 32 is a schematic block diagram for showing a data
producing circuit;
[0048] FIG. 33 is a schematic block diagram for representing a data
selecting circuit;
[0049] FIG. 34 is a schematic block diagram for indicating an
input/output circuit;
[0050] FIG. 35 shows an input/output timing chart; and
[0051] FIG. 36 is a schematic block diagram for denoting a
selecting circuit.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0052] Referring now to drawings, various embodiments according to
the present invention will be described.
[0053] FIG. 1 is a schematic block diagram for representing an
arrangement of a digital signal recording/reproducing apparatus. It
should be understood that although this apparatus is commonly
capable of recording and also reproducing the digital signal, this
apparatus may separately record and reproduce the digital signal.
In this drawing, reference numeral 100 shows a rotary head,
reference numeral 101 indicates a capstan, reference numeral 102a
represents a recording signal processing circuit for producing a
recording signal used during a recording operation, and reference
numeral 102b indicates a reproducing signal processing circuit for
demodulating a reproducing signal used during a reproducing
operation. Also, reference numeral 104 is a control circuit such as
a microprocessor for executing a control operation of a
recording/reproducing mode, reference numeral 104a shows a key for
controlling operations of the recording/reproducing apparatus,
reference numeral 105 shows a timing signal generating circuit for
generating a timing signal which constitutes a basic signal of
rotations of the rotary head 100, reference numeral 106 shows a
servo circuit for controlling feed speeds of the rotary head and a
tape, and reference numeral 107 is an input/output circuit for
inputting the recording signal or outputting the reproducing
signal. Further, reference numeral 109 indicates a timing control
circuit for controlling the timing during the recording operation,
reference numeral 40 indicates an oscillator for producing a
reference clock, reference numeral 111 represents a tape, reference
numeral 112 denotes an analog video signal recording/reproducing
circuit, reference numeral 115 indicates a data generating circuit
used when the digital signal is recorded, and reference numeral 116
denotes a data selecting circuit used when the digital signal is
reproduced.
[0054] FIG. 2 is a schematic block diagram for indicating a
structural example of a digital broadcasting receiver connected to
the digital signal recording/reproducing apparatus shown in FIG. 1.
In this drawing, reference numeral 200 shows the digital signal
recording/reproducing apparatus of FIG. 1, reference numeral 201
represents a digital broadcasting receiver, reference numeral 202
is an antenna, and reference numeral 207 denotes a monitor. Also,
reference numeral 203 shows a tuner, reference numeral 204 is a
demultiplex circuit, reference numeral 205 shows a decoder,
reference numeral 206 is an interface circuit, reference numeral
208 represents a control circuit for controlling operations of the
digital broadcasting receiver 201.
[0055] A digital compression video signal corresponds to data with
a packet format. Signals in plural channels are multiplexed in a
time divisional manner, and a signal multiplexed by the time
divisional manner is transmitted. A digital broadcasting signal
received by the antenna 202 is demodulated by the tuner, and
thereafter the demodulated digital broadcasting signal is entered
into the demultiplex circuit 204. In the demultiplex circuit 204, a
necessary digital compression video signal is selected. The
selected digital compression video signal is decoded by the decoder
205 to produce the normal video signal which will then be outputted
to the monitor 207. It should be noted when the reception signal is
scramble-processed, after this scrambled signal is released by the
demultiplex circuit 204, the decoding process is carried out for
the descrambled signal. When the recording operation is performed,
both a digital compression video signal to be recorded and relevant
information are selected in the demultiplex circuit 204, and then
are outputted from the interface circuit 206 to the input/output
terminal 108 of the digital signal recording/reproducing apparatus
200. Then, these digital compression video signal and relevant
information are inputted from the input/output terminal 108 into
the digital signal recording apparatus 200 so as to be recorded
therein. Also, a digital compression video signal and the like,
which are reproduced by the digital signal recording/reproducing
apparatus 200 are outputted from the input/output terminal 108 to
the interface circuit 206. In the interface circuit 206, the
inputted signal is entered into the demultiplex circuit 204, and a
similar process operation to that of the normal reception is
carried out for this entered signal, and then the processed signal
is outputted to the monitor 207.
[0056] In the digital signal recording/reproducing apparatus 200,
when the recording operation is performed, a portion of packet data
entered from the input/output terminal 108 is inputted via the
input/output circuit 107 (FIG. 1) to the control circuit 104. The
control circuit 104 detects a sort of the packet data based on
either information added to this packet data or information
separately sent with respect to the packet data, judges a recording
mode based upon the detection result, and sets operation modes of
the recording signal processing circuit 102a and the servo circuit
106. The input/output circuit 107 outputs the packet data to be
recorded to the data generating circuit 115. The data generating
circuit 115 generates data used in trick-play reproducing
operation, and adds this data to the packet data, and then outputs
this added packet data to the recording signal processing circuit
102a. In response to the recording mode judges by the control
circuit 104, the recording signal processing circuit 102a produces
an error correction code, ID information, and a subcode, and also
produces a recording signal which will then be recorded on the tape
111 by the rotary head 100.
[0057] When the reproducing operation is carried out, this
reproducing operation is first performed in an arbitrary
reproduction mode, and then the ID information is detected by the
reproducing signal processing circuit 102b. Then, the control
circuit 104 judges as to which mode is used to record the digital
compression video signal to thereby again set the operation modes
of the reproducing signal processing circuit 102b and the servo
circuit 106. Then, the control circuit 104 judges as to whether the
normal reproducing operation, or the trick-play reproducing
operation is carried out based on the control signal which is
entered from the key 104a, or via a control input/output terminal
108c (FIG. 1) from the digital broadcasting receiver 201 (FIG. 2).
Thus, the reproducing signal processing circuit 102b executes the
reproducing operation based on the judgement result. The
reproducing signal processing circuit 102b detects the sync signal
and executes the error detection/correction based on a reproducing
signal reproduced from the rotary based 100, and reproduces data to
output the reproduced data to the data selecting circuit 116. The
data selecting circuit 116 selects the data recorded in the normal
recording region during the normal reproducing operation, and
selects the trick-play data during the trick-play reproducing
operation, and then outputs the selected data to the input/output
circuit 107. It should be understood that when the sequence of the
data is not correctly reproduced during the trick-play reproducing
operation, this sequence is rearranged and the rearranged sequence
is outputted. In the input/output circuit 107, the reproduced data
is outputted from the input/output terminal 108 on the basis of the
timing signal produced in the timing signal generating circuit 105.
Under control of the control circuit 104, the servo circuit 106
travels the tape 111 at the same speed as in the recording
operation during the normal reproducing operation, and also travels
the tape 111 at a different speed from the tape travel speed during
the trick-play reproducing operation, for example, +7 times higher,
or -7 times lower than the tape travel speed during the recording
operation. Apparently, the trick-play reproducing operation may be
realized by employing a plurality of reproducing modes with the
different reproducing speeds.
[0058] During the recording operation, while using the rate of the
recording data entered from the input/output terminal 108 as a
reference, the operation timing of the recording/reproducing
apparatus is controlled by the timing control circuit 109. During
the reproducing operation, while using the clock oscillated from
the oscillator 110 as an operation basis, the reproducing operation
is carried out.
[0059] In the case that an analog video signal is recorded and
reproduced, during the recording operation, the analog video signal
entered from the input terminal 113 is processed in a predetermined
process operation by the analog signal recording/reproducing
circuit 112 and then the processed analog signal is recorded on the
tape 111 by the rotary head 100, whereas during the reproducing
operation, after a video signal reproduced by the rotary head 100
is processed in a predetermined process operation by the analog
signal recording/reproducing circuit 112, the processed analog
signal is outputted from the output terminal 114. In this case,
although not shown in the drawing, the servo circuit 106 is
controlled by using the frame time period of the analog video
signal as a reference. It should be noted that the analog signal
recording head may be commonly used as the digital signal recording
head, or a digital signal recording head may be independently
provided with the analog signal recording head.
[0060] FIG. 3 schematically shows a structure of a packet of a
digital compression video signal. One packet is constructed of a
fixed length, for example, 188 bytes, and is arranged by a 4-byte
packet header 306 and 184-byte packet information 307. A digital
compression video signal is arranged in the region of the packet
information 307. Also, the packet header 306 is constructed of
information such as sorts of the packet information.
[0061] FIG. 4 schematically indicates a structure of the packet
header 306. In this drawing, reference numeral 501 shows a sync
byte indicative of a head of the packet, reference numeral 502
denotes an error indication for indicating whether or not an error
happens to occur, reference numeral 503 represents a unit starting
indication for indicating a start of a unit, reference numeral 504
shows a packet priority for indicating a priority degree of the
packet, and reference numeral 505 shows a packet ID for
representing a sort of the packet. Also, reference numeral 506
denotes a scrambling control, for indicating whether or not a
scramble is present, reference numeral 507 shows an adaptation
field control for indicating whether or not additional information
is present and whether or not packet information is present, and
reference numeral 508 represents a continuity counter counted up in
unit of a packet.
[0062] FIG. 5A schematically shows a structure of a transmission
signal of the digital broadcasting system. In this drawing,
reference numeral 71 shows the packet of FIG. 3. Normally, an audio
signal and information related to a program are added to the
above-described video signal, and programs of plural channels are
multiplexed in the time divisional multiplexing manner, and then
the multiplexed program is transmitted. FIG. 5A indicates such an
example that programs of three channels are multiplexed. Symbols
"V1", "A1", and "P1" indicate a video signal, an audio signal, and
program information of a first channel. Symbols "V2", "A2", and
"P2", show a video signal, an audio signal, and program information
of a second channel. Symbols "V3", "A3", and "P3" indicate a video
signal, an audio signal, and program information of a third
channel. The packet IDs 505 different from each other are allocated
to the respective packets, so that the contents of these packets
can be discriminated from each other. Alternatively, a total number
of channels to be multiplexed may be selected to be any numbers
other than 3 channels, for instance, 4 channels. Also, other
information may be apparently multiplexed.
[0063] FIG. 5B shows another structure of a transmission signal
produced by selecting only the information of the first channel
from the structure of FIG. 5A. When information of a first channel
is recorded, this information is outputted from the digital
broadcasting receiver 201 to the recording/reproducing apparatus
200. Apparently, any information other than this information of the
first channel is involved in this information, which may be
recorded. Alternatively, a portion of the packet, such as the
header information, may be changed in order to readily execute the
process operation during the reproducing operation.
[0064] FIG. 5C indicates another structure of a transmission signal
produced by selecting only the video signal of the first channel
from the structure of FIG. 5A. The data used in the trick-play
reproducing operation is produced from this video signal
packet.
[0065] FIG. 6 schematically represents a relationship between
intraframe data and interframe data of a digital compression video
signal. The intraframe data is compressed in the unit of the frame
of the digital compression video signal. The interframe data is
produced by compressing only differential information by using a
prediction obtained from data in a preceding frame and data in a
succeeding frame. Symbol 301 is an intraframe, and symbol 302 is an
interframe. In the digital compression video signal, a preselected
number of frames, e.g., 15 frames are used as one sequence, in
which a head of a group is set as an intraframe, and the remaining
frames are set as an interframe compressed by using a prediction
obtained from the intraframe. Apparently, the intraframe may be
arranged at any position other than the head.
[0066] FIG. 7 schematically shows a structure of 1 sequence of a
digital compression video signal. A picture header is added in unit
of a frame to the digital compression video signal, and sequence
header is added in unit of a sequence thereto. The sequence header
is constructed of a sync signal, and information such as a transfer
rate. The picture header is constituted by a sync signal, and
discrimination information for discriminating the intraframe from
the interframe. Normally, a length of data of each picture is
changed in response to an information amount. It should also be
noted that in the example of FIG. 7, data of one picture is
completed in unit of a packet, and a packet of a head of the
picture is made in such a manner that a unit starting indication
(US) becomes 1. With employment of such a structure, the head of
the picture can be discriminated by the unit starting
indication.
[0067] Next, a description will now be made of a recording method
to the magnetic tape.
[0068] FIG. 8 schematically indicates a recording pattern of 1
track. In this drawing, reference numeral 3 shows a subcode
recording area for recording a subcode such as time information and
program information, reference numeral 7 shows a data recording
area for recording a digital compression video signal, reference
numerals 2 and 6 are preambles of the respective recording areas,
and reference numerals 4 and 8 denote postambles of the respective
recording areas. Also, reference numeral 5 is a gap between the
respective recording areas, and reference numeral 1 and 9 show
margins positioned at track ends. Since the postamble, the
preamble, and the gap are formed in the respective recording areas
in the above-described manner, afreco (after recording) can be
independently made in-the respective areas. Apparently, another
digital signal other than the digital compression video signal may
be recorded on the data recording area 7.
[0069] FIG. 9 schematically indicates a block structure of the data
recording area 7. In this drawing, reference numeral 20 indicates a
sync signal, reference numeral 21 indicates ID information,
reference numeral 22 represents data, and reference numeral 23
denotes a parity (C1 parity) for a first error
detection/correction. For example, the sync signal 20 is
constructed of 2 bytes, the ID information 21 is constructed of 3
bytes, the data 22 is constructed of 99 bytes, the parity 23 is
constructed of 8 bytes, and 1 block is arranged by 112 bytes.
[0070] FIG. 10 schematically shows a structure of the ID
information 21. In this drawing, reference numeral 31 is a group
number, reference numeral 32 indicates a track address, reference
numeral 33 indicates a block address within 1 track, and reference
numeral 35 is a parity used to detect errors contained in the group
number 31, the track address 32, and the block address 33. The
block address 33 is an address for discriminating blocks in the
respective recording areas. For instance, in the data recording
area 7, the block addresses are selected to be 0 to 335. The track
address 32 is such an address used to discriminate the track. For
example, the address is changed in unit of 1 track, or 2 tracks,
and the track addresses are selected to be 0 to 5, or 0 to 2, so
that 6 tracks can be discriminated. The group number 31 is changed
in the unit of, for example, 6 tracks discriminated by the track
address 32. Then, the group number 31 is selected to be 0 to 15, so
that 96 tracks can be discriminated from each other.
[0071] FIG. 11 schematically shows a data structure of 1 track in
the data recording area 7. It should be understood that both the
sync signal 20 and the ID information 21 are omitted. The data
recording area 7 is constructed of 336 blocks. The data 41 is
recorded on the first 306 blocks, and a second error correction
code (C2 parity) 43 is recorded on the next 30 blocks. As to the C2
parity 43, for example, data of 306 blocks.times.6 tracks is
subdivided by 18 in the unit of 6 tracks, and the C2 parity of 10
blocks is added to each of the 102 blocks. As the error correction
code, for instance, the Reed-Solomon code may be employed. The
99-byte data of each block is arranged by a 3-byte header 44 and
96-byte data 41.
[0072] FIG. 12 schematically shows a structure of the header 44 of
the data recording area 7. The header 44 is constituted by format
information 31, block information 32, and auxiliary information 33.
The format information 31 is such information related to a
recording format, and for example, one piece of information is
constructed of 6 bytes of 6 blocks. The block information 32
corresponds to information used to discriminate a sort of data
recorded on a data recording area 41.
[0073] FIG. 13 schematically represents a structural example of a
block in such a case that a digital compression video signal
transmitted in a 188-byte packet format is recorded on the data
recording area 41. In this case, while a 4-byte time stamp 25 is
added to become 192 bytes, 1 packet is recorded on 2 blocks.
[0074] FIG. 14 schematically shows a structure of a block in the
case that a length of a packet 71 is selected to be 140 bytes. At
this time, two packets 71 are recorded on 3 blocks.
[0075] The time stamp 25 corresponds to information about a time
duration during which a packet is transmitted. In other words,
either a time duration during which a packet (head thereof) is
transmitted or a time interval between packets is. counted by a
reference clock. This count value is recorded together with packet
data. During the reproducing operation, the time interval between
the packet is set based on this information, so that the data can
be outputted in the same form when this data is transmitted.
[0076] FIG. 15 schematically shows another structural example of
the packet shown in FIG. 13 or FIG. 14. This packet is constituted
by, for example, 3-byte time stamp 25, an identification code 72
related to a 1-byte packet, and 188-byte, or 140-byte packet data
71. It should be understood that when the byte number of this
packet data 71 is smaller than the above example, for instance, 130
bytes, dummy data may be added to this packet to be recorded, or
the region of the identification code may be increased.
[0077] The time stamp 25 corresponds to information about a time
duration during which a packet is transmitted. In other words,
either a time duration during which a packet (head thereof) is
transmitted or a time interval between packets is counted by a
reference clock. This count value is recorded together with packet
data. During the reproducing operation, the time interval between
the packet is set based on this information, os that the data can
be outputted in the same form when this data is transmitted.
[0078] As previously described, if a ratio of the byte number of 1
packet to the byte number of the recording area of 1 block may be
expressed by a simple integer ratio of "n:m", and m pieces of
packets are recorded on "n" pieces of blocks, then the packet data
may be effectively recorded even when the packet length is
different from the recording area of 1 block.
[0079] FIG. 16 schematically shows a structure of the block
information 32 shown in FIG. 12. The block information 32
corresponds to information used to discriminate data in unit of a
block. A data identification code 74 corresponds to information
used to discriminate a sort of data recorded on this block. For
example, in a block on which the normal packet data is recorded, 0
is set; in a block on which the effective data is not recorded, 1
is set; in a block on which the first trick-play reproducing data
is recorded, 2 is set; and a block on which the second trick-play
reproducing data is recorded. A block number 75 corresponds to
information used to discriminate a sequence of blocks when the
packet data are recorded in the unit of 2 blocks, or 3 blocks. For
example, when the packet data are recorded in the unit of 2 blocks,
0 to 1 are set. When the packet data are recorded in the unit of 3
blocks, 0 to 2 are set. Trick-play data information 76 corresponds
to information used to discriminate a data sequence of the
trick-play reproducing data.
[0080] FIG. 17 schematically represents a structure of the
trick-play data information 76 shown in FIG. 16. In this drawing,
reference numeral 511 indicates a picture counter for
discriminating a picture, reference numeral 512 shows a track
counter for discriminating a track, and reference numeral 513
denotes a block counter for discriminating a block in a track.
[0081] FIG. 18 is an illustration of such an example when both the
data identification code 74 and the block number 75 are recorded in
the unit of 2 blocks. In this drawing, reference numeral 51 shows a
block on which the normal packet data is recorded, reference
numeral 52 indicates a block on which the trick-play reproducing
data is recorded, and reference numeral 53 shows an unused area. In
the trick-play reproducing data recording area 52, the block number
is set to 0 to 3. It should also be noted that although the
trick-play reproducing data recording area 52 is constructed of 4
blocks, the trick-play reproducing data recording area 52 is
normally constructed of blocks larger than 4 blocks.
[0082] During the reproducing operation, the data identification
code 74 is discriminated in the unit of a block, and the data
identification code may be outputted by skipping such a block other
than 0. As a result, even when the trick-play reproducing data, or
the invalid data is recorded on any areas, the compatibility during
the reproducing operation can be maintained. Also, when any
specific data other than these trick-play reproducing data and
invalid data is recorded, there is no problem if a different data
identification code is allocated to this block.
[0083] FIG. 19 illustratively shows an arrangement example of the
first trick-play reproducing data. In this drawing, reference
numeral 311 is the first trick-play reproducing data. The first
trick-play reproducing data is recorded in such a manner that the
same data are recorded on several tracks at a predetermined place
of the tracks in a multiplex manner. As a result, even when the
rotary head is scanned over any traces, all of the data recorded
thereon can be detected. Since the trick-play reproducing data
information 76 are identical to each other, the sequence of the
data to be multiplexed can be discriminated during the reproducing
operation. The multiplexing time may be set in correspondence with
the speeds of the trick-play reproducing operation. It should also
be noted that although the trick-play reproducing data are arranged
on all of the continued tracks in FIG. 18, these trick-play
reproducing data may not be arranged on all of the tracks. For
instance, these trick-play reproducing data may be arranged on
every 2 tracks. Although, in the above example, the same trick-play
reproducing data are recorded on the several tracks in the
multiplex manner at preselected positions on the tracks, these
trick-play reproducing data may be arranged on the positions
corresponding to the scanning traces of the rotary head.
[0084] FIG. 20 schematically shows an arrangement example of
trick-play reproducing data of 1 track. An upper portion of FIG. 20
corresponds to a head of a track, namely, a lower side of the track
shown in FIG. 19. In FIG. 20, a single area of the trick-play
reproducing data is made of 10 blocks, and 3 areas are arranged on
1 track. In other words, 30 blocks (15 packets) of the trick-play
reproducing data can be recorded on a single track. Alternatively,
the block numbers of a single area, and the area numbers of a
single track may be selected to be other values than the
above-described quantities. For instance, 6 areas may be arranged
in a single track. Also, the block numbers in the respective ares
may be made different from each other. Symbol "BC" represents a
value of the block counter 513, which is added to the respective
blocks. Based on the block number 75 and the block counter 513, it
is possible to discriminate that one trick-play reproducing data
corresponds to that of which block within 1 track.
[0085] FIG. 21 schematically shows an arrangement example of the
track counter 512. In this drawing, reference numeral 7 shows 1
track indicated in FIG. 20, and symbol "TC" denotes this track
counter 512. The trick-play reproducing data is arranged in such a
manner that the same data are arranged in the plural tracks, for
example, 16 tracks. Then, the same track counter values are
allocated to the tracks on which the same data are arranged, so
that the trick-play reproducing data can be discriminated in the
unit of a track. For example, when the track counter is equal to 2
bytes, 4.times.16=64 tracks can be discriminated. Since the head
trace does not exceeds 16 tracks during the normal trick-play
reproducing operation, more than 64 tracks can be discriminated,
taking account of the scanning sequence of the rotary head.
[0086] FIG. 22 schematically indicated an arrangement example of
the picture counter 511. In this drawing, reference numeral 521
shows such tracks whose track counter values are the same, for
example, 16 tracks, and symbol "PC" indicates this picture counter
511. FIG. 22 is such a case that first k.times.16 tracks and next
k'.times.16 tracks constitute one picture. For example, one picture
is arranged by 100 packets. When 15 packets can be recorded on one
track, it may be defined by: (100/15)+1>k .gtoreq.100/15. In
other words, a single picture may be arranged on 7.times.16 tracks.
Apparently, if k.gtoreq.100/15, then more tracks may be
allocated.
[0087] When data of one picture is completed in unit of a track, a
data producing process operation and a data reproducing operation
may be readily performed. Also, in the case that the remaining
track portion when the data of one picture is ended in a half way
of the relevant track may be used as a block of dummy data, for
instance, the data identification code 74 may be set to "1". Also,
invalid data may be arranged as the trick-play reproducing data.
Apparently, the data of one picture may not be completed. In this
case, the value of the picture counter 511 is changed in a half way
of the relevant track.
[0088] Since the picture counter 511 is added in such a manner that
a cut-out portion of a picture can be discriminated, even when the
data are not sequentially reproduced as during the trick-play
reproducing operation along the reverse direction, the data of one
picture can be readily discriminated. In other words, the data of
one picture is discriminated by the picture counter 511, and the
sequence of the data contained in one picture is discriminated
based upon the track counter 512, the block counter 513, and the
block number 75, so that the data of one picture can be outputted
in the correct sequence.
[0089] FIG. 23 schematically represents an arrangement example of
the second trick-play reproducing data. In this drawing, reference
numeral 312 indicates this second trick-play reproducing data.
Since the second trick-play reproducing data is arranged in
correspondence with the scanning trace of the rotary head in this
manner, the areas used to record the trick-play reproducing data
are decreased, but the scanning control of the rotary head becomes
difficult.
[0090] It should also be noted that, as indicated in FIG. 17, the
trick-play data information 76 may be added in unit of 2 blocks, or
3 blocks discriminatable by a block number 75. Also, since no time
stamp is required in the trick-play reproducing data, as indicated
in FIG. 24, the trick-play data information 76 may be arranged
instead of the time stamp 25. Apparently, two places may be
commonly used.
[0091] FIG. 25 is a flow chart for describing an operation to
produce the trick-play reproducing data from the video signal
packet data shown in FIG. 5C. Since the trick-play reproducing data
must be independently decoded, this trick-play reproducing data
must be intraframe data. As a result, since the intraframe data is
extracted in unit of a packet, the trick-play reproducing data can
be easily produced.
[0092] In this flow chart, a confirmation is first made of a unit
starting indication of an inputted packet so as to detect a head of
a picture. Alternatively, the head of the picture may be detected
based upon a picture header and so an. Next, another confirmation
is made as to whether or not a sequence header is present in a
packet of the head of the picture. Accordingly, a head of a
sequence, namely an intraframe picture is detected. Apparently, the
intraframe picture may be alternatively detected based on any
information other than the sequence header. Then, data packets from
this packet up to a head packet of a second picture are filtered as
trick-play reproducing data, namely data of one intraframe picture
is filtered as this trick-play reproducing data.
[0093] Alternatively, the trick-play reproducing data may be
reconstructed from the extracted intraframe picture. For example,
when trick-play reproducing data is reconstructed so as to lower
resolution of a picture, a data amount of this trick-play
reproducing data may be reduced.
[0094] FIG. 26 is a flow chart for describing an operation to
produce trick-play reproducing data from the recording packet data
of FIG. 6(b). Since the trick-play reproducing data must be
independently decoded, this trick-play reproducing data must be
intraframe data. As a result, since the intraframe data is
extracted in unit of a packet, the trick-play reproducing data
can-be easily produced.
[0095] First, in this flow chart, a confirmation is made of a
packet header of an inputted packet to thereby select only a packet
of a video signal. Then, packet information of the selected packet
is confirmed so as to detect such a packet having a sequence
header. Then, data packets from this packet to a packet having a
second picture header are filtered as the trick-play reproducing
data. As to a packet having a final second picture header, the data
subsequent to the second picture header is replaced by dummy data,
so that erroneous operation occurred during the decoding operation
can be prevented. To simplify the process operation, the data
packets prior to the packet having the last second picture head may
be filtered.
[0096] Normally, since a intraframe is located behind a sequence
header, a head of trick-play reproducing data is used as the
sequence header, the process operation can be readily carried out.
Also, there are many cases that a decoding operation is carried out
while using a sequence header as a basis in a normal decoding
circuit. As a result, since the data contains the sequence header,
the easy decoding operation can be done. When the decoding circuit
executes the decoding operations by using the picture head as the
reference, the head of the trick-play reproducing head may be
employed as the picture header. In this case, the information of
the picture header is detected, so that the intraframe may be
selected.
[0097] As previously described, the trick-play reproducing data can
be produced in the above-described manner. In such a case that the
data amount of the intraframe is large, and is greater than the
recording capacity of the area for recording the trick-play
reproducing data, the data may be deleted in unit of the frame, or
a portion of the data contained in the frame may be deleted. In the
former case, the image represents coarse motion, but the image
quality is not changed. For example, only data of 1 frame is
filtered every 2 frames, or 3 frames (sequence) as the trick-play
reproducing data. In the latter case, although noise appears in the
reproduced image, the motion of the image can be maintained to some
extent. In this case, a preselected amount of frames from the heads
of the respective frames may be filtered out. However, instead of
this filtering method, when the different image portions in the
respective frames is deleted, the reproduced image quality may be
improved, as shown in FIG. 27. In FIG. 27, hatched portions
correspond to image portions to be deleted. Apparently, the
above-described two methods may be combined to be executed.
[0098] FIG. 28 illustratively indicates a timing chart for
explaining data extract timing of an intraframe picture. FIG. 28(a)
shows video signal data corresponding to FIG. 5C, and reference
numeral 531 indicates data of the intraframe picture. The normal
reproducing data is recorded at this timing. FIG. 28(b) shows
trick-play reproducing data arranged on a tape, and reference
numeral 532 shows data of the intraframe picture. In the case that
1 sequence is equal to 15 frames, it becomes 2 intraframe pictures
per 1 second. On the other hand, assuming now that the rotation
number of the rotary head is equal to 1,800 rpm, 60 tracks are
recorded per 1 second. As a result, if 1 intraframe picture can be
arranged on 30 tracks, then the recording picture can be satisfied.
However, since the capacity of the trick-play reproducing data area
is limited, more than 30 tracks are normally required to this end,
the first picture (picture 0) is arranged on the track, and the
next packet extraction may be commenced at the time when the
picture arrangement is ended. Apparently, the packet extraction may
be commenced not at the time when the picture arrangement is ended,
but at the time before/after the picture arrangement is
accomplished.
[0099] FIG. 29 and FIG. 30 are timing charts in the case that the
trick-play reproducing data recorded in FIG. 28 are reproduced in
the trick-play reproducing mode. FIG. 29. shows a timing chart when
the trick-play reproducing operation is performed along a normal
direction. During this normal direction, the trick-play reproducing
data is reproduced along the same order used during the recording
operation. As a consequence, the reproduced trick-play reproducing
data may be sequentially outputted. Otherwise, as indicated in FIG.
29(c), at a time instant when one picture data is reproduced, the
reproduced trick-play reproducing data may be outputted in the unit
of this picture. FIG. 30 indicates a timing chart when the
trick-play reproducing operation is carried out along a reverse
direction. During the reverse direction, the trick-play reproducing
data are reproduced along a direction opposite to the direction
during the recording operation. As a consequence, a cut-out portion
of a picture is discriminated by the picture counter 511, and then
the data contained in the picture are rearranged by the track
counter 512 and the block counter 513 along the data arrangement
order during the recording operation. Then, at a time instant when
data of one picture is reproduced, as indicated in FIG. 30(c),
these picture data may be outputted in unit of this picture.
[0100] FIG. 31 shows a timing chart when the trick-play reproducing
operation is stopped. In this drawing, symbol "A" indicates such a
position when the trick-play reproducing operation is stopped. At
this position "A", the picture under reproduction corresponds to a
picture recorded at another position "B". As a consequence, if the
tape is returned to the position B after the trick-play reproducing
operation is stopped, then the same picture when the trick-play
reproducing operation is stopped can be reproduced during the
reproducing operation. It should be understood that the amount of
the tape to be returned must be determined by considering not only
the position on the tape, but also the time shifts occurred when
the signal is processed during the trick-play reproducing
operation, and the picture is decoded. In such a case that the
positional shifts on the tape differ from each other, depending
upon the tape locations, the tape may be returned based on an
average value of these positional shifts. Furthermore, if the total
number of tracks on which one picture is recorded is counted, or
the total number of packets are counted and then the tape return
amount is determined based on the counted value, the tape can be
returned in higher precision. FIG. 31 shows the timing when the
trick-play reproducing operation is carried out along the normal
direction, which similarly may be applied to the trick-play
reproducing operation along the reverse direction. It should be
understood that when the trick-play reproducing data is recorded as
in FIG. 28, since there is substantially no positional shift on the
tape when the trick-play reproducing operation is carried out along
the reverse direction, the resultant tape return amount may be
reduced. The tape may be returned at timing immediately after the
trick-play reproducing operation is ended, or at timing when the
trick-play reproducing operation is ended and thereafter is changed
to the normal reproducing operation.
[0101] Also, during the trick-play reproducing operation for
detecting a specific position such as a head of a program, a flag
indicative of the head of this program, recorded on the tape, may
be detected so as to stop the trick-play reproducing operation. In
this alternative case, the tape returning operation after stopping
the trick-play reproducing operation is not required.
[0102] FIG. 32 is a schematic block diagram for indicating an
arrangement of the data generating circuit 115 shown in FIG. 1. In
this drawing, reference numeral 401 is a time stamp adding circuit,
reference numeral 402 shows a memory circuit, reference numeral 403
indicates a video signal packet filtering circuit, reference
numeral 404 denotes a picture detecting circuit, reference numeral
405 is a writing circuit, reference numeral 406 shows a memory
circuit, reference numeral 407 indicates a reading circuit, and
reference numeral 408 shows a block information adding circuit. A
packet outputted from the input/output circuit 107. is entered via
an input terminal 409 to the time stamp adding circuit 401, and
thus the time stamp 25 is added to this packet. It should be
understood that when a packet to which the time stamp 25 has been
added is entered to this data generating circuit 115, this process
operation need not be carried out. The packet to which the time
stamp is added is stored in the memory circuit 402. At the same
time, in the video signal packet filtering circuit 403, the picture
packet is filtered out based on the packet ID 505 of the entered
packet, and then is outputted to the writing circuit 405 and the
picture detecting circuit 404. It should also be noted that
although the time stamp is added only to such a packet which is
stored in the memory circuit 402 and used during the normal
reproducing operation, a similar time stamp may be added to the
trick-play reproducing data.
[0103] In the picture detecting circuit 404, the header information
is detected which is contained in the packet information 307, and
the trick-play reproducing data is stored in the memory circuit 406
by controlling the writing circuit 405 in accordance with the flow
chart of FIG. 22 and the timing chart of FIG. 23. At the same time,
a range where one picture is stored is memorized. In the reading
circuit 407, the packet data stored in the memory circuit 402 and
also the memory circuit 406 are sequentially read out to obtain the
recording data with the arrangement of FIG. 18. Then, the block
information 32 is added to this recording data by the block
information adding circuit 408, and the resultant data is outputted
to the recording/reproducing signal processing circuit 102. As to
trick-play reproducing data, the block counter 513, the counter
512, and the track counter 512 are generated based on the position
of the block on which the data is arranged and also the track
number to be added, and also the picture counter 511 is generated
based upon the range of one picture stored in the memory circuit
406 to be added. Then, the recording signal of FIG. 8 is produced
to be recorded in the recording/reproducing signal processing
circuit 102.
[0104] FIG. 33 is a schematic block diagram for indicating the data
selecting circuit 116 of FIG. 1. In this drawing, reference numeral
411 indicates a packet data distributing circuit, reference numeral
412 represents a memory circuit, reference numeral 413 denotes a
reading circuit, reference numeral 414 shows a switching circuit,
and reference numeral 417 denotes a counting circuit.
[0105] During the normal reproducing operation, the content of the
packet is detected based on the block information of the
reproduction packet data inputted from the input terminal 415 in
the distributing circuit 411. Then, the normal reproducing packet
is selected and outputted via the switching circuit 414 from the
output terminal 416 to the input/output circuit 107.
[0106] During the normal reproducing operation, the packet of the
trick-play reproducing data is selected in the distributing circuit
411 to thereby be outputted to the memory circuit 412. This packet
is written to positions corresponding to the data sequence of the
trick-play reproducing data information 76 into the memory circuit
412. Then, the packet data are sequentially read by the reading
circuit 413 to-be outputted via the switching circuit 414 from the
output terminal 416 to the input/output circuit 107. At the same
time, in the counting circuit 417, a quantity of packets, or tracks
for constituting one picture is counted. The counted value is
outputted via the output terminal 418 to the control circuit 104.
In the control circuit 104, the tape return amount after the
trick-play reproducing operation is. determined by this count
value, and then the servo control circuit 106 is controlled based
on this tape return amount. During the trick-play reproducing
operation, especially during the trick-play reproducing operation
along the reverse direction, the trick-play reproducing data are
not reproduced in accordance with the sequential order. As a
consequence, as represented in the timing chart of FIG. 25, if the
data reading operation is commenced after the data has been firstly
written and a preselected time period has passed, it is possible to
avoid that the data is not read before being written.
[0107] FIG. 34 is a schematic block diagram for showing an
arrangement of the input/output circuit 107 shown in FIG. 1. In
this drawing, reference numeral 420 is a packet detecting circuit,
reference numeral 423 shows a buffer, and reference numeral 424
represents an output timing control circuit.
[0108] During the recording operation, both data and a strobe clock
are entered from an input/output terminal 108a and another
input/output terminal 108b at timing as indicated in FIG. 35. Both
the entered data and strobe clock are inputted to the packet
detecting circuit 420, and a packet is detected in response to the
clock produced from the timing signal generating circuit 105 (FIG.
1), which is entered from an input terminal 427. Then, the detected
packet 71 is supplied via an output terminal 425a to the data
generating circuit 115 (FIG. 1). The control signal and the like,
which are added to the packet to be transmitted are outputted from
an output terminal 426a to the control circuit 104 (FIG. 1), so
that the sort of this packet is discriminated, and the recording
mode is determined.
[0109] During the normal operation, in response to the control
signal derived from the control circuit 104 (FIG. 4) and entered
from the input terminal 426b, the output control circuit 422 is
controlled to an output mode, and the reproduced packet 71 is
outputted in synchronism with the reference clock oscillated from
the oscillator 110. A packet entered from the input terminal 425b
is stored in the buffer 423. The time stamp 25 contained in the
packet is inputted to the output timing control circuit 424. In
response to the clock entered from the input terminal 427 and the
time stamp 25, the output timing control circuit 424 controls the
timing at which the packet is read from the buffer 423, and also
generates the stroke clock. Then, the output timing control circuit
424 outputs the strobe clock at the same timing as the timing shown
in FIG. 33, namely, the timing at which the recording data is
inputted. As a result, in a decoding apparatus of a digital
compression video signal, or in an apparatus for receiving a packet
reproduced by another digital signal recording/reproducing
apparatus to process this packet, a signal after being
recorded/reproduced can be processed by the same process operation
executed in such a case that a signal before being recorded is
directly processed.
[0110] During trick-play reproducing operation, the trick-play
reproducing data is changed from the original data stream, and
therefore there is no meaning to control the time stamp. As a
result, as indicated in the timing of FIG. 29 or FIG. 16, the
trick-play reproducing data are outputted in unit of the picture at
constant timing. It should also be noted that if the output timing
is acceptable in the digital broadcasting receiver 201, then any
timing may be employed.
[0111] It should also be noted that although the data input and
output operations are carried out by employing the common terminal
in the above-described embodiment, an input terminal and an output
terminal may be separately employed.
[0112] FIG. 36 is a schematic block diagram for showing an
arrangement of the demultiplex circuit 204 shown in FIG. 2. In this
drawing, reference numeral 601 is a descrambling circuit, reference
numeral 602 shows a switching circuit, reference numeral 603 is a
decode-demultiplex circuit, reference numeral 604 represents a
record-demultiplex circuit, and reference numeral 609 denotes a
clock recovering circuit.
[0113] During the receiving operation, the descrambling circuit 601
descrambles the scrambled reception signal entered via an input
terminal 605, and supplies the descrambled reception signal via the
switching circuit 602 to the decode-demultiplex circuit 603. The
decode-demultiplex circuit 602 selects a video packet and an audio
packet of a channel under reception based upon a packet ID, and
outputs a video signal and an audio signal contained in the packets
via output terminals 606a and 606b to the decoding circuit 205. At
the same time, the clock recovering circuit 609 produces an
operation reference clock having a frequency of, for instance, 27
MHz for the decoding circuit 205 based on the time stamp contained
in the received packet, which is synchronized with the reception
signal, and then outputs this operation reference clock via an
output terminal 606c. Also, the record-demultiplex circuit 604
selects a required packet of a channel to be recorded, and then
outputs the selected packet via the input/output terminal 607 to
the interface circuit 206. At this time, the packet information is
corrected, and added, if required.
[0114] When the recorded signal is reproduced, the reproduction
signal entered from the input/output terminal 607 is supplied via
the switching circuit 602 to the decode-demultiplexing circuit 603.
During the normal reproducing operation, both the video packet and
the audio packet are inputted at the same timing when the receiving
operation is carried out. As a consequence, a similar process
operation to that of the receiving operation is carried out also in
the decode-demultiplex circuit 603, and thus the video signal, the
audio signal, and the operation reference clock may be outputted
via the output terminals 606a, 606b, 606c to the decoding circuit
205. On the other hand, during the trick-play reproducing
operation, only the video packet is to be reproduced, and the
reproducing timing is different from the recording timing. As a
consequence, in the decode-demultiplex circuit 603, only the video
packet may be demultiplexed, whereas the multiplexing operation of
the audio packet may be stopped, and also the generation of the
operation reference clock in synchronism with the time stamp in the
clock recovering circuit may be stopped. As the operation reference
clock, for example, a clock internally oscillated may be outputted
via the output terminal 606c. At this time, since only the video
packet is entered to the decode-demultiplex circuit 603, all of the
packets are recognized as the video packets irrespective of sorts
of the packets. Then, if all of the packet signals are outputted
from the output terminal 606a, even when the packet ID is changed
such as even when the channel under record is changed, the video
signal can be continuously outputted without redetecting the packet
ID.
[0115] In the decoding circuit 205, while using the operation
reference clock outputted from the demultiplex circuit 204 as the
reference, both the video signal and the audio signal are decoded
during the signal receiving operation and also the normal
reproducing operation, whereas only the video signal is decoded
during the trick-play reproducing operation.
[0116] In accordance with the present invention, in the recording
apparatus for recording the digital compression video signal with
the packet format, the trick-play reproducing data is extracted in
unit of the packet, so that the trick-play reproduction data can be
readily produced without reconstructing the packet.
[0117] Also, according to the present invention, such information
used to discriminate the sequence of the data and the cut-out
portion of the picture is added to the trick-play reproducing data,
and then the resultant trick-play reproducing data is recorded, so
that the sequence of the reproduced trick-play reproducing data and
the cut-out portion of the picture can be readily discriminated
along the trick-play reproducing operation.
[0118] Furthermore, in accordance with the present invention,
during the normal reproducing operation, the reproduced signals are
outputted by controlling the output timing of the packet equal to
the input timing during the recording operation based on the time
stamp added to the packet to be recorded. During the trick-play
reproducing operation, the output timing is switched so as to
output the reproduced signals at the constant timing irrespective
of the input timing during the recording operation. Furthermore,
the demultiplex process operations by the packet demultiplex
circuit for decoding the data packet are switched. As a result, the
reproducing operated of the recording/reproducing apparatus can be
commonly applied to the normal reproducing operation and the
trick-play reproducing operation. Moreover, since a constant amount
of the tape is returned when the trick-play reproducing operation
is accomplished, when the reproducing operation is changed from the
trick-play reproducing operation to the normal reproducing
operation, the picture can be continued.
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