Motion video signal processing for recording or reproducing – Local trick play processing – With randomly accessible medium
Reexamination Certificate
1999-01-05
2003-02-25
Tran, Thai (Department: 2615)
Motion video signal processing for recording or reproducing
Local trick play processing
With randomly accessible medium
C386S349000, C386S349000
Reexamination Certificate
active
06526216
ABSTRACT:
This Application is a U.S. National Phase Application of PCT International Application PCT/JP98/01513.
FIELD OF THE INVENTION
The present invention relates to a video production system of a progressive scanning television format, and a recording and play-back equipment of the progressive scanning television format used in the same system.
BACKGROUND OF THE INVENTION
A video production system employing a current interlaced scanning television (hereinafter referred to as “TV”) format is described hereinafter. One example of the video production systems of the interlaced scanning TV format is shown in FIG.
11
.
The system comprises a camera
301
of the interlaced scanning TV format (hereinafter referred to as “interlaced scan camera”), two VTRs
302
and
303
of the interlaced scanning TV format (hereinafter referred to as “interlaced scan VTR” or simply “VTR”), a time-code generator
4
, an editing controller
5
and an interlaced scanning TV synchronizing signal source
6
(hereinafter referred to as “interlaced scan synchronizing signal source”).
Each item of equipment in this system, except for the interlaced scan synchronizing signal source
6
, are provided with interlaced scan synchronizing signal input terminals (I_REF input)
301
a
,
302
a
,
303
a
,
4
a
and
5
a
. The interlaced scan synchronizing signal source
6
outputs to these terminals an interlaced scan synchronizing signal that serves as a base of the system.
Timing of each of the items of equipment is controlled on the basis of this interlaced scan synchronizing signal, and the entire system is synchronized.
Also, the time-code generator
4
supplies a time-code signal from an output terminal (TC output)
4
d
to a time-code input terminal (EXT_TC input)
302
c
of the VTR
302
. This time-code signal represents a signal recorded in a recording tape as a time code at the same time when a video signal is recorded.
The time-code is used later for a positional alignment of material location when executing an editing or a play back of a recorded image material.
When editing the recorded image material, the VTR
302
functions as a play back VTR, and the VTR
303
functions as a recording VTR. A part of the image material recorded on a tape in the VTR
302
is recorded again on a part of a tape in the VTR
303
. In this case, the VTR
302
forwards a time-code signal from a time-code output terminal
302
d
(TC output) of the VTR
302
to a time-code input terminal (EXT_TC input)
303
c
of the VTR
303
.
The editing controller
5
, which is connected with the VTRs
302
and
303
by control command bus bars
7
and
8
, plays back the VTR
302
, records the image material in the VTR
303
, and gives commands of a traveling speed of the tape and an operation of recording and play back while searching for a location according to the time-code signal recorded in the tape.
FIG. 13
shows an example of recording track pattern on a tape
412
for use with the VTRs.
There exists a helical track
440
, a control track
441
and a time-code track
443
on the tape
412
.
Image information is recorded on the helical track
440
aslant with the tape, and each helical track is recorded with an image equivalent to one field (for {fraction (1/60)} of a second in case of the NTSC) of interlaced TV signal. Therefore, an image equivalent for one frame (for {fraction (1/30)} of a second in case of the NTSC) of the interlaced scanning TV signal is recorded on two tracks.
The control track
441
is recorded with a marking signal
442
which indicates a location (i.e., indicating an end of a second field and a beginning of a first field) of a frame signal (to be described later).
The image signal recorded on the tape
412
is assigned with an address, or a time-code for each frame (a time-code address equals to a frame number if an input signal is the interlaced scanning TV signal). In other words, the time-code track
443
is recorded with a time-code signal. The time-code signal is a signal, which is standardized according to SMPTE12M.
FIG. 12
is a drawing depicting a flow of operation in a VTR of the prior art that records and plays back an interlaced scanning TV signal.
FIG. 12
is described hereinafter by referring to FIG.
11
and FIG.
13
.
During recording, a video signal is fed in at an input terminal
309
, and recorded on the tape
412
after passing through a recording amplifier
310
and rotary heads
311
f
and
311
g
. One field of the video signal (every {fraction (1/60)} of a second of the video signal in case of the NTSC) is recorded on one helical track.
During play back, the video signal is picked up from the tape
412
by the rotary heads
311
f
and
311
g
, and output from an output terminal
318
after passing through a play back amplifier
317
.
Numerals
313
,
314
,
315
and
316
represent switches for turning on a “REC” side during the recording and a “PB” side during the play back.
In the interlaced scanning TV signal, vertical synchronization signals for the first and second fields are positioned at locations, each of which lags a different number of lines from a line where an image display of the preceding field ends. By detecting the above difference, a recorded frame detector
319
detects a location of the first field from the interlaced scanning TV signal of the input terminal
309
, and generates a signal to represent the location of the first field. This signal is referred to as a frame signal hereinafter. The frame signal represents the location of the first field, and it also corresponds to two fields of the interlaced scanning TV signal at the same time.
A servo circuit
320
controls a motor
321
according to the frame signal in order to advance the tape
412
at a constant speed during recording. Simultaneously, the servo circuit
320
also sends a control signal (CTL signal) which is phase-synchronized with the frame signal, to record it as a marking signal
442
on the control track
441
by a control head
324
.
The control signal defined as the marking signal
442
indicates a punctuation of a frame (i.e., a position at an end of a second field and a start of a first field).
A play back frame detector
323
detects the frame signal out of the interlaced synchronization signal fed in through an interlaced synchronization signal input terminal
322
during the play back.
The servo circuit
320
controls the motor
321
to advance the tape in a manner to maintain the frame signal detected by the play back frame detector
323
to be at a fixed phase with the control signal reproduced by the control head
324
.
Frame synchronization between the video signal output from an output terminal
318
and the interlaced synchronization signal from the input terminal
322
is executed in this manner, so as to achieve the frame synchronization without confusing the first field with the second field.
The time-code signal is a time-code value assigned to each of the frames of the video signal recorded on the helical track
440
.
The time-code values are, for instance, a series of numbers that increase in successive order (1, 2, 3, 4, 5, . . . , etc.), and each frame of the video signal is assigned with numerals that increase successively. In case of the interlaced scanning TV signal, the time-code values are frame numbers.
During the play back, the time-code is reproduced by the time-code reader
327
, and it is output from a time-code output terminal (TC output)
328
via a time-code head
326
and the switch
315
.
Simultaneously, the reproduced time-code is forwarded to an external editing controller
5
through a CPU
329
and the control command bus bar
7
.
The editing controller
5
ascertains that a desired location on the tape material is correctly played back by monitoring the time-code signal. The editing controller
5
outputs a command to the CPU
329
via the control command bus bar
7
for changing a tape travelling speed if there is a shift. Also, the CPU
329
outputs a phase shifting command to the servo circuit
320
, and the servo circuit
320
outputs a motor control modific
Morimoto Takeshi
Yamashita Toru
Matsushita Electric - Industrial Co., Ltd.
RatnerPrestia
Tran Thai
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