Motion video signal processing for recording or reproducing – Local trick play processing – With randomly accessible medium
Reexamination Certificate
1999-06-04
2004-02-17
Nguyen, Huy (Department: 2615)
Motion video signal processing for recording or reproducing
Local trick play processing
With randomly accessible medium
C386S349000, C386S349000
Reexamination Certificate
active
06694088
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a progressive scan video production system and magnetic recording/reproducing apparatus which conduct management of the positioning of video material at a half of the frame frequency during transmission or editing of video signals between component apparatuses of the system.
BACKGROUND OF THE INVENTION
Conventionally, position management and phase lock for video material between the component apparatuses of a video production system of NTSC system have been carried out at 30 Hz. This is because NTSC employs the interlace scan system and its frame frequency is 30 Hz, of which information is integrated in NTSC system. There has been a problem in introducing the progressive scan video system in the NTSC market. The frame frequency of a progressive scan video signal is 60 Hz and not 30 Hz. Therefore, unless an appropriate method is proposed, all the related apparatuses would have to be replaced with progressive scan video signal compatible apparatuses in order to introduce this system. One of such proposed methods is described as a conventional example hereinafter.
FIG. 3
is a block diagram of a configuration of a conventional progressive scan video production system.
The example comprises a recording/reproducing apparatus
1
(hereinafter, VTR) based on the progressive scan TV system, a VTR
20
based on the progressive scan TV system, and an interlace TV sync signal source
5
.
In editing a video material, the VTR
1
is used as a reproduction apparatus and the VTR
20
is used as a recording apparatus.
The interlace TV sync signal source
5
outputs interlace reference signals (hereinafter, I_REF), a reference for the management of the frame position and the like of the system. I_REF is a 30 Hz signal synchronizing with an interlace sync signal. Apparatuses other than the interlace TV sync signal source
5
, namely the progressive scan VTR
1
and VTR
20
, have a I_REF input terminal
1
a
and a I_REF input terminal
20
a
provided respectively thereon.
Timing of each apparatus is controlled according to the I_REF, thereby synchronizing the whole system.
A video output terminal
1
e
of the VTR
1
and a video input terminal
20
b
of the VTR
20
are connected. During the editing of video material, the video signals recorded on the VTR
1
are input into the VTR
20
via the video output terminal
1
e
and the video input terminal
20
b
. The video signals are multiplexed with audio signal and supplementary data such as time code signal. The VTR
20
separates the audio signal and the supplementary data such as time code signal from the multiplexed signal, and re-records a new time code on a tape in the VTR
20
while simultaneously recording the video signals.
In the time code, frame data including time (hour, minute, second) and frame numbers which show the position of the frame are included to be used for positioning the video material during editing or reproduction.
The interlace TV sync signal source
5
supplies I_REF to the I_REF input terminal
1
a
of the VTR
1
and the I_REF input terminal
20
a
of the VTR
20
. When the video material is edited or reproduced, VTR
1
and VTR
20
are phase locked at 30 Hz according to the I_REF. Besides VTR
1
and VTR
20
, needless to say, other peripherals are also controlled at 30 Hz through receiving the frequency of 30 Hz from the I_REF.
Following is a brief description of the progressive scan TV system. (Refer to the broadcasting standard SMPTE292M, SMPTE296M and SMPTE293M for details.)
SMPTE293M (720×483 Active Line at 59. 94 Hz Progressive Scan Production Digital Representation) is a signal format generally called
525
P which is a promising system as a progressive scan TV system with 525 lines.
525
P has 525 lines in {fraction (1/60)} seconds among which 483 lines are effective, and one vertical period or {fraction (1/60)} seconds forms one frame.
Therefore, there is no information showing bounds of {fraction (1/30)} seconds in
525
P.
SMPTE296M (1280×720 Scanning, Analog and Digital Representation and Analog Interface) is a signal format generally known as
720
P. This is a promising system for a progressive scan TV for high definition TV or HDTV. In
720
P, there are 750 lines in {fraction (1/60)} seconds among which
720
lines are effective. One vertical period or {fraction (1/60)} seconds forms one frame. Therefore, there is no information indicating bounds at {fraction (1/30)} seconds in
720
P either.
On the other hand, SMPTE292M (Bit-Serial Digital Interface for High Definition Television Systems) is a transmission format called Bit-Serial Digital Interface (hereinafter, SDI) of Y luminance signals and Pb/Pr color-difference signals. SDI can transmit video signals, audio signals and time code signals via single coaxial cable. The progressive scan video signals in the SMPTE296M or SMPTE293M format can be transmitted as digital serial signals by using SDI.
In the progressive scan video production system, there is a common problem in dealing with video signals in both
525
P and
720
P format. The problem is described below taking
720
P as an example.
FIG.
5
and
FIG. 6
are abstracts of SMPTE296M.
FIGS. 5 and 6
show analog signals and digital signals in the
720
P format respectively. They all are progressive scan TV signals.
FIG. 5
shows analog signals in the
720
P format. As
FIG. 5
shows, the top line of the analog video signal is line
26
, the bottom line is line
745
, blanking line is from line
746
through line
750
and line
1
through line
25
. This format consists of progressive scan video signals with 750 lines in total. There is no information for {fraction (1/30)} seconds or 30 Hz.
FIG. 6
shows digital video signals of
720
P. As shown in
FIG. 6
, in the case of
720
P digital signals, the Line Start and the Line End of video signals are controlled by the Start Active Video (SAV) and the End Active Video (EAV). The Top Line and Bottom Line are recognizable through SAV and EAV.
This format consists of progressive scan video signals totaling 750 lines, however, there is no information for {fraction (1/30)} seconds or 30 Hz.
In contrast to progress sequence scan TV signals in the
720
P format, the format of the interlace TV signals forms one frame with a frequency of {fraction (1/30)} seconds in two fields, the first and second fields with a frequency of {fraction (1/60)} seconds. Moreover, in the interlace TV signal format, the sync signal format of the first and second fields is different, and there is information for discriminating the first field and the second field.
However, as described above, the progressive sequence scan TV signal format as set forth in
FIGS. 5 and 6
does not form fields, therefore there is no information corresponding to {fraction (1/30)} seconds or 30 Hz.
Therefore, in order to introduce the progressive scan video production system into a video production system of which the system is controlled based on information of {fraction (1/30)} seconds, the interlace TV sync signal source
5
which generates information corresponding to 30 Hz (I_REF) had to be included.
FIG.4
shows a block diagram describing the progressive scan VTR
20
as set forth in
FIG. 3
in further detail.
Following is the description of FIG.
4
.
When video is recorded, recording/reproducing (REC/PB) switches
14
and
17
are connected to the recording (REC) side. The progressive scan video signal input from the video input terminal
20
b
is recorded on a tape
25
by a rotary head
12
after passing through a recording amplifier
8
and the REC/PB switch
14
.
A recorded frame detecting circuit
7
detects the starting point of each frame of progressive scan video signals.
On the other hand, I_REF input from the I_REF input terminal
20
a
is input into a reproduction frame detecting circuit
11
. The reproducing frame detecting circuit
11
generates frame reset signals of 30 Hz and outputs the frame reset signals to the recorded frame detecting circuit
7
. The recorded frame detecting circuit
7
resets signals dete
Matsushita Electric - Industrial Co., Ltd.
Nguyen Huy
RatnerPrestia
LandOfFree
Progressive scan video production system and magnetic... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Progressive scan video production system and magnetic..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Progressive scan video production system and magnetic... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3326264