JP2002528972A - Playback device with search-playback mode - Google Patents

Abstract

(57) [Abstract] A magnetic tape transport for transporting a magnetic tape (4) at a first transport speed (V1) and at least a second transport speed (V2) higher than the first transport speed (V1) Means (17), reproducing means (8) for reproducing a digital video signal from the magnetic tape (4) transported at the first transport speed (V1) by the magnetic tape transport means (17), During the first time interval (T1), the magnetic tape (4) is operated at the first transport speed (V1), and during the second time interval (T2), at the second transport speed (V2). A reproducing apparatus (1) having a control means (16) for controlling the magnetic tape transport means (17) so as to periodically and alternately transport, and a supplying means (26) for supplying a reproduced digital video signal; Wherein the reproducing means (8) is provided on a magnetic tape (4). A digital video signal recorded and containing an MPEG transport stream (MPEG standard (system): IS0 / IEC13.818-1) is reproduced, and the supply means (26) is provided only during a first time interval (T1). Supplies a reproduced digital video signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides a magnetic tape transport means for transporting a magnetic tape at a first transport speed and at least a second transport speed higher than the first transport speed; Reproducing means for reproducing a digital video signal from a magnetic tape transported at a transport speed; a first transport speed during a first time interval and a second transport speed during a second time interval; Control means for controlling the magnetic tape transport means so as to transport the magnetic tape periodically and alternately (at an alternate speed), and a digital video signal to be reproduced (hereinafter, referred to as a reproduced digital video signal). And a supply unit for supplying.

A playback device of this type described in the opening paragraph is already known from US Pat. No. 5,239,429 and is configured as a video recorder for playing back digital video signals. The known video recorder has a magnetic tape transport means, and a magnetic tape of a magnetic tape cassette inserted into the video recorder uses the transport means to record a digital video signal on a magnetic tape. The transport may be at a first transport speed that matches the port speed.

[0003] Reproducing means of known video recorders reproduce digital video signals from magnetic tape transported at a first transport speed by magnetic tape transport means. The magnetic tape transport means further transports the magnetic tape at a second transport speed that is higher than the first transport speed, for example, equal to seven times the first transport speed.

[0004] The known video recorders further comprise control means in which a search-play mode of the video recorder is realized using the control means. The user uses this control means to
It is possible to quickly read a television broadcast recorded as a digital video signal on a magnetic tape, and quickly retrieve the broadcast from a desired magnetic tape position on the magnetic tape. The control means for controlling the magnetic tape transport means for this purpose controls the magnetic tape at the first transport speed during the first time interval and at the second transport speed during the second time interval. It is configured to achieve alternating transport on a periodic basis.

[0005] Known video recorders further comprise a picture memory. A portion of the digital video signal that is reproduced during the first time interval and that represents at least a television picture of the reproduced television broadcast is stored in the picture memory during the first time interval. First
At the end of the time interval, the storage of the reproduced video signal in the picture memory ends. During the subsequent second time interval, the magnetic tape is transported at the second transport speed and one or more television images stored in the picture memory are repeatedly supplied by the supply means of the video recorder. The supply means is constituted by address means for generating read address information stored in a picture memory and for reading a television image formed by the picture memory, during a first time interval and during a second time interval. Provides a playback digital video signal.

[0006] The known video recorders have the disadvantage that the supply means and in particular the picture memory are very expensive. Furthermore, picture memories for storing certain sequences of television images are very expensive, so that only a few television images can be stored in the picture memory.

It is an object of the present invention to solve the above difficulties and to provide an improved playback device according to the embodiment described in the opening paragraph. The object is a playback device according to the embodiment described in the opening paragraph, wherein said playback means is recorded on a magnetic tape and has an MP
Playing back a digital video signal including an EG transport stream (MPEG standard (system): IS0 / IEC13.818-1), wherein the supply means supplies the playback digital video signal only during a first time interval; Achieved in the device.

[0008] This means that a part of the digital video signal reproduced by the reproducing means during the first time interval is supplied directly (for example, to the set-top box) from the output terminal of the reproducing device constituting the supplying means. Has advantages. During the second time interval, the digital video signal is not supplied from the playback device to the set-top box and indicates, for example, "on-screen display" using the text "no input signal" during the second time interval. The choice is left to the set-top box. Thus, the search-play mode can be implemented in a playback device without the need for expensive picture memory for one or more television images to play the digital video signal. Furthermore, a sequence of any length of the reproduced television broadcast (hereinafter referred to as the reproduced television broadcast) can be advantageously reproduced by the magnetic tape during the first time interval.

[0009] In a recording device as defined in claim 1, measures as defined in claim 2
Has been found to be advantageous. This means that at least one so-called I
This has the advantage that the frame is played during the first time interval. This I frame was once included in a "picture group" (Group of Pictures, GOP), and includes picture information necessary to reproduce a television image of a reproduced television broadcast. When there is an I-frame to supply the television image and there is a complete "picture group", the processing unit for processing the MPEG transport stream further comprises a "picture group".
The evaluation of the B and P frames that may be included in a "group" provides a short sequence of consecutive television images.

[0010] The time control information can advantageously be provided by a time step provided in the video recorder. The time step measures the first time interval and supplies the time control information to the control means only after the duration of the first time interval has ended, thereby ending the first time interval as soon as possible after this duration. Let it. During this first time interval, at least the complete "picture group", and thus the I-frame, is reliably reproduced by the reproduction means. The first time interval should be large in this case, since the time interval for reproducing a complete "picture group" depends on the coding mode of the MPEG transport stream.

[0011] Preferably, the time control information may be provided by an I-frame detection stage to be provided in the video recorder. This detection stage recognizes the start and end of the “picture group” by referring to the header information of the I frame specified by the MPEG standard.

However, it is particularly advantageous to provide a measure as defined in claim 3 in a playback device as defined in claim 2. The processing device can be composed of, for example, a set-top box or a television device, and processes an MPEG transport stream. In order to process the MPEG transport stream in the processing unit,
Since the reception and processing of the complete I-frame of the "picture group" must be detected, the result of this detection can be supplied to the playback device and used as time control information. This is particularly advantageous because no additional means need be provided in the playback device, and substantially no additional means need be provided in the processing device.
Furthermore, this is achieved only by supplying time control information when the reception of at least one complete I-frame of a "picture group" with satisfactory reproduction quality is confirmed by the processing unit during the first time interval. This has the advantage that the reproduction of the digital video signal is terminated.

[0013] It has been found that it is advantageous to provide a measure as defined in claim 4 in the playback device as defined in claim 2. In the search-playback mode, when the last reproduced at least one television image during the immediately preceding first time interval is to be repeatedly played back during the second time interval, a processing device which can be connected to the playback device. It is particularly advantageous to use the playback memory to process the playback digital video signal as a picture memory and to play back at least some television pictures stored in the playback memory during the second time interval. This results in a particularly low cost playback device that uses the playback memory provided in each processing device to process the MPEG transport stream during the search-play mode of the playback device.

[0014] It has been found that it is advantageous to provide a measure as defined in claim 5 in a playback device as defined in claim 4. This involves inserting the memory blocking information directly into the MPEG transport stream to be played (hereinafter referred to as the playing MPEG transport stream) and eliminating the additional data bus means for transmitting the memory blocking information to the processing device. The advantage that can be produced.

[0015] It has been found that it is advantageous to provide a measure as defined in claim 6 in a playback device as defined in claim 1. This has the advantage that time control information or memory blocking information can be transmitted to a number of processing units via a standardized data bus. Information can be transmitted via the data bus in both synchronous data transmission and asynchronous data transmission according to the IEEE-1394 standard.

It has been found that it is advantageous to provide a measure as defined in claim 7 in the playback device as defined in claim 1. This is the On-Screen Display
The advantage is that text information can be inserted into the "on-screen display" generated by the (OSD) generating means. For example, it is possible to insert the title of the television broadcast played at the first time interval, the count of the internal tape counting mechanism or other additional information as text information. Such an "on-screen display" can be shown at a second time interval on a TV device connected to the playback device for the purpose of additional information to the user.

It has been found that it is advantageous to provide a measure as defined in claim 8 in the playback device as defined in claim 1. This has the advantage that a reverse-search-play mode in the starting direction of the magnetic tape is possible.

The above and other aspects of the present invention will become apparent from the embodiments described below.

FIG. 1 shows a playback device 1, a set-top box 2, and a television device 3. The analog video signal recorded on the magnetic tape 4 can be reproduced by the reproducing apparatus 1 in the reproducing mode of the apparatus, and can be supplied from the analog output section 5. On the other hand, a digital video signal recorded on the magnetic tape 4 can be reproduced and supplied from the digital output unit 6.

The set-top box 2 includes an analog output unit 5 and a digital output unit 6 of the playback device 1.
Connected to. The set-top box 2 constitutes a processing device, processes analog and digital video signals supplied to the processing device, and supplies an analog output signal AS from a first output terminal 7.

The television device 3 is connected to the first output terminal 7, and optically indicates and acoustically reproduces a television broadcast reproduced by the output signal AS.

The playback device 1 converts an analog video signal recorded on the magnetic tape 4 according to the VHS standard and a digital video signal recorded according to the DVHS standard (JVC, July 25, 1997, no.07015). It has a reproducing means 8 for reproducing. For this purpose, the reproducing means 8 comprises a scanner 9 in which a rotationally driven head disk 10 having a first magnetic head pair 11 and a second magnetic head pair 12 is provided on the scanner 9. The magnetic tape 4 is moved by the tape guide rolls 13 and 14 to the scanner 9 in the reproducing mode of the reproducing apparatus 1.
And is guided along the head disk 10. In the playback mode of the playback device 1, the playback signal WS is alternately output to the second by one of the magnetic heads of the magnetic head pairs 11 and 12.
It can be supplied from the output terminal 15. This reproduction signal includes an analog or digital video signal recorded on the magnetic tape 4. The reproduction means 8 is a DVHS
A digital video signal including an MPEG transport stream (MPEG standard (system): IS0 / IEC13,818-1) recorded on the magnetic tape 4 according to the standard is also reproduced.

An MPEG transport stream is a video stream containing encoded video data.
Packet, an audio packet containing encoded audio data, a data packet containing additional data, and a table packet containing table information.
Note that the transport stream packet is defined by the MPEG standard. An MPEG transport stream can include one program stream or multiple program streams, and the table information determines which video, audio, and data packets should be assigned to the program stream. . The program stream contains the picture and sound information needed to optically represent and acoustically reproduce the television broadcast. The data packet may include additional information related to the television broadcast, such additional information may be formed, for example, by the title of the television broadcast or by examining the content of the television broadcast.

The playback device 1 further has a first control means 16 and a magnetic tape transport means 17. The magnetic tape transport means 17 transports the magnetic tape 4 at a first transport speed V1 and a second transport speed V2 higher than the first transport speed V1. For this purpose, the magnetic tape transport means 17 comprises:
It has a motor 18, a capstan 19 and a pressure shaft 20. In the playback mode of the playback device 1, the motor 18 drives the capstan 19 via the connection portion 21, and the magnetic tape
4 is pressed against the capstan 19 by the shaft 20. As a result, the magnetic tape 4 is transported at the transport speed V1 or V2 depending on the rotation speed of the motor 18.

The magnetic tape transport means 17 transports the magnetic tape 4 in the first transport direction R1 during the first time interval T1, and only in the first transport direction R1 during the second time interval T2. The magnetic tape 4 is also transported in the second transport direction R2. This will be described in detail below.

The first control means 16 controls the magnetic tape transport means 17 in particular, and supplies motor control information MSI to the motor 18. In the search-play mode, the control means 16
Is at the first transport speed V1 during the first time interval T1, and at the second time interval T2
During this period, the magnetic tape transport means 17 is controlled so as to periodically and alternately transport the magnetic tape 4 at the second transport speed V2. This is described in more detail below.

The first control means 16 has a time means 22 constituted by a timer, and the first time interval T1 and the second time interval T2 can be determined in advance using this timer. This is described in more detail below. The first control means 16 further has an insertion means 23 for inserting insertion information DEI constituting memory blocking information into a table packet of an MPEG transport stream included in the reproduced digital video signal. Bit sequence "010" constitutes insertion information DEI, which can be inserted into the PES table as "trick-mode control" information. This will be described in detail below.

In a mode not shown in detail in FIG. 1, the playback device 1 determines whether the video signal recorded on the magnetic tape 4 is recorded as an analog video signal according to the VHS standard, or a digital video signal according to the DVHS standard. Is detected. When reproducing an analog video signal recorded according to the VHS standard, the reproduction signal WS supplied from the second output terminal 15 by the reproduction means 8 can be supplied to the VHS processing means 24. The VHS processing means 24 processes the reproduction signal WS including the analog video signal and supplies the first television signal FS1 to the analog output unit 5 of the reproduction device 1, as is generally known.

The playback device 1 further includes an OSD for generating an “on-screen display” including text information.
It has generation means 25. Such text information may for example consist of additional information relating to the television broadcast of the reproduced analog or digital video signal. Such additional information can be determined, for example, from teletext information contained in the reproduced television signal and can consist of the title of the television broadcast or the recording date. Further, such textual information may be stored on a tape-not shown in FIG.
It can be constituted by the count of the counting mechanism, in this case, magnetic tape 4
Thus, the position of the magnetic tape at which the reproduction signal WS starts to be reproduced can be indicated. OSD
The "on-screen display" generated by the generating means 25 can be inserted into the first television signal FS1, or by the first control means 16 by supplying OSD insertion information OSD at a given time interval. Form a first television signal FS1.

When a digital video signal recorded according to the DVHS standard is reproduced, the reproduction signal WS supplied from the second output terminal 15 by the reproduction means 8 can be supplied to the supply means 26. The supply unit 26 supplies the MPEG transport stream included in the reproduced digital video signal to the digital output unit 6 of the reproduction device 1. The supply means 26 has a DVHS processing means 27 and a first data bus means 28 for this purpose.

The DVHS processing means 27 processes a reproduced digital video signal including an MPEG transport stream corresponding to the DVHS standard, as already known, for example, from European Patent Application No. 98 201 959.8. For this purpose, the DVHS processing means 27 has, in particular, an error correction means 29 and a time stamp means 30.

The error correction means 29 evaluates error correction information included in the reproduced digital video signal according to the DVHS standard, and supplies the corrected reproduced digital video signal to the time stamp means 30. The error correcting means 29 further supplies the validity information DG to the time means 22 of the first control means 16. This is described in more detail below.

The time stamp unit 30 evaluates the time stamp information included in the reproduced digital video signal to supply a transport stream packet of an MPEG transport stream included in the reproduced digital video signal with a temporal distance. However, these transport packets have the said temporal distance when the digital video signal was recorded. The MPEG transport stream supplied by the time stamp means 30 and the DVHS processing means 27
28 can be supplied.

The first data bus means 28 communicates with another data bus means corresponding to the IEEE-1394 standard via the data bus 31. Synchronous and asynchronous data transmission is provided according to the IEEE-1394 standard. In synchronous data transmission, time-sensitive data (for example, M
PEG transport stream). In asynchronous data transmission, control information (for example, playback device control information WSI) that does not require a relatively long time can be transmitted. The playback device control information WSI received in the case of asynchronous data transmission can be supplied to the first control means 16 by the first data bus means 28. This will be described in detail below.

The first data bus means 28 is connected to the digital output unit 6. The second data bus means 32 of the set-top box 2 is connected to the digital output unit 6 via the data bus 31, and communicates with the first data bus means 28 of the playback device 1. In the case of synchronous data transmission, the MPEG transport stream included in the reproduced digital video signal is transmitted from the first data bus means 28 to the second data bus means 3 via the digital output unit 6 and the data bus 31.
2 can be transmitted. Since many data bus means comply with the IEEE-1394 standard, by complying with the IEEE-1394 standard for data transmission with the first data bus means 28, the data bus means 28 can be used for a large number of other processing devices. The advantage of communication with the data bus means is obtained.

The set-top box 2 has a demultiplexer for processing the MPEG transport stream received by the second data bus means 32 and supplying an output signal AS.
33, decoding means 34, switch 35, second control means 36, key block 37
And

The key block 37 has a plurality of keys for controlling the set-top box 2 and the playback device 1. The input information EI can be supplied from the key block 37 to the second control means 36.

The input information EI supplied to the second control means 36 by the key block 37 is
1 to control the operation mode, the playback device control information W
In the case of asynchronous data transmission, the SI is transmitted by the second control means 36 to the data bus means 28 of the reproducing apparatus 1 via the second data bus means 32 and the data bus 31, and then to the first
It can be supplied to the control means 16.

The input information EI supplied by the key block 37 to the second control means 36 is provided for selecting a program stream included in the MPEG transport stream received by the second data bus means 32 , The second control means 36
Thus, the program control information PSI can be supplied to the demultiplexer 33. When there is the program control information PSI, the demultiplexer 33 selects a program stream characterized by the program control information PSI from the program streams included in the received MPEG transport stream.

The program stream selected by the demultiplexer 33 can be supplied to a decoding unit 34 for decoding video data and audio data included in the program stream. For this purpose, the decoding means 34 comprises a decoding stage 38, a reproduction memory 39 and a table means 40. The program stream provided by the demultiplexer 33 can be provided to both the decoding stage 38 and the table means 40. The decoding stage 38 is included in the video packet of the program stream and includes the MPEG video standard (MPEG standard (video): IS0 / IEC13
The video data encoded according to .818-2) is decoded.

FIG. 2 shows a picture information sequence formed by encoded video data of a video signal included in a video packet and encoded according to the MPEG video standard. The picture information is included in the I frame, the B frame, and the P frame. An I frame, one or more B frames, and one or more P frames
A "picture group". Each time video data is encoded, it is determined how many B frames and which P frames are included in the "picture group". The I frames included in each “picture group” include sufficient picture information for displaying television pictures of television broadcasts by the television device 3.

A B-frame only contains correction information for the previous and next frames. To display a television picture of a television broadcast by the television device 3,
It is not sufficient to use only the picture information included in the B frame without the picture information of the I frame. The P frame includes correction information on the immediately preceding I frame and the next I frame. In order to display a television picture by the television device 3, it is not sufficient to use only the picture information included in the P frame without the picture information of the I frame.

The decoding stage 38 decodes the received video data in order to store the video data in the reproduction memory 39. Since the video data of the “picture group” becomes decodable only in cooperation, at least one video data of the “picture group” is stored in the reproduction memory 39. Using the picture information included in the “picture group”, the television device 3 can display a plurality of television images constituting a certain scene of the television broadcast.

The decoding stage 38 further decodes audio data contained in the received program stream. The decoded video data is an analog video signal, and the decoded audio data is an analog audio signal.
It can be supplied to the switch 35 in the form of the second television signal FS2.

The second control means 36 supplies the switching control information USI to the switch 35. The switch 35 depends on the switching control information USI supplied to the switch,
The television signal FS1 or the second television signal FS2 is supplied to the first output terminal 7 as an output signal AS.

The table means 40 is included in the table packet and includes the MPEG system standard (MPEG).
Standard (system): Evaluates table information specified in IS0 / IEC13.818-1). The table means 40 evaluates, for example, the “trick mode control” information of the PES table.
The bit sequence "010" of the "trick mode control" information represents a "freeze frame" command, which allows the processing unit (e.g., set-top box 2)
Freezes the last supplied picture information stored in the reproduction memory 39, supplies the picture information as a second television signal FS2 in another sequence, and displays a television picture on the television device 3. Is specified as

To ensure that the last supplied picture information is frozen, the table means 40 supplies the “freeze frame” information FFI to the second control means 36. When the "freeze frame" information FFI occurs, the second control means 36 decodes the storage inhibition information SSI into a decoding stage 38.
To supply. When the storage inhibition information SSI is present, the decoding stage 38 prevents excessive storage of the video data stored at this point in the reproduction memory 39 and converts the picture information of the I frame stored in the reproduction memory 39 to the second television. Supply as John signal FS2.

The decoding stage 38 detects the header information of the I frame received in the video packet. When the decoding stage 38 detects such header information, this indicates that the I-frame video data has already been received by the decoding stage 38 and stored in the playback memory 39 and further provides a "freeze frame" command. Means you can. The decoding stage 38 supplies the detection information DI to the second control means 36. When there is the detection information DI, the second control means 36 sends the time control information ZS to the second data bus means 32.
Supply I. In the case of asynchronous data transmission, the second data bus means 32 supplies the time control information ZSI to the first data bus means 28. The first data bus means 28 constitutes a receiving means for receiving the time control information ZSI from the connected processing device, and supplies the received time control information ZSI to the first control means 16.

The search-play mode of the playback device 1 can now be activated using the key block 37 of the set-top box 2. In the activated search-play mode, during the first time interval T1 during which the magnetic tape 4 is transported at the first transport speed V1, part of the television broadcast played by the playback device 1 During the second time interval T2, which is displayed alternately above and the magnetic tape 4 is transported at the high transport speed V2, the last displayed television picture is frozen as a still image. Thereby, the user can quickly read the television broadcast recorded on the magnetic tape 4 as a digital video signal. Further, a desired magnetic tape position of the magnetic tape 4 can be quickly taken out. When the search-play mode is used, the magnetic tape 4 is searched toward the end of the magnetic tape 4 in the first transport direction R1.

As already known, for example, from European Patent Application No. 98.201.959.8, DV
The "trick play" reproduction for reproducing the digital video signal recorded on the magnetic tape 4 in accordance with the HS standard is performed when the magnetic tape 4 is transported at a value which is a multiple of the first transport speed V1 when reproducing the reproduction signal WS. It should be noted that the “trick play” data can be realized by the reproducing apparatus 1 only when the data is recorded in a special “trick play” recording area on the magnetic tape 4. Advantageously, the search-play mode can also be realized when no "trick play" data is recorded on the magnetic tape 4.

The input information EI is used to activate the search-play mode in the key block 37.
Is supplied to the second control means 36, the second control means 36 supplies the corresponding playback device control information WSI to the first data bus means 28 via the data bus 31. When such playback device control information WSI occurs, the first control means 16 sets the first time interval T1
During the second time interval T2, the magnetic tape transport means 17 is controlled to periodically and alternately transport the magnetic tape 4 at the second transport speed V2 during the second time interval T2. To provide the motor control information MSI.

FIG. 3A shows a change with time of the transport speed V of the magnetic tape 4 from the time t ₁ at which the search-play mode of the playback device 1 is activated. From the time t _1,
The reproduction means 8 supplies the digital video signal recorded on the magnetic tape 4 according to the DVHS standard to the DVHS processing means 27 as a reproduction signal WS. From the time t _2, the reproduction means 8 and D
The transients in the VHS processing means 27 have been reduced to such an extent that the error correcting means 29 determines that the uncorrectable errors have a low rate, and the error correcting means 29 Supply valid information DG to 22. FIG. 3B shows the change over time of the validity information DG, which remains valid until there is a change in the transport speed V.

From time t ₂ , the reproduced MPEG transport stream is supplied by the supply means 26 to the decoding means 34 via the data bus means 28 and 32 and the demultiplexer 33. As shown in FIG. 2, the video data contained in the video packet of the MPEG transport stream includes picture information first B frame from the time t _2,
It is stored in the playback memory 39. Thereafter, the picture information of the P frame and the other two B frames is received by the decoding stage 38 and stored in the reproduction memory 39.

At time t ₃ , the picture information of the I frame is received by the decoding stage 38 and stored in the playback memory 39. From the time t _3, the decoding unit 34 supplies the first television image reproduction television as the second television signal FS2. As described above, the decoding stage 38 detects the header information of the I frame, and detects the detection information DI to the second control means 36. This detection information DI is transmitted to the time control information by the second control means 36.
The data is supplied directly to the first control means 16 via the data bus 31 as ZSI. As shown in FIG. 3C, the time control information ZSI remains valid until time t ₄ when the transport speed V of the magnetic tape 4 is changed.

The time control information ZSI characterizing the complete reproduction of at least the I frames of the reproduced MPEG transport stream can now be supplied to the first control means 16.
Even if the duration of the first time interval is very short, the first control means 16 can control the time control information ZS
Only after I occurs does the first time interval T1 end. This is advantageous in that the end and the time t ₄ the first time interval T1, always at least some I-frame is stored in the reproducing memory 39 of the set top box 2 in order to reproduce the television picture reproducing television Spawn.

As shown in FIG. 2, the duration of the first time interval T 1 is the “picture group” GOP
Still another frame making up the whole is adjusted by the decoder stage 38 to be generated during the first time interval T1 and stored in the reproduction memory 39. To time t _4, time means 22
Determines the end of the first time interval T1. This time t _4, already time control information ZSI
Is also supplied to the first control means 16, the first control means 16 supplies the motor control information MSI to the magnetic tape transport means 17 for transporting the magnetic tape 4 at the second transport speed V2. I do.

Further, the insertion unit 23 of the first control unit 16 inserts the insertion information DEI into the PES table of the reproduced MPEG transport stream at time t ₄ . Inserting information DEI has already constituting the storage blocking information SSI, freezes the picture information displayed on the television device 3 during the regeneration in the memory 39 is stored in the time t ₄ and essentially the second time interval T2 Used to

FIG. 3D shows the change with time and the validity of the storage inhibition information SSI. As described above, the insertion information D inserted in the PES table of the MPEG transport stream
The EI can be detected by the table means 40, at which time the table means 40 supplies the "freeze frame" information FFI to the second control means 36. The second control means 36
In order to freeze the storage contents of the reproduction memory 39 and prevent the picture information of the frame shown in FIG. 2 from being excessively stored, the actual storage inhibition information SSI is supplied to the decoder stage 38.

During the period in which the storage inhibition information SSI is valid, the decoder stage 38 reads out the decoded I-frame picture information from the reproduction memory 39 at time t ₄ and decodes it. This allows the first device without the need for a playback memory in the playback device 1 for this purpose.
The television picture of the television broadcast played during the time interval T1 is the second time interval T2
The advantage is that it is also regenerated during.

Since the magnetic tape 4 is transported at the second transport speed V 2, by inserting the insertion information DEI into the reproduced MPEG transport stream, further picture and sound information are just included in the MPEG transport stream. This has the advantage that the insertion information DEI is detected by the table means 40 when not inserted.

[0061] Time unit 22, when determining the end of the second time interval T2 to the time t _5, the first control means 16
Supplies the motor control information MSI to the magnetic tape transport means 17 for transporting the magnetic tape 4 at the first transport speed V1. At time t ₆ , the error correcting means 29 again determines that the uncorrectable errors have a low rate, at which time the error correcting means 29 supplies the validity information DG to the time means 22 of the first control means 16.

At time t ₇ , decoder stage 38 receives the I-frame picture information and detects the I-frame header information. Regeneration, since it is starting from different positions in the "group of pictures", the time interval between times t ₁ and t ₃ is a time t ₅ in this case
It may be different from the time interval between t _7.

The time control information ZSI is supplied to the first control means 16 by the second control means 36 after detecting the header information of the I frame, and as a result, the insertion information DEI is
3 will no longer be inserted into the PES table of the playback MPEG transport stream. From the time t _7, although television picture of a television broadcast that was being reproduced on the television device 3 during a second time interval T2 is no longer displayed, the television broadcast to be played during the time t ₇ and t ₈ The scene is displayed.

When the search-play mode is activated, the OSD insertion information OSD is sent to the OSD generation means 25 during the second time interval T2 to generate and insert an “on-screen display” containing text information. Supplied. The text information can be determined, for example, from a data packet of a reproduced MPEG transport stream in a manner not shown in FIG. This “on-screen display” is supplied to the switch 35 of the set-top box 2 as the first television signal FS1. Advantageously therefore, the second control means 36 of the set top box 2, between the storage blocking information SSI is valid (thus between the example time t ₄ and t _7), the switching control information USI to the switch 35 It is possible to provide an "on-screen display" with essentially additional information on the reproduced television broadcast during the second time interval T2. From the time t ₈ to the storage blocking information SSI is no longer valid, it is possible to reproduce the television picture stored in the replay store.

This has the advantage that the user can receive additional information relating to the reproduced television broadcast during a part of the second time interval T2 and also retrieve the desired magnetic tape position more quickly.

In the playback device 1, the reverse search-playback mode is set in the first transport direction R 1 during the first time interval T 1 and in the second time interval T 2 in a manner not shown in FIG.
During this time, the magnetic tape 4 can be activated to be transported in the second transport direction 2. Except for the transport direction R during the second time interval T2, the processing in the reverse search-reproduction mode matches the processing in the search-reproduction mode. This has the advantage that the user can also search the magnetic tape 4 towards the beginning of the magnetic tape 4 in the second transport direction R2.

It should be noted that the “on-screen display” using additional information related to the reproduced television broadcast can also be generated in the set-top box. Advantageously, the additional information can be determined from the data packets of the reproduced MPEG transport stream.

It should be noted that the duration of the time intervals T1 and T2 and the second transport speed V2 can be adjusted by the user. In this case, the user can decide that, for example, the television broadcast is reproduced during the time interval T1 of 3 seconds and displayed on the television device 3. During the subsequent second time interval T2 of, for example, 5 seconds, the magnetic tape can be transported at a second transport speed V2, which may for example correspond to a value 20 times the first transport speed V1. Depending on the desired search mode of the desired magnetic tape position, a number of other time intervals T and a second transport speed V2 are possible, for example T1 = 10 seconds, T2 = 40 seconds, V2 = 50 × The first transport speed V1 may be used.

The set-top box displays a plurality of scenes of the reproduced television broadcast during the second time interval T2.
Note that it may be configured to play (the picture information in one or more “picture groups” of the scene may be stored in the play memory of the set-top box). For example, to play at 12 times the transport speed,
When "trick play" data is recorded on magnetic tape, the first transport speed V1 corresponds to 12 times the transport speed and the second transport speed V2
May be equal to, for example, three times the first transport speed V1.

It should be noted that the playback means of the playback device in search-play mode can also play back analog video signals. Additional information that can be inserted as text information in the "on-screen display" is the VA of the analog video signal.
SS data (video address search system), or may be determined from subcode data or main code data of a digital video signal corresponding to the DVHS standard, and further, for example, archive information related to television broadcast recorded on a magnetic tape May be included. Only I frames in a plurality of "picture groups" may be stored in the playback memory, in which case these I frames can be played back as a television picture sequence during the second time interval T2. Please note that. In the case of asynchronous data transmission, the storage inhibition information may further be supplied by the first control means of the playback device to the second control means of the set top box via the data bus means and the data bus. Further, the inserting means may insert the storage inhibition information into the data packet of the reproduced MPEG transport stream.

[Brief description of the drawings]

FIG. 1 is a block diagram of a reproducing apparatus that reproduces a digital video signal recorded on a magnetic tape in a search-reproduction mode.

FIG. 2 is a schematic diagram showing a sequence of I, B, and P frames of a “picture group” in a digital video signal encoded according to the MPEG standard.

FIG. 3 shows a signal curve resulting from an activated search-play mode of the playback device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 playback device 2 processing device (set-top box) 3 television device 16 first control means 17 magnetic tape transport means

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 5/937 H04N 5/92 H 5/93 C (71) Applicant Groenewoodsweg 1, 5621 BA Eindhoven, The Netherlands F-term (reference) 5C018 DA02 DC04 5C053 FA21 GB37 HA33 JA16 LA04 LA06 5D044 AB07 BC01 CC03 FG09 FG24 HL04 5D077 AA04 BA04 BA09 EA08 HC26 HD01 HD02 HD04

Claims (8)

[Claims] 1. A magnetic tape transport means for transporting a magnetic tape at a first transport speed and at least a second transport speed higher than the first transport speed, and the first transport speed provided by the magnetic tape transport means. Reproducing means for reproducing a digital video signal from a magnetic tape transported at a transport speed; said first transport speed during a first time interval and said second transport speed during a second time interval; A reproducing apparatus comprising: a control unit that controls the magnetic tape transport unit so as to periodically and alternately transport the magnetic tape, and a supply unit that supplies a digital video signal to be reproduced. The reproducing means is an MPEG transport stream (MPE) recorded on the magnetic tape. A digital video signal including a G standard (system): IS0 / IEC13.818-1) is reproduced, and the supply unit supplies the reproduced digital video signal only during the first time interval. A playback device. 2. Time control information is supplied to said control means, said time control information being provided during a first time interval, a "picture group" (MPEG transport stream) defined by the MPEG standard. 2. The reproduction according to claim 1, characterized in that at least the complete reproduction of the I frame of the GOP is characterized, and the control means ends the first time interval only after the time control information has occurred. apparatus. 3. The supply means supplies a playback digital video signal to a processing device connectable to the playback device, and the reception means receives the time control information from the connected processing device, 3. The reproducing apparatus according to claim 2, wherein the received time control information is supplied to the control unit. 4. At the end of the first time interval, the supply means supplies storage inhibition information to a processing device connectable to the reproduction device, and supplies the reproduction digital video signal stored in the reproduction memory of the processing device. At least TV picture (I frame)
3. The reproducing apparatus according to claim 2, wherein excessive storage of picture information is prevented. 5. The method according to claim 4, wherein at the end of each first time interval insertion means are provided for inserting storage-inhibition information into the MPEG transport stream reproduced as a digital video signal. Playback device. 6. The reproducing apparatus according to claim 1, wherein the supply unit supplies information according to an IEEE-1394 standard. 7. The system according to claim 1, further comprising an OSD generating means for generating an “on-screen display” (OSD) including text information that can be provided by the playback device at a second time interval. The playback device as described in the above. 8. The magnetic tape transport means transports the magnetic tape in a first transport direction during a first time interval and in a reverse second transport direction during a second time interval. The playback device according to claim 1, wherein: