JP4040119B2 - Recording device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a recording apparatus, and more particularly to an apparatus for recording encoded data.
[0002]
[Prior art]
In recent years, digital processing of data has been actively studied. In particular, for high-efficiency coding for compressing image data, various methods have been proposed and discussed for standardization. Among them, the MPEG (Moving Picture Coding Expert Group) 2 method is a general-purpose coding method in the United States. It is attracting attention, such as being adopted as ATV (Advanced Television), the next-generation television broadcasting system.
[0003]
The MPEG2 system is a motion compensation type predictive encoding system that encodes data by compressing the amount of information using correlation between screens. In FIG. 9, the direction of prediction in encoding is indicated by an arrow. Also. FIG. 10 is a diagram showing the order of image data in the encoding process in MPEG2, the arrangement of data on the medium, and the decoding process.
[0004]
In MPEG2, a GOP (Group Of Pictures) is composed of a predetermined number of frames. Each GOP includes an intra-frame encoded image at least one frame.
[0005]
An intra-frame encoded image (hereinafter referred to as I image) is an image encoded using only image data in one frame by DCT / quantization. The image data of each predetermined N frame from this I image is encoded by inter-frame predictive encoding (hereinafter referred to as P image). Further, the image data of each frame between the I image, the P image, and the P image is encoded by bidirectional predictive encoding using the image data of the front and rear frames (hereinafter referred to as B image).
[0006]
As shown in FIGS. 9 and 10, first, an I image is formed. As described above, the I image is encoded only by the image data in one frame, and the prediction operation using the data of other frames is not performed. Next, a P image is formed, and a B image is formed after the I image or the P image. Then, the images are transmitted in the order of I, P, and B images.
[0007]
In MPEG2, encoded image data / audio data or other data string is referred to as an elementary stream. A PES (Packetized Elementary Stream) packet is defined as a structure for transmitting an elementary stream. This has a structure in which a PES payload (data part) follows a PES header. In MPEG2, a set of elementary streams having a common time axis is called a program.
[0008]
Two formats are defined in the MPEG2 multiplexing system. One is a transport stream and the other is a program stream.
[0009]
The definitions of both the transport stream and the program stream include a necessary and sufficient syntax regarding the decoding at the time of image and sound and the synchronization at the time of reproduction. The program stream combines one or more PES packets having a common time axis into a single data string, and the transport stream combines one or more programs having one or more time axes. Thus, a single data string is obtained. In the ATV system described above, a transport stream is used.
[0010]
In the transport stream, data such as video and audio is divided and transmitted in a transmission unit of a fixed length of 188 bytes called a transport packet.
[0011]
In such a transport stream, information such as various identifiers called PCR (Program Clock Reference) and PSI (Program Specific Information) used for synchronization is appropriately incorporated, and these data are detected at the time of decoding. Thus, the encoded data can be accurately decoded.
[0012]
The PSI includes information for identifying PID (Packet ID) called PAT (Program Association Table), PMT (Program Map Table), etc., and the target program and data are stored using this information. Detecting and decoding packets
[0013]
As described above, since the I image is encoded only by the image data in one frame, it can be decoded by the encoded data alone. On the other hand, since the P image and the B image are encoded using image data of other frames, the encoded data alone cannot be decoded.
[0014]
The data length of each of the image data of I, P, and B is variable. Therefore, when recording image data encoded by MPEG2 on a recording medium such as a magnetic tape, it is impossible to specify at which position on the medium the I image is recorded.
[0015]
For example, when data encoded according to MPEG2 is recorded / reproduced to / from a magnetic tape by a device such as a digital VTR, when it is reproduced at the same speed as that at the time of recording, the order of recording, that is, the order of encoding The original image data can be reproduced accurately.
[0016]
However, during special playback such as high-speed search, the head traces across the tape, so that the encoded images I, P, and B are not reproduced in the order in which they are encoded. Further, each head traces only a part of each track, and the recording position of the I image is not specified on the tape as described above, so that the I image is not always reproduced reliably. Therefore, the image data cannot be accurately reproduced during special reproduction.
[0017]
Therefore, when recording such data encoded by MPEG2, it is conceivable to record the I image at a specific position on the tape in order to enable special reproduction. This will be described with reference to FIGS.
[0018]
In FIG. 11, the ATV transport stream input to the input terminal 401 takes out the target transport packet by the packet detection circuit 403 and outputs it to the memory 405 as normal reproduction data. Output to 407.
[0019]
The trick play data forming circuit 407 takes out each stream of PES header, sequence header, picture header, and intra slice to be recorded for special reproduction from the input transport stream, and adds the changed or newly generated PSI. . Then, the header of each layer and the I image data are multiplexed for special reproduction and output to the multiplexer 409. The multiplexer 409 time-division multiplexes these normal reproduction data and special reproduction data, and outputs them to the magnetic head 411. The magnetic head 411 forms a number of helical tracks on the tape 413 and records data from the multiplexer 409.
[0020]
Here, the multiplexer 409 switches between normal reproduction data and special reproduction data, and records special reproduction data at a predetermined place on the track. This will be described with reference to FIG.
[0021]
As shown at 501 in FIG. 12A, two types of tracks having different azimuth angles are formed on the tape.
[0022]
A trace trace of the head when the tape is conveyed at a speed five times that during normal reproduction is indicated by 503. FIG. 12B shows a playback envelope at the time of 5 × speed playback. Here, by recording the special playback data for 5 × speed playback in the hatched portion of the trace locus 503, the playback image at the 5 × speed playback can be stabilized.
[0023]
Similarly, by recording image data for other playback speeds at positions where playback can be reliably performed at the respective playback speeds, stable playback images can be obtained at other playback speeds.
[0024]
[Problems to be solved by the invention]
In the transport stream used in the ATV described above, the PID of the PAT is a fixed value of 0x000, and the PMT can be extracted by detecting this PAT. A packet containing data can be detected.
[0025]
Here, as described above, when the special reproduction data stream is recorded in a different area from the normal reproduction data, the special reproduction I image is extracted from the input transport stream, and the special reproduction data stream is extracted. It is necessary to convert the data stream for reproduction into a format that can be decoded by the ATV decoder.
[0026]
In the normal reproduction data, PAT, PMT, and PCR are appropriately incorporated when ATV data is input to the terminal 401 in FIG. 11. Information necessary for decoding these special reproduction data is also added. There is a need.
[0027]
When the timing of multiplexing information such as PAT, PMT, and PCR is not taken into consideration, when performing so-called joining photography in which recording is performed following the data recorded on the magnetic tape by the apparatus of FIG. 11, joining photography is performed. Since the PCR becomes discontinuous at the boundary portion, the clock information cannot be obtained until the PCR is obtained, and there is a problem that it becomes late to obtain a reproduced image.
[0028]
The object of the present invention is to solve the above-mentioned problems.
[0029]
Another object of the present application is to provide an apparatus capable of quickly reproducing data from a recording medium.
[0030]
[Means for Solving the Problems]
In order to solve the conventional problems and achieve the above-mentioned object, the present invention provides normal reproduction data and special reproduction each having encoded image data and clock data for obtaining the decoding timing of the image data. An apparatus for connecting and recording newly inputted image data to a magnetic tape on which encoded data composed of data for recording is recorded, and reproducing means for reproducing the encoded data from the magnetic tape; Special reproduction image data to be newly recorded using means for inputting image data for special reproduction to be newly recorded and clock data in the special reproduction data in the encoded data reproduced by the reproduction means Generating means for generating clock data for the image data, the clock data from the generating means and the input special reproduction image Multiplexing means for multiplexing data and generating encoded data; and recording means for connecting and recording the encoded data output from the multiplexing means following the encoded data already recorded on the magnetic tape; It is configured with.
[0031]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0032]
In this embodiment, a case where the present invention is applied to an apparatus for recording and reproducing an ATV bit stream will be described.
[0033]
FIG. 1 is a block diagram showing a configuration of a main part of this type of apparatus.
[0034]
In FIG. 1, the TS input to the input terminal 101 is input to the transport packet sync detection circuit 104 and the packet buffer 105. The transport packet sync detection circuit 104 detects sync_byte and the like in the transport header and controls the operation timing of the packet buffer 105 and each circuit in FIG. The bit stream output from the packet buffer 105 is input to the switch 106, the PCR detection circuit 108, and the normal reproduction buffer 109, respectively.
[0035]
FIG. 2 is a diagram for explaining an operation until a desired program is selected in this embodiment. First, the PID detection circuit 107 detects a transport packet including a PAT in the TS, that is, a transport packet whose transport header PID is 0x0000, and connects the switch 106 to the a end. As a result, the transport packet having the PID of 0x0000 is downloaded to the PAT buffer 110. Then, the PAT downloaded to the PAT buffer 110 is input to the PAT selector 111, and a program_map_PID that matches the program number to be recorded is detected.
[0036]
Here, program_map_PID is the PID of the transport packet in which the PID (elementary_PID) of the transport packet including the program to be decoded / recorded is described.
[0037]
The PAT selector 111 inputs the detected program_map_PID to the PID detection circuit 107. In this way, the PID detection circuit 107 detects a transport packet having a PID that matches the program_map_PID received from the PAT selector 111 from the TS, and also detects a transport packet including the PAT as described above. When the PID detection circuit 107 detects a transport packet having a PID that matches the program_map_PID, the PID detection circuit 107 connects the switch 106 to the terminal b, and downloads the transport packet having the PID that matches the program_map_PID to the PMT buffer 112. The PMT downloaded to the PMT buffer 112 is input to the PMT selector 113, and the PMT selector 113 detects and selects elementary_PID which is the PID of the transport packet having a desired program from the PMT.
[0038]
The elementary_PID detected in this embodiment is the PID of a transport packet in which the video portion of the program to be recorded is packetized. The PMT selector 113 inputs the selected elementary_PID to the PID detection circuit 107.
[0039]
Thus, the PID detection circuit 107 detects a transport packet having a PID that matches the elementary_PID received from the PMT selector 113 from the TS. Further, as described above, the transport packet having the PID that matches the program_map_PID and the transport packet including the PAT are also detected. When the PID detection circuit 107 detects a transport packet having a PID that matches the elementary_PID, the PID detection circuit 107 connects the switch 106 to the end c, and the PID header detection circuit 115 and the PES header The data is output to the buffer 116.
[0040]
The PCR detection circuit 108 detects the PCR from the transport packet supplied from the c terminal of the switch 106, synchronizes the TS, and inputs the detected PCR to the PSI converter 114. PCR is a 48-bit signal in units of 27 MHz, and is a time stamp from which the timing of the decoder is obtained. The outputs of the PCR detection circuit 108, the PAT buffer 110, and the PMT buffer 112 are input to the PSI converter 114.
[0041]
The relationship between TS and PES is shown in FIG. FIG. 3 shows a state where a desired program is converted into a PES packet from the TS. In this embodiment, the stream input to the PES header detection circuit 115 and the PES header buffer 116 in FIG. 1 is a video PES of a program to be recorded. The PES header detection circuit 115 detects the PES header, and buffers the PES header information of the video packet to be recorded for special playback in the PES header buffer 116.
[0042]
The stream output from the PES header detection circuit 115 is input to the sequence header extension detection circuit 117 and the sequence header extension buffer 118. The sequence header extension detection circuit 117 detects the sequence header and the sequence extension part, and buffers the sequence header and sequence extension of video data to be recorded for special reproduction in the sequence header extension buffer 118. The sequence header describes parameters (image size, bit rate, etc.) effective for the image. The extension part of the sequence header is described in the sequence extension.
[0043]
The stream output from the sequence header extension detection circuit 117 is input to the picture header coding extension detection circuit 119 and the picture header coding extension buffer 120. The picture header coding extension detection circuit 119 detects a picture header and a picture coding extension stream, and buffers the picture header and picture coding extension of video data to be recorded for special reproduction in the picture header coding extension buffer 120. In the picture header, information on the picture, coding type (I, P, B) and the like are described. The picture coding extension describes information necessary for decoding the picture, a picture structure, and the like. Also, the picture header coding extension detection circuit 19 controls the switch 122 to be connected if the picture type of the supplied stream is an intra-frame encoded image.
[0044]
The stream output from the picture header coding extension detection circuit 119 is input to the slice detection circuit 121. The slice detection circuit 121 detects the header of the supplied slice and inputs it to the switch 122. The slice detection circuit 121 controls the switch 122 to be connected when an intra (intra-frame) slice stream is input.
[0045]
The switch 122 connects the input and output of the switch 122 when an intra-frame encoded image or intra-slice stream arrives. A slice is composed of a plurality of (at least one) macroblocks, and an intra slice is a slice composed of only intra macroblocks. The output of the switch 122 is input to the I picture buffer 123. The I picture buffer 123 buffers only the intra-frame encoded data, and inputs the intra-frame encoded data to the multiplexers 130 and 134.
[0046]
The outputs of the PES header buffer 116, sequence header extension buffer 118, and picture header coding extension buffer 120 are also input to the multiplexers 130 and 134.
[0047]
The PSI converter 114 changes the PSI in the input TS to another PSI or newly generates PSI so that various special reproduction data and normal reproduction data can be distinguished and reproduced. This operation will be described with reference to FIG. FIG. 4A shows an example of extracting a program to be recorded from the PSI input to the recording / reproducing apparatus of the present embodiment.
[0048]
As shown in (a), it is assumed that the program No. to be recorded is program 0x0180. 0x0180, which is the PID of the PMT with the program 0x0180, is detected from the PAT, and PID = 0x0181 and 0x0182 with the video and audio elementary streams are detected from the PID = 0x0180 packet with the PMT. Get the PID of the packet.
[0049]
The operation of the PSI converter 114 at this time will be described with reference to FIG. In the PSI converter 114, the PSI and PMT for normal reproduction use the input PSI values as they are.
[0050]
In this embodiment, it is assumed that there are two types of special playback speeds for the apparatus, and these are for special playback speed 1 and special playback speed 2 (in the middle and after in FIG. 4, they are shown as special playback 1 and special playback 2). PAT and PMT are newly set by the PSI converter 114 as data for playback 1 and special playback 2 are data other than normal playback. First, program 0x0184 and PID = 0x0184 are set for special playback 1 as PAT, and program 0x0188 and PID = 0x0188 are set for special playback 2. Next, each PMT is set. PID = 0x0185 of the elementary stream of video for special playback 1 is set in the PMT for special playback 1. Similarly, PID = 0x0189 of a video elementary stream is set for special playback 2. Further, PID = 0x0185 and PID = 0x0189 are set as the PIDs of the transport packets for the special reproduction 1 and 2 data.
[0051]
At this time, the special reproduction PID set by the PSI converter 114 is 0x0000 which is the PID of the PAT, 0x0001 which is the PID of the conditional access table, the PMT for normal recording / reproduction, and each elementary stream for normal recording / reproduction. Set so as not to overlap with the PID for use.
[0052]
Further, the PSI converter 114 operates such that the program number for normal recording / reproduction and the program number for 0x0000 are not set as the PAT program number (when the program number is 0x0000, the PID of this program indicates network_PID). To do.
[0053]
As for the PCR, the PCR input to the PSI converter 114 is changed for special reproduction, or a new PCR is generated and input to the multiplexers 130 and 134 together with the PAT and PMT.
[0054]
Here, an example of a PCR changing method in the PSI converter 114 will be described. FIG. 5 is a diagram for explaining a PCR changing method. The PCR is a time stamp for obtaining the decoder timing as described above. The PSI converter 114 obtains transport_rate (i) based on the PCR detected by the PCR detection circuit 108 of FIG. 1 as shown in the equation (1) of FIG. Generate PCR and record data. At this time, if the newly generated PCR is PCR (i ″), FPCR (i ″) can be obtained using the equation (2). The PSI converter 114 generates the PCR (i ″) thus obtained. After generating the PCR (i ″), the same thing is performed at a certain period as the special reproduction PCR. At this time, the previous PCR (i ″) obtains a new PCR (i ″) as the PCR (i ′).
[0055]
The multiplexer 130 multiplexes the PSI, header information of each layer, and intra-frame encoded data for special reproduction, inputs them to the parity generation circuit 131, and adds an error correction code. Then, the data is input to the multiplexer 137 as data for special reproduction 1 through the buffer 132.
[0056]
Similarly, the second multiplexer 134 multiplexes the PSI, header information of each layer, and intra-frame encoded data for special reproduction, inputs them to the parity generation circuit 135, and adds an error correction code. Then, the data is input to the multiplexer 137 as data for special reproduction 2 via the buffer 136.
[0057]
The normal reproduction data is input to the multiplexer 137 via the normal reproduction buffer 109.
[0058]
The multiplexer 137 converts the normal playback data output from the normal playback buffer 109, the special playback 1 data output from the buffer 132, and the special playback 2 data output from the buffer 136 into respective playback speeds on the track. Then, the data is multiplexed so as to be recorded at the position where the head is traced, thereby being converted into a recording track format and input to the parity generation circuit 138. The parity generation circuit 138 adds an error correction code to the input data and outputs it to the terminal 140 as recording data.
[0059]
Next, the recording / reproducing mechanism will be described with reference to FIG.
[0060]
6, the data stream including the special reproduction packet output to the terminal 140 in FIG. 1 is input to the input terminal 201 in FIG. 6, subjected to digital modulation processing by the modulation circuit 203, and a format suitable for magnetic recording. Is converted to At this time, pilot signal components for performing tracking control are multiplexed so that the rotary head can trace on the recording track during reproduction. The modulated data is amplified by the recording amplifier 205 and recorded on the magnetic tape 209 by the rotating head 207.
[0061]
At the time of reproduction, the reproduction signal reproduced by the rotary head 211 is amplified by the reproduction amplifier 213 and added to the demodulation circuit. The demodulation circuit 215 binarizes the reproduced signal, detects the synchronization signal, demodulates the data, and outputs it to the error correction code decoding circuit 217. The error correction code decoding circuit (ECC circuit) 217 detects and corrects an error in the data using the parity data added at the time of recording, and outputs it to the sync block memory 219 and the switch 223.
[0062]
During normal reproduction, the switch 223 is switched to the N contact side by the CPU 231, and only normal reproduction data (data encoded with I, B, P) is input to the packetizing circuit 225, and the packetizing circuit 225 receives the ATV. Alternatively, it is packetized according to the packet format of the MPEG2 transport stream and output to the output terminal 227.
[0063]
At the time of special reproduction, special reproduction data corresponding to the special reproduction speed is input to the sync block memory 219. The sync block memory 219 stores and reconstructs the intra-frame coded image, header information, and program information, and outputs them to the error correction coding circuit 221 where data errors are detected and corrected. The output of the error correction encoding / decoding circuit 531 is output to the packetizing circuit 225 via the T-side contact of the switch 223, where it is packetized and output from the output terminal 227.
[0064]
Also, the sync block memory 219 sets the DSM_trick_mode_flag of the PES header in the playback bitstream to “1” and the DSM tricm mode in order to cause the ATV decoder to decode and display the special playback image such as search during special playback. The field is changed to the special reproduction mode at that time, and the bit stream is output.
[0065]
The bit stream output from the output terminal 227 is input to the ATV decoder and decoded. The operation of the ATV decoder will be described with reference to FIG. In this figure, the bit stream output from the terminal 227 in FIG. 6 and input to the terminal 714 is output to the FIFO memory 303 and the PCR detection circuit 309. The PCR detection circuit 309 extracts a PCR packet in the data stream, calculates an average data rate using the formula shown in FIG. 5, and outputs the average data rate to the frequency divider 311. In the FIFO memory 303, packetized data that has become discontinuous is averaged and output to the decoder 305.
[0066]
The phase detection circuit 313, LPF 317, and VCO 319 constitute a PLL, and the reference clock added from the reference clock generation circuit 315 input to the phase detection circuit 309 and the clock output from the frequency divider 311 are determined. By controlling the phase to be in phase, the clock generated by the VCO 319 is controlled to be the transport rate carried in the PCR packet. Data is read from the FIFO memory 303 at a constant rate by using the clock and a clock corresponding to the horizontal / vertical scan cycle of the TV signal formed by dividing the clock by the frequency divider 321, and a stable image signal is output to the output terminal 307. Can be output.
[0067]
In addition, the CPU 232 receives a switch signal on the operation unit 233 and a switch signal installed in each mechanical unit, and controls the mechanical drive circuit 229 in accordance with this to control the direction and speed of a capstan motor (not shown). The tape is transported by instructing. Here, the operation of the CPU 232 when performing so-called continuous shooting using the recording / reproducing apparatus of the present embodiment will be described.
[0068]
When recording is instructed by the switch on the operation unit 233, the CPU 232 starts a continuous shooting operation. First, the tape is rewound by about 40 tracks by reversing the capstan motor. Next, the reproduction operation is started while tracking control is performed in the same manner as in normal reproduction. After tracking normally, the special reproduction PCR detected by the PCR detection circuit 309 in FIG. 7 from the reproduced special reproduction data stream is held in the internal register, and a new PCR is generated based on this. Therefore, the PSI converter is controlled. Then, the reproduction ends at the track including the end of the GOP after detecting the PCR, and the recording operation is started from the next track.
[0069]
FIG. 8 is a flowchart for explaining the operation of such a CPU 232, and will be described below using this flowchart.
[0070]
In FIG. 8, when a recording instruction is issued from the operation unit 229 (step S401), the magnetic tape is rewound by a track (step S402). The rewinding amount is obtained by adding the time from the start of reproduction to the time when tracking is normally performed to the interval in which PCR is included (for example, the longest interval is 0.1 second). Since PCR is transmitted at least once every 100 milliseconds, in this embodiment, it is assumed that at least one track in 30 tracks includes a PCR packet. Then, reproduction is started in a state where tracking is normally applied (step S403). Next, the target PCR is detected, and the recording operation is started when the reproduction of the currently reproduced track is completed (step S406). Then, as described above, using the PCR detected by the PCR detection circuit 309 to be continuous with the PCR recorded immediately before, the next PCR is calculated and the PSI converter is controlled to record the PCR. Thus, the data stream is recorded while inserting the PCR at a predetermined PCR writing interval (steps S307 and S411).
[0071]
Further, if it occurs that the target PSI PCR cannot be found even if all of the rewinded n tracks are reproduced (step S408), the recording operation is started from the next track (step S409), A discontinuity flag is set and a new PCR is generated by the PSI converter 114. Thereafter, normal data stream recording is continued.
[0072]
As described above, in the present embodiment, when performing a transition shot, the PCR in the data recorded immediately before is reproduced, and a new PCR is generated so as to be continuous with this PCR. PCR is not discontinuous in the reproduction data, and the continuity of PCR can be maintained.
[0073]
Accordingly, it is possible to prevent the reproduction of the image from being delayed in the joint shooting portion during special reproduction.
[0074]
In the present embodiment, the case where the present invention is applied to an apparatus for recording / reproducing an ATV bitstream has been described. However, in addition to this, data identification information and clock information are multiplexed and transmitted / recorded. The present invention is applicable to this.
[0075]
【The invention's effect】
As is apparent from the above description, in the present invention, clock data for image data to be newly recorded is generated using clock data in the reproduced encoded data, and the clock data and input image data are converted. By connecting and recording multiplexed encoded data on a recording medium, it is possible to prevent the clock data from becoming discontinuous at the boundary portion of the connected recording, and to quickly obtain a reproduced image at the boundary portion of the connected recording. be able to.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a main part of a recording / reproducing apparatus as an embodiment of the present invention.
FIG. 2 is a diagram for explaining an operation for generating recording data in the apparatus of FIG. 1;
FIG. 3 is a diagram for explaining an operation for generating recording data in the apparatus of FIG. 1;
4 is a diagram for explaining a PSI generation operation in the apparatus of FIG. 1; FIG.
FIG. 5 is a diagram for explaining a PCR generation operation in the apparatus of FIG. 1;
6 is a block diagram showing a configuration of an apparatus for recording / reproducing data generated by the apparatus of FIG. 1;
7 is a diagram showing a configuration of an apparatus for decoding data reproduced by the apparatus of FIG.
FIG. 8 is a flowchart for explaining the operation of the apparatus shown in FIGS.
FIG. 9 is a diagram illustrating a state of encoding image data.
FIG. 10 is a diagram illustrating a state of encoding / decoding of image data.
11 is a block diagram showing a configuration of an apparatus for recording / reproducing data encoded as shown in FIGS. 9 and 10. FIG.
12 is a diagram showing a recording format on a tape in the apparatus of FIGS. 1 and 11. FIG.
[Explanation of symbols]
107 PID detection circuit
108 PCR detection circuit
114 PSI converter

Claims (3)

For a magnetic tape on which encoded data composed of normal reproduction data and special reproduction data each having encoded image data and clock data for obtaining the decoding timing of the image data is recorded. A device for connecting and recording image data input to
Reproducing means for reproducing the encoded data from the magnetic tape;
Means for inputting special reproduction image data to be newly recorded;
Generating means for generating clock data for the special reproduction image data to be newly recorded, using clock data in the special reproduction data in the encoded data reproduced by the reproduction means;
Multiplexing means for multiplexing the clock data from the generating means and the input image data for special reproduction to generate encoded data;
A recording apparatus comprising recording means for connecting and recording the encoded data output from the multiplexing means subsequent to the encoded data already recorded on the magnetic tape.   The means for inputting the image data inputs encoded data including encoded image data and clock data for obtaining a decoding timing of the image data, and the input encoded data is input to the normal reproduction data. 2. The recording apparatus according to claim 1, wherein the image data for special reproduction is generated from the image data in the input encoded data and output. The recording means has a head for forming a number of helical tracks on the magnetic tape and recording the normal reproduction data and special reproduction data,
The multiplexing means inputs a first multiplexing circuit for multiplexing the clock data from the generating means and the special reproduction image data to be newly recorded to generate the special reproduction data, and the image data A second multiplexing circuit for multiplexing the normal reproduction data output from the means for performing and the special reproduction data from the first multiplexing means to generate new encoded data,
The control means for controlling the second multiplexing circuit so that the special reproduction data is recorded in an area on the helical track according to the trace trajectory of the head during special reproduction. 2. The recording device according to 2.

Images