A magnetic-tape recording apparatus for recording digital data on a magnetic tape by a rotating head includes a first obtaining unit for obtaining first-group data, including video data, audio data, or search data. A second obtaining unit obtains second-group data, including sub-code data related to the first-group data. A synthesizing unit synthesizes the first-group data and the second-group data such that they are continuous without any space disposed therebetween, on each of two sub-tracks formed with a gap sandwiched therebetween on a track in the magnetic tape. A sending unit sends data synthesized by the synthesizing unit to the rotating head in order to record the data on the magnetic tape.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to magnetic-tape recording apparatuses and methods, magnetic-tape formats, and recording media, and more particularly, to a magnetic-tape recording apparatus and method, a magnetic-tape format, and a recording medium which allow high-quality video data to be recorded into a magnetic tape.

2. Description of the Related Art

Compression technologies have been advancing these days. Video data is compressed, for example, by a Digital Video (DV) method and recorded into a magnetic tape. The format therefor is specified as a DV format for commercial digital video tape recorders.

FIG. 1shows the structure of one track in the conventional DV format. In the DV format, 24-to-25 conversion is first applied to video data, and then the data is recorded. The number of bits in each portion shown inFIG. 1is obtained after 24-to-25 conversion.

The substantial zone of one track corresponds to a wrapping angle of 174 degrees of a magnetic tape. An overwrite margin 1,250 bits long is formed outside the zone of the track. The overwrite margin is for preventing data to be deleted from remaining after deletion.

The length of the zone of one track is 134,975 bits when a rotating head is rotated at a frequency of 60×1000/1001 Hz, and is 134,850 bits when the rotating head is rotated at 60 Hz.

In a track, an insert-and-track-information (ITI) sector, an audio sector, a video sector, and a sub-code sector are sequentially disposed in a direction in which the rotating head traces (in the direction from the left to the right inFIG. 1). A gap G1is formed between the ITI sector and the audio sector, a gap G2is formed between the audio sector and the video sector, and a gap G3is formed between the video sector and the sub-code sector.

The ITI sector is 3,600 bits long. At the beginning therefor, a pre-amble 1,400 bits long used for generating a clock is formed. A start sync area (SSA) and a track information area (TIA) are next formed with a length of 1,920 bits. The SSA has a bit string (sync number) required for detecting the TIA position. The TIA includes information indicating a commercial DV format, information indicating an SP mode or an LP mode, and information indicating the pattern of a pilot signal in one frame. A post-amble 280 bits long is disposed next to the TIA.

The audio sector is 11,550 bits long. A pre-amble is disposed at the first 400 bits thereof, and a post-amble is disposed at the last 500 bits thereof. Data (audio data) is disposed at the area therebetween, which is 10,650 bits long.

The video sector is 113,225 bits long. A pre-amble is disposed at the first 400 bits thereof, and a post-amble is disposed at the last 925 bits thereof. Data (video data) is disposed at the area therebetween, which is 111,900 bits long.

The sub-code sector is 3,725 bits long when the rotating head is rotated at a frequency of 60×1000/1001 Hz, and is 3,600 bits long when the rotating head is rotated at 60 Hz. A pre-amble is disposed at the first 1,200 bits thereof, and a post-amble is disposed at the last 1,325 bits (when the rotating head is rotated at a frequency of 60×1000/1001 Hz) or at the last 1,200 bits (when the rotating head is rotated at 60 Hz) thereof. Data (sub-code) is disposed at the area therebetween, which is 1,200 bits long.

In the DV format, the gaps G1to G3are formed between the ITI sector, the audio sector, the video sector, and the sub-code sector as described above, and in addition, a preamble and a post-amble are formed in each sector. Therefore, so-called overheads are long and a sufficient recording rate cannot be obtained for substantial data.

To record high-quality video data (hereinafter called high-definition (HD) video data), for example, a bit rate of about 25 Mbps is required. In the conventional recording method, the video rate corresponding to an MP@HL Moving Picture Expert Group (MPEG) method is at most about 24 Mbps except for the rate of search-image data. As a result, standard-quality video data (hereinafter called standard-definition (SD) video data) can be recorded, but it is impossible to compress and record HD video data by the MP@HL or an MP@H-14 method.

SUMMARY OF THE INVENTION

The present invention has been made in consideration of the above conditions. Accordingly, it is an object of the present invention to allow HD data to be recorded and reproduced.

The foregoing object is achieved in one aspect of the present invention through the provision of a magnetic-tape recording apparatus for recording digital data on a magnetic tape by a rotating head, including first obtaining means for obtaining first-group data, including video data, audio data, or search data; second obtaining means for obtaining second-group data, including sub-code data related to the first-group data; synthesizing means for synthesizing the first-group data and the second-group data such that they are continuous without any space disposed therebetween, on each of two sub-tracks formed with a gap sandwiched therebetween on a track in the magnetic tape; and sending means for sending data synthesized by the synthesizing means to the rotating head in order to record the data on the magnetic tape.

The video data may be high-quality video data compressed by an MP@HL or MP@H-14 method.

The synthesizing means may synthesize information indicating the type of the video signal recorded into the track such that the information indicating the type of the video signal is recorded before the first-group data in each sub-track.

The foregoing object is achieved in another aspect of the present invention through the provision of a magnetic-tape recording method for a magnetic-tape recording apparatus for recording digital data on a magnetic tape by a rotating head, including a first obtaining step of obtaining first-group data, including video data, audio data, or search data; a second obtaining step of obtaining second-group data, including sub-code data related to the first-group data; a synthesizing step of synthesizing the first-group data and the second-group data such that they are continuous without any space disposed therebetween, on each of two sub-tracks formed with a gap sandwiched therebetween on a track in the magnetic tape; and a sending step of sending data synthesized by a process in the synthesizing step to the rotating head in order to record the data on the magnetic tape.

The foregoing object is achieved in still another aspect of the present invention through the provision of a recording medium storing a computer-readable program for controlling a magnetic-tape recording apparatus which records digital data on a magnetic tape by a rotating head, the program including a first obtaining step of obtaining first-group data, including video data, audio data, or search data; a second obtaining step of obtaining second-group data, including sub-code data related to the first-group data; a synthesizing step of synthesizing the first-group data and the second-group data such that they are continuous without any space disposed therebetween, on each of two sub-tracks formed with a gap sandwiched therebetween on a track in the magnetic tape; and a sending step of sending data synthesized by a process in the synthesizing step to the rotating head in order to record the data on the magnetic tape.

The foregoing object is achieved in yet another aspect of the present invention through the provision of a format of a magnetic tape into which digital data is recorded by a rotating head, wherein first-group data, including video data, audio data, or search data, and second-group data, including sub-code data related to the first-group data, are disposed such that they are continuous without any space disposed therebetween, on each of two sub-tracks formed with a gap sandwiched therebetween on a track in the magnetic tape.

In the magnetic-tape recording apparatus, the magnetic-tape recording method, the program stored in the recording medium, and the magnetic-tape format according to the present invention, the first-group data and the second-group data are disposed such that they are continuous without any space disposed therebetween, on each of two sub-tracks formed with a gap sandwiched therebetween on a track in a magnetic tape.

The foregoing object is achieved in still yet another aspect of the present invention through the provision of a magnetic-tape recording apparatus for recording digital data on a magnetic tape by a rotating head, including first obtaining means for obtaining first-group data, including video data, audio data, or search data; second obtaining means for obtaining second-group data, including sub-code data related to the first-group data; third obtaining means for obtaining third-group data, including audio data for after-recording; synthesizing means for synthesizing the first-group data and the second-group data such that they are continuous without any space disposed therebetween and for synthesizing the third-group data so as to form a gap between the third-group data and the first-group data, on a track in the magnetic tape; and sending means for sending data synthesized by the synthesizing means to the rotating head in order to record the data on the magnetic tape.

The video data may be high-quality video data compressed by an MP@HL or MP@H-14 method.

The foregoing object is achieved in a further aspect of the present invention through the provision of a magnetic-tape recording method for a magnetic-tape recording apparatus for recording digital data on a magnetic tape by a rotating head, including a first obtaining step of obtaining first-group data, including video data, audio data, or search data; a second obtaining step of obtaining second-group data, including sub-code data related to the first-group data; a third obtaining step of obtaining third-group data, including audio data for after-recording; a synthesizing step of synthesizing the first-group data and the second-group data such that they are continuous without any space disposed therebetween and of synthesizing the third-group data so as to form a gap between the third-group data and the first-group data, on a track in the magnetic tape; and a sending step of sending data synthesized by a process in the synthesizing step to the rotating head in order to record the data on the magnetic tape.

The foregoing object is achieved in a still further aspect of the present invention through the provision of a recording medium storing a computer-readable program for controlling a magnetic-tape recording apparatus which records digital data on a magnetic tape by a rotating head, the program including a first obtaining step of obtaining first-group data, including video data, audio data, or search data; a second obtaining step of obtaining second-group data, including sub-code data related to the first-group data; a third obtaining step of obtaining third-group data, including audio data for after-recording; a synthesizing step of synthesizing the first-group data and the second-group data such that they are continuous without any space disposed therebetween and of synthesizing the third-group data so as to form a gap between the third-group data and the first-group data, on a track in the magnetic tape; and a sending step of sending data synthesized by a process in the synthesizing step to the rotating head in order to record the data on the magnetic tape.

The foregoing object is achieved in a yet further aspect of the present invention through the provision of a format of a magnetic tape into which digital data is recorded by a rotating head, wherein, on a track in the magnetic tape, first-group data, including video data, audio data, or search data, and second-group data, including sub-code data related to the first-group data, are recorded such that they are continuous without any space disposed therebetween, and third-group data, including audio data for after-recording, is recorded such that a gap is formed between the third-group data and the first-group data.

In the magnetic-tape recording apparatus, the magnetic-tape recording method, the program stored in the recording medium, and the magnetic-tape format according to the present invention, the first-group data and the second-group data are recorded such that they are continuous without any space disposed therebetween, and the third-group data is recorded such that a gap is formed between the first-group data and the third-group data.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 2shows an example structure of a recording system of a magnetic-tape recording and reproduction apparatus to which the present invention is applied. An MPEG-method recording-signal processing section2compresses an input HD video signal by an MPEG method, such as an MP@HL or MP@H-14 method, and also compresses HD audio signal corresponding to the HD video signal, for example, by an MPEG audio compression method. A controller11inputs HD system data formed of auxiliary (AUX) data, sub-code data, and others to the MPEG-method recording-signal processing section2.

The MPEG-method recording-signal processing section2also appropriately selects compressed video data, compressed audio data, and system data at a predetermined timing, adds an error detecting and correcting code and an ID, applies interleaving processing to 8 tracks (16 sub-tracks), and outputs to a 24-to-25 conversion section4through a switch3.

A digital-8-method recording-signal processing section1compresses an SD video signal and SD audio signal corresponding thereto by a method specified by a digital-8 format. The digital-8-method recording-signal processing section1appropriately selects compressed SD video data, compressed SD audio data, and SD system data corresponding to the signals, adds an error-correcting code and an ID, and outputs to the 24-to-25 conversion section4through the switch3.

The 24-to-25 conversion section4adds one redundant bit selected so as to enhance a pilot signal for tracking to convert data input in units of 24 bits to 25-bit data.

A sync and ITI generating section5generates sync data to be added to main data (FIG. 7) or to a sub code (FIG. 8), described later, and generates amble data.

A switch6is controlled by the controller11to select the output of the 24-to-25 conversion section4or the output of the sync and ITI generating section5and to output to a modulation section7. The modulation section7modulates data input through the switch6by a method (the same method as for the digital-8 format) appropriate for recording into a magnetic tape21, and outputs to a parallel-to-serial (P/S) conversion section8.

The parallel-to-serial conversion section8converts input data from parallel data to serial data. An amplifier9amplifies data input from the parallel-to-serial conversion section8, and sends it to a rotating head10mounted to a rotating drum (not shown) and rotated, to record into the magnetic tape21.

FIG. 3shows the format of tracks formed by the rotating head10on the magnetic tape21. The rotating head10traces on the magnetic tape21in the direction from the bottom right to the top left in the figure to form tracks at an angle against the longitudinal direction of the magnetic tape21. The magnetic tape21is moved in the direction from the right to the left in the figure.

Each track is F0, F1, or F2according to the type of a pilot signal recorded therein for tracking control. Tracks are formed in the order of F0, F1, F0, F2, F0, F1, F0, and F2.

In a track F0, neither a pilot signal having a frequency of f1nor that having a frequency of f2is recorded. In contrast, a pilot signal having a frequency of f1is recorded in a track F1, and a pilot signal having a frequency of f2is recorded in a track F2.

A track pattern having these frequency characteristics is the same as that in the digital-8 format. Therefore, a magnetic tape, a rotating head, a driving system, a demodulation system, and a control system for digital-8 commercial digital video tape recorders can be used in the present embodiment as they are.

A tape speed and a track pitch used in the present embodiment are the same as those used for the digital-8 format.

Each track is divided into two sub-tracks, and an inter-track gap (ITG) is formed between the sub-tracks.

FIG. 4shows an example sector arrangement of each track. InFIG. 4, the number of bits indicates the length of each part, obtained after the 24-to-25 conversion. The length of one track is 274,624.35 bits when the rotating head10is rotated at a frequency of 60×1000/1001 Hz, and is 274,350 bits when the rotating head10is rotated at 60 Hz. The length of one track corresponds to a wrapping angle of 177 degrees of the magnetic tape21. An ITG is formed thereafter.

The length of each sub-track is 134,975 bits when the rotating head10is rotated at a frequency of 60×1000/1001 Hz, and is 134,850 bits when the rotating head10is rotated at 60 Hz. The length of an ITG is 4,674.35 bits when the rotating head10is rotated at a frequency of 60×1000/1001 Hz, and is 4,650 bits when the rotating head10is rotated at 60 Hz.

This format is the same as the digital-8 format.

FIG. 5shows a detailed example structure of sectors inside two sub-tracks (sub-track A and sub-track B).

InFIG. 5, the rotating head10traces on a track in the direction from the left to the right. At the beginning of each sub-track, a preamble 1,800 bits long is disposed. In this preamble, data required to generate a clock, such as that obtained by combining a pattern A and a pattern B shown inFIG. 6, is recorded. The pattern A has a 0-and-1 pattern reversed to that of the pattern B. Tracking patterns for tracks F0, F1, and F2are made by appropriately combining the patterns. Run patterns shown inFIG. 6are those obtained after the 24-to-25 conversion section4shown inFIG. 2applies 24-to-25 conversion.

After the preamble having 1,800 bits, a main sector 130,425 bits long is disposed.FIG. 7shows the structure of the main sector.

As shown in the figure, the main sector is formed of 141 sync blocks. Each sync block is 888 bits (111 bytes) long.

In each of 123 sync blocks, a 16-bit sync, a 24-bit ID, an 8-bit sync-block (SB) header, 760-bit main data, and a 80-bit parity C1are disposed. The sync is generated by the sync and ITI generating section5. The ID is added by the MPEG-method recording-signal processing section2. The SB header includes identification information for identifying the type of the main data, such as audio data, video data, search video data, transport-stream data, and AUX data. The controller11sends the header data as a kind of system data.

The parity C1is calculated by using the ID, the header, and the main data in each sync block and added by the MPEG-method recording-signal processing section2.

Each of 18 sync blocks among the 141 sync blocks includes a sync, an ID, a parity C2, and a parity C1. The parity C2is obtained by calculating the headers or the main data in the vertical direction inFIG. 7. This calculation is performed by the MPEG-method recording-signal processing section2.

The total amount of data in the main sector is 888 bits ×141 sync blocks=125,208 bits. The total amount of data is 130,425 bits after the 24-to-25 conversion. The substantial maximum data rate is 760 bits×123 sync blocks×10 tracks×30 Hz=28.044 Mbps when the rotating head10is rotated at 60 Hz if 10 sub-tracks are formed in one frame in average. This bit rate is sufficient for recording HD video data, compressed audio data, AUX data and search video data by the MP@HL or MP@H-14 method.

After the main sector, a sub-code sector 1250 bits long is disposed.FIG. 8shows the structure of the sub-code sector.

The sub-code sector in one sub-track is formed of 10 sub-code sync blocks. One sub-code sync block is formed of a sync, an ID, sub-code data, and a parity.

At the beginning of each sub-code sync block in the sub-code sector 1250 bits long (after the 24-to-25 conversion) shown inFIG. 8, a 16-bit sync is disposed, whose length is obtained before 24-to-25 conversion. A 24-bit ID is disposed thereafter. The sync is added by the sync and ITI generating section5. The ID is added by the MPEG-method recording-signal processing section2.

After the ID code, 40-bit sub-code data is disposed. This sub-code data is sent from the controller11, and includes, for example, a track number and a time-code number. After the sub-code data, a 40-bit parity is added. The parity is added by the MPEG-method recording-signal processing section2.

24-to-25 conversion is applied to the data of the sub-code sync block, which is 120 bits long before 24-to-25 conversion, and the data has 125 bits (=120×25/24).

After the sub-code sector, a post-amble is disposed. The post amble is also recorded by combining the pattern A and the pattern B shown inFIG. 6. Its length is 1,500 bits when a synchronization is achieved at 60×1000/1001 Hz, and is 1,375 bits when a synchronization is achieved at 60 Hz.

Both the sub-track A and the sub-track B have the sector structure described above. An ITG, which serves as a gap to separate the sub-tracks, is disposed between the two sub-tracks.

The operation of the apparatus shown inFIG. 2will be described next. An HD video signal is compressed together with search video data (thumbnail video data) by the MPEG-method recording-signal processing section2, for example, by the MP@HL or MP@H-14 method. An audio signal is also compressed. HD system data, such as sub-code data, AUX data, and a header, is also sent from the controller11to the MPEG-method recording-signal processing section2.

The MPEG-method recording-signal processing section2obtains compressed video data (including search video data), compressed audio data, or system data at a predetermined timing, and synthesizes the data.

The MPEG-method recording-signal processing section2adds a 24-bit ID to each sync block shown inFIG. 7in the main sector. The MPEG-method recording-signal processing section2also calculates and adds a parity C1shown inFIG. 7for and to each sync block, and adds a parity C2to each of 18 sync blocks among the 141 sync blocks, instead of the header and main data.

In addition, as shown inFIG. 8, the MPEG-method recording-signal processing section2adds a 24-bit ID to each sub-code sync block in the sub-code sector, and calculates and adds a 40-bit parity.

Further, the MPEG-method recording-signal processing section2records identification information indicating that data being recorded is that compressed by an MPEG method into the ID of the main sector shown inFIG. 7and into the ID of the sub-code sector shown inFIG. 8.

Furthermore, the MPEG-method recording-signal processing section2holds data for 16 sub-tracks, and applies interleaving to the data within the 16 sub-tracks.

The 24-to-25 conversion section4converts data sent from the MPEG-method recording-signal processing section2through the switch3in units of 24 bits to 25-bit data. With this conversion, the pilot signals for tracking having frequencies of f1and f2have large magnitudes.

The sync and ITI generating section5adds a 16-bit synchronizing data (sync) to each sync block in the main sector, as shown inFIG. 7. The sync and ITI generating section5also adds 16-bit synchronizing data (sync) to each sub-code sync block in the sub-code sector, as shown inFIG. 8. In addition, the sync and ITI generating section5generates a run pattern (a combination of the pattern A and the pattern B) for a pre-amble or a post-amble shown inFIG. 6.

More specifically, the foregoing data is added (synthesized) when the controller11switches the switch6to selectively send the data output from the sync and ITI generating section5and the data output from the 24-to-25 conversion section4to the modulation section7.

The modulation section7modulates input data by a method corresponding to the digital-8 format, and outputs to the parallel-to-serial conversion section8. The parallel-to-serial conversion section8converts input data from parallel data to serial data, and sends it to the rotating head10through the amplifier9. The rotating head10records input data into the magnetic tape21.

When recording an SD video signal is instructed, the controller11switches the switch3to the side of the digital-8-method recording-signal processing section1. As a result, an SD video signal, an SD audio signal, and SD system data processed by the digital-8-method recording-signal processing section1are sent to the 24-to-25 conversion section4through the switch3. And then, in the same way as that described above, the signals and the data are recorded into the magnetic tape21.

FIG. 9shows an example structure of a reproduction system for reproducing data recorded into the magnetic tape21as described above.

The rotating head10reads data recorded into the magnetic tape21, and outputs it to an amplifier41. The amplifier41amplifies an input signal, and sends it to an A/D conversion section42. The A/D conversion section42converts an input signal from an analog signal to a digital signal, and sends it to a demodulation section43. The demodulation section43demodulates data sent from the A/D conversion section42by a method corresponding to the modulation method used by the modulation section7.

An ID detecting section44detects from data demodulated by the demodulation section43an ID in each sync block of the main sector shown inFIG. 7and an ID in each sub-code sync block in the sub-code sector shown inFIG. 8, and switches a switch46correspondingly to identification information included therein to the side of a digital-8-method reproduction-signal processing section47, or the side of an MPEG-method reproduction-signal processing section48. A 25-to-24 conversion section45converts data sent from the demodulation section43from 25-bit data to 24-bit data correspondingly to the conversion performed by the 24-to-25 conversion section4.

The operation of the reproduction system will be described next. The rotating head10reads data recorded into the magnetic tape21, and the amplifier41amplifies it and sends it to the A/D conversion section42. The A/D conversion section42converts an input analog signal to a digital signal, and sends it to the demodulation section43. The demodulation section43demodulates input data by a method corresponding to the modulation method used by the modulation section7shown inFIG. 2.

The output of the A/D conversion section42is also sent to a servo circuit (not shown). The data (FIG. 6) of the pattern A and the pattern B recorded in the pre-amble and the post-amble are read in the servo circuit to generate pilot signals for tracking, and tracking control is executed.

The 25-to-24 conversion section45converts data demodulated by the demodulation section43from 25-bit data to 24-bit data.

The ID detecting section44detects from data output from the demodulation section43identification information included in IDs in the main sector shown inFIG. 7or IDs in the sub-code sector shown inFIG. 8. According to the result of identification, when data being read is the data of an HD video signal, the ID detecting section44switches the switch46to the side of the MPEG-method reproduction-signal processing section48, and sends data output from the 25-to-24 conversion section45to the MPEG-method reproduction-signal processing section48. When data being read is the data of a digital-8-method SD video signal, the switch46is switched to the upper side inFIG. 9, and the data output from the 25-to-24 conversion section45is sent to the digital-8-method reproduction-signal processing section47.

The MPEG-method reproduction-signal processing section48stores data for 16 tracks, applies deinterleaving, and achieves error-correcting processing with the use of the parities C1and C2of the main sector shown inFIG. 7. The MPEG-method reproduction-signal processing section48also detects an SB header in the main sector to determine whether data included in each sync block is audio data, video data, AUX data, or search video data.

In addition, the MPEG-method reproduction-signal processing section48uses a parity of the sub-code sector shown inFIG. 8to apply error-correcting processing to sub-code data, and detects an ID to determine the type of the sub-code data. With this operation, it is determined whether the sub-code data indicates a track number or a time-code number.

The MPEG-method reproduction-signal processing section48decompresses video data by a method corresponding to the compression method used by the MPEG-method recording-signal processing section2shown inFIG. 2, and outputs as a video signal.

In the same way, audio data is decompressed by a method corresponding the compression method used by the MPEG-method recording-signal processing section2shown inFIG. 2, and output as an audio signal.

The MPEG-method reproduction-signal processing section48outputs AUX data and sub-code data which have been error-corrected, to the controller11.

The digital-8-method reproduction-signal processing section47decompresses data input through the switch46by the digital-8 method, and output as an SD video signal and an SD audio signal. SD system data corresponding thereto is sent to the controller11.

FIG. 10shows another example arrangement of sectors in a track. Also in this case, one track is divided into two sub-tracks. The length of each sub-track and that of an ITG disposed between sub-tracks are the same as those shown inFIG. 5.

InFIG. 10, the rotating head10traces on a track in the direction from the left to the right. At the beginning of each sub-track, an ITI sector 3,600 bits long, having the same format as the ITI sector of the DV format shown inFIG. 1is disposed. At the beginning of the ITI sector, an ITI pre-amble 1,400 bits long is disposed. An ITI pre-amble has data shown inFIG. 11in a track F0, has data shown inFIG. 12in a track F1, and has data shown inFIG. 13in a track F2.

Following the ITI pre-amble, an SSA 1,830 bits long is disposed. An SSA has data shown inFIG. 14in a track F0, has data shown inFIG. 15in a track F1, and has data shown inFIG. 16in a track F2.

The start of a TIA, following the SSA, is detected by using the SSA.

Following the SSA, an TIA 90 bits long is disposed. The TIA is formed of three sync blocks. Each sync block is formed of 30 bits, b29to b0, as shown inFIG. 17. The three sync blocks have the same data. Therefore, the same data is substantially recorded in the TIA three times.

By APT2, APT1, and APT0, the type of data recorded in a track is indicated in the DV format, as shown inFIG. 19. For example, when APT2, APT1, and APT0are all zero, it means that data for commercial digital video cassette recorders is recorded in the track, that is, data having the DV format is recorded. When APT2, APT1, and APT0are all 1, it means that data has not been recorded in the track. Therefore, when it is determined that APT2, APT1, and APT0are all 1, a magnetic-tape recording and reproduction apparatus for the DV format substantially operates so as not to read data from the magnetic tape.

In the present embodiment, as shown inFIG. 18, 1's are recorded in APT2, APT1, and APT0. As a result, when a magnetic-tape reproduction apparatus for the DV format attempts to read the magnetic tape21shown inFIG. 2, reading is not executed. In contrast, when a magnetic-tape recording and reproduction apparatus for recording and reproducing the data of an HD video signal reads the magnetic tape21, if it is determined that APT2, APT1, and APT0have all 1's, reading processing is executed for the magnetic tape since it is deemed that the data of an HD video signal has been recorded.

As shown inFIG. 18, TP1is recorded in bits b22and b23, and TP0is recorded in bits b24and b25. In the DV format, when TP1is 1 and TP0is 1, it means that the track pitch is set to track pitch 0 for the SP mode; when TP1is 1 and TP0is 0, it means that the track pitch is set to track pitch 1 for the LP mode; when TP1is 0 and TP0is 1, it means that the track pitch is set to track pitch 2; and when TP1is 0 and TP0is 0, it means that the track pitch is set to track pitch 3. In the present invention, TP1and TP0have the same meaning as in the DV format.

In the case shown inFIG. 18, since TP1is 1 and TP0is 1, it is specified that the SP mode has been selected.

PF0is recorded in a bit b26, and PF1is recorded in a bit b27. PF0and PF1indicate a pilot frame; a value of 0 indicates pilot frame0; and a value of 1 indicates pilot frame1. Pilot frame0means that a track F0and a track F1are disposed in that order as the first two tracks in 10 tracks constituting one frame. Pilot frame1means that a track F0and a track F2are disposed in that order.

In other words, as described by referring toFIG. 3, tracks are formed in the order of F0, F1, F0, F2, F0, F1, F0, and F2. In the commercial DV format, since one frame is formed of 10 tracks, when first two tracks are formed as a track F0and a track F1in a predetermined frame, the first two tracks of the next frame are formed as a track F0and a track F2. The pilot frame indicates which track pattern is used in a frame.

The TIA having three sync blocks (90 bits long), each sync block being formed of the bits b29to b0shown inFIG. 17, has data shown inFIG. 20in a track F0, has data shown inFIG. 21in a track F1, and has data shown inFIG. 22in a track F2.

Following the TIA, as shown inFIG. 10, a post-amble280bits long is disposed. This post-amble has data shown inFIG. 23in a track F0, has data shown inFIG. 24in a track F1, and has data shown inFIG. 25in a track F2.

The foregoing ITI-sector data is generated by the sync and ITI generating section5.

After the post-amble having 280 bits in the ITI sector, a main sector 128,575 bits long is disposed.FIG. 26shows the structure of the main sector.

As shown in the figure, the main sector is formed of 139 sync blocks. Each sync block is 888 bits (111 bytes) long.

In each of 121 sync blocks, a 16-bit sync, a 24-bit ID, an 8-bit sync-block (SB) header, 760-bit main data, and a 80-bit parity C1are disposed. The sync is generated by the sync and ITI generating section5. The ID is added by the MPEG-method recording-signal processing section2. The SB header includes identification information for identifying the type of the main data, such as audio data, video data, search video data, transport-stream data, and AUX data. The controller11sends the SB-header data as a kind of system data.

The parity C1is calculated by using the ID, the SB header, and the main data in each sync block and added by the MPEG-method recording-signal processing section2.

Each of 18 sync blocks among the 139 sync blocks includes a sync, an ID, a parity C2, and a parity C1. The parity C2is obtained by calculating the SB headers or the main data in the vertical direction inFIG. 26. This calculation is performed by the MPEG-method recording-signal processing section2.

The total amount of data in the main sector is 888 bits×139 sync blocks=123,432 bits. The total amount of data is 128,575 bits after the 24-to-25 conversion. The substantial maximum data rate is 760 bits×121 sync blocks×10 tracks×30 Hz=27.588 Mbps when the rotating head10is rotated at 60 Hz if 10 sub-tracks are formed in one frame in average. This bit rate is sufficient for recording HD video data, compressed audio data, AUX data and search video data by the MP@HL or MP@H-14 method.

After the main sector, a sub-code sector 1,250 bits long is disposed. The structure of the sub-code sector is the same as that shown inFIG. 5(FIG. 8).

After the sub-code sector, a post-amble is disposed. The data of the pattern A and the pattern B shown inFIG. 6, required for generating a clock, is combined and recorded in the post-amble in the same way as in the pre-amble.

FIG. 27shows still another example structure of tracks. In the case shown inFIG. 27, interleaving is applied to 16 tracks. In this example structure, tracks are not divided into sub-tracks and are used as they are.FIG. 28shows a detailed sector structure in a track.

As shown in the figure, at the beginning of the track, a pre-amble 2,000 bits long is disposed. In this pre-amble, data obtained by combining the pattern A and the pattern B shown inFIG. 6is recorded.

After the pre-amble, a main sector 269,175 bits long is disposed.FIG. 29shows the structure of the main sector.

The basic structure thereof is the same as in the case shown inFIG. 7. One track is formed of 291 sync blocks. Among them, main data is disposed in 254 sync blocks, and a parity C2is disposed in each of the remaining 37 sync blocks.

In this case, the maximum recording data rate is 760 bits×254 sync blocks×5 tracks×30 Hz (frame) 28.956 Mbps at 60-Hz synchronization.

FIG. 30shows another example structure of sectors in the track formed as shown inFIG. 27. In this example structure, an ITI sector 3,600 bits long is disposed at the beginning. The structure of the ITI sector is the same as that shown inFIG. 10. An ITI pre-amble 1,400 bits long, an SSA 1,830 bits long, a TIA 90 bits long, and an ITI post-amble 280 bits long are disposed.

After the ITI sector, a main sector 267,325 bits long is disposed.FIG. 31shows the structure of the main sector.

As shown in the figure, basically, the structure of the main sector is also the same as in the case shown inFIG. 7. One track is formed of 289 sync blocks. Among them, main data is disposed in 252 sync blocks, and a parity C2is disposed in each of the remaining 37 sync blocks.

Therefore, in this case, the maximum recording data rate is 720 bits×252 sync blocks×5 tracks×30 Hz (frame)=28.728 Mbps at 60-Hz synchronization.

After the main sector, a sub-code sector 1,250 bits long is disposed. The structure of the sub-code sector is the same as that shown inFIG. 8.

After the sub-code sector, a post-amble 2449.35 bits long is disposed. The length thereof is 2,175 bits at 30-Hz synchronization. Data obtained by combining the pattern A and the pattern B is recorded in the post-amble in the same way as in the case shown inFIG. 6.

FIG. 32shows yet another example structure of sectors in the track formed as shown inFIG. 27. In this example structure, an ITI sector 3,600 bits long is disposed at the beginning. The structure of the ITI sector is the same as that shown inFIG. 10andFIG. 30.

Following the ITI sector, an audio sector for after-recording 13,850 bits long is disposed through a gap G1625 bits long. The audio sector for after-recording is formed of a 400-bit pre-amble, a 12,950-bit data section, and a 500-bit post-amble. In the data section 12,950 bits long, audio data for after-recording is disposed.

In other words, in the cases which have been described so far, video data, audio data, or AUX data is selectively disposed in the main sector, and a sub-code sector is disposed so as to follow the main sector (without a gap therebetween). Therefore, in the cases, after-recording is basically difficult to achieve. In the case shown inFIG. 32, however, since gaps are formed, after-recording is made possible.

After the audio sector for after-recording, a main sector 250,150 bits long is disposed through a gap G2700 bits long. At the beginning of the main sector, a 400-bit pre-amble is disposed, followed by a data section 248,825 bits long, and then, followed by a 925-bit post-amble.

In the data section, video data, audio data not for after-recording, and AUX data are selectively disposed.

After the main sector, a sub-code sector 4149.35 bits long is disposed through a gap G31,550 bits long. The length of the sub-code sector is 3,650 bits at a 30-Hz synchronization.

At the beginning of the sub-code sector, a 1,200-bit pre-amble is disposed. And then, a 1,250-bit data section is disposed, and a post-amble is formed, which is 1699.35 bits long when the rotating head is synchronized at 60×1000/1001 Hz, and which is 1,425 bits long when the rotating head is synchronized at 60 Hz. Sub-codes are disposed in the 1,250-bit data section.

FIG. 33shows the structure of the data section for audio data for after-recording. One track has 14 sync blocks. Among them, six sync blocks include audio data for after-recording. Each of the remaining eight sync blocks has a parity C2. Therefore, the maximum recording data rate is 720 bits×6 sync blocks×5 tracks×30 Hz (frame)=684 Kbps at a 60-Hz synchronization.

FIG. 34shows the structure of the data section in the main sector. One track includes 269 sync blocks. Among them, 235 sync blocks have main data. Each of the remaining 34 sync blocks has a parity C2.

In this case, the maximum recording rate is 760 bits×235 sync blocks×5 tracks×30 Hz (frame)=26.790 Mbps at a 60-Hz synchronization.

In the above embodiments, as the components in the recording system shown inFIG. 2except the MPEG-method recording-signal processing section2, more specifically, as the digital-8-method recording-signal processing section1, the 24-to-25 conversion section4, the sync and ITI generating section5, the modulation section7, the parallel-to-serial conversion section8, the rotating head10, and the magnetic tape21, the same circuit devices as those used in the digital-8 method can be used. In the same way, as the components in the recording system shown inFIG. 9except the MPEG-method reproduction-signal processing section48, more specifically, as the amplifier41, the analog-to-digital conversion section42, the demodulation section43, the ID detecting section44, the 25-to-24 conversion section45, and the digital-8-method reproduction-signal processing section47, the same circuit devices as those used for the digital-8 format can be used. Therefore, an apparatus which allows not only an SD video signal but also an HD video signal to be recorded and to be reproduced is implemented at a low cost.

The above-described series of processing can be executed by software as well as by hardware. When the series of processing is achieved by software, a program constituting the software is installed from a recording medium to a computer built in a special hardware, or to a unit which can execute various functions after various programs are installed therein, such as a general-purpose personal computer.

The recording medium can be a package medium which stores the program and is distributed for providing the users with the program, separately from a magnetic-tape recording and reproduction apparatus, as shown inFIG. 2andFIG. 9, such as a magnetic disk31(including a floppy disk), an optical disk32(including a compact disk-read only memory (CD-ROM) and a digital versatile disk (DVD)), a magneto-optical disk33(including a Mini disk (MD)), or a semiconductor memory34. The recording medium can also be a device which stores the program and is provided for the users in a state in which it is built in an apparatus in advance, such as a ROM or a hard disk.

In the present specification, steps describing the program stored in a recording medium include processes performed in a time sequential manner in the order in which they are described, and in addition, include processes which are not necessarily performed in a time sequential manner but executed in parallel or independently.

As described above, according to a magnetic-tape recording apparatus, a magnetic-tape recording method, and a program stored in a recording medium of the present invention, first-group data and second-group data are synthesized such that they are continuous without any space disposed therebetween on each of two sub-tracks formed with a gap disposed therebetween on a track in a magnetic tape and recorded into the magnetic tape. Therefore, a large amount of data, typical of which is the data of an HD video signal, can be recorded on the magnetic tape in a digital manner.

According to a magnetic-tape format of the present invention, first-group data and second-group data are recorded such that they are continuous without any space disposed therebetween on each of two sub-tracks formed with a gap disposed therebetween. Therefore, a magnetic tape in which a large amount of data, typical of which is the data of an HD video signal, is recorded can be implemented.

According to a magnetic-tape recording apparatus, a magnetic-tape recording method, and a program stored in a recording medium of the present invention, first-group data and second-group data are synthesized such that they are continuous without any space disposed therebetween on a track in a magnetic tape, and third-group data is synthesized such that a gap is formed between the first-group data and the third-group data. Therefore, a large amount of data, typical of which is the data of an HD video signal, can be recorded on the magnetic tape in a digital manner.

According to a magnetic-tape format of the present invention, first-group data and second-group data are recorded such that they are continuous without any space disposed therebetween, and third-group data is recorded such that a gap is formed between the first-group data and the third-group data. Therefore, an HD video signal can be recorded, and after-recording of audio data is allowed.