JP3298307B2 - Moving image recording device and playback device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system apparatus for recording and reproducing moving images (information) compressed and encoded on a medium (for example, a tape-shaped recording medium) such as a digital VTR. The present invention relates to a recording device and a reproducing device that support special reproduction such as high-speed image search.

[0002]

[Prior art]

<High-speed search in digital VTR> A special playback such as a high-speed search is required in a VTR (video tape recorder), and in particular, a high-speed image search (hereinafter, referred to as 5 to 50 times the original reproduction speed (standard speed)). High-speed search) is an essential function. In the case of this high-speed search, the track of the helical scan recording is read obliquely, and a part of the image is obtained in a fragmented state. In an analog VTR, one screen is divided and displayed as a result.

On the other hand, digital VTRs use high-efficiency coding, in which information compression is performed using variable-length codes. In this case, since the recording position on the tape and the position of the image signal on the screen are not synchronized, the position of the data obtained by the search on the screen fluctuates and becomes extremely difficult to see.

Therefore, a method has been considered in which information dedicated to high-speed image search is separately recorded at a predetermined position on a tape. For example, a predetermined number of positions in the track direction are set as recording positions of high-speed image search information, and the same information is repeatedly recorded there, for example, over 10 tracks. in this case,
In the case of a high-speed search up to 10 times, any one of the 10 tracks is always read, so that all the information dedicated to the high-speed search can be obtained, and a high-speed search of a complete frame or field (hereinafter, representatively described as a frame) An image is obtained.

At this time, the information dedicated to the high-speed search recorded at a predetermined position on the track is a large amount of data, so that one frame cannot be recorded on one track. Is recorded separately. For example, it is divided into ten and recorded over ten tracks. As a result, if the information is repeatedly recorded over 10 tracks as described above, the information dedicated to the high-speed search for one frame is recorded over 100 tracks.

<Conventional Recording Apparatus> FIG. 3 shows a configuration example of a conventional moving picture recording apparatus. In FIG. 3, the moving image signal given from the image information input 1 has been data-compressed by high-efficiency coding using inter-frame prediction, and is given to the search information forming unit 31. Here, one frame out of 10 to 30 frames is independently encoded in the frame,
This becomes a high-speed search image called an intra frame.

The search information forming unit 31 separates only this intra frame and reduces the amount of information according to the amount of information that can be recorded. If it is difficult to record all the data of one frame, it is processed into only low-frequency information of the image such as a DC component of 8 × 8 pixels, and given to the search memory 3 as high-speed search information. The search memory 3 stores information for one frame and outputs the information to the multiplexer 32 for recording over a plurality of tracks. On the other hand, general information used in normal reproduction is provided from the search information forming unit 31 to the buffer 6. The buffer 6 intermittently reads out general information in accordance with the multiplexing, and supplies the general information to the multiplexer 32.

The multiplexer 32 creates a data stream while switching between general information and high-speed search information, and supplies the data stream to the signal recorder 7. Here, the multiplexing process is performed so that high-speed search information is recorded in a specific portion of a predetermined track. In addition, the same information is repeated from several tracks to several tens of tracks in accordance with the maximum search speed for high-speed search information.

A signal recorder 7 adds an error correction code to a data stream for recording on a medium, modulates the signal into a signal suitable for medium recording, and records moving image information on a recording medium 8. The recording medium 8 is a video tape or the like, in which high-speed search information is recorded in a specific portion of a track, and general information is recorded in other portions.

<Conventional Reproducing Apparatus> FIG. 4 shows a configuration example of a conventional moving picture reproducing apparatus. The signal read from the recording medium 8 in FIG. 4 is demodulated by the signal reproducer 21 and subjected to error correction processing, and the obtained data stream is provided to the search information separator 22. The search information separator 22 determines the type of information from the periodically inserted sector number and the like, and separates the high-speed search information to the search memory 25.

On the other hand, general information is supplied from the search information separator 22 to the buffer 6. Since the general information is used as it is during normal reproduction, the discontinuity of the code due to the separation of the high-speed search information in the buffer 6 is absorbed, and is output from the reproduction output 28 via the switch 41 as continuous information. At the time of high-speed search, general information can obtain only a part of information, but is unnecessary because only high-speed search information is used.

When search information for one frame is prepared in the search memory 25, it is output from the reproduction output 28 via the switch 41 as search information for each frame.
In the high-speed search, only one-third of the search speed is read, but since the same high-speed search information is repeatedly recorded, all the search information can be obtained up to the search speed up to the number of repetitions. .

The switch 41 is connected to the buffer 6 during normal reproduction.
At the time of high-speed search, the output of the search memory 25 is selected and given to the reproduction output 28. Each piece of information output from the playback output 28 is decoded by a decoder built in a television receiver or the like, and is displayed as a playback image.

<Azimuth Recording> When recording on a tape with two heads having different azimuth angles, information cannot be read unless the azimuth of the track and the azimuth of the head match, so the recording method should be adapted to that. I have. Specifically, information is divided for each track of each azimuth angle, and repetitive recording is also performed on tracks of the same azimuth. In some cases, search information is recorded only on one track having an azimuth angle, and reading is performed using only one head.

[0015]

In the conventional method of recording information for high-speed search in which the same information is repeatedly recorded, the same repetitive recording as the magnification of the high-speed search is required. Therefore, at a high search speed, the number of repetitions increases, so that many tracks are required to record information for one frame or one field. As a result, the number of frames of the recorded search image is reduced, and the search reproduction image is likely to be in a frame-dropped state.

The present invention has been made in view of the above points. When a high-speed search image is recorded, a recording position on a track is changed depending on an image portion, and the search information of each divided frame is changed. In addition, by incorporating the information of the other divided frames into the form and integrating and displaying the divided information at the time of high-speed search reproduction, a search image can be obtained even at a high-speed search speed higher than conventionally possible search speed. It is an object of the present invention to provide a moving image recording / reproducing apparatus as described above.

[0017]

According to the present invention, when a moving image is recorded on a medium, high-speed search information of a plurality of frames (or fields) is obtained from input moving image information.
The high-speed search information of each frame (or field) is divided into a plurality of regions based on the position on the screen, and further divided within the region based on the amount of information. The divided information is stored in different frames (or fields) by synchronizing the recording position in one track with each position on the screen.
However, an object of the present invention is to provide a moving image recording apparatus that performs recording in such a manner as to alternately enter every predetermined number of tracks. That is, as shown in FIG. 1, a device for recording high-speed image search information from input moving image information (search information forming unit 2) in a device for recording a compression-encoded moving image on a medium, Means (search memories 3 and 13) for storing high-speed image search information of a frame or a field; and dividing the high-speed image search information of each frame or a field into a plurality of regions based on positions on a screen. Means for dividing the information in each divided area based on the information amount (the divided readout units 4, 1
4) and multiplexing the divided information so that each position on the screen is at a different position in one track, and different frames or fields are alternately recorded every predetermined number of tracks. A moving image recording apparatus comprising: means for obtaining a high-speed image search signal (multiplexer 5); and means for recording the high-speed image search signal at a predetermined position (signal recorder 7). I will provide a.

Further, according to the present invention, when a moving image signal recorded on a medium by the moving image recording apparatus is searched and reproduced at a high speed, a plurality of frames (or fields) of high speed image searching signals are transmitted to a predetermined medium of the medium. Read from the recording position,
It is an object of the present invention to provide a moving image reproducing apparatus that integrates a plurality of screen regions of a plurality of frames (or fields) and forms a high-speed image search image in units of frames (or fields). That is, as shown in FIG. 2, in a device for reproducing a moving image recorded by being compressed and encoded by the moving image recording device described above, means for reading a high-speed image search signal from a predetermined recording position of the medium. (Signal reproducer 21) and means for integrating a plurality of frame or field screen regions from the read high-speed image search signal to form a search image in frame or field units (divided writer 23, 27) , Search memories 24, 28)
And a moving image reproducing apparatus characterized by the following.

[0019]

According to the present invention, the recording position on the track is changed according to the image portion, and the information of the other divided frames (or fields) is interposed between the search information of each divided frame (or field). By recording the search image in a form that fits in, and displaying the divided images integrated during playback, all information can be read as in the conventional example in the case of high-speed search up to the number of repeated recordings. Thus, a high-speed search image similar to the conventional example can be obtained.

On the other hand, if a high-speed search is performed at a speed higher than the search speed (for example, by repetitive recording), a reproduced image is not completed because only half of the information can be obtained with the conventional apparatus. However, according to the present invention, for example, two frames (or fields) are multiplexed by dividing into two and recorded at different positions depending on the image portion. Then, the image portion of the obtained information changes between one frame (or field) and the other frame (or field), and an image for one screen is obtained although the frame (or field) is different. When N frames are further multiplexed into N frames, a search image can be obtained even at N times the conventional search speed.

[0021]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of a moving picture recording apparatus and a reproducing apparatus according to the present invention. <Recording Apparatus 1> FIG. 1 is a block diagram showing a first embodiment of the moving picture recording apparatus. The same components as those in the conventional example of FIG. 3 are denoted by the same reference numerals. 3 is different from the conventional example shown in FIG.
3. The configuration is different in that there are divided readout units 4 and 14. Also, the operations of the search information former 2 and the multiplexer 5 are different.
The basic processing flow in FIG. 1 is the same as that of the conventional example, and only the method of forming the multiplexed signal is different.

FIGS. 5A to 5C show how recording signals are formed by the main moving image recording apparatus. FIG. 1A shows an intra frame used for a search in a moving image information sequence, FIG. 2B shows a divided intra frame, and FIG. 1C shows a state of recording on a tape T. (Recording pattern on a track on a magnetic tape).
Each track t is finely divided in the vertical direction by a thin line on the tape T, and a hatched portion is a recording position of the search information. Further, recording is performed on the track t in the direction f in the figure in the order of the direction e in the figure on the tape T. In the case of the helical scan, the actual track t (the direction f in the figure) is the tape T
Although it is oblique with respect to the direction (e direction in the figure), it is shown vertically in FIG. 5C for convenience.

Hereinafter, the flow of recording signal formation will be described with reference to FIGS. From the image information input 1, compression-encoded image information (for example, an inter-frame predicted image signal predicted and encoded between frames and an intra-frame image signal encoded within a frame) is input. In the input signal, the search information forming unit 2 detects an intra frame. Usually, an intra frame is inserted about once every 0.5 seconds, but it is not recorded but extracted as search information (high-speed search information). In this embodiment, an intra frame is detected every second.

In the inter-frame coding, there is a case where only a part of an image is changed to an intra (independent coding) instead of the intra in a frame unit, and the part is moved for each frame. Even in this case, by synthesizing the intra part for one cycle of the movement, intra information for one frame can be obtained, and it can be handled in the same manner as an intra frame. Since the time is different depending on the image part, the image is shifted due to the movement, but can be used as search information.
The description will be made as a frame.

As the search information, only a recordable amount of information is extracted from all the information of the intra frame. For example, a DC component of 8 × 8 pixels is used. The search information thus formed is supplied to the search memory 3 and the search memory 13 alternately for each frame. Each of the search memories 3 and 13 has a capacity for a total of two frames so that search information for one frame can be simultaneously written and read.

On the other hand, general information for normal reproduction (inter-frame predicted image signal and intra-frame image signal input as image information) is supplied to a buffer 6. In this general information, unnecessary information duplication can be avoided by deleting the content of the search information. However, when the search information is processed, the processing becomes complicated. On the other hand, the duplication of information is not so large in view of the total information amount, and the deletion does not have to be performed.

Next, a recording arrangement on a tape which is a feature of the present embodiment will be described. This arrangement is determined in the form of a data array by the divided readers 4 and 14 and the multiplexer 5. As shown in FIG. 5 (A), I ₀ , I ₁ , I ₂ ...
Sign. Intra frame is border n on the screen
Then, for example, the image is horizontally divided into two parts a and b. Further, each of the divided areas a and b is divided into, for example, five in the vertical direction.

Here, since the division at the boundary n is divided and displayed on the search screen, the position of the boundary n is specified and fixed so that the boundary does not fluctuate on the screen. However, the screen is not necessarily equally divided. There is no need to divide into two. In the case of multiplexing N frames that are temporally adjacent to each other, this division may be performed by dividing the N frames by more than N.

On the other hand, the division into which the areas a and b are divided into five divisions is such that the information amount of each divided area is the same as the amount of search information recorded on the track. Absent. Here, since the search information is a fixed-length code of the DC component, the information amount is equally and fixedly divided. In FIG. 5B, the search information is vertically divided into five regions. In this division, search information for one frame (areas a and b divided into two as described above) cannot be recorded at the recording position of the search information on one track. belongs to.

Each area of each frame is, for example, "02b"
The first left digit is a frame number (0), the middle digit is a vertical division number (0-4), and the right digit is a horizontal position (a / b) based on the boundary n. Show. On the other hand, the recording position of the divided search information on the tape is two predetermined positions on one track (the hatched portion on the tape T in FIG. Shown). The number of divisions (two places) of the recording position is equal to the number of frames to be multiplexed, that is, the number of divisions at the boundary n (N = 2 in two divisions).
It is equal to 2). Note that the recording length r of each search information is set short enough to read continuously even if the track is read diagonally during the maximum high-speed search. Further, general information for normal reproduction is recorded in portions other than the search information.

In the arrangement of search information on each track t, the same information is repeatedly recorded on the data of each area over five tracks. And
The horizontal division a is set below the search information recording section (recorded sequentially from the bottom), and b is set above (the rear). Also,
In the vertical division, two different frames (frames that are temporally preceding and succeeding) are alternately inserted, and are arranged every five tracks. In other words, the divided area of I ₀ → the divided area of I ₁ → the divided area of I ₀ → the divided area of I ₁ → the divided area of I ₀ → the divided area of I ₁ → the divided area of I ₂ → the divided area of I ₁ → The divided area of I ₂ → the divided area of I ₁ → the divided area of I ₂ is arranged (as shown in FIG. 3C, the leading part of the divided area number indicating the frame number is 0 → 1 → 0 → 1). ...)

Therefore, looking at the search information every five tracks, the lower portion from the left end of FIG. 9C is "02a", the upper portion is "02b", the next is "10a" and "10b", and the next is "03a". , "03b"...

For this reason, in the recording apparatus shown in FIG.
I ₀ frame search information in dividing read unit 4 from the search memory 3 are recorded, and in I ₁ frame search information divided reading device from the search memory 13 that is recorded 14, wherein like split order by The search information is read and provided to the multiplexer 5. In the multiplexer 5, I ₀ and I
_One search information and general information are time-division multiplexed.
Here, the same search information is read and multiplexed five times. The data stream thus formed is subjected to error correction code addition and modulation by the signal recorder 7 in the same manner as in the conventional example, and is recorded on the recording medium 8.

<Embodiment Reproducing Apparatus> FIG. 2 is a block diagram showing an embodiment of the reproducing apparatus. In the same part as the conventional example of FIG.
The same numbers are assigned. 4 in that a search memory 28 and divided writers 23 and 27 are provided. FIG.
(A)-(C) is a figure explaining the reproduction | regeneration state at the time of a high-speed search.

As shown in FIG. 2, the signal read from the recording medium 8 is converted into a data stream by a signal reproducer 21 and supplied to a search information separator 22. The search information separator 22 determines the search information from the sector number and separates only the search information. The separated search information is allocated to the memory for each frame, and the first frame (for example,
I ₀ ) is supplied to the divided writer 23, and the second frame (for example, I ₁ ) is supplied to the divided writer 27. The division writers 23 and 27 determine which position of the divided search information, and record the search information at the corresponding position in the search memories 24 and 28.

When the search magnification is 5 or less, FIG.
Thus, even if the read track changes, the same information is repeatedly recorded, so that all search information can be obtained. That is, the reading area is "02
a, 02b, 10a, 10b, 03a, 03b, 11a, 11b, 04a, 04b, 12a, 12b, 20a,
20b, ... ". As described above, in the data, the same information is repeatedly recorded over five tracks. Therefore, when information for one frame is obtained, each of the search memories 24 and 28 outputs it as search information. I ₀
And I ₁ are recorded with a time lag, so that reproduced images are alternately output from the memories. In addition, since the intra frame is reproduced at 5 × speed, one frame per second, the search image is 5 frames per second.

Here, each memory may not be for one frame but may be only for the horizontal division a or b. In this case, if only a is recorded in the search memory 24 and only b is recorded in the search memory 28 and the other is discarded, and the reading is performed one by one, the left and right frames are temporally different. can get. In this case, the playback device can be configured with half the capacity of the search memories 24 and 28.

Next, at the time of 10 times speed which is an advantage of this embodiment, reading is performed over 10 tracks as shown in FIG. 6B. In this case, information of both a and b cannot be obtained in a certain vertical division area. However, since the multiplexing cycle and the reading cycle are synchronized, either a or b obtains all the vertically divided information. be able to. That is, two different frames (two frames that are temporally preceding and succeeding) alternately enter, and are multiplexed and recorded at a cycle of 10 tracks every 5 tracks, and are read every 10 tracks at 10 × speed. All information of either a or b can be obtained. In addition, since the horizontally divided information area a is divided and recorded in the track direction f so that the information area b is located at a position below the search information recording section and the information area b is located at an upper position, the information area is alternately arranged at 10 × speed. If one of the recorded frames is a, the other is b, and as a result, a search image for one screen is obtained with a total of two frames.

That is, as shown in FIG. 6B, the reading area is “02a, 10b, 03a, 11b, 04a, 12b, 20a, 13b, 21a, 14b, 22”.
a,… ”. As a result, although the frames are temporally different between the left and right, a search image of the entire screen is obtained. In other words, all the information in the area a (right side) is obtained for the frame I ₀ , and all the information in the area b (left side) is obtained for the frame I _1. Will be obtained. However, since the speed is doubled, the number of frames per second can be obtained twice that in the case of the 5 × speed.

<In the case of N division> In the above embodiment, two divisions correspond to twice the conventional speed. However, the number of frames and the number of display divisions on the search screen (the number of screen horizontal divisions in the above embodiment) Is increased to N divisions, which corresponds to N times speed. In this case, recording is performed at N positions in the track direction f, and multiplexed and recorded in a cycle in which different N frames are sequentially repeated. For example, in the case of three divisions corresponding to three times the speed of the related art, the intra frames I ₀ , I
_1, each region I _2, may be multiplexed recording the divided area → ... order of the divided regions → I ₀ of the divided regions → I ₁ divided region → I ₂ of I _0.

In the case of the N division, even if the number N is divisible, it is synchronized with the multiplexing cycle. For example, if N is 6, good search images can be obtained even if the number is 2 and 3 times.

In the above embodiment, the screen is divided horizontally, but if the division is easy to see even if the division is made, a vertical or vertical / horizontal combination may be used. Further, in the above-described embodiment, the division based on the information amount is vertical, but the division is not limited to such.

<Azimuth Recording> When recording on a tape with two heads having different azimuth angles, the search speed is restricted due to the relationship between the track azimuth and the head azimuth. For example, in the above embodiment, at 10 × speed, the track and the azimuth cannot be matched by one head, and reading can be performed only by the other head.

In this case, if the speed is 9 times as shown in FIG. 6C, reading is possible with both heads, and the reading area is "02a, 10b, 03a, 11b, 04a, 04b, 12a, 20b, 13a, 21b". , 30a,… ”
Becomes However, since the multiplexing cycle and the reading cycle are not synchronized, the screen division area (a / b) and the frame are not synchronized, and the frame is changed even by the vertical division. As a result, the image is divided horizontally and vertically into two parts, and the division points are shifted for each frame.
Although it is difficult to see as compared with the above-mentioned 10 × speed, it can be used as a search image.

When recording is performed on only one track having an azimuth angle, the multiplexing cycle and the reading cycle can be synchronized with each other, although there is a speed limitation, and a good search image can be obtained.

[0046]

According to the present invention, the recording position on the track is changed according to the image portion, the information is multiplexed in a plurality of frames, high-speed image search information is recorded, and the divided images are integrated and displayed during reproduction. In addition, a reproduced image can be obtained even at a high-speed search speed higher than the search speed that can be conventionally achieved. As a result, a higher search speed is possible while maintaining the number of frames per second of the search image. Conversely, when the search speed is the same as the conventional one, the number of repetitive recordings can be reduced, and more search frames can be recorded, so that a search image with a smooth motion can be obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of a moving image recording apparatus according to the present invention.

FIG. 2 is a configuration diagram showing an embodiment of a moving image reproducing apparatus according to the present invention.

FIG. 3 is a diagram illustrating a configuration example of a conventional moving image recording apparatus.

FIG. 4 is a diagram illustrating a configuration example of a conventional moving image reproducing apparatus.

FIG. 5 is a diagram illustrating a method for recording high-speed image search information by the present apparatus.

FIG. 6 is a diagram illustrating a method of reproducing high-speed image search information by the present apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Image information input, 2, 31 ... Search information formation device, 3, 13, 24, 28 ... Search memory, 4, 14 ... Division | segmentation readout device, 5, 32 ... Multiplexer, 6 ... Buffer, 7 ... Signal recording 8: recording medium, 21: signal reproducer, 22: search information separator, 23, 27: divided writer, 25: selector, 26: reproduction output, 41: switch.

Claims (2)

(57) [Claims] An apparatus for recording a compression-encoded moving image on a medium, means for obtaining high-speed image searching information from input moving image information, and storing high-speed image searching information of a plurality of frames or fields. Means for dividing the high-speed image search information of each frame or field into a plurality of regions based on a position on a screen, and further dividing the information in each divided region based on the amount of information, The high-speed image search information divided as described above is recorded at different positions in one track for each position on the screen, and different frames or fields are alternately recorded every predetermined number of tracks. And a means for recording the multiplexed high-speed image search information at a predetermined position on a medium. 2. The high-speed image search information of a plurality of frames or fields is divided into a plurality of regions based on a position on a screen, and each of the divided regions is divided based on an information amount. Are multiplexed so that the information for high-speed image search divided as described above becomes a different position in one track for each position on the screen, and different frames or fields alternately enter a predetermined number of tracks. Means for reproducing a moving image from a medium recorded at a predetermined position, comprising: means for reading high-speed image search information from the medium; and a plurality of frame or field screen areas from the read high-speed image search information. A moving image reproducing apparatus comprising: a unit configured to form a search image in units of frames or fields by integrating the above.