KR100209680B1 - Additional information recording and reproducing device of magnetic recording medium - Google Patents

Abstract

Additional information recording and reproducing apparatus of magnetic recording media is provided. Even if the user does not want to see the recorded subtitles (additional information), the user cannot play the background screen without subtitles and complicated screens such as graphic information and moving images There is another problem that cannot be configured and can only configure one screen.

In order to solve this problem, a feature of the recording and reproducing apparatus for additional information of the magnetic recording medium is that the first and second encoding means encode the original image input and the additional information input according to the user's selection, respectively, and record the data on one recording area of the tape. The original image and the additional information recorded on the tape are decoded by the first and second decoding means, respectively, so that the original image is reproduced as it is and the additional information is reproduced according to the user's selection. In addition, the user can arbitrarily select playback and various additional information such as caption captions, OSD information, graphics, and moving images can be recorded and played back, thereby providing various information to the user.

Description

Apparatus for recording and playing additional information on magnetic recording media

The present invention relates to a recording and reproducing apparatus of a magnetic recording medium, and more particularly, to an additional information recording and reproducing apparatus of a magnetic recording medium for recording and reproducing additional information desired by a user in a magnetic recording medium.

In general, in the standard of SD (Digital Definition) -DVC (Digital Video Camcoder), a frame of one frame is 720 * 480, and HD (High Definition) is 1008 * 1024.

This screen is divided into 8 * 8 DCT blocks and consists of four Y (luminance signal) DCT blocks and six DCT blocks, one each of Cb and Cr (color difference signal) blocks, to form a macro block.

FIG. 1A shows the structure of the macroblock, and FIG. 1B shows the structure of the bit string of the encoded macroblock.

Conventionally, when information such as OSD (On Screen Display) is sprayed on the screen, the information is recorded as the original background screen.

At this time, the information on the original screen hidden behind the OSD information is completely lost.

In addition, the recorded screen is reproduced like the OSD information recorded at all times during playback even when the user does not want to.

In the SD-DVC standard, a text pack can be selectively used in a subcode area of a tape.

The pack records the font and size of the characters, and reproduces the text information at the time of rehashing.

Since the text pack has a small size of 32 bits, text information to be displayed on one screen can be recorded by dividing it into sub-code areas of several frames.

This takes into account the property that text information does not change for several frames. The text information recorded here may or may not be reproduced at the user's convenience during reproduction.

Such a method may be effective for some predetermined letters or pictures, but it is not possible to predetermine all letters or graphics of many foreign languages as promise symbols.

In addition, it is not possible to record all the pictures or screens to be added on the original screen.

In other words, this method is an extremely limited way for text and graphic governments to record information.

Conventionally, there is a method of recording additional information other than the original screen, such as a caption caption or OSD.

However, in the existing analog VCR or the current DVC standard, if the caption subtitle or OSD is displayed after recording, the subtitle is recorded with the background screen hidden, so the original background behind the subtitle disappears, and the background again. There is a problem that can not play the screen.

In addition, even if the user does not want to see the recorded subtitles (additional information), there is another problem in that only the background image without subtitles can be played.

In addition, there is another problem in that complex screens such as graphic information and moving images cannot be configured, but only one screen can be configured.

Accordingly, the present invention has been made to solve the above-mentioned problems according to the prior art, and an object of the present invention is to provide an original video signal and an additional signal, that is, a caption caption, OSD information, graphics and moving pictures, etc. in a magnetic recording and reproducing apparatus. The present invention provides an apparatus for recording and reproducing additional information of a magnetic recording medium for recording a signal of and allowing a user to selectively view the recorded information when playing a recorded tape.

1A and 1B illustrate a bit string structure of a macro block stored in a tape according to the prior art.

2 is a block diagram showing an apparatus for recording and reproducing additional information of a magnetic recording medium according to the present invention.

FIG. 3 is a diagram illustrating a DCT block for an input original image and additional information, and shows an embodiment of signal processing performed by the input processor of FIG.

4 is a diagram illustrating a DCT block for an input original image and additional information, and shows another embodiment of signal processing performed by the input processor of FIG.

5 is a diagram illustrating an example of a screen in which additional information is inserted into an original image.

6a to 6d are diagrams showing the arrangement of a bitstream of a macro block and a DCT block in which additional information is inserted according to the present invention.

* Explanation of symbols for main parts of the drawings

10: additional information input unit 11: input processing unit

12,13: first and second compression unit 14: encoder

15 recording / reproducing section 16 decoding section

17,18: first and second kidney 19: control unit

20: playback processing unit

A feature of the apparatus for recording and reproducing additional information of a magnetic recording medium according to the present invention is that the original information and the additional information input according to the user's selection are encoded by the first and second encoding means, respectively, and recorded in one recording area of the tape. It is characterized by.

In addition, another feature of the present invention is characterized in that when the original video and the additional information recorded on the tape is reproduced by the first and second decoding means, respectively, the original video is reproduced as it is and the additional information is reproduced according to a user's selection. .

In still another aspect of the present invention, one recording area of the additional information is recorded in a part of a DCT block in which an original video signal is recorded.

In addition, another feature of the present invention is characterized in that the additional information encoded after inserting the additional information start code into the partial region when recording the additional information is recorded.

Hereinafter, an apparatus for recording and reproducing additional information of a magnetic recording medium according to the present invention will be described with reference to the accompanying drawings.

FIG. 2 is a block diagram showing an apparatus for recording and reproducing additional information of a magnetic recording medium according to the present invention. FIG. 3 is a block diagram illustrating a DCT block for input original images and additional information. FIG. 4 is a diagram illustrating one embodiment of a process on a screen, and FIG. 4 is a diagram illustrating a DCT block for an input original image and additional information. FIG. 4 is a diagram showing another embodiment of signal processing performed by an input processor of FIG. to be.

5 is a diagram illustrating an example of a screen in which additional information is inserted into an original image, and FIGS. 6A to 6C are diagrams illustrating an arrangement of a bitstream of a macroblock and a DCT block in which additional information is inserted according to the present invention. to be.

First, referring to FIG. 2, the configuration thereof may include: an additional information input unit 10, an input processing unit 11, first and second compression units 12 and 13, an encoding unit 14, and a recording / reproducing unit 15. ), The decoding unit 16, the first and second extension units 17 and 18, the control unit 19 and the playback processing unit 20.

First, the operation at the time of recording the original image information and the additional information is as follows.

The additional information input unit 10 generates additional information such as caption subtitles or OSD information according to a user's selection and is applied to the input processing unit 11 together with the original image information.

The input processor 11 samples, blocks, and shuffles the input original image and additional information according to the DVC standard.

In addition, it is to determine which block among the various blocks of the background screen is a block into which additional information is inserted and determines a block value to be passed to the next DCT block.

The additional information blocked by the input processor 11 is a pixel value obtained by subtracting the pixel value of the additional information from the pixel value of the original image.

Here, FIG. 3 illustrates a process in which the input processing unit 11 processes a block containing an original image block and additional information.

That is, the original image block is applied to the first compression unit 12 as it is, DCT converted and the converted image is applied to the encoding unit 14, but the additional information block is composed of the pixel value minus the additional information insertion block from the original image. The block is applied to the encoder 14 by performing a DCT conversion process on the second compressor 13.

In this case, the DCT of the original image block and the additional information block may be connected in parallel to process the compression units 12 and 13 differently as shown in FIG. 2, or DCT processing may be performed using the same single compression unit.

Here, in case of configuring the same single compression unit, there should be a spare time as many as the number of blocks for DCT the additional information block, and when using the compression units 12 and 13 as shown in FIG. Since additional information blocks are DCT processed simultaneously, no extra time is required.

The block without additional information may be processed in the same manner as a conventional processing apparatus.

The original image block is DCTed and quantized in the first compression unit 12.

At this time, the block containing the additional information and the block that does not contain the additional information is quantized in the same way as the conventional quantization process and determines the quantization size.

However, the block to which the additional information is added determines the quantization size so that the bit string becomes 112-N bits or less when encoded.

The 112-N bits will be described later.

On the other hand, as described above, the DCT subtracted from the original image when the additional information block DCT has been described.

However, if the amount of pixels to which additional information is added in one block is very large, coding efficiency of DCT alone as an additional information block may be higher than DCT of a subtracted value from the original image.

That is, as shown in FIG. 4, the original video block and the additional information block are completely DCT recorded, respectively, and restored in an appropriate method at the time of reproduction.

However, this method is possible when additional information is designated with a specific value such as white or black.

When playing a block value during playback, compare the pixel values of the original video block and the additional information block, and play the pixel value that appears as a specific value in the additional information block as additional information. have.

The coefficient values DCT in the first and second compression units 12 and 13 are encoded in the bit string in the encoder 14.

That is, the encoder 14 formats the entire bit string of the frame and adds the error correction code and the ID for each block to perform sampling.

The sampled bit string is recorded on the tape of the recording / reproducing section 15.

Referring to the operation during reproduction of the original image and the image to which the additional information is added as described above, the information recorded on the tape is demodulated by the recording / reproducing unit 15 and applied to the decoding unit 16.

The decoder 16 descrambles the reproduced bit stream, corrects an error using an error correction code added during recording, and deformats the data in units of macroblocks.

The bit strings of the macroblocks are decoded in units of DCT blocks and applied to the first and second extension units 17 and 18.

In this case, in the block to which the additional information is not added, the bit strings are all decoded into the DCT values of the original image block, and the block to which the additional information is added is restored to the DCT values of the original image block and the DCT values of the additional image information.

Each of the decoded DCT coefficient values has an additional information image IDCT in the first extension unit 17, and the DCT values of the original image are IDCT in the second extension unit 18 and restored to pixel values.

Like the first and second compression units 12 and 13, the first and second extension parts 17 and 18 may use the same chip as one extension part or may have a parallel structure as shown in FIG. 2.

In this case, the reconstructed additional information block pixel value is a pixel value subtracted from the original image block and restored to a value added with the original image block to be displayed on the screen, and applied to the reproduction processor 20.

The playback processor 20 deshuffles the macroblocks and outputs the finally reconstructed image to the screen.

At this time, when the user wants to see additional information, the control unit 19 applies one control signal to the playback processing unit 20 by the user's additional information on / off selection signal, and then applies the original image to the playback processing unit 20. And the screen with the additional information video.

On the other hand, when the user does not want to view the additional information, the controller 19 applies the original image selection control signal to the playback processor 20 to output only the original image by the user's additional information on / off selection signal.

FIG. 5 shows a screen in which additional information such as an OSD is added to an original image, and the original image is divided into 8 * 8 size DCT blocks and encoded. These blocks are blocks with additional information added according to a user's selection. Blocks that are not added may be divided as shown in FIG. 6a.

Referring to FIG. 6A, there is a macroblock consisting of four DCT blocks, and among the DCT blocks, a Y ₀ DCT block is a block to which additional information is added according to a user's selection.

As shown in FIG. 6B, since the Y DCT block is encoded with a length of 14 bytes (112Bit), the AC value is encoded by 100Bit for each Y block and 68Bit for Cr and Cb blocks.

After all of the AC values are encoded, as shown in FIG. 6C, an end of block (EOB) code is added to indicate the end of each block.

In the present invention, when recording the additional information, the DCT block in which the additional information appears is recorded on the tape in the format as shown in FIG. 6C.

In FIG. 6C, additional information of N bits is previously recorded in the existing DCT block array. The additional information is encoded by DCT after subtracting the additional information from the original image.

That is, when the total size of each DCT block is 112 bits and the recording size of additional information is Nbit, the DCT block of the original image is allocated by encoding the remainder (112-Nbit) subtracted by the Nbit.

In this case, the image quality deteriorates as much as Nbit, but it is possible to eliminate the occurrence of the image deterioration by recording the additional information as much.

When recording of the additional information is started, the encoded additional information is recorded after inserting the additional information start code (Caption Start Code) into the additional information recording area.

In general, the OSD information, caption caption, or additional information occupies a small amount on the entire screen, and thus the number of blocks in which the additional information is mixed is limited. Therefore, the image quality deterioration is not great.

In the recording and reproducing signal processing, the block to which the additional information is added and the block to which the additional information is added are encoded and decoded in different structures.

That is, a block without additional information is encoded and decoded using the existing DVC standard, and only a block to which additional information is added is recorded in the additional information recording format.

In the case of the general DVC without the additional information decoding apparatus, when decoding the DCT block to which the additional information is added, as shown in FIG. 6C and FIG. 6D, the last bit of the AC has an EOB (End of Block) code. Only the original image will be restored without doing.

Therefore, even in a DVC without the additional information decoding apparatus, the tape on which the additional information is recorded can be reproduced.

In this case, however, the additional information cannot be reproduced.

Meanwhile, in the additional information recording and reproducing apparatus of the magnetic recording medium according to the present invention having the additional information decoding apparatus, after decoding the EOB of the original video block, the additional information start code is read and the next data is recognized as additional information. Decrypt the rest of the additional information.

In this case, the additional information recorded according to the user selection may or may not be decoded according to the additional information selection signal of the user.

The additional information recording and reproducing apparatus of the magnetic recording medium according to the present invention records the additional information desired by the user separately from the original image, and reproduces the original background image and the additional information only when the user wants to reproduce the additional information at the time of reproduction. If the user does not want to play the additional information, only the original video minus the additional information can be played back, so that the user can freely select the recording and playback of the additional information.

In addition, it is possible to record and play various additional information such as caption caption, OSD information, graphics, and moving image, thereby providing various information to the user.

Claims (5)

The additional information input unit for inputting additional information added to the original image, and inputs the additional information and the original image together to perform sampling, blocking, and sampling, and simultaneously converts additional information from the pixel value of the original image to the pixel value of the additional information. And an input processing unit for subtracting the pixel value into a pixel value, a compression unit for compressing the original image block and the additional information block among the images output from the input processor, and an encoding unit for encoding the compressed information. Device for recording additional information on record carrier. The apparatus as claimed in claim 1, wherein the input processing unit assigns additional information to a part of a block of the original image and inserts a start code indicating that the additional information exists in the block. The block of claim 1, wherein the compression unit DCT has a random quantization size for a block having only original image information, and a block having additional information has a value smaller than a value obtained by subtracting the quantization size N of additional information from the random value. And additional information recording apparatus for a magnetic recording medium, characterized in that configured to DCT with a quantization size. A decoder which decodes information read from an information recording medium, an decompressor which decompresses the original image block and the additional information block of the decoded image information differently, and restores the image by sampling the decompressed image information. And a reproduction processing unit which performs display processing on the screen by subtracting the pixel value of the additional information block restored at the same time from the pixel value of the original image block, and a controller which controls to selectively output the additional information during the reproduction processing. Apparatus for recording additional information on magnetic recording media. 5. The apparatus as claimed in claim 4, wherein the decompression unit is configured to IDCT the original image block and the block including the additional information according to the original quantization size.