JP2002199339A - Recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recorder capable of reproducing data smoothly in special reproduction such as fast forwarding, rewinding in the case of recording a multi-program with a many pieces of program data multiplexed to a single TS on a recording medium, in the case of recording data that a single TS has various kinds of screen format or even in the case of recording data at various recording speeds. SOLUTION: TS analysis is performed in recording data and a method for reducing data for special reproduction is switched to an optimal method depending on the number of programs to be multiplexed, the format of an original picture and the recording speed of data and recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording apparatus for recording digital video signals and digital audio signals, and more particularly, to generating and recording recording data for special reproduction used when reproducing at a speed different from normal reproduction. The present invention relates to a recording device that performs the recording.

[0002]

2. Description of the Related Art In a conventional analog recording VTR such as an S-VHS or VHS format, one track on a tape corresponds to one field of a video signal.
At the time of special reproduction (high-speed reproduction) such as EVIEW, a method of connecting reproduced signals obtained by scanning a magnetic head across a track on a field memory to obtain a reproduced image is generally used.

However, in recent years, digital broadcast receivers and I
MPEG2 (Moving Picture Experts Group 2) in which digital video signals and digital audio signals supplied from a digital interface such as EEE1394 are multiplexed.
A recording / reproducing apparatus for recording / reproducing a transport stream (hereinafter referred to as TS) as an input has been developed. For example, D-VH which is a standard of a digital recording VTR has been developed.
In the S system VTR, the video signal is included in an MPEG2-TS which is a source-coded bit stream, and the positional correspondence between a track and a frame of the video signal as in a conventional analog recording VTR. Do not have.

[0004] For this reason, a reproduced signal obtained by scanning the magnetic head across the track during high-speed reproduction becomes a fragment of a bit stream. Therefore, it is impossible to obtain a reproduced signal from the fragment of the bit stream. It is possible.

[0005] Therefore, digital recording of CUE / REVI
To realize high-speed reproduction such as EW, for example,
As described in JP-A-292123 and JP-A-11-46792, data for special reproduction is arranged separately from normal reproduction data around the position of the tape scanned by the magnetic head during high-speed reproduction. In addition, there is disclosed a technique in which a reproduction screen is reconstructed from the special reproduction data and output during high-speed reproduction.

Hereinafter, this conventional technique will be described with reference to FIGS. FIG. 4 is a schematic diagram of a recording track on the recording medium 202. In FIG. 4, reference numeral 202 denotes a magnetic tape on which digital signals are recorded; 301, a data recording area for normal reproduction; 302, a data recording area for special reproduction; The normal reproduction data is recorded in the special reproduction data recording area 302, and the special reproduction data is recorded in the special reproduction data recording area 302. The trajectory scanned by the magnetic head when the magnetic tape 202 is fast-forwarded is indicated by a dotted line 311.

FIG. 5 is a block diagram showing a configuration of a conventional recording apparatus. In FIG. 5, the conventional recording apparatus includes a recording data generating unit 1 for normal reproduction, a recording data generating unit 2 for special reproduction, a recording unit 3, and a recording head 5. The recording head 5 is a head device for recording data on the recording medium 202, and is, for example, a magnetic head. The recording medium 202 is a tape-shaped recording medium, for example, a magnetic recording medium.

[0008] The recording data generating unit 1 for normal reproduction and the recording data generating unit 2 for special reproduction have transport packets composed of video signals and audio signals encoded using the correlation between screens. A format bit stream 201 is input. The normal reproduction data generation unit 1 generates normal reproduction recording data composed of a plurality of predetermined recording blocks from the input bit stream 201. The trick play data generation unit 2 generates, from the input bit stream 201, record data for trick play (fast forward playback, rewind playback, etc.) composed of a plurality of predetermined recording blocks.

The recording unit 3 determines the recording order of both data to record the normal reproduction recording data and the special reproduction recording data in a predetermined area on the recording medium 202, The data is recorded on the recording medium 202.

[0010]

However, as shown in FIG. 4, a recording area 302 for special reproduction data is used.
Is smaller than the recording area 301 for the normal reproduction data, and the amount of information that can be recorded on the recording medium for the special reproduction data is smaller than that of the normal reproduction data. Needs to be reduced.

FIG. 6 is a block diagram showing an example of a detailed configuration of the recording data reproducing unit 2 for special reproduction shown in FIG. FIG.
, The recording data generating unit for special reproduction 2 includes an I picture extracting unit 21 and a high-frequency component deleting unit 22.

The I-picture extraction unit 21 extracts only I-pictures (intra-frame coded pictures) from the original video stream to reduce the amount of data, and outputs B-pictures (bidirectionally coded pictures) and P-pictures (pictures). (Inter-frame forward prediction coded image) is deleted. High-frequency component removing unit 22
Performs DCT high-frequency component reduction in macroblock units from the I picture extracted by the I picture extraction unit 21.

FIG. 7 is an explanatory diagram for explaining the extraction of an I-picture and the reduction of the data amount. FIG. 8 shows an example of image output timing of special reproduction when recording is performed by a conventional recording apparatus. FIG.

7A shows an input bit stream, FIG. 7B shows a bit stream from which an I picture has been extracted by the I picture extraction unit 21, and FIG.
(C) shows the bit stream from which the DCT high-frequency component has been reduced by the high-frequency component deletion unit 22.

As shown in FIG. 7C, the high-frequency component removing unit 22 can reduce the information amount of the I picture although the image quality of the reproduced image is reduced by removing the DCT high-frequency component. . Therefore, the frame update period of the reproduced image of the data recorded by the conventional recording apparatus can be increased, and the special reproduction is realized.

However, since the removal amount of the DCT high-frequency component for each macroblock by the high-frequency component removal unit 22 is always constant, for example, as shown in FIG.
(A) and the program is P1, P2, P
3, the amount of the DCT high-frequency component removed for each macroblock is the same in the case of the multi-program multiplexed as in (b).

Therefore, assuming that the reproduction screen is updated at the timing when the special reproduction frame data is reconstructed, as shown in FIG. 8, when the number of program data multiplexed in one TS is small, for example, When the program is only P1 (a), the output screen is updated every time P1 is reconfigured, so that special reproduction can be performed smoothly. However, the number of program data multiplexed in one TS For example, if the programs are multiplexed like P1, P2, and P3, the reproduced image is updated at the timing when the specific program (here, the program P1) is reconstructed. , P1 takes a long time to be reconstructed, and the update cycle of the reproduced image is delayed (from timing 401 to timing 402), so that the special reproduction is not performed smoothly. We had a problem that.

Also, when one TS records data having various screen formats or when a TS records data at various recording speeds, the high-frequency component removing unit 22 removes DCT high-frequency components. Since the amount is always constant, there is a problem that trick play cannot be performed smoothly as in the case where a large number of program data are multiplexed in one TS.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and is directed to a case where a multi-program in which a large number of program data are multiplexed on one TS is recorded on a recording medium, Provided is a recording apparatus capable of performing smooth reproduction during special reproduction such as fast-forward or rewind even when data having a screen format is recorded or when data is recorded at various recording speeds. The purpose is to do.

[0020]

In order to solve the above-mentioned problems, a recording apparatus according to the present invention converts a bit stream composed of a video signal and an audio signal encoded by utilizing the correlation between screens. A recording apparatus for performing digital recording on a recording medium, wherein the bit stream is input, and normal reproduction for generating normal reproduction recording data composed of a plurality of predetermined recording blocks is used. Analyzing means for analyzing at least one of the number of multiplexed programs of the input bit stream, the format of the original picture, and the recording speed of data, and generating analysis result information; It is composed of a plurality of predetermined recording blocks that are used as input and are used when performing reproduction at a speed different from the normal reproduction (hereinafter referred to as special reproduction). The trick play recording data, which is,
Recording data for special reproduction generated based on the analysis result information output from the analysis means, and the recording data for normal reproduction in a normal reproduction area configured on the recording medium via a recording head. Recording means for recording the recording data for trick play in a trick play area formed on the recording medium.

Further, in the recording apparatus according to the present invention, the analysis means analyzes at least one of the number of multiplexed programs of the input bit stream, the format of the original picture, and the data recording speed, and reproduces the data. The analysis result information is generated such that the update cycle of the reproduced image at the time becomes a constant cycle.

Further, the recording apparatus according to the present invention is characterized in that the analysis result information is information indicating an amount of DCT (discrete cosine transform) high-frequency component deleted.

[0023]

(Embodiment 1) Hereinafter, a recording apparatus according to Embodiment 1 of the present invention will be described with reference to FIGS.
This will be described with reference to FIG. The recording apparatus according to the first embodiment of the present invention determines the method of reducing the DCT high frequency component of the data for special reproduction at the time of data recording by analyzing the number of multiplexed programs, the format of the original picture, and the recording speed, Data is recorded so that special reproduction such as high-speed reproduction can be performed smoothly.

FIG. 1 is a block diagram showing an example of the configuration of the recording apparatus according to the first embodiment of the present invention. In FIG. 1, the recording apparatus according to the first embodiment of the present invention receives a bit stream 201 as input, is data used when performing normal reproduction, and records normal reproduction recording data composed of a plurality of predetermined recording blocks. This is data to be used when performing a special reproduction (fast-forward reproduction, rewind reproduction, etc.), which is a recording data generation unit 1 for normal reproduction to be generated and a bit stream 201, which are reproduced at a different speed from the normal reproduction. A special reproduction recording data generation unit 2 that generates recording data for special reproduction composed of a plurality of predetermined recording blocks based on analysis result information output from the analysis unit 4; In the normal reproduction area (see 301 in FIG. 4) formed on the medium 202, the normal reproduction recording data generated by the normal reproduction recording data generation unit 1 is stored. A recording unit 3 for recording and recording the special reproduction recording data generated by the special reproduction recording data generation unit 2 in a special reproduction area (see 302 in FIG. 4) configured on the recording medium 202; An analysis unit 4 for generating analysis result information 203 indicating a method of deleting a DCT high-frequency region for each bit stream from the number of multiplexed programs of the bit stream to be multiplexed, the format of the original picture, and the recording speed;
A recording head 5 for recording data on the recording medium 202.

It is to be noted that here, the recording signal is an MPEG2 format defined by the MPEG2 system standard (ISO / IEC13818-1).
-TS, and the recording apparatus is a D-VHS which is a standard for digital recording / reproducing VTR for recording / reproducing on a magnetic tape.

FIG. 2 is a block diagram showing an example of a detailed configuration of the recording data generating unit 2 for special reproduction and the analyzing unit 4 in FIG. 2, the analysis unit 4 includes a program number acquisition unit 41 that acquires the number of multiplexed programs of a bit stream, an image format acquisition unit 42 that acquires the encoding format of each program, and a program number acquisition unit 41. Number of multiplexed programs 204 of the acquired bit stream, image format acquisition unit 42
Format 205 of the encoded data obtained by
And an optimal high-frequency component deletion method is selected based on the recording mode 206 indicating the recording speed and the like output from the system control unit 207. And a high-frequency component deletion method selection unit 43 to be output to the unit 22.

The special reproduction recording data generation unit 2
An I-picture extracting unit 21 for extracting an I-picture and a high-frequency component deleting unit 22 for deleting a DCT high-frequency component in macroblock units from the I-picture extracted by the I-picture extracting unit 21.

Next, the operation will be described. MPEG2
The TS is multiplexed and demultiplexed by a 188-byte fixed-length transport packet, and the program number acquisition unit 41 of the analysis unit 4 checks the PAT packet that describes the multiplexed program information to determine the program number. To get. Further, the image format acquisition unit 42
The encoding format is obtained by checking the PALI packet indicating the classification and level of the function described in the encoded data of the video signal of each program.

Next, the high-frequency component deletion method selection unit 43 acquires the recording mode 206 indicating the data recording speed and the like from the system control unit 207, and the recording mode 206 and the program acquired by the program number acquisition unit 41. The optimum high-frequency component deletion method is selected based on Equation 204 and the encoding format 205 acquired by the image format acquisition unit 42, and the high-frequency component deletion unit of the special reproduction recording data generation unit 2 is used as the analysis result information 203. 22.

The selection of the high-frequency component deletion method by the high-frequency component deletion method selection unit 43 is performed, for example, when the number of programs to be multiplexed is large, when the image format is high in image quality, or when the recording speed is low. If the amount of data to be recorded on the recording medium is large, for example, when the speed is high, select a high-frequency component deletion method that increases the amount of DCT high-frequency component deletion. When the amount of data recorded on the recording medium is small, such as when the image quality is low in the image format or the image format, or when the recording speed is low,
A method of deleting the high-frequency component that reduces the amount of CT high-frequency component deletion is selected, so that the deterioration of the image quality during reproduction is suppressed, and the reproduction image is adjusted so that the reproduction image can be updated at a constant cycle. .

Next, the high-frequency component deletion unit 22 of the special reproduction recording data generation unit 2 receives the received analysis result information 203.
, The DCT high frequency component of the recording data for special reproduction is reduced.

FIG. 3 shows a specific example in which the DCT high-frequency component of the recording data for special reproduction is deleted by the high-frequency component deleting unit 22 of the recording apparatus according to the first embodiment of the present invention.
This will be described with reference to FIG. Here, for the sake of simplicity, it is assumed that the high-frequency component deletion method determined based on the number of programs to be multiplexed is output to the high-frequency component deletion unit 22 as the analysis result information 203. .

FIG. 3 is an explanatory diagram for explaining an example of output timing of special reproduction when data is recorded using the recording apparatus according to the first embodiment of the present invention. The high-frequency component deletion unit 22 reduces the DCT high-frequency component of the recording data for special reproduction based on the received analysis result information 203, so that the program is one of P1 as shown in FIG. And the case where the programs P1, P2, and P3 are multiplexed (b), the amount of DCT high-frequency component deletion is changed.

That is, based on the analysis result information 203, the amount of DCT high-frequency components to be deleted when the programs P1, P2, and P3 are multiplexed is made larger than when the program P1 is used as one program, and data is reproduced. The recording data for special reproduction is generated such that the update period of the reproduced image at the time becomes constant.

Thus, even when a multi-program in which a large number of program data are multiplexed on one TS is recorded on a recording medium and special reproduction is performed on the recording medium, an optimal packet amount can be obtained. Since the reconstructed image can be reconstructed, deterioration of the image quality can be suppressed and smooth special reproduction can be performed.

In the first embodiment of the present invention, the analyzing unit 4 determines the number of multiplexed programs, the format of the original picture,
And the recording speed are analyzed to determine the high-frequency component removal method. However, at least one of the number of multiplexed programs, the format of the original picture, and the recording speed is analyzed to determine the high-frequency component removal method. The same effect can be obtained even if it is determined.

[0037]

As described above, according to the recording apparatus of the present invention, a bit stream composed of a video signal and an audio signal encoded using the correlation between screens is digitally recorded on a recording medium. A recording device for recording, wherein the bit stream is input, and used for performing normal reproduction, and a recording data generating unit for normal reproduction configured to generate recording data for normal reproduction composed of a plurality of predetermined recording blocks; and Analyzing means for analyzing at least one of the number of multiplexed programs of the input bit stream, the format of the original picture, and the recording speed of data, and generating analysis result information; Is a special reproduction recording composed of a plurality of predetermined recording blocks, which is used when reproducing at a different speed (hereinafter referred to as special reproduction). A special reproduction recording data generating means for generating data based on the analysis result information output from the analysis means; and a normal reproduction area formed on the recording medium via a recording head. Recording means for recording the recording data for special reproduction in the special reproduction area configured on the recording medium, so that a large number of program data can be stored in one TS on the recording medium. Fast-forward or rewind even when multiplexed multi-programs are recorded, when one TS records data having various screen formats, or when data is recorded at various recording speeds. Smooth reproduction can be performed during special reproduction such as.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an example of a configuration of a recording device according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing an example of a detailed configuration of a recording data generation unit for special reproduction 2 and an analysis unit 4 in FIG. 1;

FIG. 3 is an explanatory diagram illustrating an example of output timing of trick play when data is recorded using the recording device according to the first embodiment of the present invention.

FIG. 4 is a schematic diagram of a recording track on a recording medium 202.

FIG. 5 is a block diagram illustrating a configuration of a recording apparatus according to a conventional technique.

FIG. 6 is a block diagram showing an example of a detailed configuration of a recording data recording unit for special reproduction 2 of FIG. 5;

FIG. 7 is an explanatory diagram for describing extraction of an I picture and reduction of a data amount.

FIG. 8 is an explanatory diagram illustrating an example of image output timing of special reproduction when recording is performed by a conventional recording apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Recording data generation part for normal reproduction 2 Recording data generation part for special reproduction 3 Recording part 4 Analysis part 5 Recording head 21 I picture extraction part 22 High frequency component deletion part 41 Program number acquisition part 42 Image format acquisition part 43 High frequency component Deletion method selection unit 201 Bit stream 202 Recording medium 203 Analysis result information 204 Program number acquisition result 205 Image format acquisition result 206 Recording mode 207 System control unit 301 Recording data recording area for normal reproduction 302 Recording data recording area for special reproduction 311 Special reproduction Trajectory 401, 402 Special playback image output timing

Claims (3)

[Claims] 1. A bit stream composed of a video signal and an audio signal encoded using correlation between screens,
A recording device for digitally recording on a recording medium, wherein the bit stream is input and used for normal reproduction, and used for normal reproduction which generates recording data for normal reproduction composed of a plurality of predetermined recording blocks. Recording data generating means; analyzing means for analyzing at least one of the number of multiplexed programs of the input bit stream, format of the original picture, and data recording speed, and generating analysis result information; The special reproduction recording data composed of a plurality of predetermined recording blocks, which is used when performing reproduction at a speed different from the normal reproduction (hereinafter referred to as special reproduction), Special reproduction recording data generating means for generating based on the result information; and a recording head configured on the recording medium via a recording head. Recording means for recording the normal reproduction recording data in a normal reproduction area and the special reproduction recording data in a special reproduction area formed on the recording medium. . 2. The recording apparatus according to claim 1, wherein the analysis unit analyzes at least one of the number of multiplexed programs of the input bit stream, a format of an original image, and a recording speed of data. A recording apparatus for generating analysis result information such that an update cycle of a reproduced image at the time of data reproduction is constant. 3. The recording apparatus according to claim 1, wherein the analysis result information is information indicating a deletion amount of a DCT (discrete cosine transform) high frequency component.