JP2002165181A - Video-recording apparatus and video-reproducing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve easy search of recording positions, when recording inter- frame compressed data in the unit GOP on a recording medium. SOLUTION: In a video-recording apparatus, a fixed-length filling means 12 for filling variable-length coded data with non-specified length into a fixed recording area preset on a recording medium 16 in 1 GOP composed of n frames. A temporary storage means 13 temporarily stores data which are cannot fill the recording area as the remaining data. The filling means 12 reads out the last remaining data from the storage means 13 to be crammed into coded data of this time, when inputting the variable-length coded data in the next n frames units.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video recording apparatus for compressing and recording a video signal using a high-efficiency encoding technique and recording the same, and a video reproducing apparatus for reproducing a video signal by extending the code data in a band. It is.

[0002]

2. Description of the Related Art In recent years, a large number of video recording devices and video reproducing devices for recording a video signal on a magnetic recording medium such as a magnetic tape or an optical disk as a digital signal have been introduced to the market. If a video signal is directly recorded as a digital signal in the first place, the amount of data becomes enormous, and requires a much larger recording capacity than the conventional analog recording method. Therefore, as a method of reducing the data amount of the video signal,
It is generally known to perform high efficiency coding. High-efficiency coding is a coding method that removes redundant components of a video signal to reduce the amount of data.

[0003] As a typical technique, an international standard MPEG (Motion Picture Explorer) is used.
t Group). This technique is a method of compressing the amount of information by removing redundancy within and between frames. A frame to be subjected to intra-frame encoding is defined as an I picture. A predicted image is generated by performing motion compensation on the decoded image of the immediately preceding I picture or P picture, and a frame to be subjected to forward prediction coding using a result obtained by calculating a difference between the predicted image and the input image is defined as a P picture. . Then, a frame existing between the immediately preceding and succeeding I-pictures or P-pictures and subjected to bidirectional predictive encoding by motion compensation is defined as a B-picture. By combining such three types of encoding schemes, a high compression ratio can be realized by utilizing the correlation between space and time.

[0004] First, the intra-frame encoding (I picture) will be specifically described. The effective image area in the screen which is divided into blocks each having a certain number of pixels is called a macroblock. The macro block is further divided into a plurality of DCT blocks, for example, four luminance signal DCT blocks and two color difference signal DCT blocks. The orthogonal transform is performed in units of this DCT block. The orthogonal transform generally uses a technique called DCT (discrete cosine transform). The DCT block that has been subjected to such orthogonal transformation is
Since data conversion from the spatial domain to the frequency domain has been performed, energy is concentrated on DC components and low frequency components due to correlation of video signals, and energy of high frequency components is less likely to appear. In terms of human visual characteristics, a quantization table in which quantization distortion is less noticeable, that is, a quantization table having a larger value for a higher frequency component is prepared, and energy of each frequency is divided by the quantization table to increase zero data. To do. The result is scanned from the low-frequency component to the high-frequency component, and the amount of information is reduced by performing variable-length coding on a pair of a number of consecutive zeros (zero run) and a non-zero coefficient value (amplifier). be able to.

Next, the forward prediction coding (P picture) will be specifically described. As described above, the input frame is divided into macroblock units. As the reference screen, input image data of an I picture (or P picture) previously input and decoded image data of an I picture (or P picture) that has been already encoded are used. A block including image data closest to each macroblock of the P picture is searched in the reference image (motion detection), a difference from the decoded image data in the searched area is obtained, and the result is subjected to orthogonal transformation. Processes such as orthogonal transform, quantization, and variable-length coding are the same as the above-described processes for I-pictures. Also, it is necessary to transmit and record a motion vector indicating the position of the searched block in the reference screen. As described above, the P picture has a characteristic that it cannot be decoded unless there is an already decoded I or P picture which is a reference image at the time of decoding.

Next, bidirectional predictive coding (B picture) will be specifically described. A B picture is a picture located between I or P pictures, and requires the immediately preceding and succeeding I or P pictures as reference pictures. The above-described motion detection is performed for each picture, and the difference data is subjected to orthogonal transform, quantization, and variable-length coding. Of course, it is necessary to record the motion vector. As described above, a B picture cannot be decoded unless there is an I or P picture located immediately before and immediately after decoding as a reference image at the time of decoding.

Now, the amount of code generated by encoding is:
It can be controlled by changing the quantization scale code from the code amount control means. Here, a general operation of the code amount control will be described. Code amount control is to monitor whether the amount of data that has occurred so far is large or small for a given transmission rate or recording rate, and quantize the result of the image that is currently being encoded. That is, the amount of generated bits is reflected on a scale to increase or decrease. That is, when the consumed bit amount is large relative to the recording rate, the quantization scale is increased and the amount of division at the time of quantization is increased to suppress the generated bit amount. Here, the frame interval in which the I picture exists is defined as GOP (G
loop of Pictures). In a general system, encoding is performed in GOP units so as to substantially satisfy a target bit rate calculated from a recording rate. Then, control is performed so that the code bit rate in the fixed time range becomes equal to the recording rate. Therefore, when viewed locally, the amount of code generated for each GOP unit may be higher or lower than the assigned target bit rate.

As a means for recording code data generated by the above-described inter-frame coding on a recording medium, a video recording apparatus for recording the generated bit stream as it is on a recording medium such as a magnetic tape. (Streamer). FIG. 18 is a block diagram showing the configuration of this conventional video recording apparatus. Video signal is input terminal 100
, The high-efficiency encoder 101 performs high-efficiency encoding by the method described above to generate variable-length code data. Next, the error correction encoder 102 performs an error correction encoding process on the variable length code data. The modulator 103 modulates the error correction coded data into a format suitable for recording on a recording medium, and records the modulated data on a recording medium 104. FIG. 19 shows a recording pattern on a recording medium recorded by such a video recording device.

FIG. 1 shows a state in which variable-length code data of one GOP is recorded on several recording tracks on a recording medium 16 (magnetic tape). As described above, in the case of variable-length encoded data, the recording bit amount differs for each GOP unit. Then, since the code data of the next GOP is recorded following the code data of the previous GOP, the boundary of the GOP comes in the middle of the track. Therefore, it is not easy to detect the number of GOP data on which track.

Another example of the prior art is disclosed in Japanese Patent Application Laid-Open No. 8-163499. According to this method, a specific recording area is secured for each GOP, and high-efficiency encoding is performed so that the encoding rate is lower than the recording rate, thereby preventing the specific area from overflowing. Used. In this case, there is an advantage that it is easy to detect where the recording position in each GOP unit is recorded in the recording track, but it cannot be said that the recording capacity is sufficiently utilized in making the encoding rate lower than the recording rate. .

There is also a processing method for filling a vacant area of a track after the GOP with dummy data so that the boundary of the GOP does not fall on a recording track on the recording medium. Also in this case, the code amount in GOP units is unspecified,
Since the number of recording tracks is variable for each GOP, a complicated process of controlling the tape running system in accordance with the number is required.

[0012]

As described above, when data compressed by inter-frame compression is recorded by a conventional video recording apparatus, the recording position in GOP units becomes unclear at the time of reproduction, and high-speed recording such as cueing is performed. There was a problem that search became difficult. Furthermore, in order to realize editing or overwriting from the middle of the track, there is a problem that the detection of the position of the boundary of the GOP and the control of the recording head become very complicated. In addition, even if control such as editing and overwriting in GOP units can be simplified, there is a problem that it is not possible to perform encoding using a recording rate sufficiently.
Further, when recording is performed such that the number of recording tracks is variable in GOP units, there is a problem that the control of the tape running system becomes complicated accordingly.

[0013] Claims 1-3,5-7,9,11-
The invention described in 16 is made in view of such a conventional problem, and provides a video recording apparatus that records inter-frame compression-encoded data so that the recording position of a GOP can be easily detected. The purpose is to do.

Further, claims 1-3,5,7,9,1 of the present application
Another object of the inventions described in 1 to 16 is to provide a video recording apparatus capable of recording a video signal with high image quality by sufficiently utilizing a recording rate.

Further, claims 1-3,5,7,9,1 of the present application
Another object of the invention described in 1 to 16 is to provide a video recording apparatus capable of recording in a format suitable for performing editing or overwriting in GOP units.

It is a further object of the present invention to provide a video reproducing apparatus for reproducing variable-length code data recorded as described above with a simple structure and high image quality. is there.

[0017]

According to a first aspect of the present invention, there is provided an input means for inputting a video signal, and a video signal input by the input means is band-compressed by high-efficiency coding to perform variable-length coding. And a data arrangement for packing variable-length code data output from the high-efficiency encoding means and having an unspecified length every n frames into a fixed recording area provided on a recording medium. Fixed-length stuffing means, and temporary storage means for holding the remaining data until the next n-frame recording period when residual data that cannot be distributed to the fixed recording area is generated by the fixed-length stuffing means. The fixed-length stuffing means may include an identification code indicating that the remaining data output from the temporary storage means is the remaining data in the immediately preceding n-frame period. Added to, and is characterized in that the packing the residual data to the fixed recording area.

According to a second aspect of the present invention, in the video recording apparatus according to the first aspect, the fixed length stuffing means stores the remaining data in the immediately preceding n frame period in a specific area provided in the fixed recording area. It is characterized by being packed so as to be recorded.

According to a third aspect of the present invention, there is provided an input means for inputting a video signal, and a high-efficiency coding means for compressing a band of the video signal input by the input means by high-efficiency coding and performing variable-length coding. Fixed-length stuffing means for arranging data for stuffing variable-length code data output from the high-efficiency coding means and having an unspecified length every n frames into a fixed recording area provided on a recording medium And temporary storage means for holding the residual data until the next n-frame recording period when residual data that cannot be allocated to the fixed recording area is generated by the fixed-length stuffing means;
Based on the variable-length code data amount detected by the fixed-length stuffing means, determine the quantization rate so that the average generated code data amount of each n frame unit becomes a preset average target data amount, Code amount control means for outputting a quantization control signal to the high-efficiency coding means, wherein the fixed-length stuffing means sets the last n An identification code indicating residual data in a frame period is added, and the residual data is packed in the fixed storage area, and the code amount control means is provided from the temporary storage means via the fixed length packing means. The data amount information of the residual data is acquired every n frame units, and if the residual data exists, the target data amount for the next n frame units is calculated as the average target amount. The quantization rate for the high-efficiency encoding means is determined to be a data amount calculated by subtracting the data amount of the residual data from the data amount. If the residual data does not exist, the next n frames A quantization rate for the high-efficiency encoding means is determined so that a target data amount for a unit becomes the average target data amount.

According to a fourth aspect of the present invention, a video signal is variable-length coded in units of n frames, and variable-length code data of an unspecified length is recorded in a fixed recording area on a recording medium. When the remaining data in the n-frame period is in the fixed recording area, data input means for obtaining reproduction data from a recording medium in which the remaining data is recorded together with an identification code; and a fixed recording area output from the data input means. Code data separating means for recognizing the identification code from the reproduced data and separating it into residual data of the immediately preceding n-frame period and code data of the current n-frame period; and a current data separated by the code data separating unit. temporary storage means for temporarily storing code data for n frame periods; and residual data for n frame periods immediately before output from the code data separation means. Code data concatenating means for inputting code data for the immediately preceding n-frame period output from the temporary storage means and concatenating it with the residual data to obtain variable-length code data in n-frame units; High-efficiency decoding means for performing variable-length decoding on the variable-length code data from the means and performing expansion processing.

According to a fifth aspect of the present invention, there is provided an input means for inputting a video signal, and a high-efficiency coding means for compressing a band of the video signal input by the input means by high-efficiency coding and performing variable-length coding. And a first fixed arrangement for arranging data for packing variable-length code data output from the high-efficiency encoding means and having an unspecified length in units of n frames into a fixed recording area provided on a recording medium. When remaining data that cannot be allocated to the fixed recording area is generated by the long filling unit and the first fixed length filling unit, at least a part of the remaining data is held until a next n-frame recording period. Temporary storage means, second temporary storage means for holding the code data packed in the fixed recording area by the first fixed length packing means until the next n-frame recording period, And stuffing the code data output from the second temporary storage means, and stuffing the residual data output from the first fixed length stuffing means into the free area when there is a free area in the code data of the fixed recording area. A second fixed-length stuffing means.
The fixed-length stuffing means adds an identification code indicating that the data is the remaining data in the immediately preceding n-frame period to the remaining data output from the first temporary storage means, and stores the remaining data in the fixed recording area. While stuffing data, stuffing the code data of the current n frame period output from the high efficiency encoding means into the fixed recording area,
When the code data overflows from the fixed recording area, a part of the new residual data is output to the second fixed length stuffing means, and the rest of the new residual data is output to the first temporary storage means. The second fixed-length stuffing means stuffs the code data output from the second temporary storage means, and if the coded data in the fixed recording area has an empty area, The residual data output from the long padding means is padded into the empty area by adding an identification code indicating that it is residual data for the immediately following n frame periods.

According to a sixth aspect of the present invention, in the video recording apparatus of the fifth aspect, the first fixed length stuffing means comprises:
The remaining data in the immediately preceding n-frame period is packed so as to be recorded in a specific area provided in the fixed recording area.

According to a seventh aspect of the present invention, there is provided an input means for inputting a video signal, and a high efficiency encoding means for compressing a band of the video signal input by the input means by high efficiency coding and performing variable length coding. And a first fixed arrangement for arranging data for packing variable-length code data output from the high-efficiency encoding means and having an unspecified length in units of n frames into a fixed recording area provided on a recording medium. When remaining data that cannot be allocated to the fixed recording area is generated by the first fixed-length filling unit and the first fixed-length filling unit, the first remaining unit stores the remaining data until the next n-frame recording period.
A temporary storage unit, a second temporary storage unit for holding the code data packed in the fixed recording area by the first fixed length packing unit until the next n-frame recording period, and a second temporary storage unit. A second fixed-length stuffing unit that stuffs the output code data and stuffs the remaining data output from the first fixed-length stuffing unit into the free space when there is a free space in the code data of the fixed recording area; Means for quantizing the data so that the average generated code data amount for each n-frame unit becomes a predetermined average target data amount based on the variable length code data amount detected by the first fixed length packing means. A code amount control means for determining a rate and outputting a quantization control signal to the high-efficiency coding means, wherein the first fixed-length stuffing means comprises: The remaining data output from the time storage unit is added with an identification code indicating that it is the remaining data in the immediately preceding n-frame period, the remaining data is packed in the fixed recording area, and the high-efficiency encoding unit is added. Is packed into the fixed recording area, and when the code data overflows from the fixed recording area, a part of new residual data is output to the second fixed length packing means. And outputting the remainder of the new residual data to the first temporary storage means, wherein the second fixed length packing means comprises:
Code data output from the temporary storage means, and if there is an empty area in the code data of the fixed recording area, the remaining data output from the first fixed length packing means is replaced with the immediately following n frame period. The code amount control unit adds an identification code indicating that the data is residual data to the empty area, and the code amount control unit sends n bits from the first temporary storage unit via the first fixed length packing unit.
Obtain data amount information of residual data for each frame unit,
If the residual data is present, the high-efficiency code is set so that the target data amount for the next n frame units is a data amount calculated by subtracting the data amount of the residual data from the average target data amount. Is determined for the quantization means, and if the residual data does not exist, the next n
A quantization rate for the high-efficiency encoding means is determined such that a target data amount for each frame unit is a data amount calculated by adding the data amount of the empty area to the average target data amount. It is assumed that.

According to the invention of claim 8 of the present application, a video signal is variable-length coded in units of n frames, and variable-length coded data of an unspecified length is recorded in a fixed recording area on a recording medium. If the remaining data in the n-frame period is in the fixed recording area, the remaining data is recorded together with the first identification code. If the remaining data in the immediately preceding n-frame period is in the fixed recording area, the remaining data is recorded in the fixed recording area. Data input means for obtaining reproduction data from a recording medium recorded together with the identification code of 2, and from the reproduction data of the fixed recording area output from the data input means, code data for the current n frame period is extracted; Extracting residual data of the immediately preceding n-frame period using an identification code indicating that the data is residual data of the immediately preceding n-frame period;
Code data separating means for extracting the residual data of the immediately following n frame period using an identification code indicating that the data is the residual data of the immediately following n frame period; A first temporary storage unit for temporarily storing residual data of a frame period, a second temporary storage unit for temporarily storing the code data of the current n frame period extracted by the code data separation unit,
Code data for n frame periods output from the second temporary storage means, residual data for the immediately preceding n frame period output from the code data separation means, and
Code data linking means for inputting and adaptively linking the remaining data of the immediately following n-frame period output from the temporary storage means to obtain variable-length code data in n-frame units;
A high-efficiency decoder for performing variable-length decoding on the variable-length code data from the code data concatenating means and performing decompression processing.

The invention of claim 9 of the present application is directed to claims 1, 2,
8. The video recording apparatus according to any one of 3, 5, 6, and 7, wherein the high-efficiency encoder performs inter-frame compression encoding using the n-frame unit as a compression unit.
One of n frames is subjected to intra-frame coding, and the other frames are subjected to forward-only or bidirectional predictive coding.

The invention of claim 10 of the present application provides claims 4 and 8
In the video reproducing device according to any one of the above, the high-efficiency decoder performs a frame-to-frame compression encoding in which the n-frame unit is a compression unit. The intra-frame encoding is performed, and the other frames are characterized by performing efficient decoding of variable-length code data that has been subjected to forward prediction encoding or bidirectional prediction encoding.

The invention of claim 11 of the present application is directed to claim 1,
4. The video recording apparatus according to claim 2, wherein the fixed-length stuffing unit comprises: first variable-length coded data of a frame subjected to bidirectional predictive encoding; and a frame subjected to forward predictive encoding. And a residual data generating means for generating residual data by selecting in order of the second variable-length coded data and the third variable-length coded data of the intra-frame coded frame. is there.

The twelfth aspect of the present invention provides the fifth aspect,
6. The video recording apparatus according to claim 6, wherein the first fixed-length stuffing means includes first variable-length coded data of a frame subjected to bidirectional predictive coding, and forward-predictive coding of the frame. Residual data generating means for generating residual data by selecting the second variable-length coded data of the performed frame and the third variable-length coded data of the intra-frame coded frame in this order. Is what you do.

The invention of claim 13 of the present application is directed to claim 1,
2. The video recording device according to claim 2, wherein the fixed-length stuffing unit converts code data representing a high-frequency component among frequency components included in variable-length code data generated for each of the n frames. It is characterized by having residual data generating means for generating as residual data.

The invention of claim 14 of the present application is directed to claim 5,
6. The video recording apparatus according to claim 6, wherein the first fixed-length stuffing unit represents a high-frequency component among frequency components included in variable-length code data generated for each of the n frames. It is characterized by having residual data generating means for generating code data as residual data.

The invention according to claim 15 of the present application is based on claim 1,
4. The video recording apparatus according to claim 2, wherein the fixed-length stuffing unit generates, as residual data, code data obtained by performing variable-length coding on an outer peripheral portion of the video signal at a screen position. It is characterized by having means.

The invention of claim 16 of the present application is directed to claim 5,
6. In the video recording apparatus according to any one of 6 and 7, the first fixed length stuffing unit generates, as residual data, code data obtained by performing variable length coding on an outer peripheral portion of the video signal at a screen position. It is characterized by having residual data generating means.

[0033]

(Embodiment 1) A video recording apparatus according to Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the video recording device according to the present embodiment. This video recording apparatus includes an input unit 10, a high-efficiency encoder 11, a fixed-length stuffing unit 1.
2. It includes a temporary storage unit 13, an error correction encoder 14, a modulator 15, and a recording medium 16.

The input means 10 is a means for externally inputting a video signal. The high-efficiency encoder 11 is a high-efficiency encoding unit that compresses a band of the video signal input by the input unit 10 by high-efficiency encoding and performs variable-length encoding. The fixed-length stuffing unit 12 stuffs variable-length code data output from the high-efficiency encoder 11 and having an unspecified length in units of n frames into a fixed recording area provided on the recording medium 16. Is a means for performing The temporary storage unit 13 holds the remaining data until the next n-frame recording period when the fixed-length packing unit 12 generates residual data that cannot be allocated to the fixed recording area.

The operation of the video recording apparatus having such a configuration will be described. The rearrangement of the code data performed by the fixed-length padding means will be expressed as code data padding in the following description. First, when a video signal is input through the input means 10, the high-efficiency encoder 11 compresses n frames into one GOP with respect to the video signal according to the above-described method and compresses the variable-length code data. Generate. The code amount of this variable-length code data in a GOP unit period is
The length is unspecified for each OP unit.

When such variable-length code data (hereinafter referred to as code data) is recorded on the recording medium 16, a data area to be recorded on the recording medium 16 for each GOP is determined in advance. Such a data area is called a fixed recording area. The fixed recording area includes a certain number of continuous tracks on the recording medium 16. For example, as shown in FIG. 2, the fixed recording areas of GOP (i) and GOP (i + 1) are each composed of five tracks.

The fixed-length stuffing means 12 records an unspecified length of code data Q in a specific fixed recording area for each GOP unit, so that a basic unit of a size uniquely determined from the size of the fixed recording area. This code data Q is divided into the data amount P _0, and the code data Q ₀ is packed by this data size. When the code data Q of the GOP is smaller than the basic unit data amount P ₀ , all the code data Q can be used as the basic unit data. When the code data Q of the GOP is larger than the basic unit data amount P ₀ , the residual data of Q−Q ₀ = ΔQ remains after the basic unit data is extracted. The temporary storage means 13 holds the residual data ΔQ until the next GOP period.

The error correction encoder 14 performs an error correction encoding process on the extracted basic unit data Q ₀ . Next, the modulator 15 modulates the error correction coded data and records it in a fixed recording area of the recording medium 16.

Assuming that the code data of the GOP in the current period i is Q _i , the residual data ΔQ _i held in the temporary storage means 13 is the GO data in the next period (i + 1).
When the code data Q _{i + 1 of} P is input to the fixed length stuffing means 12, it is read out at the same time. The operation of the fixed length stuffing means 12 in this case will be described.

First, the residual data Δ
Pack Q _i . At this time, I packed by adding the identification code C _i to indicate that this data is residual data Delta] Q _i of the previous GOP. Here, the identification code C determines whether or not each code data is related to the immediately preceding GOP during reproduction.
In other words, this is for easily recognizing whether or not it is the residual data ΔQ of the immediately preceding GOP. This is because the residual data included in the reproduction data of the first fixed recording area at the start of reproduction loses the relevance of the code data due to the absence of the code data of the immediately preceding GOP, and cannot be identified (cannot be restored). This is to prevent that.

Second, in the period (i + 1), an empty area other than the area where the residual data is packed
The GOP code data Q _{i + 1} in the period (i + 1) is packed. The size of the stuffed code data Q _{i + 1} is determined from the data size uniquely determined from the fixed recording area,
It is determined as a value obtained by subtracting the code amount of the already packed residual data ΔQ _i . At this time, the code data ΔQ _{i + 1 that} has not been packed is newly stored in the temporary storage unit 13 as residual data. After the stuffing process is completed, the data is recorded in the fixed recording area of the recording medium 16 through the above-described process.

FIG. 2 shows an example of a recording pattern of a fixed recording area recorded by the above-described processing. According to FIG. 2, 5 provided for the code data in the period of (i + 1)
In the fixed recording area of the track, the remaining data is packed in the area at the head of the fourth track with an identification code added thereto.

As described above, in the video recording apparatus of the present embodiment, variable-length code data having an unspecified length is recorded in a fixed recording area set in advance on a recording medium for each GOP unit. And GOP numbers correspond to each other, so that video data can be recorded in a format that facilitates high-speed search such as cueing during reproduction.

It is assumed that n is the number of frames forming a GOP, and the value of n can be an integer of 1 or more. GO
The picture type of each frame included in the n frames can be arbitrarily determined depending on the configuration of P.
For example, the same applies to the case where the number n of constituent frames of a GOP is set to 1 and code data subjected to intra-frame compression is recorded on a recording medium.

The fixed-length padding means 12 can pack the remaining data from the temporary storage means 13 from the beginning in the fixed recording area, or, as shown in FIG. It can also be packed from a specific area. Where it is packed can be set arbitrarily.

It should be noted that the identification code may be inserted not in the area where the video code data is recorded but in the area where the video additional information is recorded, and the identification code itself may have position information in which residual data is packed. In addition, an area for recording an identification flag may be provided at a specific position in each unit of recording video code data, that is, each error correction encoding processing unit (referred to as a sync block).

(Embodiment 2) Next, a video recording apparatus according to Embodiment 2 of the present invention will be described. FIG. 3 is a block diagram showing the configuration of the video recording apparatus according to the present embodiment. The same parts as those in FIG. This video recording apparatus includes an input unit 10, a high-efficiency encoder 11, a fixed-length stuffing unit 12, and a temporary storage unit 1.
3, error correction encoder 14, modulator 15, recording medium 16
And a code amount control unit 20.

The code amount control means 20 sets the average generated code data amount for each n frame to a predetermined average target data amount based on the variable length code data amount detected by the fixed length filling means 12. Thus, the quantization rate is determined, and a quantization control signal is output to the high efficiency encoder 11. More specifically, the code amount control unit 20 acquires the data amount information of the residual data every n frame units from the fixed length filling unit 12, and if there is residual data, the target amount for the next n frame unit is obtained. The quantization rate for the high-efficiency encoder 10 is determined so that the data amount becomes a data amount calculated by subtracting the data amount of the residual data from the average target data amount. The quantization rate for the high-efficiency encoder 11 is determined such that the target data amount for n frame units becomes the average target data amount.

The operation of the thus configured video recording apparatus of the present embodiment will be described. The operation of recording the variable-length code data in GOP units in the fixed recording area of the recording medium is almost the same as that of the first embodiment, and the operation of the different portion will be described here.

The fixed length stuffing means 12 extracts the basic unit data Q ₀ by the method as described above. At this time, the sum of the bit amounts of the target GOP code data Q _i and the immediately preceding GOP residual data ΔQ _i−1 is
When the size of the fixed recording area is larger than the basic unit data amount P ₀ , the residual data ΔQ _i remains after extracting the basic unit data Q _i0 . The fixed length filling unit 12 outputs the code amount of the residual data ΔQ _i to the code amount control unit 20. Conversely, if all the GOP code data Q _i is contained in the basic unit data amount P ₀ , including the residual data of the immediately preceding GOP, the code amount of the residual data ΔQ _i is zero. In such a case, an empty area may be left on the fixed recording area.

The code amount control means 20 receives the code amount of the residual data and performs adaptive code amount control on the high efficiency encoder 11. That is, when there is residual data of the immediately preceding GOP, the residual data ΔQ is calculated from the average target code amount R ₀ corresponding to a preset fixed recording area.
_The bit amount calculated by subtracting the code amount of _i-1 is set as a new target code amount R _i . Then, in order to encode the current GOP so as to achieve the target code amount R _i , the code amount control means 2
0 outputs specific quantization information to the high efficiency encoder 11. If the code amount of the residual data ΔQ _i−1 of the immediately preceding GOP is 0, the average target code amount R ₀ corresponding to the preset fixed recording area is used as it is, and the current GO
Specific quantization information is output to the high-efficiency encoder 11 so as to encode P.

According to the above-described video recording apparatus, accurate code amount control can be performed to realize the recording operation in the first embodiment. For this reason, it is possible to perform encoding while suppressing waste of the recording rate, and it is possible to improve the image quality of the video recorded on the recording medium.

(Embodiment 3) Next, a video reproducing apparatus according to Embodiment 3 of the present invention will be described. FIG. 4 is a block diagram showing the configuration of the video playback device according to the present embodiment. This video reproducing device reproduces a recording medium recorded by the video recording device of the first or second embodiment and outputs a video signal. This video reproducing apparatus has a recording medium 1
6, demodulator 30, error correction decoder 31, code data separation means 32, temporary storage means 33, code data connection means 3
4. High efficiency decoder 35 and output means 36 are included.

The demodulator 30 and the error correction decoder 31 have the function of data input means. That is, the data input means performs variable length coding of the video signal in units of n frames, records variable length code data of an unspecified length in the fixed recording area on the recording medium 16, and simultaneously stores the remaining data of the immediately preceding n frame period. When the data is in the fixed recording area, the reproduction data is obtained from the recording medium in which the remaining data is recorded together with the identification code.

The code data separating means 32 recognizes the identification code from the reproduction data of the fixed recording area outputted from the data input means and converts the data into the remaining data of the immediately preceding n frame period and the code data of the current n frame period. What separates. The temporary storage means 33 temporarily stores the code data of the current n frame period separated by the code data separation means 32. The code data concatenating means 34 receives the remaining data of the immediately preceding n-frame period output from the code data separating means 32 and inputs the code data of the immediately preceding n-frame period outputted from the temporary storage means 33 to generate the residual data. To obtain variable-length code data in units of n frames. The high-efficiency decoder 35 performs variable-length decoding on the variable-length code data from the code data coupling unit 34,
The extension processing is performed.

The operation of the video reproducing apparatus configured as described above will be described. The video recording device described in the first or second embodiment records variable-length code data in GOP units in a predetermined fixed recording area of the recording medium 16. The demodulator 30 receives the modulated error correction coded data from the recording medium 16 and performs demodulation processing. The error correction decoder 31 performs an error correction process on the error correction encoded data. At this point, the reproduced code data has a code amount corresponding to the fixed recording area, and the code data of the current GOP and the remaining data of the immediately preceding GOP are packed.

The code data separating means 32 receives the code data output from the error correction decoder 31, detects an identification code Ci _-1 indicating that it is residual data, and detects the residual data of the immediately preceding GOP. It is separated into ΔQ _i−1 and code data Q _i of the current GOP. Code data Q _{i of the} current GOP
Are stored in the temporary storage unit 33. When the next fixed recording area is reproduced and the residual data ΔQ _i is separated by the code data separating means 32 as described above, the code data linking means 34 reads the code data read from the temporary storage means 33. The residual data ΔQ _i is connected to Q _i by a predetermined method and output. If the residual data is not separated from the code data separating means 32, it means that there is no residual data for the code data, and this code data is output as it is as the GOP code data.

If the reproduction data of the first fixed recording area at the start of reproduction includes the remaining data of the immediately preceding GOP, the code data of the immediately preceding GOP to be connected does not originally exist. Invalidate the remaining data.

The variable-length code data output from the code data concatenating means 34 in this manner is
Are subjected to processes such as variable-length decoding, inverse quantization, and inverse orthogonal transform, and output means 36 outputs a video signal.

As described above, the video reproducing apparatus of the present embodiment converts the variable-length code data recorded by the video recording apparatus of the first or second embodiment to the original complete code using a very simple configuration. Data can be restored. For this reason, it is possible to reproduce a high-quality video.

Incidentally, the temporary storage means 33 is not limited to the above configuration. For example, code data which does not hold all the code data of the GOP and can be restored without residual data is directly input to the high-efficiency decoder 35 through the code data separating means 32 and the code data connecting means 34. Alternatively, only the code data requiring the residual data may be stored in the temporary storage unit 33. However, in this case, it is necessary to arrange a temporary storage means for adjusting the output timing of the GOP code data at a subsequent stage. Thus, various configurations of the temporary storage unit 33 are conceivable.

(Embodiment 4) Next, a video recording apparatus according to Embodiment 4 of the present invention will be described. FIG. 5 is a block diagram showing the configuration of the video recording apparatus according to the present embodiment. The same parts as those in FIG. This video recording apparatus includes an input unit 10, a high-efficiency encoder 11, a first fixed length stuffing unit 40, a first temporary storage unit 41, a second fixed length stuffing unit 42, and a second temporary storage unit 43. , Error correction encoder 14, modulator 1
5, including the recording medium 16.

The high-efficiency encoder 11 compresses the band of the video signal input by the input means 10 by high-efficiency encoding and performs variable-length encoding. The first fixed-length stuffing unit 40 stuffs variable-length code data output from the high-efficiency encoder 11 and having an unspecified length every n frames into a fixed recording area provided on the recording medium 16. In order to write, data is rearranged according to a predetermined rule. Such rearrangement of data is called “stuffing”. The first temporary storage means 41 holds at least a part of the remaining data until the next n-frame recording period when the first fixed-length packing means 40 generates residual data that cannot be allocated to the fixed recording area. It is.

The second temporary storage means 42 holds the code data packed in the fixed recording area by the first fixed length packing means 40 until the next n-frame recording period. The second fixed length stuffing means 43 stuffs the code data output from the second temporary storage means 42 and, if there is a free space in the coded data of the fixed recording area, the first fixed length stuffing means 40 Is to pack the remaining data output from the vacant area.

More specifically, the first fixed-length stuffing means 40 adds an identification code to the remaining data output from the first temporary storage means 41 to indicate that it is the remaining data in the immediately preceding n-frame period. In addition, the remaining data is packed in the fixed recording area, and the high efficiency encoder 11
Is packed in the fixed recording area in the current n-frame period, and when the code data overflows from the fixed recording area, a part of the new residual data is output to the second fixed length packing means 43, The remainder of the new residual data is output to the first temporary storage means 41.

The second fixed length stuffing means 43 stuffs the code data output from the second temporary storage means 42 and, if there is an empty area in the coded data of the fixed recording area, the first fixed length stuffing means 43. The remaining data output from the means 40 is stuffed into an empty area by adding an identification code indicating that it is the remaining data for the immediately following n frame periods.

The operation of the thus configured video recording apparatus of the present embodiment will be described. Embodiment 1
The variable-length code data in GOP units is recorded in the fixed recording area of the recording medium 16 by an operation substantially similar to the operation described in (1). Here, the operation of the different parts will be described with reference to FIGS.

In FIG. 6, GO for three consecutive periods
Think about P. GO for GOP in current period i
Let P (i) be the GOP of the immediately preceding period, GOP (i-1)
And the GOP in the immediately subsequent period is GOP (i + 1).
In this example, the code data Q in the (i-1) period_i-1 Is basic
Unit data amount (fixed length) P₀ Less, i period sign
Data Q_i Is the basic unit data amount P₀ More (i +
1) Code data Q of period _{i + 1} Is the basic unit data amount P₀ Yo
Less. Note that, for example, code data Q_iIs basic
Unit data amount P₀ Code data Q_i0Call
Huh.

FIG. 7 is a timing chart showing the operation of the video recording apparatus according to the present embodiment.
P (i-1) and GOP (i + 1). First, as shown in FIGS. 7A and 7B, the high-efficiency encoder 11 performs variable-length code data Q of an unspecified length in GOP units.
_i−1 , Q _i , and Q _{i + 1} are output, respectively.

For example, in the GOP (i-1) shown in FIG. 6, since the data amount of the code data Q _i-1 is smaller than the basic unit data amount P ₀ , the first fixed length stuffing means 40 is provided in FIG.
As shown in the figure, the code data Q _i-1 is directly packed. This code data Q _i-1 is also output to the second temporary storage means 42. Since the residual data ΔQ _i-1 is 0, FIG.
No residual data is output to the first temporary storage means 41 as shown in FIG. Therefore, at the end of the period (i-1), the data storage area of the second temporary storage unit 42 is as shown in FIG.
A blank as shown in FIG. The GOP shown in FIG.
In (i-1), since the code data Q _i-2 has not been clarified, the result of stuffing by the second fixed length stuffing means 43 is not shown.

In GOP (i), as shown in FIGS. 6 and 7B, the code data Q _i is larger than the basic unit data amount P ₀ by ΔQ _i . As shown in FIG. 7C, the first fixed-length stuffing unit 40 stuffs the code data Q _i0 corresponding to the basic unit data amount P ₀ among the code data Q _i . The packed code data Q _i0 is output to the second temporary storage means 42. Further, assuming that the residual data ΔQ _i is ΔQ _i1 + ΔQ _i2 and Q _i = Q _i0 + ΔQ _i , the second fixed-length stuffing means 43 transmits the first fixed-length stuffing means 40 as shown in FIG. The residual data ΔQ _i1 of the output residual data ΔQ _i is fetched, and the residual data ΔQ _i1 is immediately packed in a vacant area of the data read from the second temporary storage means 42 during the period i. Next, as shown in FIG. 7D, the overflowing residual data ΔQ _i2 of ΔQ _i is output to the first temporary storage means 41. Next, the second fixed length stuffing means 43 stuffs the code data Q _i-1 of the period (i-1) held in the second temporary storage means 42 and sets the remaining data ΔQ _i1 to the remaining data of the period i. And an identification code C _i1 indicating that it is a part of

In GOP (i + 1), FIGS. 6 and 7
As shown in (b), the code data Q _{i + 1} is considerably smaller than the basic unit data amount P ₀ . As shown in FIG. 7C, the first fixed-length stuffing unit 40 stuffs all the code data Q _{i + 1} . And the first fixed length stuffing means 40 is
Reads residual data Delta] Q _i2 held in the temporary storage means 41 of stuffs residual data Delta] Q _i2 in the free space of the data with the identification code C _i2. Packed code data Q
_{i + 1} and the residual data ΔQ _i2 are output to the second temporary storage means 42.

The second fixed length stuffing means 43 is provided in FIG.
As shown in (f), the code data Q _i0 read from the second temporary storage unit 42 is packed in the period (i + 1).
In the next period (i + 2), the second fixed length stuffing means 43
Is the code data Q held in the second temporary storage means 42
_{i + 1} and the residual data ΔQ _i2 are read, and those data are packed in the data area of GOP (i + 1). By such a packing method, the residual data is packed into the free area of the immediately preceding fixed recording area and the immediately following fixed recording area.

Here, the recording of the residual data with the identification code added thereto is performed by combining the residual data with the immediately preceding or succeeding GOP.
This is to make it possible to recognize the relevance of the information. In other words, this is to prevent the remaining data contained in the first fixed recording area at the start of reproduction from being lost due to lack of the code data of the immediately preceding GOP and becoming unrecognizable (unrecoverable). .

FIG. 6 shows a recording pattern on the magnetic medium recorded by the above processing. According to such an embodiment, data can be recorded in a format that facilitates high-speed search such as cueing during reproduction. Further, in the present embodiment, waste of the recording area is reduced as compared with the first embodiment, and the image quality can be further improved.

(Embodiment 5) Next, a video recording apparatus according to Embodiment 5 of the present invention will be described. FIG. 8 is a block diagram showing the configuration of the video recording apparatus according to the present embodiment. The same parts as those in FIG. 5 are denoted by the same reference numerals, and description thereof will be omitted. This video recording apparatus includes an input unit 10, a high-efficiency encoder 11, a first fixed length stuffing unit 40, a first temporary storage unit 41, a second fixed length stuffing unit 43, and a second temporary storage unit 42. , Error correction encoder 14, modulator 1
5. In addition to the recording medium 16, a code amount control means 44 is included.

The code amount control means 44 determines the average generated code data amount of each n frame unit based on the variable length code data amount detected by the first fixed length The quantization rate is determined so as to obtain a quantity, and a quantization control signal is output to the high-efficiency encoder 11.

More specifically, the code amount control means 44 acquires the data amount information of the residual data every n frames from the first fixed-length stuffing means 40. The quantization rate for the high-efficiency encoder 11 is determined so that the target data amount for the n-frame unit becomes a data amount calculated by subtracting the data amount of the residual data from the average target data amount. Does not exist, the quantization for the high-efficiency encoder 11 is performed such that the target data amount for the next n-frame unit is a data amount calculated by adding the data amount of the free area to the average target data amount. Determine the rate.

The operation of the thus configured video recording apparatus of the present embodiment will be described. By substantially the same operation as that described in the fourth embodiment, variable-length code data in GOP units is recorded in the fixed recording area of the recording medium 15. Hereinafter, the difference will be described.

The first fixed length stuffing means 40 extracts the basic unit data by the method as described above. At this time, the code data of the current GOP of interest and the G
When the sum of the code amount of the OP and the residual data is larger than the basic unit data amount P _{0 of} the fixed recording area, the residual data ΔQ
Remains. The first fixed length padding means 40 outputs the code amount of the residual data ΔQ to the code amount control means 44. Conversely, if the if the residual data of the immediately preceding GOP which including the sign data Q of the GOP to the base unit data amount P ₀ is accommodated all would be free space in the fixed recording region. In this case, the code amount corresponding to the empty area is output to the code amount control means 44.

The code amount control means 44 inputs the code amount of the residual data ΔQ and performs adaptive code amount control. That is, when there is residual data of the immediately preceding GOP, the average target code amount R ₀ corresponding to a preset fixed recording area is set.
From subtracts the code amount of the residual data Delta] Q, to perform encoding of the current GOP subtraction result as a new target code amount R _i, and outputs the quantized information to the high-efficiency encoder 11. If there is a free area, a bit amount calculated by adding the code amount of this free area to the average target code amount R ₀ corresponding to a preset fixed recording area is calculated as a new target code amount R. _{As i} , the quantization information is output to the high-efficiency encoder 11 so as to encode the current GOP.

As described above, according to the present embodiment, accurate code amount control for realizing the recording operation in the fourth embodiment can be performed. Furthermore, encoding can be performed while suppressing waste of the recording rate, and the image quality can be further improved.

In the video recording apparatus according to the fourth or fifth embodiment, the first temporary storage means 41 for storing the remaining data
And second temporary storage means 42 for holding basic unit data.
Are prepared separately, but these functions can also be realized by one temporary storage unit.

(Embodiment 6) Next, a video reproducing apparatus according to Embodiment 6 of the present invention will be described. FIG. 9 is a block diagram showing the configuration of the video reproducing apparatus according to the present embodiment. The same parts as those in FIG. 4 are denoted by the same reference numerals, and description thereof will be omitted. This video reproducing device reproduces a signal of a recording medium recorded by the video recording device of the fourth or fifth embodiment, and outputs a video signal. This video reproducing apparatus includes a recording medium 16, a demodulator 30, an error correction decoder 31, a code data separating means 50, a code data linking means 51, a first temporary storage means 52, a second temporary storage means 53, It comprises an efficiency decoder 35 and output means 36.

The demodulator 30 and the error correction decoder 31 have the function of data input means. That is, the data input means performs variable length coding of the video signal in units of n frames, records variable length code data of an unspecified length in a fixed recording area on the recording medium 16, and simultaneously stores the remaining data of the immediately following n frame period. If the data is in the fixed recording area, the remaining data
When the remaining data in the immediately preceding n-frame period is in the fixed recording area, the reproduction data is obtained from the recording medium 16 in which the remaining data is recorded together with the second identification code.

The code data separating means 50 extracts the code data of the current n frame period from the reproduction data of the fixed recording area outputted from the data input means, and determines that the data is the residual data of the immediately preceding n frame period. The remaining data in the immediately preceding n-frame period is extracted using the identification code shown, and the remaining data in the immediately following n-frame period is extracted using the identification code indicating that it is the remaining data in the immediately following n-frame period. . The first temporary storage means 52
This is to temporarily store the remaining data of the n-frame period immediately after being extracted by the code data separating means 50.

The second temporary storage means 53 temporarily stores the current n-frame code data extracted by the code data separation means 50. Code data linking means 5
1 is the code data of the n-frame period output from the second temporary storage means 53, the residual data of the immediately preceding n-frame period output from the code data separation means 50, and the output from the first temporary storage means 52 The remaining data of the n-frame period immediately after the input is input and adaptively connected to obtain variable-length code data in n-frame units. The high-efficiency decoder 35 performs variable-length decoding on the variable-length code data from the code-data concatenating means 51 and performs expansion processing.

The operation of the thus constructed video reproducing apparatus of the present embodiment will be described with reference to FIGS. 10 and 11. FIG. 10 is an explanatory diagram showing the track arrangement of the code data reproduced from the recording medium 16. FIG. 11 is a timing chart showing the operation of the video recording apparatus of the present embodiment, and includes GOP (i-1), GOP (i), GO in FIG.
P (i + 1). By substantially the same operation as that described in the third embodiment, variable-length code data in GOP units is reproduced from the fixed recording area of the recording medium 16.
Here, the operation of the different parts will be described with reference to FIGS.

First, it is assumed that variable length code data in GOP units as shown in FIG. 10 is recorded in a predetermined fixed recording area of the recording medium 16. GOP (i) in the current period i in three consecutive GOPs
, The immediately preceding GOP (i-1) and the immediately following GOP (i +
1) exists. In this example, (i-
1) The code data Q _i-1 in the period is larger than the basic unit data amount P ₀ , and the code data Q _{i in the} i period is the basic unit data amount P
It is assumed that the code data Q _{i + 1 in the} period (i + 1) is smaller than _{0 and} larger than the basic unit data amount P ₀ .

The data reproduced from the recording medium 16 is demodulated by the demodulator 30 shown in FIG. The data is subjected to an error correction process by the error correction decoder 31. At this point, the reproduced code data has a code amount corresponding to the fixed recording area, and during the period i, as shown in FIGS.
And code data Q _i of (i), has a residual data Delta] Q _i-1 of the immediately preceding GOP (i-1), a state in which the residual data Delta] Q _{i + 1} is packed in GOP (i + 1) immediately after the .

The code data separating means 50 shown in FIG. 9 receives this code data and outputs the residual data ΔQ _{i-1 of the} immediately preceding GOP.
GOP identifying code C _i-1, and after indicating that the
Code C indicating that the residual data is ΔQ _{i + 1}
Detect _{i + 1} . Then, as shown in FIGS. 11B and 11C, these two types of residual data ΔQ _i−1 and ΔQ _{i +
1,} is separated into a code data Q _i of the current GOP. Code data Q _i of the current GOP is held in the second temporary storage means 53 as shown in FIG. 11 (e). Further, the remaining data ΔQ _{i + 1} of the GOP immediately after this is held in the first temporary storage means 52. The residual data ΔQ _i−1 of the immediately preceding GOP is output to the code data concatenating means 51.

The code data concatenating means 51 is provided with residual data to be concatenated from the first temporary storage means 52 to the GOP code data Q _{(i-1) 0} read out from the second temporary storage means 53 in the period i. When ΔQ _i-1 is given, FIG.
These data are linked by a predetermined method as shown in FIG. Further, as shown in FIG. 11C, when the residual data ΔQ _{i + 1} to be connected to the code data of GOP (i + 1) is output from the residual data ΔQ _{i + 1} in the period (i + 2), _{i + 1} is linked to the code data Q _{(i + 1) 0} by a predetermined method.

If there is no residual data .DELTA.Q to be connected to the code data of the GOP in the code data separating means 50 or the first temporary storage means 52, the code data is left unconnected without any connection. Q is output as GOP code data.

When the reproduction data of the first fixed recording area at the start of reproduction includes the residual data ΔQ of the immediately preceding GOP, there is no code data of the immediately preceding GOP to be connected. The data ΔQ is invalidated. If all the code data of the current GOP are not present in the reproduction data of the first fixed recording area, the remaining data may be packed in the empty area of the immediately preceding fixed recording area. Since there is no data in the immediately preceding fixed recording area, nothing is connected.

The variable-length code data output from the code data linking means 51 is subjected to processing such as variable-length decoding, inverse quantization, and inverse orthogonal transform by the high-efficiency decoder 35, and is decoded into a video signal. You. The video signal thus reproduced from the recording medium 16 is output via the output means 36.

As described above, the video reproducing apparatus according to the present embodiment can restore the variable-length code data recorded by the video recording apparatus according to the fourth or fifth embodiment to the original code data with a very simple configuration. . Therefore, the video signal can be reproduced with high image quality.

The second temporary storage means 53 is not limited to the above configuration. For example, code data that does not hold all the code data of the GOP and can be restored without residual data is transmitted as it is via the code data separating means 50 and the code data connecting means 51,
Only the code data requiring the residual data may be stored in the second temporary storage unit 53. However, in this case,
For adjusting the output timing of the GOP code data, it is necessary to arrange a new temporary storage means at the subsequent stage.

As described above, the function of the second temporary storage means 53 is achieved by any number of realizing means. The first
Although the temporary storage unit 52 and the second temporary storage unit 53 have been described as separate temporary storage units, their functions can be realized using one temporary storage unit.

(Embodiment 7) Next, as Embodiment 7 of the present invention, a fixed length stuffing means used in a video recording apparatus will be specifically described. FIG. 12 is a configuration diagram of the fixed length stuffing means 12A or 40A of the present embodiment.
The fixed-length padding units 12A and 40A include a picture-by-picture data alignment unit 60, a padding unit 61, a fixed-length discriminating unit 62, a selector 63, a writing control unit 64, and a reading control unit 65.

The operation of the fixed length stuffing means 12A, 40A thus constructed will be described with reference to FIGS. In any one of the video recording apparatuses according to the first, second, fourth, and fifth embodiments, the fixed length stuffing unit operates in a similar manner. The input variable-length code data of the GOP is sorted by the picture-by-picture data sorting means 60 in the order of I picture, P picture, and B picture. As shown in FIG. 13, for example, one GOP is composed of seven pictures, and the input order is as shown in FIG.
The encoding order is as shown in FIG. The picture-by-picture data sorting means 60 sorts the code data input in the order of FIG. 13B into the order of an I picture, a P picture, and a B picture. The data output as a result is in the order as shown in FIG.

On the other hand, the read control means 65 of FIG.
The remaining data generated in the immediately preceding GOP is read from the temporary storage means 13 or 41. The stuffing means 61 receives the output data from the picture-by-picture data arranging means 60 and the residual data output from the read control means 65, and stuffs the data into a fixed recording area. Packing means 6
The data packed in 1 is supplied to the selector 63 and the fixed length discriminating means 62. The fixed length discriminating means 62 outputs a control signal, switches the selector 63 so that the input data is output as basic unit data until the code amount satisfies the fixed recording area, and outputs the remaining data after exceeding the fixed recording area. The selector 63 is switched to perform the operation. The basic unit data selected at this time is output to the error correction encoder 14 shown in any of FIGS. On the other hand, the selected residual data is output to the temporary storage unit 13 or 41 by the write control unit 64 and held.

Here, picture-by-picture data sorting means 60,
Stuffing means 61, fixed length determining means 62, selector 63
Are the first variable-length coded data of the frame subjected to bidirectional predictive encoding, the second variable-length coded data of the frame subjected to forward predictive encoding, and the second variable-length coded data of the frame subjected to intra-frame encoding. Thus, the function of the residual data generating means for generating the residual data by selecting the variable length coded data in the order of 3 is achieved.

As described above, the fixed length stuffing means 12A and 40A of the present embodiment can set the picture type that can be the residual data of one GOP in the order of I picture, P picture, and B picture. That is, an I picture or a P picture that can be a reference screen in decoding processing at the time of reproduction can be preferentially protected. For example, residual data that can be lost by editing is part of the B picture in most cases. be able to. Therefore, when the recorded data is edited or rewritten, a better reproduced video can be obtained.

(Embodiment 8) Next, as Embodiment 8 of the present invention, another fixed length stuffing means used in a video recording apparatus will be specifically described. FIG. 14 is a configuration diagram of another fixed length stuffing means 12B or 40B. The fixed length stuffing means 12B and 40B include a frequency order data sorting means 70, a stuffing means 61, a fixed length discriminating means 62,
It is configured to include a selector 63, a write control unit 64, and a read control unit 65.

The operation of the fixed length stuffing means 12B, 40B thus constructed will be described with reference to FIGS. In any one of the video recording apparatuses according to the first, second, fourth and fifth embodiments, the fixed-length stuffing means 12B and 40B perform the same operation. The input variable-length code data of the GOP is input to the frequency-order data aligning means 70. The frequency-sequential data sorting unit 70 classifies data according to a certain rule from DC data and low-frequency data to high-frequency data for each DCT block, and separates the data into a low-frequency data set and a high-frequency data set. . Then, data is output so as to be preferentially recorded from a set of low-frequency data. FIG. 15 shows this state.

For example, a macro block is a DCT block of four luminance signals (Y) and two color difference signals (Cr, C
b) each DCT block
The code data of the block is as shown in FIG. That is, the frequency-sequential data sorting unit 70 divides the data from each DCT block in order from data representing a relatively low frequency band including DC data (DC) so as to fit within a certain specific length, and sets this as a set of low-frequency data. Then, the remaining data representing relatively high frequency ranges is defined as a set of high frequency range data. When this macro block is one that has been predictively coded by motion compensation, FIG.
Although not shown in FIG. 5, a motion vector can be preferentially included in a set of low-frequency data.

On the other hand, the read control means 65 of FIG.
The temporary storage means 13 stores the residual data generated in the immediately preceding GOP.
Or read from 41. The stuffing means 61 inputs the output data from the frequency-order data arranging means 70 and the residual data output from the reading control means 65, and stuffs the fixed recording area.

The data output from the packing means 61 is given to the selector 63 and the fixed length discriminating means 62. The fixed length discriminating means 62 outputs a control signal, switches the selector 63 so that the data is output as basic unit data up to the code amount that satisfies the fixed recording area, and outputs the remaining data after exceeding the fixed recording area. Selector 63 is switched as described above. At this time, the selected basic unit data is output to the error correction encoder 14 (not shown). Then, the selected remaining data is written to the temporary storage means 13 or 41 by the write control means 64.

Here, the frequency-sequential data sorting means 70, the stuffing means 61, the fixed length discriminating means 62, and the selector 63
Among the frequency components included in the variable-length code data generated for each frame unit, the function of a residual data generation unit that generates code data representing a high frequency component as residual data is achieved.

The fixed length stuffing means 12B and 40B of the present embodiment as described above can set data that can be residual data to data representing a relatively high frequency.
Therefore, even when the residual data is lost due to, for example, editing or the like, it is possible to perform processing in which distortion is relatively invisible to human eyes. Therefore, when the recorded data is edited or rewritten, a better reproduced video can be obtained.

(Embodiment 9) Next, as Embodiment 9 of the present invention, another fixed length stuffing means used in a video recording apparatus will be specifically described. FIG. 16 is a configuration diagram of further fixed length stuffing means 12C and 40C. The fixed length stuffing means 12C and 40C include a screen position data aligning means 80, a stuffing means 61, a fixed length determining means 62,
It is configured to include a selector 63, a write control unit 64, and a read control unit 65.

The operation of the fixed length stuffing means 12C, 40C thus constructed will be described with reference to FIGS. In any one of the video recording apparatuses according to the first, second, fourth and fifth embodiments, the fixed length stuffing means 12C and 40C operate in the same manner. The input variable length code data of the GOP is input to the screen position data aligning means 80.

The screen position data sorting means 80 sorts the input variable length code data of the GOP according to the position of each macroblock on the screen. The screen position data arranging means 80 rearranges the macroblocks at the center of the screen in order from the macroblocks at the outer periphery and outputs the rearranged macroblocks. For example, it is assumed that the screen is divided into macroblock units as shown in FIG. The screen position data arranging means 80 rearranges and outputs data in order from a central macroblock to a peripheral macroblock in accordance with a predetermined rule.

On the other hand, the read control means 65 reads the residual data generated in the immediately preceding GOP from the temporary storage means 13 or 41. The stuffing means 61 includes output data from the screen position data aligning means 80 and read control means 65.
The remaining data output from is input and packed in the fixed recording area.

The data output from the packing means 61 is given to the selector 63 and the fixed length discriminating means 62. The fixed length discriminating means 62 outputs a control signal, switches the selector 63 so that the data is output as basic unit data up to the code amount that satisfies the fixed recording area, and outputs the remaining data after exceeding the fixed recording area. Selector 63 is switched as described above. The basic unit data selected at this time is output to an error correction encoder 14 (not shown). Then, the selected remaining data is stored in the temporary storage unit 13 or 41 by the write control unit 64.

Here, the screen position data aligning means 80, the stuffing means 61, the fixed length discriminating means 62, and the selector 63 generate, as residual data, code data obtained by performing variable length coding on the outer peripheral portion of the video signal at the screen position. The function of the residual data generating means is achieved.

The fixed length stuffing means 12C and 40C of the present embodiment as described above can set data that can be residual data as data relatively located on the outer periphery of the screen. Therefore, for example, even when the residual data is lost due to editing, the deterioration of the image quality can be relatively dispersed on the outer peripheral portion of the screen. Therefore, when the recorded data is edited or rewritten, a better reproduced video can be obtained.

Note that the definition of the outer peripheral portion need not be the one described above, and it is not always necessary to perform the ordering as shown in FIG. Many other methods are also conceivable. Although the seventh, eighth, and ninth embodiments have been described as independent fixed-length stuffing means, these functions can be easily combined, and a better effect can be obtained by combining the respective effects. Can be.

[0119]

As described above, according to the present invention, each GO
Variable-length code data of an unspecified length for each P unit can be recorded in a preset fixed recording area on a recording medium, and a high-speed search such as cueing can be easily performed during reproduction. Further, even when recording is performed in this format, high-efficiency encoding that can make full use of the recording rate can be performed, and video can be recorded with high image quality.
In addition, variable-length code data recorded in such a format can be reproduced with high image quality by a very simple configuration. Furthermore, even in the case of recording in such a format, and in the case of editing or overwriting, it is possible to suppress deterioration of image quality and obtain a good reproduced video.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a video recording device according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a data recording method of the video recording device according to the first embodiment.

FIG. 3 is a configuration diagram of a video recording device according to a second embodiment of the present invention.

FIG. 4 is a configuration diagram of a video reproduction device according to a third embodiment of the present invention.

FIG. 5 is a configuration diagram of a video recording device according to a fourth embodiment of the present invention.

FIG. 6 is an explanatory diagram showing a data recording method of a video recording device according to a fourth embodiment.

FIG. 7 is a time chart illustrating a data recording operation of the video recording device according to the fourth embodiment.

FIG. 8 is a configuration diagram of a video recording device according to a fifth embodiment of the present invention.

FIG. 9 is a configuration diagram of a video reproduction device according to a sixth embodiment of the present invention.

FIG. 10 is an explanatory diagram showing a data reproducing method of the video reproducing device according to the sixth embodiment.

FIG. 11 is a time chart illustrating a data reproducing operation of the video reproducing device according to the sixth embodiment.

FIG. 12 is a configuration diagram of a fixed length stuffing unit in a video recording device according to a seventh embodiment of the present invention.

FIG. 13 is a diagram illustrating the operation of a fixed-length stuffing unit in the video recording apparatus according to the seventh embodiment.

FIG. 14 is a configuration diagram of a fixed-length stuffing unit in a video recording device according to an eighth embodiment of the present invention.

FIG. 15 is a diagram illustrating the operation of a fixed-length stuffing unit in the video recording apparatus according to the eighth embodiment.

FIG. 16 is a configuration diagram of a fixed-length stuffing unit in a video recording device according to a ninth embodiment of the present invention.

FIG. 17 is a diagram illustrating the operation of a fixed-length stuffing unit in the video recording apparatus according to the ninth embodiment.

FIG. 18 is a configuration diagram of a conventional video recording apparatus.

FIG. 19 is an explanatory diagram showing a data recording method of a conventional video recording device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Input means 11 High-efficiency encoder 12, 12A, 12B, 12C Fixed length stuffing means 40, 40A, 40B, 40C First fixed length stuffing means 13, 33 Temporary storage means 14 Error correction encoder 15 Modulator 16 Recording medium 20, 44 Code amount control means 30 Demodulator 31 Error correction decoder 32, 50 Code data separation means 34, 51 Code data connection means 35 High efficiency decoder 36 Output means 40 Second fixed length packing means 41 , 52 first temporary storage means 42, 53 second temporary storage means 60 picture-by-picture data arranging means 61 stuffing means 62 fixed-length discriminating means 63 selector 64 writing control means 65 read-out control means 70 frequency-ordered data arranging means 80 screen Position data alignment means

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hidemi Oka 1006 Kazuma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. 72) Inventor Tadashi Yoshino 1006 Kazuma Kadoma, Kadoma City, Osaka Prefecture F-term (reference) 5C053 FA14 FA22 FA23 GA16 GB06 GB08 GB15 GB26 GB37 GB40 HA24 HA29 JA21 KA04 5C059 KK21 LA10 MA00 MA05 MA23 ME01 PP05 PP06 PP07 RB01 RB15 RC00 RF04 SS11 TA46 TB03 TC18 5D044 DE28 DE49 DE72 EF03 EF05 FG10 FG24 GK12 GK14 HH07 HL14

Claims (16)

[Claims] An input unit for inputting a video signal; a high efficiency coding unit for compressing a band of the video signal input by the input unit by high efficiency coding and performing variable length coding; Fixed-length stuffing means for arranging data for stuffing variable-length code data output from the means and having an unspecified length in units of n frames into a fixed recording area provided on a recording medium; and Temporary data storage means for holding the remaining data until the next n-frame recording period when residual data that cannot be distributed to the fixed recording area is generated, For the residual data output from
A video recording apparatus, characterized by adding an identification code indicating that the data is residual data in the immediately preceding n frame periods, and filling the fixed recording area with the residual data. 2. The video according to claim 1, wherein the fixed length padding means packs the remaining data in the immediately preceding n frame periods so as to be recorded in a specific area provided in the fixed recording area. Recording device. 3. An input means for inputting a video signal, high efficiency coding means for band-compressing the video signal input by the input means and performing variable length coding by high efficiency coding, and said high efficiency coding. Fixed-length stuffing means for arranging data for stuffing variable-length code data output from the means and having an unspecified length in units of n frames into a fixed recording area provided on a recording medium; and When residual data that cannot be distributed to the fixed recording area is generated, a temporary storage unit that retains the residual data until the next n-frame recording period; and a variable length code data amount detected by the fixed length filling unit. The quantization rate is determined so that the average generated code data amount for each n-frame unit becomes a predetermined average target data amount, and the high-efficiency code is determined. Anda code amount control means for outputting the quantization control signal to means, the fixed length packing means, with respect to the residual data output from the temporary storage means,
An identification code indicating remaining data in the immediately preceding n-frame period is added, and the fixed data is packed in the fixed storage area. The code amount control means controls the temporary length through the fixed length packing means. The data amount information of the residual data is obtained from the storage means for every n frame units, and if the residual data exists, the target data amount for the next n frame unit is calculated from the average target data amount to the data amount of the residual data. The quantization rate for the high-efficiency encoding means is determined so as to be a data amount calculated by subtracting the remaining data. If the residual data does not exist, the target data amount for the next n frame units is calculated as the average target data amount. A video recording apparatus, wherein a quantization rate for the high-efficiency encoding means is determined so as to obtain a data amount. 4. A video signal is variable-length coded in n-frame units, variable-length coded data of unspecified length is recorded in a fixed recording area on a recording medium, and at the same time, residual data of the immediately preceding n-frame period is recorded. A data input unit for obtaining reproduction data from a recording medium in which the residual data is recorded together with an identification code when the data is in the fixed recording area; and the identification based on the reproduction data in the fixed recording area output from the data input means. Code data separating means for recognizing the code and separating it into residual data of the immediately preceding n-frame period and code data of the current n-frame period; and code data of the current n-frame period separated by the code data separating means. A temporary storage unit for temporarily storing, and inputting the residual data for the immediately preceding n-frame period output from the code data separating unit, Code data concatenating means for inputting code data for the immediately preceding n-frame period output from the storage means and concatenating it with the residual data to obtain variable-length code data in n-frame units; A video decoding apparatus comprising: a high-efficiency decoding unit that performs variable-length decoding of code data and performs expansion processing. 5. An input means for inputting a video signal, a high efficiency coding means for band-compressing the video signal input by said input means by high efficiency coding and performing variable length coding, and said high efficiency coding. First fixed-length stuffing means for arranging data for stuffing variable-length code data output from the means and having an unspecified length every n frames into a fixed recording area provided on a recording medium; A first temporary storage unit that holds at least a part of the remaining data until a next n-frame recording period when remaining data that cannot be allocated to the fixed recording area is generated by the first fixed-length stuffing unit; A second temporary storage unit for holding the code data packed in the fixed recording area by the first fixed length packing unit until the next n-frame recording period; A second fixed-length stuffing unit that stuffs the output code data and stuffs the remaining data output from the first fixed-length stuffing unit into the free space when there is a free space in the code data of the fixed recording area; Means, the first fixed-length stuffing means, for the residual data output from the first temporary storage means, an identification code indicating that it is residual data in the immediately preceding n-frame period In addition, the fixed data area is stuffed with the residual data, and the coded data for the current n-frame period output from the high-efficiency coding means is stuffed into the fixed recording area, and the coded data overflows from the fixed recording area. In this case, a part of the new residual data is output to the second fixed-length stuffing means, and the rest of the new residual data is stored in the first temporary storage. The second fixed length stuffing means stuffs the code data output from the second temporary storage means, and when there is a free area in the coded data of the fixed recording area, A video recording apparatus characterized in that the residual data output from the first fixed-length stuffing unit is stuffed into the empty area by adding an identification code indicating that it is the residual data for the immediately following n-frame period. . 6. The first fixed length stuffing unit stuffs the remaining data in the immediately preceding n-frame period so as to be recorded in a specific area provided in the fixed recording area. The video recording device as described in the above. 7. An input means for inputting a video signal; a high efficiency coding means for band-compressing the video signal input by said input means by high efficiency coding to perform variable length coding; and said high efficiency coding. First fixed-length stuffing means for arranging data for stuffing variable-length code data output from the means and having an unspecified length every n frames into a fixed recording area provided on a recording medium; A first temporary storage unit for holding the remaining data until the next n-frame recording period when remaining data that cannot be distributed to the fixed recording area is generated by the first fixed length packing unit; A second temporary storage unit for holding the code data packed in the fixed recording area by the packing unit until the next n-frame recording period; and a code output from the second temporary storage unit. A second fixed-length stuffing unit that stuffs the remaining data output from the first fixed-length stuffing unit into the vacant region when code data in the fixed recording area has a vacant region, A quantization rate is determined based on the variable-length code data amount detected by the first fixed-length stuffing means so that the average generated code data amount for each n-frame unit becomes a preset average target data amount. And a code amount control unit that outputs a quantization control signal to the high-efficiency encoding unit. The first fixed-length stuffing unit is output from the first temporary storage unit. To the residual data, an identification code indicating that it is residual data in the immediately preceding n-frame period is added, the residual data is packed in the fixed recording area, and The code data of the current n frame period output from the means is packed in the fixed recording area, and when the code data overflows from the fixed recording area, a part of the new residual data is sent to the second fixed length packing means. And outputting the remainder of the new residual data to the first temporary storage means, wherein the second fixed-length stuffing means stuffs the code data output from the second temporary storage means. In addition, when there is a free area in the code data of the fixed recording area, an identification code is added to the remaining data output from the first fixed length stuffing means, indicating that the remaining data is the remaining data of the immediately following n frame periods. The code amount control means, from the first temporary storage means via the first fixed length stuffing means, every n frame units The data amount information of the residual data is obtained, and if the residual data exists, the target data amount for the next n frame units is calculated by subtracting the data amount of the residual data from the average target data amount. The quantization rate for the high-efficiency encoding means is determined so as to obtain the target data amount for the next n-frame unit if the residual data does not exist.
A video recording apparatus, wherein a quantization rate for the high-efficiency encoding means is determined so as to be a data amount calculated by adding the data amount of the empty area to the average target data amount. 8. A video signal is variable-length coded in units of n frames, variable-length coded data of an unspecified length is recorded in a fixed recording area on a recording medium, and at the same time, residual data of the immediately following n frame period is recorded. If it is in the fixed recording area, the residual data is recorded together with the first identification code,
Data input means for obtaining reproduction data from a recording medium in which the residual data is recorded together with a second identification code, when the residual data of the frame period is in the fixed recording area; and fixed recording output from the data input means. From the reproduction data of the area, the code data of the current n frame period is extracted, and the residual data of the immediately preceding n frame period is extracted using an identification code indicating that the data is the residual data of the immediately preceding n frame period, Code data separating means for extracting residual data of the immediately following n frame period using an identification code indicating that the data is residual data of the immediately following n frame period; First temporary storage means for temporarily storing residual data of a frame period, and the current data extracted by the code data separation means. Second temporary storage means for temporarily storing code data in a frame period; code data for n frame periods output from the second temporary storage means; and the immediately preceding n frame period output from the code data separation means. And the first data
Code data linking means for inputting and adaptively linking the residual data of the immediately following n-frame period output from the temporary storage means, and obtaining variable-length code data in units of n frames; A video reproducing apparatus comprising: a high-efficiency decoder for performing variable-length decoding of variable-length code data and performing expansion processing. 9. The high-efficiency encoder performs inter-frame compression encoding using the n-frame unit as a compression unit, wherein one of n frames is subjected to intra-frame encoding. The video recording apparatus according to any one of claims 1, 2, 3, 5, 6, and 7, wherein the frame is subjected to predictive encoding in only a forward direction or bidirectionally. 10. The high-efficiency decoder, wherein one of n frames is intra-frame coded by a high-efficiency coder that performs inter-frame compression coding using the n-frame unit as a compression unit. 9. The video reproducing apparatus according to claim 4, wherein the other frames are subjected to high-efficiency decoding of variable-length code data subjected to forward prediction coding or bidirectional prediction coding. 11. The fixed-length stuffing means includes: first variable-length coded data of a frame subjected to bidirectional prediction encoding; second variable-length coded data of a frame subjected to forward prediction encoding; 4. The apparatus according to claim 1, further comprising: a residual data generation unit that generates residual data by selecting the third variable length encoded data in the frame in which the intra-frame encoding has been performed. The video recording device according to the item. 12. The first fixed-length stuffing means includes: first variable-length coded data of a frame subjected to bidirectional predictive encoding; and second variable-length coded data of a frame subjected to forward predictive encoding. 8. A residual data generating means for generating residual data by selecting encoded data and third variable-length encoded data of a frame subjected to intra-frame encoding in order. The video recording device according to claim 1. 13. The fixed-length stuffing unit includes: a residual-data generating unit that generates, as residual data, code data representing a high-frequency component among frequency components included in variable-length code data generated for each of n frames. The video recording device according to any one of claims 1, 2, and 3, wherein the video recording device has: 14. A method according to claim 1, wherein said first fixed-length stuffing means generates, as residual data, code data representing a high-frequency component among frequency components included in variable-length code data generated for each of n frames. 8. The video recording apparatus according to claim 5, further comprising a generation unit. 15. The apparatus according to claim 1, wherein said fixed-length padding means has residual data generating means for generating, as residual data, code data obtained by performing variable-length coding on an outer peripheral portion of the video signal at a screen position. The video recording device according to any one of 1, 2, and 3. 16. The apparatus according to claim 1, wherein said first fixed-length stuffing means includes residual data generating means for generating, as residual data, code data obtained by performing variable-length coding on an outer peripheral portion of the video signal at a screen position. The video recording device according to claim 5, wherein