JP2003259307A - Audio and video recording system, audio and video recording method, audio and video recording/reproducing system, and recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an audio video recording system wherein a final average bit rate is controlled to approach an average bit rate target value and the quality of a video image after compression is not fluctuated depending on the contents of the video image received by a signal input section as a method for avoiding occurrence of buffer under-run. <P>SOLUTION: The audio video recording system comprises: the signal input section 2 for capturing an analog video signal 1 and converting the signal into digital data; a variable rate compression means 3 for compressing the data from the signal input section 2 while varying the compressing rate; a recording buffer 5 for temporarily storing the data and transferring the data to a recording means at a prescribed transfer speed; the recording means 6 for recording the data to a DVD disk; a bit rate control means 7 for varying the bit rate of the data after compression within a range between a permissible maximum bit rate setting value and a permissible minimum bit rate setting value; and a recording rate setting means 9 for setting the recording rate by the recording means to record the data to the DVD disk at a speed slower than a standard reproduction speed. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording / recording system, and more particularly to a method for avoiding a buffer underrun of a DVD.

[0002]

2. Description of the Related Art Conventionally, in a read-only optical disk such as a CD or a DVD, a structure in which data is continuously located in a relatively long unit has been adopted to reduce the frequency of disk access during reproduction and facilitate reproduction. On the other hand, there is a recordable optical disc that ensures reproduction compatibility with the reproduction-only optical disc after recording. For example, CD-R, CD
A recordable optical disc such as -RW, DVD-R, and DVD-RW can be reproduced by a read-only device by recording with the same data structure as that for read-only. As described above, the structure in which data is continuous in a long unit is advantageous for reproduction but disadvantageous for recording. Conventionally, the recording operation is recorded with a continuous data structure without interruption, so if a buffer underrun occurs due to a delay in data transfer to the recording device due to some malfunction, at least all long recording units cannot be used. In the worst case, all the disks could not be used. As a solution to this problem, recording is interrupted before a buffer underrun occurs, and after the situation where a buffer underrun occurs is avoided, recording of the subsequent data is started from a seamless position in the final recorded data. A method for restarting is Japanese Patent Laid-Open No. 2000-403.
No. 02 publication, which has been put to practical use. However,
Even if the discontinuity of data is avoided by this method, the quality of the recording interruption / resumption portion is deteriorated. Therefore, it is preferable to perform the recording so as not to cause the interruption / resumption of recording as much as possible.

Further, the DVD video disc supports a variable bit rate of MPEG2 in order to effectively utilize the recording capacity. Highest standard bit rate 1
Bit rate allocation within a range of 0.08 Mbps or less is variable according to the scene of a moving image, a high bit rate is allocated to a scene in which image quality is severely deteriorated by compression, and a low bit rate is allocated to a scene with little image deterioration. By allocating, high-quality recorded contents can be realized for a long time despite the limited storage capacity. Also, when playing back a DVD video disc, a constant speed of 11.08 Mbps, which is slightly higher than the standard maximum bit rate (hereinafter referred to as standard playback speed), so that the image is not interrupted even in the scene of the maximum standard bit rate. To read the data from the disc. Also, when the bit rate is lower than the maximum bit rate, the speed of data read from the disc exceeds the speed of data consumed for video playback, so reading from the disc is sometimes interrupted. The current situation. For example, the average bit rate of a standard DVD video disc at 4.7 Gbyte for 2 hours is about 5.2 Mbps, and reading from the disc is suspended for a half of the time during video playback. is there. Also, by recording DVD video format data on a recordable optical disc, D
When creating a VD video disc, prepare data to be written on a high-speed disc such as an HDD once and transfer the data from the high-speed disc to an optical disc recording device.
It is possible to record in a continuous data structure without interruption of writing on the optical disc. However, if the video being broadcast or the video captured by the video camera is converted to the DVD video format in real time and recorded in real time on the optical disc at the same speed as the standard playback speed,
The writing to the optical disk is always interrupted, and the buffer underrun avoiding method as described above is used to record in a continuous data structure. Furthermore, the average bit rate of video data is set to the standard 5.2M.
When set to bps, the speed of the data recorded on the optical disk is about twice as high as the generation speed of the video data, so that the recording is frequently interrupted and many poor quality connection parts are formed.

[0004]

SUMMARY OF THE INVENTION In view of the above problems, the present invention provides a method for avoiding buffer underrun so that the video quality after compression does not change according to the video content input to the signal input section, and , It is an object of the present invention to provide a recording / recording system in which the final average bit rate is controlled so as to approach an average bit rate target value.

[0005]

In order to solve the above problems, the present invention provides a recording system for compressing video or audio information at a variable information rate and recording the compressed information on a recording medium. A signal input unit that takes in data and converts it into digital data, a variable rate compression unit that compresses the data from the signal input unit while varying the compression rate, and a constant rate by temporarily storing the data from the variable rate compression unit. A recording buffer that transfers at the transfer speed,
Recording means for recording the data of the recording buffer on a recording medium, bit rate control means for varying the bit rate after compression within a range from an allowable maximum bit rate setting value to an allowable minimum bit rate setting value, and an average bit rate Recording rate setting means for setting a recording rate of the recording means according to a target value, the allowable maximum bit rate setting value, and the allowable minimum bit rate setting value.

The signal input section takes in analog video data output from a broadcast receiver or a video camera, converts it into digital data, and transfers it to the variable rate compression means. Then, the variable rate compression means compresses the data from the signal input section in the JPEG mode while varying the compression rate by the bit rate control means and transfers it to the recording buffer. The recording buffer temporarily stores the data from the variable rate compression means and transfers the data to the recording means at a constant transfer rate. The recording means records the data on the DVD disc. Further, the bit rate control means controls the variable rate compression means so that the video quality after compression does not change according to the content of the video and the final average bit rate approaches the average bit rate target value. The bit rate after control is controlled to fluctuate within a range from the maximum allowable bit rate setting value to the minimum allowable bit rate setting value.
The recording rate setting means sets the recording rate to be recorded on the DVD disc by the recording means in accordance with the average bit rate target value, the allowable maximum bit rate setting value, and the allowable minimum bit rate setting value. According to the invention, the bit rate control unit controls the variable rate so that the image quality after compression does not change according to the content of the image and the final average bit rate approaches the average bit rate target value. The compression means is controlled to change the bit rate after compression within the range from the maximum allowable bit rate setting value to the minimum allowable bit rate setting value, and the recording rate setting means sets the average bit rate target value and the maximum allowable bit rate. Since the recording means sets the recording rate for recording on the DVD disc according to the rate setting value and the allowable minimum bit rate setting value, the difference between the generation speed of the information to be written and the writing speed becomes small, and the writing to the recording medium is performed. The frequency of interruptions can be reduced.

According to a second aspect of the present invention, the bit rate control means ensures that the image quality after compression does not change according to the image content input to the signal input section, and the final average bit rate is the same. Controlling the variable rate compression means so as to approach the average bit rate target value is also an effective means of the present invention. The bit rate control means assigns a high bit rate to a scene in which image quality is severely deteriorated due to compression and a low bit rate to a scene in which image deterioration is little, according to the video content input to the signal input unit. , The average bit rate is controlled to approach the target value. As a result, high-quality recorded contents can be realized for a long time despite the limited storage capacity. According to such a technical means, the bit rate control means prevents the video quality after compression from fluctuating according to the video content input to the signal input unit, and the final average bit rate is
Since the variable rate compression unit is controlled so as to approach the average bit rate target value, it is possible to realize high-quality recorded contents for a long time despite the limited storage capacity. According to a third aspect of the present invention, it is also an effective means of the present invention that the recording rate setting means sets the recording rate for recording on the recording medium by the recording means to a speed slower than the standard reproduction speed. According to such a technical means, since the recording medium on which the video information compressed at the variable rate is recorded is written at a speed slower than the reproducing speed, the video information is compressed at the variable rate in real time and the recording medium. At the time of recording, the difference between the generation speed of the information to be written and the writing speed is reduced, the frequency of interruption of writing on the recording medium is reduced, and the number of quality deterioration points due to interruption restart can be reduced.
According to a fourth aspect of the present invention, it is also an effective means of the present invention that the recording rate setting means sets the recording rate recorded on the recording medium by the recording means substantially equal to the average bit rate target value. According to such a technical means, the average bit rate target value that can be arbitrarily set is written to the recording medium at a speed equal to the target bit rate. Therefore, the average generation speed of the information to be written matches the writing speed, and the recording is performed without interruption. It is possible to write to the medium.

According to a fifth aspect, the recording rate setting means is
It is also an effective means of the present invention to set the recording rate for recording on the recording medium by the recording means to be substantially equal to the allowable maximum bit rate target value. According to such a technical means, since the data is written to the recording medium at a speed equal to the maximum bit rate setting value that can be arbitrarily set, the recording interruption is performed within the range in which the recording buffer never overflows even if the recording buffer capacity is small. It can be the least frequent. According to a sixth aspect of the present invention, in a sound recording system for compressing video or audio information at a variable information rate and recording the information on a recording medium, a signal input unit for taking in analog video data and converting it into digital data, and varying the compression rate. A variable rate compression unit for compressing data from the signal input unit, a recording buffer for temporarily storing the data from the variable rate compression unit and transferring at a constant transfer speed, and recording the data in the recording buffer on a recording medium. Recording means, bit rate control means for varying the bit rate after compression within a range from an allowable maximum bit rate setting value to an allowable minimum bit rate setting value, an average bit rate target value, the allowable maximum bit rate setting value, And recording rate setting means for setting the recording rate of the recording means according to the allowable minimum bit rate setting value Buffer monitoring means for monitoring the amount of data in the recording buffer, detecting increase / decrease of a predetermined amount of data from the amount of data, and detecting an average transfer rate of data transferred from the variable rate compression means, A recording interruption / resuming control means for interrupting the recording operation of the recording means in accordance with the recording interruption instruction from the buffer monitoring means and resuming the recording operation of the recording means in accordance with the recording resumption instruction from the recording rate setting means. It is characterized by This further comprises buffer monitoring means and recording suspend / resume control means added to the structure of claim 1, and the buffer monitoring means monitors the buffer data amount and reduces the buffer data amount to a predetermined minimum amount. When this is done, and when it has been increased to a predetermined maximum amount, an instruction to interrupt recording is sent to the recording interrupt / restart control means. Further, the average transfer speed of the data transferred from the variable rate compression means is detected and the detected value is sent to the recording rate setting means. Further, the recording suspension / resumption control means suspends the recording operation of the recording means according to the recording suspension instruction from the buffer monitoring means, and restarts the recording operation of the recording means according to the recording restart instruction from the recording rate setting means. According to the invention, since the buffer is monitored and the recording is interrupted before the buffer underrun or the buffer overflow occurs, the recording speed is set again and the recording is restarted, the recording capacity is the most even if the buffer capacity is small. It is possible to record at a recording rate with a low interruption frequency.

According to a seventh aspect of the present invention, the buffer monitoring means monitors the amount of data in the recording buffer to reduce the amount of data to a predetermined minimum amount, and a predetermined maximum amount. And sends an instruction to suspend recording to the recording suspending / resuming control means,
Further, it is also an effective means of the present invention to detect the average transfer rate of the data transferred from the variable rate compression means and send the detected value to the recording rate setting means. According to such a technical means, the buffer monitoring means constantly monitors the amount of data in the recording buffer and, when the amount of data increases or decreases and reaches the respective limit amounts, instructs the recording suspension / resumption control means. To suspend or resume recording. further,
Since the average transfer rate recorded in the recording buffer is obtained and the recording rate is set so that the average transfer rate approaches the average bit rate value, overflow of the recording buffer can be prevented. According to an eighth aspect of the present invention, in the buffer monitoring means, the amount of data in the recording buffer is approximately 1 /
2 When it is detected that the data has been accumulated, the average transfer rate of the data transferred from the variable rate compression means is obtained, and the recording rate of the recording means is set to the value of the obtained average transfer rate with respect to the recording rate setting means. Setting is also an effective means of the present invention. According to such a technical means, when the data amount in the recording buffer becomes about 1/2, the recording rate is recorded at a rate equal to the average transfer rate of the data, thereby recording without increasing or decreasing the recording buffer capacity. You can According to a ninth aspect of the present invention, when the data amount in the recording buffer reaches the maximum limit amount or the minimum limit amount and the recording interruption / resumption control means receives a recording interruption instruction from the buffer monitoring means, The recording operation is interrupted, a reset instruction is sent to the recording rate setting means, the recording rate is reset to a higher recording rate based on the average transfer speed immediately before the recording interruption obtained by the buffer monitoring means, and the recording interruption / resumption is performed. Sending a recording restart instruction to the control means is also an effective means of the present invention. When the transfer rate to the recording buffer continues to exceed the recording rate to the optical disc, the storage amount in the recording buffer increases, and when the storage amount reaches the maximum limit, the buffer monitoring unit sends a suspension instruction to the recording suspension / resumption control unit. . The recording suspension / resumption control means suspends the recording operation of the recording means and sends a reset instruction to the recording rate setting means. The recording rate setting means resets the recording rate faster than before based on the average transfer rate immediately before the recording interruption determined by the buffer monitoring means, and sends a restart instruction to the recording interruption / resumption control means. Further, if the transfer rate to the recording buffer continues to fall below the recording rate to the optical disc, the storage amount in the recording buffer decreases, and when the storage amount reaches the minimum limit, the buffer monitoring unit instructs the recording suspension / resumption control unit to suspend. To send.
After that, recording is interrupted and restarted by performing the same operation as when the maximum limit is reached, and the decrease in the buffer storage amount is resolved.
According to such a technical means, the recording suspension / resumption control means restarts the recording operation of the recording means, the recording is performed at a higher recording rate than ever, and the increase or decrease of the buffer storage amount is eliminated.

According to a tenth aspect of the present invention, in a recording and recording method for compressing video or audio information at a variable information rate and recording it on a recording medium, a signal input step of capturing analog video data and converting it into digital data, and varying a compression rate. A variable rate compression step for compressing the data from the signal input step, a recording buffer step for temporarily storing the data from the variable rate compression step and transferring at a constant transfer rate, and data for the recording buffer step. A recording step for recording on a recording medium, a bit rate control step for varying the bit rate after compression within a range from an allowable maximum bit rate setting value to an allowable minimum bit rate setting value, an average bit rate target value, and the allowable maximum bit rate. Depending on the bit rate setting value and the allowable minimum bit rate setting value A recording rate setting step of setting a recording rate of the recording step, wherein the bit rate control step is performed so that the image quality after compression does not change according to the image content input by the signal input step, and Controlling the variable rate compression step so that the final average bit rate approaches the average bit rate target value, and the recording rate setting step,
In the recording step, the recording rate of recording on the recording medium is set to a speed slower than the standard reproduction speed. According to this invention, the same effects as those of the first and second aspects are achieved.

According to an eleventh aspect of the present invention, in a recording / recording method of compressing video or audio information at a variable information rate and recording it on a recording medium, a signal input step of capturing analog video data and converting it into digital data, and varying a compression rate. A variable rate compression step for compressing the data from the signal input step, a recording buffer step for temporarily storing the data from the variable rate compression step and transferring at a constant transfer rate, and data for the recording buffer step. A recording step for recording on a recording medium, a bit rate control step for varying the bit rate after compression within a range from an allowable maximum bit rate setting value to an allowable minimum bit rate setting value, an average bit rate target value, and the allowable maximum bit rate. Depending on the bit rate setting value and the allowable minimum bit rate setting value A recording rate setting step of setting the recording rate of the recording step, monitoring the amount of data in the recording buffer step, detecting increase / decrease of a predetermined amount of data from the amount of data, and transferring from the variable rate compression step. A buffer monitoring step for detecting an average transfer rate of data to be recorded, a recording operation of the recording step is interrupted according to a recording interruption instruction from the buffer monitoring step, and a recording of the recording step is performed according to a recording restart instruction from the recording rate setting step. A recording interruption / resumption control step for restarting the operation, wherein the buffer monitoring step monitors the amount of data in the recording buffer,
Detecting that the amount of data has decreased to a predetermined minimum amount and that the amount of data has increased to a predetermined maximum amount, a recording interruption instruction is sent to the recording interruption / restart control step, and The average transfer rate of the data transferred from the variable rate compression step is detected and the detected value is sent to the recording rate setting step. According to this invention, the same effects as those of the sixth and seventh aspects are achieved.

A twelfth aspect of the present invention compresses video and audio information at a variable information rate, records the compressed information on a recording medium at a constant recording rate, and compresses the compressed information at the variable information rate. It is a recording / recording / reproducing system that reproduces a recording medium on which information is recorded at a constant reproduction rate, expands the reproduced compressed information to extract audio and video, and is required to reproduce video and audio without interruption. The recording rate is set to be slower than the minimum reproduction rate. According to such a technical means, since writing is performed at a speed slower than the speed at which the recording medium on which the video information compressed at the variable rate is recorded is written, the video information is compressed at the variable rate in real time to the recording medium. At the time of recording, the difference between the generation speed of information to be written and the writing speed becomes small, the frequency of interruption of writing on the recording medium is reduced, and the number of quality deterioration points due to interruption restart can be reduced. The thirteenth aspect of the present invention is also an effective means of the present invention in that the recording characteristics of the recording medium are optimized for recording at a recording rate slower than the minimum reproduction rate. A recordable optical disc is normally recorded at a speed higher than the standard reproduction speed. The faster the recording speed, the more severe the recording conditions, so
The recording characteristics of the optical disc are adjusted according to the maximum recording speed. In particular, rewritable phase change recording materials have a high recording linear velocity dependence and do not support low-speed recording from 1 × to several times, thereby realizing high-speed recording. In each of the recording systems of the present invention, recording is performed at a speed lower than the standard reproduction speed. Therefore, a disk capable of recording at a recording speed of 1 × speed or less is required, and a disk optimized in this speed range is desirable. According to such a technical means, the recording characteristics are optimized for recording at a speed lower than the standard reproduction speed, so that it is possible to reduce the number of recording interruptions with good recording quality. Claim 14 and Claim 10
Alternatively, the recording method described in 11 is recorded as a computer-executable program. According to this invention, a recording / recording system can be realized by a general-purpose computer.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below with reference to the embodiments shown in the drawings. However, the constituent elements, types, combinations, shapes, relative arrangements, and the like described in this embodiment are merely explanatory examples, not the gist of limiting the scope of the present invention thereto, unless specifically stated. . FIG. 1 shows a recording system according to the first embodiment of the present invention. This configuration includes a signal input unit 2 that takes in an analog video signal 1 output from a broadcast receiver or a video camera (not shown), converts it into digital data and transfers it to a variable rate compression unit, and a bit rate control unit 7. A variable rate compression unit 3 that compresses the data from the signal input unit 2 and transfers it to the recording buffer 5 while varying the compression rate under control, and the data from the variable rate compression unit 3 is temporarily stored and transferred at a constant rate. The recording buffer 5 for transferring data to the recording means at a speed, and the data from the recording buffer 5 to the DVD
The recording means 6 for recording on the disk and the variable rate compression means 3 are provided so that the image quality after compression does not vary depending on the content of the image and the final average bit rate approaches the average bit rate target value. Bit rate control means 7 for controlling and varying the bit rate after compression within a range from an allowable maximum bit rate setting value to an allowable minimum bit rate setting value, an average bit rate target value, and an allowable maximum bit rate setting According to the value and the allowable minimum bit rate setting value, the recording means is composed of a recording rate setting means 9 for setting the recording rate for recording on the DVD disc to a speed slower than the standard reproduction speed of 11.08 Mbps. The maximum allowable bit rate can be arbitrarily set within the range of 10.08 Mbps which is the upper limit of the DVD standard, and the average bit rate target can be set arbitrarily within the range of the maximum allowable bit rate setting value or less. The minimum allowable bit rate can be arbitrarily set within the range of the average bit rate target value or less.

Next, the user sets each setting value to the maximum allowable bit rate setting value: 6 Mbps, the average target bit rate value: 4 Mbps, and the minimum allowable bit rate setting value: 2 Mb.
A specific description will be given by taking the case of setting to ps as an example. Conventionally, the recording rate of the recording means is 11.08, which is the same as the standard reproduction speed.
Since it is Mbps, the speed of data transferred from the recording buffer is always higher than the speed of data transferred to the recording buffer, with a maximum of 9.08 Mbps and a minimum of 5.08.
The buffer data decreases at a speed of Mbps and an average of 7.08 Mbps. In the present invention, the recording rate is set to a speed slower than the standard reproduction speed 11.08 Mbps according to each set value. With a configuration in which the recording rate is set to 6 Mbps, which is the same as the maximum allowable bit rate setting value, a maximum of 4
The buffer data decreases at a rate of bps, at least 0 Mbps, and an average of 2 Mbps, and the reduction rate becomes slower than in the past. Therefore, the recording buffer 5 becomes empty and the frequency of interrupting recording on the optical disk is reduced. Further, in the configuration in which the recording rate is set to the same value as the average bit rate target value, 4 Mbps, the buffer data increases and decreases at a maximum speed of 2 Mbps, and the average amount of data stored in the buffer is constant. By preparing the buffer capacity as much as possible to allow the increase or decrease of the buffer data, the recording can be completed without interrupting the recording on the optical disc. Further, in the case of compressing with a variable bit rate in real time, in order to bring the final average bit rate close to the target value, there is a fluctuation that repeatedly increases and decreases around the average bit rate target value. A bit rate that is far from the average bit rate target value cannot last for a long time. Therefore,
If there is a certain amount of buffer capacity, it is possible to allow the buffer data to increase or decrease.

FIG. 2 shows a recording system according to the second embodiment of the present invention. Since the same components are designated by the same reference numerals, duplicate description will be omitted. 2 is different from FIG. 1 in that a buffer monitoring means and a recording suspend / resume control means are added. The buffer monitoring means monitors the buffer data amount of the recording buffer 5 and detects that the buffer data amount has decreased to a predetermined minimum amount and has increased to a predetermined maximum amount, A recording interruption instruction 14 is sent to the recording interruption / resumption control means 11. Further, the average transfer speed of the data transferred from the variable rate compression means 3 is detected, and the recording rate setting value 15 is sent to the recording rate setting means 9. Further, the recording rate setting means 9 sets the recording rate 8 at which the recording means records a DVD disk at the start of recording and at the time of recording interruption to the same rate as the average data transfer rate detected by the buffer monitoring means 13. Further, when the recording is interrupted, the recording rate is reset and then the recording restart / restart control means 11 is sent with the recording restart instruction 17. The recording suspending / resuming control means 11 suspends the recording operation of the recording means according to the recording suspending instruction 14 from the buffer monitoring means 13, and restarts the recording operation of the recording means according to the recording restart instruction 17 from the recording rate setting means 9. When recording is started, the video data 1 is accumulated in the recording buffer 5 via the signal input unit 2 and the variable rate compression means 3.

When about half of the buffer capacity is accumulated, the buffer monitoring means 13 obtains the average transfer rate, and the recording rate setting means 9 sets the recording rate 8 of the recording means to the same rate as the average transfer rate detection value and records. The recording operation of the means 6 is started. When the transfer rate to the recording buffer 5 continues to exceed the recording rate to the optical disc, the recording buffer 5
When the storage amount increases, and the storage amount reaches the maximum limit, the buffer monitoring means 13 sends the interruption instruction 14 to the recording interruption / resumption control means 11. The recording suspension / resumption control means 11 suspends the recording operation of the recording means 6 and sends a reset instruction 16 to the recording rate setting means 9. The recording rate setting means 9 resets the recording rate faster than before based on the average transfer rate immediately before the recording interruption determined by the buffer monitoring means 13, and sends a restart instruction 17 to the recording interruption / resumption control means 11. The recording suspending / resuming control means 11 restarts the recording operation of the recording means 6, recording is performed at a higher recording rate than ever, and the increase in the buffer storage amount is eliminated. Further, if the transfer rate to the recording buffer 5 continues to be lower than the recording rate to the optical disc, the storage amount in the recording buffer decreases, and when the storage amount reaches the minimum amount, the buffer monitoring means 13 causes the recording suspension / restart control means. The interruption instruction 14 is sent to 11. After that, the same operation as when reaching the maximum limit is performed and recording is interrupted and restarted,
The decrease in the buffer storage amount is resolved. In the configuration of FIG.
In order to set the recording rate to a value lower than the maximum allowable bit rate setting value, that is, a value close to the average bit rate target value, it was necessary to have sufficient buffer capacity to allow the fluctuation of the buffer storage amount. In the configuration of 2, the recording rate is close to the average bit rate target value even if the buffer capacity is small, and the recording is interrupted only when the fluctuation of the buffer storage amount cannot be tolerated.

FIG. 3 shows an example in which this system is constructed using a personal computer. Since the same components are designated by the same reference numerals, duplicate description will be omitted. In this configuration, the signal input unit 2, the variable rate compression unit 3, the recording buffer 5, and the bit rate control unit 7 described with reference to FIG. Further, the drive control function of the optical disc recording drive control software 40 includes the buffer monitoring means 13, the recording interruption / resumption control means 11, the recording rate setting described in FIG. 2 in addition to the existing functions such as the recording start / end control means 19. It has means 9. Optical disk drive 5
0 is the recording interruption / from the drive control software 40.
It has a function of operating in response to a restart control and a recording rate setting request. Since a hard disk installed in a personal computer can be assigned to a recording buffer during recording, a large recording buffer capacity can be secured. Figure 4
Is another example of the construction of this system using a personal computer. Since the same components are designated by the same reference numerals, duplicate description will be omitted. Optical disk drive 51
Includes the recording buffer 5, the buffer monitoring means 13, the recording interruption / restart control means 11, and the recording rate setting means 9 described in FIG. The drive control function of the optical disc recording drive control software 41 has only existing functions such as the recording start / end control means 19. In the configuration of FIG. 3, real-time recording with little interruption of recording cannot be performed unless combined with dedicated drive control software, but in the configuration of FIG. 4, the recording buffer 5, the buffer monitoring unit 13, the recording interruption / resumption control unit 11 are provided. Since all the operations peculiar to the present invention such as the recording rate setting means 9 are processed by means built in the optical disk drive 51, real-time recording with little interruption of recording can be performed regardless of the drive control software. Here, a recordable optical disc is normally recorded at a speed higher than the standard reproduction speed. Since the recording conditions become more severe as the recording speed becomes faster, the recording characteristics of the optical disc are adjusted according to the maximum recording speed. In particular, rewritable phase change recording materials have high recording linear velocity dependence,
It supports high-speed recording by not supporting low-speed recording from 1x to several times. Therefore, in the recording system of the present invention, recording is performed at a speed lower than the standard reproduction speed. Therefore, a disk capable of recording at a recording speed of 1 × speed or less is required, and a disk optimized in this speed range is desirable. Specifically, a disc that is optimized for 0.5 × speed recording and is capable of recording up to 1 × speed is most suitable.

[0018]

As described above, according to the invention of claim 1, the bit rate control means prevents the compressed video quality from varying in accordance with the content of the video, and the final average bit rate is The variable rate compression means is controlled so as to approach the average bit rate target value, and the bit rate after compression is varied within the range from the maximum allowable bit rate setting value to the minimum allowable bit rate setting value to set the recording rate. Since the recording means sets the recording rate at which the recording means records on the DVD disc in accordance with the average bit rate target value, the allowable maximum bit rate setting value, and the allowable minimum bit rate setting value, the generation speed of the information to be written and the writing speed And the frequency at which writing to the recording medium is interrupted can be reduced. Further, in claim 2, the bit rate control means prevents the image quality after compression from changing in accordance with the image content input to the signal input unit, and the final average bit rate is the average bit rate. Since the variable rate compression means is controlled so as to approach the rate target value, it is possible to realize a high-quality recorded content for a long time despite the limited storage capacity. Further, in claim 3, since the recording medium on which the video information compressed at the variable rate is recorded is written at a speed slower than the reproduction speed, the video information is compressed at the variable rate in real time to the recording medium. At the time of recording, the difference between the generation speed of the information to be written and the writing speed becomes small, the frequency of interruption of writing on the recording medium is reduced, and the number of quality deterioration points due to interruption restart can be reduced. Further, in claim 4,
Since the average bit rate that can be set arbitrarily is written to the recording medium at the same speed as the target value, the average generation speed of the information to be written matches the writing speed, and writing to the recording medium without interruption You can Further, according to the present invention, since the data is written to the recording medium at a speed equal to the maximum bit rate setting value that can be set arbitrarily, the recording interruption frequency within the range in which the recording buffer never overflows even if the recording buffer capacity is small. Can be the lowest.

According to the present invention, the buffer is monitored and the recording is interrupted before the buffer underrun or the buffer overflow occurs, the recording speed is set again, and the recording is restarted. Therefore, even if the buffer capacity is small. It is possible to record at the recording rate with the lowest recording interruption frequency.
Recording is interrupted before buffer underrun or buffer overflow occurs, the recording speed is set again, and recording is restarted, so even if the buffer capacity is low, the recording rate with the lowest frequency of recording interruptions Can be recorded at. Further, in claim 7, the buffer monitoring means constantly monitors the data amount in the recording buffer, and when the data amount increases or decreases to reach the respective limit amounts, it instructs the recording interruption / resumption control means. Stop or resume recording. Furthermore, since the average transfer rate recorded in the recording buffer is obtained and the recording rate is set so that the average transfer rate approaches the average bit rate value, overflow of the recording buffer can be prevented. Further, in claim 8, when the amount of data in the recording buffer becomes about 1/2, the recording is performed at a rate equal to the average transfer rate of data, so that the recording can be performed without increasing or decreasing the recording buffer capacity. it can. Further, in claim 9, the recording suspending / resuming control means restarts the recording operation of the recording means, the recording is performed at a higher recording rate than ever, and the increase or decrease of the buffer storage amount is eliminated.
Further, in the tenth aspect, the same operational effects as those of the first and second aspects are achieved. In the eleventh aspect, the same operational effect as the sixth and seventh aspects is achieved. Further, in claim 12, since the writing is performed at a speed slower than the speed of reproducing the recording medium on which the video information compressed at the variable rate is recorded, the video information is compressed at the variable rate and recorded on the recording medium in real time. In doing so, the difference between the generation speed of the information to be written and the writing speed becomes small, the frequency of interruption of writing on the recording medium is reduced, and the number of quality deterioration points due to interruption restart can be reduced. In the thirteenth aspect, since the recording characteristics are optimized for recording at a speed lower than the reproduction standard speed, it is possible to reduce the number of recording interruptions with good recording quality. Further, in claim 14, the recording and recording system can be realized by a general-purpose computer.

[Brief description of drawings]

FIG. 1 is a diagram showing a recording system according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a recording system according to a second embodiment of the present invention.

FIG. 3 is a diagram of an example in which the system is constructed using the personal computer of the present invention.

FIG. 4 is a diagram of an example in which the present system is constructed using the personal computer of the present invention.

[Explanation of symbols]

1 analog video signal, 2 signal input section, 3 variable rate compression means, 5 recording buffer recording buffer, 6 recording means, 7 bit rate control means, 9 recording rate setting means

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 5C052 AA02 AB04 CC11 DD04 DD06                 5C053 FA24 GB17 GB26 LA11                 5C059 KK35 SS13 TA60 TB04 TC37                       TD05 UA02 UA32                 5D044 AB05 AB07 BC04 CC06 EF03                       GK08 GK10 HH02

Claims (14)

[Claims] 1. A sound recording system for compressing video or audio information at a variable information rate and recording it on a recording medium, wherein a signal input section for taking in analog video data and converting it into digital data, and varying the compression rate. A variable rate compression unit for compressing data from the signal input unit, a recording buffer for temporarily storing the data from the variable rate compression unit and transferring at a constant transfer speed, and recording the data in the recording buffer on a recording medium. Recording means, bit rate control means for varying the bit rate after compression within a range from an allowable maximum bit rate setting value to an allowable minimum bit rate setting value, an average bit rate target value, the allowable maximum bit rate setting value, And a recording rate setting means for setting the recording rate of the recording means according to the allowable minimum bit rate setting value. Recording recording system, characterized in that it comprises a and. 2. The bit rate control means is configured so that the image quality after compression does not change according to the image content input to the signal input unit, and the final average bit rate is the average bit rate. 2. The variable rate compression means is controlled so as to approach a target value.
Recording system described in. 3. The recording and recording system according to claim 1, wherein the recording rate setting means sets the recording rate of the recording medium recorded by the recording means to a speed slower than a standard reproduction speed. 4. The recording / recording system according to claim 1, wherein the recording rate setting unit sets a recording rate for recording on a recording medium by the recording unit to be substantially equal to the average bit rate target value. 5. The recording / recording system according to claim 1, wherein the recording rate setting unit sets a recording rate of the recording medium recorded on the recording medium substantially equal to the allowable maximum bit rate target value. . 6. A sound recording system for compressing video or audio information at a variable information rate and recording it on a recording medium, wherein a signal input unit for taking in analog video data and converting it into digital data, and varying the compression rate. A variable rate compression unit for compressing data from the signal input unit, a recording buffer for temporarily storing the data from the variable rate compression unit and transferring at a constant transfer speed, and recording the data in the recording buffer on a recording medium. Recording means, bit rate control means for varying the bit rate after compression within a range from an allowable maximum bit rate setting value to an allowable minimum bit rate setting value, an average bit rate target value, the allowable maximum bit rate setting value, And a recording rate setting means for setting the recording rate of the recording means according to the allowable minimum bit rate setting value. Buffer monitoring means for monitoring the amount of data in the recording buffer, detecting an increase or decrease in a predetermined amount of data from the amount of data, and detecting an average transfer rate of data transferred from the variable rate compression means, A recording interruption / resumption control means for interrupting the recording operation of the recording means according to the recording interruption instruction from the buffer monitoring means, and resuming the recording operation of the recording means according to the recording restart instruction from the recording rate setting means. A recording and recording system characterized by that. 7. The buffer monitoring means monitors the amount of data in the recording buffer and decreases the amount of data from the amount of data to a predetermined minimum amount and to increase it to a predetermined maximum amount. That is detected, an instruction to suspend recording is sent to the recording suspending / resuming control means, the average transfer speed of the data transferred from the variable rate compressing means is detected, and the detected value is sent to the recording rate setting means. 7. The recording and recording system according to claim 6, wherein 8. The buffer monitoring means, when detecting that the amount of data in the recording buffer has been accumulated to approximately ½, obtains an average transfer rate of data transferred from the variable rate compression means, and records the data. The recording and recording system according to claim 6 or 7, wherein the recording rate of the recording means is set to the value of the obtained average transfer rate with respect to the rate setting means. 9. When the amount of data in the recording buffer reaches the maximum limit or the minimum limit and the recording suspension / resumption control means receives a recording suspension instruction from the buffer monitoring means, The recording operation is interrupted, a reset instruction is sent to the recording rate setting means, and a higher recording rate is reset based on the average transfer speed immediately before the recording interruption determined by the buffer monitoring means.
7. The recording / recording system according to claim 6, wherein a recording restart instruction is sent to the restart control means. 10. A recording and recording method for compressing video or audio information at a variable information rate and recording the same on a recording medium, wherein a signal input step of capturing analog video data and converting it into digital data and varying the compression rate. A variable rate compression step for compressing data from the signal input step, a recording buffer step for temporarily storing the data from the variable rate compression step and transferring at a constant transfer rate, and data for the recording buffer step on a recording medium. Recording step for recording, bit rate control step for varying the bit rate after compression within the range from the maximum allowable bit rate setting value to the minimum allowable bit rate setting value, the average bit rate target value, and the maximum allowable bit rate setting Value and the recording according to the allowable minimum bit rate setting value A recording rate setting step for setting a recording rate of the step, the bit rate controlling step is performed so that the image quality after compression does not change according to the image content input by the signal inputting step, and The variable rate compression step so that a typical average bit rate approaches the average bit rate target value, and the recording rate setting step comprises setting the recording rate recorded on the recording medium by the recording step above the standard reproduction speed. A recording and recording method characterized by setting a slow speed. 11. A recording and recording method for compressing video or audio information at a variable information rate and recording it on a recording medium, the signal input step of capturing analog video data and converting it into digital data, and varying the compression rate. A variable rate compression step for compressing data from the signal input step, a recording buffer step for temporarily storing the data from the variable rate compression step and transferring at a constant transfer rate, and data for the recording buffer step on a recording medium. Recording step for recording, bit rate control step for varying the bit rate after compression within the range from the maximum allowable bit rate setting value to the minimum allowable bit rate setting value, the average bit rate target value, and the maximum allowable bit rate setting Value and the recording according to the allowable minimum bit rate setting value A recording rate setting step for setting the recording rate of the step, and monitoring the amount of data in the recording buffer step, detecting increase or decrease of a predetermined amount of data from the amount of data, and data transferred from the variable rate compression step. Buffer monitoring step for detecting the average transfer speed of the recording step, the recording operation of the recording step is interrupted according to the recording interruption instruction from the buffer monitoring step, and the recording operation of the recording step is performed according to the recording restart instruction from the recording rate setting step. A recording suspending / resuming control step for restarting, wherein the buffer monitoring step monitors the amount of data in the recording buffer and decreases from the amount of data to a predetermined minimum amount, and The recording suspension / resuming control step is detected by detecting that the maximum limit is reached. It transmits an instruction of recording interruption, further recording a recording method, wherein the variable rate average transfer rate of data transferred from the compression step detects and sends the detected value to the recording rate setting step. 12. The video or audio information is compressed at a variable information rate, and the compressed compression information is recorded on a recording medium at a constant recording rate, while the compressed information compressed at the variable information rate is recorded. A recording / reproducing system that reproduces a recorded recording medium at a constant reproduction rate, expands the compressed information that has been reproduced to extract audio and video, and is the minimum reproduction necessary to reproduce video and audio without interruption. A recording / reproducing system characterized in that the recording rate is set lower than the rate. 13. The recording medium according to claim 12, wherein the recording characteristics of the recording medium are optimized for recording at a recording rate slower than the minimum reproduction rate. 14. A recording medium, wherein the recording method according to claim 10 or 11 is recorded as a computer-executable program.