JP2007018695A - Compressed information storage device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive and high vibration resistant device by increasing a compression rate of an information amount to reduce the storage capacity of a temporary storage means when the storage device is in a storage disabled state. <P>SOLUTION: This device is provided with a compression circuit 1 for compressing digital information from a camera part 8 to generate compressed information, a buffer memory 2 for temporarily storing the compressed information, a disk device 4 for storing the compressed information from the buffer memory 2 at a rate faster than that of storage in the buffer memory 2, and a system controller 5 for detecting the recording disabled state of the disk device 4 to increase the compression rate of the compression circuit. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an information storage device, and more particularly to a compressed information storage device that compresses and stores information.

  In recent years, the amount of digital information has increased dramatically as various types of information including image information and audio information have been digitized. Along with this, an increase in capacity and density of information storage devices has been promoted, and a technique for compressing the amount of information by digital signal processing has been introduced.

  For example, when recording / reproducing an RGB image of 8 bits for each pixel of 640 × 480 at 30 screens / second, information of about 220 Mbits per second is generated and stored for 2 hours. A storage capacity of about 200 GB is required. By compressing this enormous amount of information, it has become possible to compress it to several GB with a storage capacity of 4 to 5 Mbps for 2 hours at a transfer rate. When compression processing close to 1/100 times is performed like this image compression, even if the compressed information is decompressed, it cannot be restored to the same information as the original information. For this reason, degradation of image quality due to compression occurs. In general, the higher the compression rate, that is, the lower the amount of information, the more noticeable the image quality deteriorates. Therefore, a method has been proposed in which a large amount of information is allocated to an image of a scene with a high movement that is likely to cause image quality degradation, and a small amount of information is allocated to an image of a scene with a small movement. Yes. According to this method, since the allocation of the information amount is changed according to the image, in other words, the compression rate of the information amount is changed according to the image, it is possible to reduce image quality deterioration.

  Next, another problem caused by compressing information will be described. In portable disk devices, there is an issue of preventing servo detachment due to vibration, impact, etc. during use. To solve this problem, measures such as providing a vibration isolation mechanism and improving servo characteristics are required. It has been implemented. However, these measures alone cannot cope with a large impact, etc., and the servo is disconnected and recording / reproduction may not be possible. An apparatus that solves such a problem and improves the earthquake resistance is disclosed in Japanese Patent Laid-Open No. 4-103079. In this apparatus, the compressed information is temporarily stored in a buffer memory and then recorded on a disk. The conventional configuration and operation will be described below with reference to the drawings.

  FIG. 7 shows a block diagram of a conventional compressed information storage device. The input signal is converted into a digital signal by the A / D converter 7 at the time of recording on the disk device 4 and sent to the compression / decompression circuit 12, while at the time of reproduction by the disk device 4, it is converted via the compression / decompression circuit 12 to It is converted into an analog signal by the A converter 13 and output. The compression / decompression circuit 12 is a circuit that compresses and decompresses information. Here, a compression process related to the present invention will be described. The data input to the compression / decompression circuit 12 is subjected to compression processing. Many methods have been proposed for the compression processing method. When image information or audio information is targeted, human visual characteristics and auditory characteristics are used to obtain a high compression rate. As a result, the input data is compressed from a fraction to a few tenths. The data compressed by the compression / decompression circuit 12 is temporarily stored in the buffer memory 2 via the memory controller 3. The memory controller 3 is a circuit that controls the flow of data among the compression / decompression circuit 12, the buffer memory 2, and the disk device 4. The memory controller 3 controls the address in the buffer memory 2 of the data transferred from the compression / decompression circuit 12 to the buffer memory 2. The address of the data sent from the buffer memory 2 to the disk device 4 is managed, and the remaining amount of the buffer memory 2 is detected based on these addresses. The disk device 4 is a device for storing data, and an optical disk device, a hard disk device, or the like is used. Both devices precisely control the optical pickup and magnetic head on the order of microns, so if a large vibration or impact is applied to the device, the position of the optical pickup or magnetic head will deviate from the normal position. Recording / playback is not possible.

  Next, the operation of the conventional compressed information storage device will be described. FIG. 8 shows a temporal change in the remaining amount of the buffer memory 2. The remaining capacity of the buffer memory 2 means the amount of usable memory, and is obtained by subtracting the amount of data remaining in the buffer memory 2 without being transferred to the disk device 4 from the total capacity of the buffer memory 2. Therefore, when data is transferred from the compression / decompression circuit 12 to the buffer memory 2, the remaining capacity of the buffer memory 2 decreases. When data is transferred from the buffer memory 2 to the disk device 4, the remaining capacity of the buffer memory 2 is reduced. To increase. In FIG. 8, compression is started by the compression / decompression circuit 12 at time 0. At this time 0, there is no data in the buffer memory 2, so the remaining capacity of the buffer memory 2 is equal to the total capacity of the buffer memory 2. Since the compressed information is transferred from the compression / decompression circuit 12 to the buffer memory 2 at a constant transfer rate, the remaining amount of the buffer memory 2 decreases with time. When the remaining capacity of the buffer memory 2 falls below a predetermined first set value TH1 at time T1, the memory controller 3 notifies the system controller 5 of this. In response to this, the system controller 5 gives a command to the memory controller 3 to start data transfer from the buffer memory 2 to the disk device 4, and writes data to the disk to the disk device 4. Issue a start command. Since the data transfer rate from the buffer memory 2 to the disk device 4 is set higher than the data transfer rate from the compression / decompression circuit 12 to the buffer memory 2, the data is temporarily stored in the buffer memory 2 over time. The compressed data that has been reduced decreases, and the remaining amount of the buffer memory 2 increases. Next, when the remaining amount of the buffer memory 2 exceeds the second set value TH2 at time T2, the memory controller 3 notifies the system controller 5 of this. In response to this, the system controller 5 gives a command to the memory controller 3 to stop the transfer of data from the buffer memory 2 to the disk device 4 and writes the data to the disk to the disk device 4. Issue a stop command. In normal operation, thereafter, when the remaining capacity of the buffer memory 2 falls below TH1, data is written to the disk device 4, and when it exceeds TH2, writing of data to the disk device 4 is stopped.

  Now, assume that at time T3, data cannot be written to the disk device 4 due to an impact, and it takes time until time T5 to return to the writable state. The remaining capacity of the buffer memory 2 decreases with time and falls below the first set value TH1 at time T4. At this time, the disk device 4 cannot write data yet, so the system controller 5 Data transfer from the memory 2 to the disk device 4 is not performed. For this reason, the remaining amount of the buffer memory 2 further decreases. At time T5, the system controller 5 detects that the disk device 4 is ready to write data, and gives an instruction to the memory controller 3 to start data transfer from the buffer memory 2 to the disk device 4. As a result, the remaining amount of the buffer memory 2 increases, and thereafter the normal operation is repeated.

  As described above, even if the disk device 4 temporarily falls into a writable state, if it can be restored to a writable state before the remaining capacity of the buffer memory 2 becomes 0, the data in the meantime is temporarily stored in the buffer memory 2. By accumulating data, correct data can be written to the disk device 4 without data loss, so that the seismic performance is improved.

  In order to realize the operation as described above, the apparatus has a buffer memory and satisfies the condition that the data transfer rate from the buffer memory to the disk device is higher than the data transfer rate from the input to the buffer memory. However, if the compression circuit is arranged on the path from the input to the buffer memory, the data transfer rate from the input to the buffer memory can be lowered, so that this condition can be easily satisfied. In the example of the moving image data described above, the data transfer rate can be reduced from 220 Mbps to 4 Mbps by compression. Therefore, the data transfer rate to the disk device needs to be 220 Mbps or more when not compressed, but the condition can be relaxed to about 4 Mbps by compressing.

  As described above, according to the prior art, a device having high earthquake resistance can be easily realized by combining a buffer memory and a compression circuit.

  However, if the conventional apparatus is applied to information with a high data transfer rate, the amount of buffer memory required increases. For example, in the case of moving image data, if it takes 5 seconds to recover from an impact, a buffer memory of 4 Mbps × 5 s = 20 Mb is required. As described above, the conventional apparatus has a problem that an amount of necessary buffer memory is increased particularly for information having a high data transfer rate, resulting in an expensive apparatus.

  An object of the present invention is to solve such a problem and to provide a compressed information storage device that is inexpensive and has high earthquake resistance.

  In order to solve the above problems, a compressed information storage device of the present invention compresses information to generate compressed information, temporary storage means for temporarily storing compressed information, and storage in the temporary storage means. Storage means for storing compressed information from the temporary storage means at a rate faster than the rate to be generated, remaining amount detection means for detecting an unused capacity of the temporary storage means, and unused capacity detected by the remaining amount detection means A compression information storage device comprising: a control means for detecting an unstorable state of the storage means when the value is smaller than a predetermined set value, and increasing a compression rate of information of the compression means based on the detection. After detecting that the storage means is in a writable state, the means waits for the unused capacity detected by the remaining amount detecting means to increase to another set value exceeding the predetermined set value. From before It is characterized by returning the compression rate of information compression means to the original compressibility.

  According to the above configuration, after detecting that the storage unit is in a writable state, after waiting for the unused capacity of the temporary storage unit to increase to another set value exceeding the predetermined set value By returning the compression rate to the original value, the compression rate will be lowered when the remaining capacity of the temporary storage means is sufficient. There is a margin in the time until the remaining amount of the storage means becomes zero.

  According to the present invention, the following effects can be obtained.

  (1) When the storage device is incapable of storage, the compression rate of the information amount is increased, so that the storage capacity of the temporary storage means can be reduced, and as a result, an inexpensive and high earthquake-resistant device can be realized. In particular, since the optical pickup of the optical disk apparatus is heavy, the time during which recording cannot be performed becomes longer, so that a greater effect can be obtained.

  (2) Even when recording is impossible due to a continuously generated impact, there is a margin in the time until the remaining amount of the temporary storage means becomes zero.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 shows a block diagram of a compressed information storage device according to the first embodiment of the present invention. Here, a case where the present invention is applied to a camera-integrated video recorder is shown. The image information converted into an electric signal by the camera unit 8 is converted into a digital signal by the A / D converter 7 and sent to the compression circuit 1. Data input to the compression circuit 1 is subjected to compression processing. Many methods have been proposed for the compression processing method. When image information is a target, human visual characteristics are used to obtain a high compression rate. As a result, the input data is compressed to a few tenths. In the compression circuit 1 according to the first embodiment, the data compression rate can be changed by a command from the system controller 5. Therefore, data indicating the compression rate at that time is added to the compressed data. The data compressed by the compression circuit 1 is temporarily stored in the buffer memory 2 via the memory controller 3. The memory controller 3 is a circuit that controls the flow of data between the compression circuit 1, the buffer memory 2, and the disk device 4, and the address in the buffer memory 2 of the data transferred from the compression circuit 1 to the buffer memory 2 and the buffer memory 2 The address of the data sent from the disk to the disk device 4 is managed, and the remaining amount of the buffer memory 2 is detected based on these addresses. The disk device 4 is a device for storing data, and an optical disk device is used. The optical disk apparatus has a high access speed and has the largest storage capacity as a storage apparatus capable of exchanging disks. Therefore, the optical disk apparatus is an optimal apparatus when a large storage capacity is required such as image information. However, in the optical disk apparatus, the optical pickup is precisely positioned and controlled on the micron order. Therefore, if a large vibration or impact is applied to the apparatus, the position of the optical pickup is deviated from the normal position, and recording becomes impossible. In particular, the optical pickup of the optical disk apparatus is heavier than the magnetic head of the hard disk apparatus, and thus is greatly affected by vibration and impact. That is, once it deviates from the normal position, it takes a long time to return to the original position.

  Next, the operation in the first embodiment will be described. FIG. 2A shows a temporal change in the remaining amount of the buffer memory 2. The remaining capacity of the buffer memory 2 means the amount of usable memory, and is obtained by subtracting the amount of data remaining in the buffer memory 2 without being transferred to the disk device 4 from the total capacity of the buffer memory 2. Therefore, when data is transferred from the compression circuit 1 to the buffer memory 2, the remaining capacity of the buffer memory 2 decreases. When data is transferred from the buffer memory 2 to the disk device 4, the remaining capacity of the buffer memory 2 increases. To do. FIG. 2B shows a temporal change in the compression rate of the compression circuit 1. The higher the compression rate, the smaller the amount of data output from the compression circuit 1. As a result, the higher the compression rate, the lower the data transfer rate of output data. In FIG. 2A, recording is started at time 0. Simultaneously with the start of recording, compression is started by the compression circuit 1. At this time 0, there is no data in the buffer memory 2, so the remaining capacity of the buffer memory 2 is equal to the total capacity of the buffer memory 2. Since the compressed information is transferred from the compression circuit 1 to the buffer memory 2 at a constant transfer rate, the remaining amount of the buffer memory 2 decreases with time. When the remaining capacity of the buffer memory 2 falls below a predetermined first set value TH1 at time T1, the memory controller 3 notifies the system controller 5 of this. In response to this, the system controller 5 gives an instruction to the memory controller 3 to start data transfer from the buffer memory 2 to the disk device 4 and writes data to the disk to the disk device 4. Issue a start command. Since the data transfer rate from the buffer memory 2 to the disk device 4 is set to be higher than the data transfer rate from the compression circuit 1 to the buffer memory 2, it is temporarily stored in the buffer memory 2 over time. The compressed data decreases and the remaining amount of the buffer memory 2 increases. Next, when the remaining amount of the buffer memory 2 exceeds the second set value TH2 at time T2, the memory controller 3 notifies the system controller 5 of this. In response to this, the system controller 5 gives a command to the memory controller 3 to stop the transfer of data from the buffer memory 2 to the disk device 4 and writes the data to the disk to the disk device 4. Issue a stop command. In normal operation, thereafter, when the remaining capacity of the buffer memory 2 falls below TH1, data is written to the disk device 4, and when it exceeds TH2, writing of data to the disk device 4 is stopped. In such a normal operation, the compression rate is held at a predetermined value K1.

  Now, assume that data cannot be written to the disk device 4 due to an impact at time T3, and it takes time until time T7 to return to a writable state. The remaining amount of the buffer memory 2 decreases with time and falls below the first set value TH1 at time T4. At this time, the disk device 4 is still in a state where data cannot be written. No data transfer from 2 to the disk device 4 is performed. For this reason, the remaining amount of the buffer memory 2 further decreases. When the remaining amount of the buffer memory 2 falls below the third set value TH3 at time T5, the memory controller 3 notifies the system controller 5 of this. In response to this, the system controller 5 gives a command to the compression circuit 1 to increase the compression rate to K2. In response to this, the compression circuit 1 increases the data compression rate to K2, and reduces the data transfer amount to the buffer memory 2. The compression processing of the image information is performed for each data block having a predetermined amount of data, and the compression ratio cannot be changed in the middle of processing one data block, so the compression circuit 1 increases the compression ratio. Is from time T6 when the processing of the data block being processed when the command from the system controller 5 is received is completed and the next data block is processed. At time T6, the system controller 5 detects that the compression rate in the compression circuit 1 has been changed to K2, and displays it on the display device 6. Specifically, in the case of a camera-integrated video recorder, a monitor screen using liquid crystal is provided, so that an indication that the compression rate has increased is displayed on the screen. Alternatively, an LED may be used as the display element, and the LED may emit light when the compression rate increases. Thus, by performing the display, the user can take measures corresponding to the display. For example, when the compression rate is increased as described above, the image quality generally deteriorates. However, if the user recognizes that the compression rate has increased and operates the camera so as to avoid recording fast-moving video, the image quality deterioration can be suppressed. In addition, the cause of the increase in the compression ratio is that a large vibration or impact is applied to the camera. Therefore, when the user holds the camera so that the camera is not subjected to the vibration or impact, the disk device 4 is affected by the impact. It is possible to shorten the time until returning from the unwritable state. Such usage instructions may be displayed on the liquid crystal monitor. In this way, the user can respond appropriately only by operating according to the instructions on the screen. Since the compression rate increases at time T6, the transfer rate of data transferred from the compression circuit 1 to the buffer memory 2 decreases. As a result, the rate of decrease in the remaining amount of the buffer memory 2 is reduced, and as shown in FIG.

  Thereafter, at time T7, the system controller 5 detects that the disk device 4 is ready for data writing, and instructs the memory controller 3 to start data transfer from the buffer memory 2 to the disk device 4. As a result, the remaining amount of the buffer memory 2 increases. At the same time, the system controller 5 instructs the compression circuit 1 to return the compression rate to K1. Similar to when the compression rate is increased, the compression circuit 1 sets the compression rate from the time T8 when the processing of the data block being processed when the instruction is given is completed and the processing of the next data block is started. Return to K1. The system controller 5 detects that the compression ratio has become K1, and displays it on the display device 6. After this, normal operation is repeated.

  In the first embodiment, it is detected that the disk device 4 is in a data writable state, and the compression rate is returned to K1. By doing so, the compression rate is lowered at an early point, and thus the image deterioration is also eliminated at an early point.

  Next, another case will be described in which the compression rate is returned to K1 when the remaining amount of the buffer memory 2 exceeds a predetermined value. 3A and 3B show temporal changes in the remaining amount of the buffer memory 2 and the compression rate in that case. Here, since it is the same as FIG. 2 (a), (b) until the time of T7, it demonstrates after that. At time T7, the system controller 5 detects that the disk device 4 is ready to write data, and instructs the memory controller 3 to start data transfer from the buffer memory 2 to the disk device 4. As a result, the remaining amount of the buffer memory 2 increases. Furthermore, the system controller 5 instructs the compression circuit 1 to return the compression rate to K1 at time T8 when the remaining amount of the buffer memory 2 becomes TH4. The compression circuit 1 returns the compression ratio to K1 from time T9 when the processing of the data block being processed when the instruction is given is completed and the processing of the next data block is started. The system controller 5 detects that the compression ratio has become K1, and displays it on the display device 6. After this, normal operation is repeated. As described above, if the compression rate is restored after waiting for the remaining amount of the buffer memory 2 to increase to TH4, the compression rate is lowered when the remaining amount of the buffer memory 2 is sufficient. Therefore, even when the recording is impossible due to the continuously generated impact, there is enough time until the remaining amount of the buffer memory 2 becomes zero. TH4 may be larger than TH3, but is preferably larger than TH1.

  The above operation will be described with reference to the flowchart of FIG. When recording is started, the remaining memory capacity is first compared with TH1 (S1). If the remaining memory capacity is less than TH1, it is checked whether or not the disk device 4 can record (S2). If recording is possible, data transfer from the buffer memory 2 to the disk device 4 is started (S3). Next, it is checked whether or not the recording is finished (S4). If the recording is continued, S1 is re-executed. Since the above-described loop is executed, the remaining memory capacity is increased from TH1, so the process proceeds to S5, where the remaining memory capacity is compared with TH2. When the remaining memory capacity is increased from TH2 as the disk device 4 performs the recording operation, data transfer from the buffer memory 2 to the disk device 4 is stopped (S6). The above operation is a normal recording operation.

  Next, a flow when the disk device 4 becomes unrecordable will be described. In this case, it is assumed that the remaining amount of memory is less than TH1 and the disk device 4 is in a recording impossible state. That is, the process proceeds from S2 to S7, where the remaining memory capacity is compared with TH3. If the remaining memory capacity is less than TH3, the compression rate is increased to K2 and displayed at the same time (S8). In this state, it waits for the disk device 4 to be recordable (S9). If recording is possible, it is detected that the disk device 4 is capable of recording, the compression rate is returned to K1, and this is displayed.

  In FIG. 2A, during the period from T6 to T8, the rate of decrease in the remaining amount of the buffer memory 2 is reduced due to the increase in the compression rate. This means that the time until the remaining amount of the buffer memory 2 becomes 0 becomes longer, and there is a margin for the time until the disk device 4 returns from the write-incapable state. Further, if the time until the remaining amount of the buffer memory 2 becomes 0 is the same, the amount of memory used can be reduced. This point will be described in more detail. As an example, when a 16 Mbps memory is used for the buffer memory 2 and data is sent to the memory at the transfer rate of 4 Mbps for the first 3 seconds, and then the data transfer rate is lowered and the data is sent at 1.4 Mbps, the buffer memory When calculating the time until the remaining amount becomes 0, 3s + (16 Mbps-4 Mbps × 3 s) /1.4 Mbps = 5.86 s. Since 5.86 seconds are required for the remaining amount of the buffer memory 2 to become 0, it can be seen that there is a maximum of 5.86 seconds before the disk device 4 returns from the unwritable state. In the case of a transfer rate fixed at 4 Mbps as in the conventional apparatus, 16 Mbps / 4 Mbps = 4 s, and there is only 4 seconds, so in the first embodiment according to the present invention, the recovery time can be extended by about 1.5 times. I understand that. Conversely, when the amount of buffer memory for securing the recovery time of 5.86 seconds is calculated, it becomes 4 Mbps × 5.86 s = 23 Mb in the conventional apparatus, and in the first embodiment of the present invention, about 30% memory is obtained. It can be seen that the amount can be reduced. As described above, according to the first embodiment of the present invention, it is possible to realize a significant reduction in the amount of buffer memory or an increase in the return time margin from a write-disabled state. In addition, since the fact that the compression rate has increased is displayed, it is possible for the user to take a usage method that reduces image quality degradation and a usage method that speeds up recovery from the unrecordable state. .

  In the first embodiment described above, an example in which the compression rate is switched to two stages has been described, but switching of three or more stages may be performed. In this case, the compression rate switching control is complicated, but since the image quality gradually deteriorates, there is an advantage that the image quality deterioration is not noticeable. In the first embodiment, the remaining amount of the buffer memory 2 is fixed to a predetermined value. However, the compression rate may be made variable according to the remaining amount of the buffer memory 2.

  In the first embodiment, the compression rate is increased when the remaining capacity of the buffer memory 2 falls below TH3. However, the compression rate is increased at time T3 when the disk device 4 is in a record-disabled state. The compression ratio may be returned to K1 at time T7 when 4 becomes recordable. In this case, since the compression rate is increased at an earlier time than in the first embodiment, the image degradation accompanying the compression starts at an earlier time. However, the amount of buffer memory can be further reduced as compared with the first embodiment.

  Next, a second embodiment of the present invention will be described. FIG. 5 shows a block diagram of a compressed information storage device according to the second embodiment of the present invention. Here, as in the first embodiment, a case where the present invention is applied to a camera-integrated video recorder is shown. The image information converted into an electric signal by the camera unit 8 is converted into a digital signal by the A / D converter 7 and sent to the compression circuit 1. Similarly, the audio information converted into an electrical signal by the audio unit 9 is converted into a digital signal by the A / D converter 10 and sent to the compression circuit 1. Data input to the compression circuit 1 is subjected to compression processing. Image data and audio data are input to the compression circuit 1, a compression method suitable for the image data is applied to the image data, and a compression method suitable for the audio data is applied to the audio data. Two pieces of data are simultaneously compressed in parallel in the compression circuit 1. In the compressed data, image data and audio data are combined into one data series. In this process, an identification code indicating the image data is added to the image data, and an identification code indicating the sound data is added to the audio data. Since the image data and the audio data are respectively compressed in parallel, the compression circuit 1 can compress only the image data or only the audio data, which can be selected by a command from the system controller 5. The data compressed by the compression circuit 1 is temporarily stored in the buffer memory 2 via the memory controller 3. The memory controller 3 is a circuit that controls the flow of data between the compression circuit 1, the buffer memory 2, and the disk device 4, and the address in the buffer memory 2 of the data transferred from the compression circuit 1 to the buffer memory 2 and the buffer memory 2. The address of the data sent from the disk to the disk device 4 is managed, and the remaining amount of the buffer memory 2 is detected based on these addresses. The disk device 4 is a device for storing data, and an optical disk device is used. The additional data generation circuit 11 is a circuit for adding predetermined image data when only audio data is compressed.

  Next, the operation in the second embodiment will be described. FIG. 6A shows a temporal change in the remaining amount of the buffer memory 2. FIG. 6B shows the state of image data compression processing. It is ON when image data compression processing is being performed, and is OFF when image data compression processing is not being performed. Similarly, FIG. 6C shows the state of audio data compression processing. In FIG. 6A, recording is started at time 0. Simultaneously with the start of recording, compression is started by the compression circuit 1. At this time 0, there is no data in the buffer memory 2, so the remaining capacity of the buffer memory 2 is equal to the total capacity of the buffer memory 2. Since the compressed information is transferred from the compression circuit 1 to the buffer memory 2 at a constant transfer rate, the remaining amount of the buffer memory 2 decreases with time. When the remaining capacity of the buffer memory 2 falls below a predetermined first set value TH1 at time T1, the memory controller 3 notifies the system controller 5 of this. In response to this, the system controller 5 gives a command to the memory controller 3 to start data transfer from the buffer memory 2 to the disk device 4, and writes data to the disk to the disk device 4. Issue a start command. Since the data transfer rate from the buffer memory 2 to the disk device 4 is set higher than the data transfer rate from the compression circuit 1 to the buffer memory 2, it is temporarily stored in the buffer memory 2 as time passes. The compressed data that has been reduced decreases, and the remaining amount of the buffer memory 2 increases. Next, when the remaining amount of the buffer memory 2 exceeds the second set value TH2 at time T2, the memory controller 3 notifies the system controller 5 of this. In response to this, the system controller 5 gives a command to the memory controller 3 to stop the transfer of data from the buffer memory 2 to the disk device 4 and writes the data to the disk to the disk device 4. Issue a stop command. In normal operation, thereafter, when the remaining capacity of the buffer memory 2 falls below TH1, data is written to the disk device 4, and when it exceeds TH2, writing of data to the disk device 4 is stopped. In such a normal operation, the compression circuit 1 compresses both image data and audio data, and the additional data generation circuit 11 is not operating.

  Now, assume that data cannot be written to the disk device 4 due to an impact at time T3, and it takes time until time T7 to return to a writable state. The remaining amount of the buffer memory 2 decreases with time and falls below the first set value TH1 at time T4. At this time, the disk device 4 is still in a state where data cannot be written. No data transfer from 2 to the disk device 4 is performed. For this reason, the remaining amount of the buffer memory 2 further decreases. When the remaining amount of the buffer memory 2 falls below the third set value TH3 at time T5, the memory controller 3 notifies the system controller 5 of this. In response to this, the system controller 5 gives a command to the compression circuit 1 to stop the compression processing of the image data. In response to this, the compression circuit 1 stops the compression process of the image data and performs only the compression process of the audio data. The amount of compressed image data is about 4 Mbps as described above, but the amount of audio data is about 0.3 Mbps, so the amount of data transferred to the buffer memory 2 is stopped by stopping the image data compression process. Decreases to less than 1/10. The compression processing of the image information is performed for each data block having a predetermined amount of data. Since the compression processing cannot be stopped in the middle of processing one data block, the compression circuit 1 compresses the image data. The stop is from time T6 when the processing of the data block being processed at the time of receiving the command from the system controller 5 is completed and the next data block is processed. At time T6, the system controller 5 detects that the compression processing of the image data in the compression circuit 1 has been stopped, and displays it on the display device 6. Specifically, since the camera-integrated video recorder has a monitor screen using liquid crystal, the fact that the compression processing of the image data is stopped is displayed on the screen. Alternatively, an LED may be used as the display element, and the LED may emit light when the image data compression process is stopped. Thus, by performing the display, the user can take measures corresponding to the display. For example, the reason why the compression processing of the image data is stopped is that a large vibration or impact is applied to the camera. Therefore, when the user holds the camera so that the camera is not subjected to the vibration or impact, the disk device 4 It is possible to shorten the time until the device recovers from the unwritable state due to the impact. Such usage instructions may be displayed on the liquid crystal monitor. The system controller 5 stores the time T6 when the image data compression processing is stopped. Since the compression processing of the image data is stopped at time T6, the transfer rate of the data transferred from the compression circuit 1 to the buffer memory 2 is lowered. As a result, the rate of decrease in the remaining amount of the buffer memory 2 decreases, and the slope becomes gentle from the time T6 as shown in FIG.

  Thereafter, at time T7, the system controller 5 detects that the disk device 4 is ready for data writing, and instructs the memory controller 3 to start data transfer from the buffer memory 2 to the disk device 4. As a result, the remaining amount of the buffer memory 2 increases. At the same time, the system controller 5 instructs the compression circuit 1 to start the image data compression process, and displays on the display device 6 that the image data compression process has started. In response to this, the compression circuit 1 starts compression processing of the image data. Further, the system controller 5 stores a time T7 at which the image data compression process is started.

  Since the image data is not compressed during the period from T6 to T7, the buffer memory 2 stores only the audio data without any image data during that period. The data to be transferred from the buffer memory 2 to the disk device 4 may be only audio data for the period, but when the user reproduces the disk at a later date, it is not known why only audio is reproduced. Therefore, during the period, the additional data generation circuit 11 generates fixed image data and transfers it to the disk device 4. Specifically, since the system controller 5 stores the times T6 and T7, the additional data generation circuit 11 generates the image data to be added when the audio data during this time is transferred from the buffer memory 2 to the disk device 4. In addition, a command is given to the memory controller 3 to transfer the image data generated by the additional data generation circuit 11 to the disk device 4. As an image to be added, it is preferable to clearly indicate that the compression of the image has been stopped, but it may be a simple landscape. Further, the image immediately before stopping the compression processing of the image data may be generated as a still image. After this, normal operation is repeated.

  In FIG. 6A, the reduction rate of the remaining amount of the buffer memory 2 is reduced by stopping the compression processing of the image data from T6 to T7. This means that the time until the buffer memory 2 becomes 0 becomes longer, and there is an allowance for the time until the disk device returns from the unwritable state. Further, if the time until the remaining amount of the buffer memory 2 becomes 0 is the same, the amount of memory used can be reduced. This point will be described in more detail. As an example, a 16 Mb memory is used as the buffer memory 2, data is sent to the memory at the transfer rate of 4.3 Mbps for the first 3.5 seconds, and then the compression process of the image data is stopped, and the data transfer rate is 0. In the case of 3 Mbps, when the time until the remaining amount of the buffer memory 2 becomes 0 is calculated, 3.5 s + (16 Mbps−4.3 Mbps × 3.5 s) /0.3 Mbps = 6.2 s is obtained. Since it takes 6.2 seconds for the remaining amount of the buffer memory 2 to become 0, it can be seen that there is a maximum of 6.2 seconds before the disk device returns from the write-disabled state. When image data and audio data are always subjected to compression processing as in the conventional apparatus, the data transfer rate is fixed at 4.3 Mbps, so 16 Mbps / 4.3 Mbps = 3.7 s, so that there is only a margin of 3.7 seconds. In the second embodiment according to the present invention, it can be seen that the recovery time can be extended by about 1.7 times. Conversely, if the amount of buffer memory for securing the return time of 6.2 seconds is calculated, it becomes 4.3 Mbps × 6.2 s = 27 Mb in the conventional apparatus. In the second embodiment of the present invention, about 40 % Memory can be reduced. As described above, according to the second embodiment of the present invention, it is possible to realize a significant reduction in the amount of buffer memory or an increase in the return time margin from a write-disabled state.

  In the second embodiment described above, an example of compressing two data of image data and audio data has been described, but the present invention can also be applied to a case of compressing three or more data. In this case, since it is necessary to control which of the three or more data is to be stopped, the control becomes complicated, but there is an advantage that the data transfer rate can be greatly reduced.

  In the second embodiment, the compression of the image is stopped when the remaining amount of the buffer memory falls below TH3. However, the compression of the image is stopped at the time T3 when the disk device 4 becomes unrecordable. Image compression may be started at time T7 when the apparatus 4 becomes recordable. In this case, since the compression of the image is stopped at an earlier time than in the second embodiment, the period without image data becomes longer. However, the buffer memory can be further reduced as compared with the second embodiment.

  Further, in the second embodiment, it is detected that the disk device 4 is in a state where data can be written, and the image data compression process is started. However, as described in the first embodiment, Similarly to the above, the compression process of the image data may be started when the remaining amount of the buffer memory 2 becomes a predetermined value or more. As a result, the compression of the image data is started when the remaining capacity of the buffer memory 2 is sufficient, so that the remaining capacity of the buffer memory 2 can be used even in a recording impossible state due to a continuously generated shock. There is room for the time to reach 0.

  The compressed information storage device of the present invention includes a compression means for compressing information to generate compressed information, a temporary storage means for temporarily storing the compressed information, and a rate faster than the rate stored in the temporary storage means. The storage means for storing the compression information from the temporary storage means, and the control means for detecting the incomprehensible state of the storage means and increasing the compression rate of the information of the compression means may be provided.

  The compressed information storage device of the present invention includes a compression unit that compresses information to generate compressed information, a temporary storage unit that temporarily stores compressed information, and a rate faster than the rate stored in the temporary storage unit. A storage unit that stores compression information from the temporary storage unit; a remaining amount detection unit that detects an unused capacity of the temporary storage unit; and an unused capacity detected by the remaining amount detection unit is smaller than a predetermined set value. It is good also as a structure provided with the control means which detects the memory impossible state of the said memory | storage means, and enlarges the compression rate of the information of the said compression means based on this detection.

  In the compressed information storage device of the present invention, in addition to the above configuration, the control unit may detect the storage enabled state of the storage unit and return the compression rate of the information of the compression unit to the original compression rate.

  The compressed information storage device of the present invention detects a compression means for compressing information to generate compressed information, a storage means for storing the compressed information, and an unstorable state of the storage means, and the compression based on this detection Control means for increasing the compression rate of the information of the means may be provided.

  The compressed information storage device of the present invention stores compression means for compressing information to generate compressed information, temporary storage means for temporarily storing the compressed information, and compressed information sent from the temporary storage means Storage means, remaining amount detection means for detecting unused capacity of the temporary storage means, and when the unused capacity detected by the remaining capacity detection means is smaller than a predetermined set value, It is good also as a structure provided with the control means which detects and enlarges the compression rate of the information of the said compression means based on this detection.

  Furthermore, the compressed information storage device of the present invention includes a compression means for compressing a plurality of types of information to generate compressed information, a temporary storage means for temporarily storing the compressed information, and a rate stored in the temporary storage means. Storage means for storing compressed information from the temporary storage means at a faster rate, and the compression means for detecting an unstorable state of the storage means and compressing only predetermined information from a plurality of types of information based on this detection And a control means for instructing to.

  The compressed information storage device of the present invention compresses a plurality of types of information to generate compressed information, temporary storage means for temporarily storing compressed information, and a rate faster than the rate stored in the temporary storage means Storage means for storing compression information from the temporary storage means at a rate; remaining amount detection means for detecting unused capacity of the temporary storage means; and unused capacity detected by the remaining amount detection means is a predetermined set value And a control means for detecting an unstorable state of the storage means when the time is smaller, and instructing the compression means to compress only predetermined information from the plurality of types of information based on the detection. good.

  The compressed information storage device of the present invention includes a compression unit that compresses information to generate compressed information, a temporary storage unit that temporarily stores compressed information, and a rate faster than the rate stored in the temporary storage unit. A storage means for storing compression information from the temporary storage means; a control means for detecting a non-storable state of the storage means to increase the compression ratio of the information of the compression means; and the compression ratio increases when the compression ratio increases. And a display means for displaying that.

  The compressed information storage device of the present invention includes a compression unit that compresses information to generate compressed information, a temporary storage unit that temporarily stores compressed information, and a rate faster than the rate stored in the temporary storage unit. A storage unit that stores compression information from the temporary storage unit; a remaining amount detection unit that detects an unused capacity of the temporary storage unit; and an unused capacity detected by the remaining amount detection unit is smaller than a predetermined set value. A control means for detecting a non-storable state of the storage means and increasing the compression rate of the information of the compression means based on this detection; a display means for displaying that the compression rate has increased when the compression rate has increased; A compressed information storage device comprising:

  In addition to the above configuration, the compressed information storage device of the present invention may be configured to further include display means for displaying uncompressed information from a plurality of types of information.

  In the compressed information storage device of the present invention, in addition to the above configuration, it is preferable that the control unit compresses all information of a plurality of types of the compression unit by detecting a storage enabled state of the storage unit.

  In addition to the above configuration, the compressed information storage device of the present invention is configured such that when the unused capacity detected by the remaining amount detecting means is larger than another set value that is equal to or greater than the predetermined set value, the control means It is preferable to compress a plurality of types of information of the compressing means by detecting a storable state of the means.

  In addition to the above configuration, the compressed information storage device of the present invention may further include additional information generating means for outputting additional information to the recording means in response to an instruction from the control means.

  In the compressed information storage device of the present invention, in addition to the above configuration, the additional information is preferably built in the additional information generating means and is any one kind of information among the plurality of types of information. .

  In the compressed information storage device of the present invention, in addition to the above configuration, the additional information may be any information other than information when the control unit instructs the compression unit to compress only predetermined information from a plurality of types of information. It is preferable that the information is one.

  In addition to the above configuration, the compressed information storage device of the present invention is stored in the temporary storage unit when the control unit records the period from the unrecordable state to the recordable state in the recording unit. It is preferable to record both the compressed information and the additional information.

  In addition to the above configuration, the compressed information storage device of the present invention compresses information to generate compressed information, control means for changing the compression rate of the information of the compression unit, and when the compression rate increases And a display means for displaying that the compression rate has increased.

  In addition to the above configuration, the compressed information storage device of the present invention further includes temporary storage means for temporarily storing the compressed information, and the control means stores information on the compression means according to the remaining memory capacity of the temporary storage means. It is preferable to change the compression ratio.

In addition to the above configuration, the compressed information storage device of the present invention compresses a plurality of types of information to generate compressed information, and controls the compression unit to compress only predetermined information from the plurality of types of information. Control means for displaying, display means for displaying uncompressed information from the plurality of types of information,
The structure provided with may be sufficient.

  In addition to the above configuration, the compressed information storage device of the present invention further includes temporary storage means for temporarily storing the compressed information, and the control means controls the compression means by the remaining memory capacity of the temporary storage means. Thus, it is preferable to compress only predetermined information from a plurality of types of information.

  The compressed information storage device of the present invention detects a compression means for compressing a plurality of types of information to generate compressed information, a storage means for storing the compressed information, and an unstorable state of the storage means. And a control unit that instructs the compression unit to compress only predetermined information from a plurality of types of information.

  The compressed information storage device of the present invention includes a compression means for compressing a plurality of types of information to generate compressed information, a temporary storage means for temporarily storing the compressed information, and compressed information sent from the temporary storage means Storage means for storing the remaining capacity detecting means for detecting the unused capacity of the temporary storage means, and the storage means cannot be stored when the unused capacity detected by the remaining capacity detecting means is smaller than a predetermined set value. It may be configured to include a control unit that detects a state and instructs the compression unit to compress only predetermined information from a plurality of types of information based on the detection.

  Further, according to the present invention, the following effects can be obtained.

  When the storage device is incapable of storage, only a part of the plurality of types of information is compressed, so that the storage capacity of the temporary storage means can be reduced, and as a result, an inexpensive device with high seismic performance can be realized.

  Further, when the compression rate is increased or when the number of pieces of information to be compressed is reduced, it is displayed so that the user can take a corresponding action.

It is a block diagram of the compression information storage device in a 1st embodiment. It is a figure which shows the time change of the residual amount of the buffer memory of the compression information storage device in 1st Embodiment, and the time change of a compression rate. It is a figure which shows the time change of the residual amount of the buffer memory in another case of the compression information storage device in 1st Embodiment, and the time change of a compression rate. It is a flowchart which shows operation | movement of the compression information storage device in 1st Embodiment. It is a block diagram of the compression information storage device in a 2nd embodiment. It is a figure which shows the time change of the residual amount of the buffer memory of the compression information storage device in 2nd Embodiment, and the time change of a compression state. It is a block diagram of the conventional compression information storage device. It is a figure which shows the time change of the residual amount of the buffer memory of the conventional compression information storage device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Compression circuit 2 Buffer memory 3 Memory controller 4 Disk apparatus 5 System controller 6 Display apparatus 7 A / D converter 8 Camera part 9 Audio | voice part 10 A / D converter 11 Additional data generation circuit

Claims (1)

Compression means for compressing information to generate compressed information;
Temporary storage means for temporarily storing the compression information;
Storage means for storing compressed information from the temporary storage means at a rate faster than the rate stored in the temporary storage means;
A remaining amount detecting means for detecting an unused capacity of the temporary storage means;
A control means for detecting an unstorable state of the storage means when the unused capacity detected by the remaining amount detection means is smaller than a predetermined set value, and for increasing the compression rate of the information of the compression means based on this detection; A compressed information storage device comprising:
After the control unit detects that the storage unit is in a writable state, the unused capacity detected by the remaining amount detection unit increases to another set value exceeding the predetermined set value. A compression information storage device which waits and returns the compression rate of the information of the compression means to the original compression rate.

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