Data compression and decompression method and device

Abstract

The present disclosure provides a data compression and decompression method and device. The data compression method includes: defining a compressed data format, the data format including a data area and a flag area; comparing the current data frame of the data to be compressed with the previous data frame to determine the most significant bit of the data change; expressing the number of bits corresponding to the most significant bit in a preset base and storing it in the flag area as the flag of the current data frame; intercepting data of a preset bit width from the most significant bit of the data change to the lowest bit of the current data frame and storing it in the data area to obtain compressed data; wherein the preset bit width is equal to the bit width of the data area. The method and device can achieve real-time data compression with a fixed compression ratio without requiring computing power.

Description

Technical Field

[0001] The present disclosure relates to the technical field of data processing and data compression, and in particular to a data compression and decompression method and device. Background Art

[0002] Data compression is required in data processing, transmission, storage, and other fields. The requirements for data compression vary depending on the application scenario. For example, if data must be compressed and decompressed without any loss of information, requirements for the compression ratio and compression / decompression efficiency may be relaxed. Extremely high compression ratio requirements inevitably sacrifice data quality, meaning that some information features may be lost after decompression. Extremely high compression / decompression efficiency requirements, such as those requiring complete real-time processing, may also sacrifice data quality and compression ratio.

[0003] Current compression methods primarily rely on offline computing, and these methods require a certain level of computing power. For example, multiple data compression methods must be used simultaneously based on data characteristics. However, in real-time data transmission scenarios, even if a certain degree of data quality loss is acceptable, effective compression and decompression cannot be achieved without the computing power required to compress and decompress data. Furthermore, high-speed digital converters, such as analog-to-digital converters (ADCs) and digital-to-analog converters (DACs), often use parallel data buses to transfer data to and from data sources. However, as data resolution increases, the wider the data bit width, the greater the crosstalk during transmission. Furthermore, during circuit layout design, the larger the area occupied and the larger the number of chip I / Os. Summary of the Invention

[0004] In response to the above technical problems, the present disclosure provides a data compression and decompression method and device, which are used to at least partially solve the above technical problems.

[0005] Based on this, the first aspect of the present disclosure provides a data compression method, including: defining the compressed data format, the data format includes a data area and a flag area; comparing the current data frame of the data to be compressed with the previous data frame to determine the highest bit of the data change; expressing the number of bits corresponding to the highest bit as a preset base and storing it in the flag area as the flag of the current data frame; intercepting data of a preset bit width from the highest bit of the data change to the low bit of the current data frame and storing it in the data area to obtain compressed data; wherein the preset bit width is equal to the bit width of the data area.

[0006] According to an embodiment of the present disclosure, the sum of the bit widths of the data area and the flag area is equal to the preset total bit width of the data to be compressed.

[0007] According to an embodiment of the present disclosure, an XOR operation is performed on the current data frame and the previous data frame to determine the most significant bit of the data change.

[0008] According to an embodiment of the present disclosure, when the current data frame is identical to the previous data frame, the flag value corresponding to the previous data frame is subtracted from the data bit width to serve as the flag of the current data frame.

[0009] According to an embodiment of the present disclosure, data to be compressed is compressed through hardware description language or digital gate circuits.

[0010] According to an embodiment of the present disclosure, the data area is located in the high-order area, and the flag area is located in the low-order area; or the data area is located in the low-order area, and the flag area is located in the high-order area.

[0011] The second aspect of the present disclosure provides a data compression device, including: a definition module, used to define the compressed data format, the data format includes a data area and a flag area; a comparison module, used to compare the current data frame of the data to be compressed with the previous data frame to determine the highest bit of the data change; a first filling module, used to express the number of bits corresponding to the highest bit as a preset base and store it in the flag area as the flag of the current data frame; a second filling module, used to intercept data of a preset bit width from the highest bit of the data change to the low bit of the current data frame and store it in the data area to obtain compressed data; wherein the preset bit width is equal to the bit width of the data area.

[0012] The third aspect of the present disclosure provides a data decompression method based on the above-mentioned data compression method, including: extracting a flag bit of a preset base in a flag bit area, parsing the flag bit of the preset base, and obtaining the number of filling bits of the data; extracting data of a preset bit width in the data area, filling the data of the preset bit width from the position indicated by the number of filling bits from high to low, and for the low bits of the unfilled data, filling them with data of the corresponding number of bits in the previous data frame to obtain decompressed data.

[0013] The fourth aspect of the present disclosure provides a data decompression device based on the above-mentioned data compression device, including: a first extraction module, used to extract the flag bit of a preset base in the flag bit area, and parse the flag bit of the preset base to obtain the number of filling bits of the data; a second extraction module, used to extract data of a preset bit width in the data area, and fill the data of the preset bit width from the position where the filling bit number indication is obtained from the high bit to the low bit, and for the low bit of the unfilled data, use the data of the corresponding bit number of the previous data frame to fill it to obtain decompressed data.

[0014] The embodiment of the present disclosure also provides a data compression and decompression method, including: performing the following operations by a compression end: defining a compressed data format, the data format including a data area and a flag area; comparing a current data frame of the data to be compressed with a previous data frame to determine the highest bit of the data change; expressing the number of bits corresponding to the highest bit in a preset base and storing it in the flag area as the flag of the current data frame; intercepting data of a preset bit width from the highest bit of the data change to the low bit in the current data frame and storing it in the data area to obtain compressed data; wherein the preset bit width is equal to the bit width of the data area; performing the following operations by a decompression end: receiving compressed data transmitted by the compression end, extracting the flag of the preset base in the flag area, parsing the flag of the preset base to obtain the number of padding bits of the data; extracting data of the preset bit width in the data area, filling the data of the preset bit width from the position indicated by the number of padding bits from the high bit to the low bit, and for the low bit of the unfilled data, filling it with data of the corresponding number of bits of the previous data frame to obtain decompressed data.

[0015] The data compression and decompression method and device provided by the embodiment of the present disclosure at least include the following

[0016] Beneficial effects:

[0017] This compression method defines the data area and flag area based on the bit width of the transmission bus, fixes the compression ratio, compares the current data frame to be compressed with the previous data frame, determines the most significant bit of the data change as the flag, and then intercepts the data of the preset bit width from the most significant bit to the least significant bit based on the flag and stores it in the data area. This achieves real-time data compression without requiring any computing power. Furthermore, since data compression requires no computing power, it can be easily implemented using hardware description languages ​​or digital gate circuits, eliminating the large footprint and high chip I / O requirements associated with existing circuit layout designs. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and other objects, features and advantages of the present disclosure will become more apparent through the following description of the embodiments of the present disclosure with reference to the accompanying drawings, in which:

[0019] Figure 1 The flowchart of the data compression method provided by the embodiment of the present disclosure is schematically shown.

[0020] Figure 2 The flowchart of the data decompression method provided by the embodiment of the present disclosure is schematically shown.

[0021] Figure 3 The structure diagram of the data compression device provided by the embodiment of the present disclosure is schematically shown.

[0022] Figure 4 The structure diagram of the data decompression device provided by the embodiment of the present disclosure is schematically shown. DETAILED DESCRIPTION

[0023] To make the objectives, technical solutions, and advantages of the present disclosure more clearly understood, the present disclosure is further described below in conjunction with specific embodiments and with reference to the accompanying drawings. It is apparent that the embodiments described are only a portion of the embodiments of the present disclosure, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present disclosure without inventive effort are intended to fall within the scope of protection of the present disclosure.

[0024] The terms used herein are only for describing specific embodiments and are not intended to limit the present disclosure. The terms "comprise," "include," etc. used herein indicate the presence of the features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0025] In this disclosure, unless otherwise expressly specified or limited, terms such as "mounted," "connected," "connect," and "fixed" should be understood broadly. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections, electrical connections, or communication; direct connections or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of these terms in this disclosure based on specific circumstances.

[0026] In the description of the present disclosure, it should be understood that the terms "longitudinal", "length", "circumferential", "front", "rear", "left", "right", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present disclosure and simplifying the description, and do not indicate or imply that the subsystem or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present disclosure.

[0027] Throughout the drawings, identical elements are denoted by identical or similar reference numerals. Conventional structures or configurations are omitted where they may obscure the understanding of this disclosure. The shapes, sizes, and positional relationships of components in the drawings do not reflect actual size, proportion, or positional relationships. In addition, in the claims, any reference signs placed between parentheses should not be construed as limitations of the claims.

[0028] Similarly, in order to streamline the present disclosure and aid in understanding one or more of the various disclosed aspects, in the above description of exemplary embodiments of the present disclosure, the various features of the present disclosure are sometimes grouped together into a single embodiment, figure, or description thereof. Descriptions with reference to the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples" and the like mean that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present disclosure. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in an appropriate manner.

[0029] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. Throughout the present disclosure, "plurality" means at least two, such as two or three, unless otherwise specifically defined.

[0030] In the process of implementing the embodiments of the present disclosure, the inventors found that under normal circumstances, the data characteristics and compression and decompression requirements are as follows: first, the data is a digital representation of an analog waveform signal; second, in most cases, the data is sent to the DAC and converted into an analog signal output; third, the data is naturally encoded, or can be restored to a naturally encoded state; fourth, the width of the data bus that can be used to transmit data is fixed, but lower than the original bit width of the data; fifth, real-time data compression and decompression computing power is not provided, but simple digital gate circuits and their combinations can be provided.

[0031] Based on these requirements analysis, the data compression method provided by the present disclosure needs to achieve the following functions:

[0032] First, data changes are relatively stable. This is because for a digital representation of an analog signal, each data point describes a point on the analog signal, and the two data points before and after are two consecutive points on the signal. Considering that the signal bandwidth and DAC sampling rate must comply with the sampling theorem, data changes are relatively stable and continuous.

[0033] Second, a certain amount of data loss can be tolerated. This is because in DAC applications, the DAC output generally has a bandwidth-limited filter that can smooth out signal jumps caused by factors such as data loss through filtering.

[0034] Third, the compression ratio can be fixed because the transmission bus width is fixed. As long as the compressed data width is the same as the bus width, there is no need to dynamically change the width.

[0035] Fourth, it can be implemented through a combination of digital gate circuits without the need for CPU-type computing power.

[0036] Based on the above analysis, the embodiments of the present disclosure provide a data compression and decompression method for achieving real-time, fixed compression ratio, and computing power-free data compression and decompression.

[0037] Figure 1 The flowchart of the data compression method provided by the embodiment of the present disclosure is schematically shown.

[0038] like Figure 1 As shown, the data compression method may include, for example, operations S101 to S104.

[0039] In operation S101 , a compressed data format is defined, where the data format includes a data area and a flag area.

[0040] In an embodiment of the present disclosure, the bit width of the data area and the bit width of the flag area are allocated based on the preset total bit width for transmitting the data to be compressed. That is, the sum of the bit widths of the data area and the flag area equals the preset total bit width of the data to be compressed. The preset total bit width can be set based on the actual application scenario, and this disclosure does not impose any restrictions. For example, in a scenario where data is transmitted in real time, the preset total bit width can be set to the bit width of the transmission bus used to transmit the data to be compressed.

[0041] The data area is B1, the corresponding bit width is W1, the flag area is B2, the corresponding bit width is W2, the bit width of the transmission bus is W, and the bit width of the transmitted data to be compressed is W0. The bit width of the compressed data should meet the condition: the sum of W1 and W2 is W, wherein the specific width is determined by the bit width W0 of the input data to be compressed and the loss that can be accepted by data compression. The compression ratio of the data is (W0-W) / W. For example, if the bit width of the transmitted data to be compressed is 20 and the bus bit width (the bit width of the compressed data) is 8, then the compression ratio of the data is 60%. The front and back position relationship of the data area B1 and the flag area B2 is not limited. The data area B1 is located in the high-order area and the flag area B2 is located in the low-order area, or the data area B1 is located in the low-order area and the flag area B2 is located in the high-order area, that is, the data area B1 is before the flag area B2, or the flag area B2 is before the data area B1. It depends on the specific application requirements and is not limited by this disclosure.

[0042] In operation S102 , the current data frame of the data to be compressed is compared with the previous data frame to determine the most significant bit of the data change.

[0043] In an embodiment of the present disclosure, the most significant bit of the data change can be determined by performing an XOR operation on the current data frame and the previous data frame. During the XOR operation, the most significant bit of the data change refers to the position where the first 1 appears at the end of the current data. The XOR operation can be implemented by a circuit. In a non-real-time data transmission application scenario, the current data frame can be the data frame at the current position, and the previous data frame can be the data frame at the position before the current position. In a real-time data transmission application scenario, the current data frame can be the data frame transmitted at the current moment, and the previous data frame can be the data frame transmitted at the previous moment.

[0044] In operation S103, the number of bits corresponding to the highest bit is expressed in a preset base and stored in a flag area as a flag of the current data frame.

[0045] In the embodiment of the present disclosure, the number of bits corresponding to the highest bit can be expressed as binary and stored in the flag bit area B2.

[0046] In operation S104, data of a preset bit width is intercepted from the highest bit to the lowest bit of the data change in the current data frame and stored in the data area to obtain compressed data.

[0047] In the embodiment of the present disclosure, the preset bit width is equal to the bit width of the data area.

[0048] Based on the above data compression method, the embodiment of the present disclosure also provides a data decompression method.

[0049] Figure 2 The flowchart of the data decompression method provided by the embodiment of the present disclosure is schematically shown.

[0050] like Figure 2 As shown, the data decompression method may include, for example, operations S201 to S202.

[0051] In operation S201, a flag bit of a preset base is extracted from a flag bit area, and the flag bit of the preset base is parsed to obtain the number of padding bits of the data.

[0052] In operation S202, data of preset bit width is extracted from the data area, and the data of preset bit width is filled from high bit to low bit at the position indicated by the number of filling bits. For the low bit of unfilled data, the data of corresponding bit number of the previous data frame is used to fill it to obtain decompressed data.

[0053] In the embodiment of the present disclosure, during the decompression process, the previous data frame is modified according to the compression information, and the content of the data area B1 is overwritten to the position starting from the highest bit indicated by the flag area B2, and the data at other uninvolved positions remains unchanged.

[0054] Furthermore, after decompression, the maximum error deviation can be reviewed:

[0055] For example, if the data frame on the decompression end is all 0 and the data to be transmitted on the compression end is all 1, then after compression, the highest bit of the data area B1 obtained on the decompression end is 1 and the other low bits are 0. The deviation between the decompressed data value and the original data value is:

[0056]

[0057] That is, the error ratio is:

[0058]

[0059] Furthermore, based on the above embodiment, when the current data frame is identical to the previous data frame, the value of the flag bit corresponding to the previous data frame is subtracted by the data bit width to serve as the flag bit of the data transmitted at the current moment.

[0060] Specifically, when the compression end encounters that the two previous and subsequent data are consistent, that is, it finds that the value of the flag area B2 that needs to be transmitted is 0, the value of the flag area B2 is reassigned to the value of the previous flag area B2 minus the bit width W1 of the data area B1, and the data area B1 takes data of W1 length from the new position and fills it into the data area B1.

[0061] The data compression and decompression method provided by the embodiment of the present disclosure is easy to implement through hardware description language or digital gate circuits, only requires clock drive of digital circuits, does not require computing power, and can directly complete data compression in adjacent clocks or pipeline types.

[0062] It should be understood that the above-mentioned data compression method and data decompression method can be executed separately or in combination, and the specific selection is based on actual application requirements, and this disclosure does not limit it.

[0063] In order to further clarify the data compression and decompression process, a specific example is given below to illustrate the data compression and decompression process in detail.

[0064] Assume that the bit width W0 of the data to be compressed is 16, the bit width W of the data to be compressed is 8, and the bit width W2 of the flag area B2 is selected as 4 bits according to the numerical characteristics of the data to be compressed, then the bit width W1 of the data area B1 is 4 bits.

[0065] Previous data frame 0: 0111_aaaa_aaaa_aaaa;

[0066] Current data frame 1: 1000_bbbb_bbbb_bbbb.

[0067] Define the left side as the high bit. Perform an XOR operation on data 0 and data 1. If the most significant bit of the data changes to bit 16 (or 15 in the 0-15 representation), write 15 (1111) in binary format to flag area B2. The contents of data area B1, starting from bit 15 and ending with 1000, are 4 bits. If data area B1 precedes flag area B2, the compressed 8-bit data is 10001111. If flag area B2 precedes data area B1, the compressed 8-bit data is 11111000.

[0068] When the data is decompressed, the data 1000 in the data area B1 is filled in starting from the 15th bit, that is, 1000_xxxx_xxxx_xxxx is obtained, where the following xxx is the value of the previous data.

[0069] Based on the same inventive concept, an embodiment of the present disclosure also provides a data compression device.

[0070] Figure 3 The structure diagram of the data compression device provided by the embodiment of the present disclosure is schematically shown.

[0071] like Figure 3 As shown, the data compression device 300 may include, for example, a definition module 310 , a comparison module 320 , a first filling module 330 , and a second filling module 340 .

[0072] The definition module 310 is used to define the compressed data format, which includes a data area and a flag area.

[0073] The comparison module 320 is used to compare the current data frame of the data to be compressed with the previous data frame to determine the most significant bit of the data change.

[0074] The first filling module 330 is configured to express the number of bits corresponding to the highest bit in a preset base and store the result in the flag area as the flag of the current data frame.

[0075] The second filling module 340 is used to intercept data of a preset bit width from the highest bit of the data change to the lowest bit of the current data frame and store it in the data area to obtain compressed data; wherein the preset bit width is equal to the bit width of the data area.

[0076] It should be noted that the data compression device part of the present disclosure corresponds to the data compression method part in the embodiment of the present disclosure, and their specific implementation details and technical effects are also the same, which will not be repeated here.

[0077] Figure 4 The structure diagram of the data decompression device provided by the embodiment of the present disclosure is schematically shown.

[0078] like Figure 4As shown, the data compression device 400 may include, for example, a first extraction module 410 and a second extraction module 420 .

[0079] The first extraction module 410 is configured to extract a flag bit of a preset base from the flag bit area, and parse the flag bit of the preset base to obtain the number of padding bits of the data.

[0080] The second extraction module 420 is used to extract data of a preset bit width in the data area, fill the data of the preset bit width from the position where the filling bit number indication is obtained from the high bit to the low bit, and fill the low bit of the unfilled data with the data of the corresponding bit number of the previous data frame to obtain decompressed data.

[0081] It should be noted that the data decompression device part of the present disclosure corresponds to the data decompression method part in the embodiment of the present disclosure, and their specific implementation details and technical effects are also the same, which will not be repeated here.

[0082] The embodiment of the present disclosure also provides a data compression and decompression method, which can be applied to the scenario of performing certain data compression in the process of sending data from the data source chip to the digital-to-analog converter (DAC) in real time. The method includes: performing operations S101 to S104 by the compression end to obtain compressed data. The decompression end receives the compressed data transmitted by the compression end, and performs operations S201 to S202 to decompress the data. In the process of real-time data transmission, the data compression and decompression method of the embodiment of the present disclosure is used to achieve real-time compression of data while saving bandwidth or bus width.

[0083] It should be understood that the data compression and decompression method provided by the embodiment of the present disclosure is not limited to application in this scenario, but is also applicable to other scenarios involving data compression and decompression.

[0084] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present disclosure. It should be understood that the above are only specific embodiments of the present disclosure and are not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure should be included in the scope of protection of the present disclosure.

Claims

1. A data compression method, characterized in that: include: Defining a compressed data format, wherein the data format includes a data area and a flag area; Compare the current data frame of the data to be compressed with the previous data frame to determine the most significant bit of the data change; The number of bits corresponding to the highest bit is expressed in a preset base and stored in the flag bit area as the flag bit of the current data frame; The data of the preset bit width is intercepted from the highest bit to the lowest bit of the data change in the current data frame and stored in the data area to obtain compressed data; wherein the preset bit width is equal to the bit width of the data area.

2. The data compression method according to claim 1, wherein: The sum of the bit widths of the data area and the flag area is equal to the preset total bit width of the data to be compressed.

3. The data compression method according to claim 1, wherein: An XOR operation is performed on the current data frame and the previous data frame to determine the most significant bit of the data change.

4. The data compression method according to claim 1, wherein: In the case that the current data frame is identical to the previous data frame, the flag value corresponding to the previous data frame is subtracted from the data bit width to obtain the flag value of the current data frame.

5. The data compression method according to claim 1, wherein: The data to be compressed is compressed through hardware description language or digital gate circuits.

6. The data compression method according to claim 1, wherein: The data area is located in the high-order area, and the flag area is located in the low-order area; or The data area is located in the low-order area, and the flag area is located in the high-order area.

7. A data compression device, characterized in that: include: A definition module, used to define a compressed data format, wherein the data format includes a data area and a flag area; A comparison module is used to compare the current data frame of the data to be compressed with the previous data frame to determine the most significant bit of the data change; A first filling module is used to express the number of bits corresponding to the highest bit in a preset base and store it in the flag bit area as the flag bit of the current data frame; The second filling module is used to intercept data of a preset bit width from the highest bit of the data change to the lowest bit of the current data frame and store it in the data area to obtain compressed data; wherein the preset bit width is equal to the bit width of the data area.

8. A data decompression method based on the data compression method according to any one of claims 1 to 6, characterized in that: include: Extracting a flag bit of a preset base in the flag bit area, parsing the flag bit of the preset base, and obtaining a number of padding bits of data; Extract data with a preset bit width from the data area, fill the data with the preset bit width from the position indicated by the number of filling bits from high to low, and fill the low bits of unfilled data with data of the corresponding number of bits in the previous data frame to obtain decompressed data.

9. A data decompression device based on the data compression device according to claim 7, characterized in that: include: A first extraction module is used to extract the flag bit of the preset base in the flag bit area, parse the flag bit of the preset base, and obtain the number of padding bits of the data; The second extraction module is used to extract data with a preset bit width in the data area, fill the data with the preset bit width from the position where the filling bit number indication is obtained from the high bit to the low bit, and fill the low bit of the unfilled data with the data of the corresponding bit number of the previous data frame to obtain decompressed data.

10. A data compression and decompression method, characterized in that: include: The compression side does the following: Defining a compressed data format, wherein the data format includes a data area and a flag area; Compare the current data frame of the data to be compressed with the previous data frame to determine the most significant bit of the data change; The number of bits corresponding to the highest bit is expressed in a preset base and stored in the flag bit area as the flag bit of the current data frame; intercepting data of a preset bit width from the highest bit of the data change to the lowest bit of the data in the current data frame and storing the data in the data area to obtain compressed data; wherein the preset bit width is equal to the bit width of the data area; Perform the following operations on the decompressor: receiving compressed data transmitted by the compression end, extracting a flag bit of a preset base in the flag bit area, parsing the flag bit of the preset base, and obtaining a number of padding bits of the data; Extract data with a preset bit width from the data area, fill the data with the preset bit width from the position indicated by the number of filling bits from high to low, and fill the low bits of unfilled data with data of the corresponding number of bits in the previous data frame to obtain decompressed data.

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