Audio playing control device, control method and playing equipment

Abstract

The invention discloses an audio playing control device, a control method and playing equipment, when a read pointer and a write pointer in an internal cache of a conversion module are the same, the outside stops inputting an audio signal to the audio playing control device, and the conversion module outputs a null signal with an effective level and a fixed amplitude digital signal; the delay module receives a null signal with an effective level and a fixed amplitude digital signal, and outputs a first enable signal with an effective level when the delay time reaches a first time; the adjusting module carries out amplitude reduction processing on the determined initial value to obtain an amplitude reduction signal and outputs the amplitude reduction signal; when the selection module responds to the fact that the first enable signal with the effective level is effective, the received amplitude reduction signal is output, and the amplitude value of the amplitude reduction signal is reduced, so that the amplitude value difference between the amplitude reduction signal and the 0 level can be reduced, mutation can be reduced, pop noise can be weakened, and the playing effect when playing is started next time can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of audio playback, and in particular to an audio playback control device, a control method and a playback equipment. Background Art

[0002] The audio playback control device obtains the audio signal from the outside, processes the audio signal and outputs it to the player. If for some reason, the audio signal is temporarily input to the audio playback control device, the audio playback control device will generate a fixed amplitude digital signal, and the amplitude of the fixed amplitude digital signal may be random and therefore cannot be determined. When the audio signal is re-input into the audio playback control device, since the audio signal generally starts from the 0 level (the amplitude can be considered to be 0), when the amplitude of the fixed amplitude digital signal is large, a sudden change from a large amplitude to 0 will occur, which is an obvious pop (explosion) noise in terms of hearing. Then, how to reduce the pop noise and improve the playback effect has become a technical problem that needs to be solved in this field. Summary of the invention

[0003] The embodiment of the present invention provides an audio playback control device, a control method and a playback device, which are used to reduce pop noise and improve the playback effect.

[0004] In a first aspect, an embodiment of the present invention provides an audio playback control device, comprising: a conversion module, a delay module, an adjustment module and a selection module;

[0005] The conversion module is used to: process the audio signal input from the outside; in response to the read pointer and the write pointer in the internal cache being the same, output a null value signal with a valid level and a fixed amplitude digital signal;

[0006] The delay module is used to: in response to satisfying a preset condition, output a first enable signal with a valid level, wherein the preset condition includes: receiving the null value signal with a valid level and the fixed amplitude digital signal, and the delay time reaches a first time;

[0007] The adjustment module is used to: perform amplitude reduction processing on the determined initial value according to a preset operation cycle, obtain an amplitude reduction signal and output it; wherein the initial value is determined according to the fixed amplitude digital signal;

[0008] The selection module is used for outputting the amplitude reduction signal in response to receiving the first enable signal having a valid level.

[0009] In a second aspect, an embodiment of the present invention provides an audio playback control method, comprising:

[0010] In response to the read pointer and the write pointer in the internal cache being the same, outputting a null value signal and a fixed amplitude digital signal having a valid level;

[0011] In response to satisfying a preset condition, outputting a first enable signal with a valid level, wherein the preset condition includes: receiving the null value signal with a valid level and the fixed amplitude digital signal, and the delay time reaches a first time;

[0012] According to a preset operation cycle, the determined initial value is subjected to a reduction processing to obtain a reduction signal and output it; wherein the initial value is determined according to the fixed amplitude digital signal;

[0013] In response to receiving the first enable signal having an effective level, the amplitude reduction signal is output.

[0014] In a third aspect, an embodiment of the present invention further provides a playback device, comprising: a player, and the audio playback control device as described in the first aspect;

[0015] The audio playback control device is used to process the audio signal input from the outside and then output it to the player for the player to play.

[0016] The beneficial effects of the present invention are as follows:

[0017] An audio playback control device, a control method and a playback device provided by an embodiment of the present invention, when a read pointer and a write pointer in an internal cache of a conversion module are the same, it indicates that the outside world stops inputting audio signals into the audio playback control device, and the conversion module outputs a null value signal with a valid level and a fixed amplitude digital signal; when the delay module receives the null value signal with a valid level and the fixed amplitude digital signal and the delay time reaches a first time, the delay module outputs a first enable signal with a valid level; the adjustment module performs amplitude reduction processing on the determined initial value to obtain an amplitude reduction signal; when the selection module responds to the validity of the first enable signal with a valid level, the selection module outputs the amplitude reduction signal, and since the amplitude of the amplitude reduction signal is reduced, the amplitude difference between the amplitude reduction signal and the 0 level can be reduced, and the mutation can be reduced, thereby reducing the pop noise and improving the playback effect when the playback starts next time. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of a first audio playback control device provided in an embodiment of the present invention;

[0019] Figure 2 It is a structural schematic diagram of a second audio playback control device provided in an embodiment of the present invention;

[0020] Figure 3 A schematic diagram of the structure of the adjustment module provided in an embodiment of the present invention;

[0021] Figure 4 A schematic diagram of the structure of a playback device provided in an embodiment of the present invention;

[0022] Figure 5 The present invention provides a flowchart of an audio playback control method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0023] The following will be combined with the accompanying drawings to describe in detail the specific implementation of an audio playback control device, a control method, and a playback device provided by an embodiment of the present invention. It should be noted that the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0024] The embodiment of the present invention provides an audio playback control device, such as Figure 1 As shown, it includes: a conversion module 30, a delay module 10, an adjustment module 20 and a selection module 40;

[0025] The conversion module 30 is used to: process the audio signal Din input from the outside; in response to the read pointer and the write pointer in the internal cache being the same, output a null value signal Empty with a valid level and a fixed amplitude digital signal D2;

[0026] The delay module 10 is used to: output a first enable signal Enable1 with a valid level in response to satisfying a preset condition, wherein the preset condition includes: receiving a null value signal Empty with a valid level and a fixed amplitude digital signal D2, and the delay time reaches a first time;

[0027] The adjustment module 20 is used to: perform amplitude reduction processing on the determined initial value according to a preset operation cycle, obtain and output the amplitude reduction signal D3; wherein the initial value is determined according to the fixed amplitude digital signal D2;

[0028] The selection module 40 is configured to output the amplitude reduction signal D3 in response to receiving the first enable signal Enable1 having an effective level.

[0029] In this way, when the selection module 40 receives the first enable signal Enable1 with a valid level, it outputs the received amplitude reduction signal D3. Since the amplitude of the amplitude reduction signal D3 is reduced, the amplitude difference between the amplitude reduction signal D3 and the 0 level can be reduced, and the sudden change can be reduced, so that the pop noise can be weakened and the playback effect at the next start of playback can be improved. The next start of playback refers to the initial moment when the playback device receives the external input audio signal Din again and plays it.

[0030] It should be understood that the write pointer indicates the write position of the signal. Each time a signal is written into the cache, the value of the write pointer increases by one; the read pointer indicates the read position of the signal. Each time a signal is read from the cache, the value of the read pointer increases by one. When there is a continuous input of the signal, the value of the write pointer will generally always be greater than the value of the read pointer. When the audio signal input from the outside is interrupted, the position of the write pointer will remain unchanged. After a period of time, the read pointer will be in the same position as the write pointer, that is, the write pointer is the same as the read pointer. At this time, it means that there is no new signal to read in the cache, so the conversion module outputs a null value signal with a valid level, and the conversion module will continue to read the signal corresponding to the position of the read pointer from the cache. Before there is no new signal input, the read signal will remain unchanged, so the conversion module will also output a fixed amplitude digital signal. Although the amplitude of the fixed amplitude digital signal is fixed, the specific amplitude cannot be determined for the time being.

[0031] Of course, when the write pointer is different from the read pointer, the conversion module outputs a null value signal with an invalid level, wherein the valid level may be a high level and the invalid level may be a low level; or, the valid level may be a low level and the invalid level may be a high level.

[0032] Optionally, the delay module is further configured to: in response to not meeting the preset condition, output a first enable signal with an invalid level; in this case, the selection module is further configured to: in response to receiving the first enable signal with an invalid level, output the fixed amplitude digital signal or the processed audio signal. In this way, the selection module can output different types of signals under the control of the first enable signal, so that the pop noise can be reduced when the playback starts next time. Among them, not meeting the preset condition can be understood as: only receiving at most one of the null value signal and the fixed amplitude digital signal with a valid level, or even if the null value signal and the fixed amplitude digital signal with a valid level are received, but the delay time does not reach the first time.

[0033] The function and structure of each module are explained below.

[0034] 1. Delay module:

[0035] For the delay module: when receiving a null value signal with a valid level and the fixed amplitude digital signal, the delay processing starts, and when the delay time reaches the first time, the delay processing is stopped, and the first enable signal with a valid level is output, thereby realizing the delay operation of the delay module.

[0036] Optionally, in an embodiment of the present invention, if Figure 2 As shown, the delay module 10 includes: a first delay unit 11 and a second delay unit 12;

[0037] The first delay unit 11 is used for: in response to obtaining a second enable signal Enable2 with a valid level provided by the outside world and an empty value signal Empty with a valid level output by the conversion module 30, counting starts from 0 at a first counting frequency, stopping counting when the count value is greater than or equal to a first sub-time corresponding to a first threshold, and outputting a third enable signal Enable3 with a valid level; the second delay unit 12 is used for: in response to obtaining a third enable signal Enable3 with a valid level and a fixed amplitude digital signal D2 output by the conversion module 30, counting starts from 0 at a second counting frequency, stopping counting when the count value is greater than or equal to a second sub-time corresponding to the second threshold, and outputting a first enable signal Enable1 with a valid level; wherein the first counting frequency is less than the second counting frequency.

[0038] That is to say, the second enable signal Enable2 is obtained from the outside world (such as but not limited to a controller), and the second enable signal Enable2 is used to indicate when the first delay unit 11 starts working, so when the first delay unit 11 obtains the second enable signal Enable2 with a valid level, it starts working and waits for receiving the empty value signal Empty with a valid level. When receiving the empty value signal Empty with a valid level, the first delay unit 11 starts counting operation, thereby realizing the first step of delay processing.

[0039] For the second delay unit 12, the third enable signal Enable3 is used to indicate when the second delay unit 12 starts working, so when the second delay unit 12 receives the third enable signal Enable3 with a valid level, it starts working and waits for receiving the fixed amplitude digital signal D2. When receiving the fixed amplitude digital signal D2, the second delay unit 12 starts counting operation, thereby realizing the second step of delay processing.

[0040] In this way, the function of the delay module can be realized through two-step delay processing; and when the first counting frequency is less than the second counting frequency, it is conducive to realizing that the delay time of the first delay unit is greater than the delay time of the second delay unit, so that the delay time can be accurately controlled, and accurate control of the delay can be achieved, which is conducive to reducing the amplitude difference between the amplitude reduction signal and the 0 level, and improving the attenuation effect of the pop noise.

[0041] When the conversion module 30 is also used to increase the frequency of the acquired audio signal from the initial frequency to the preset frequency, the first counting frequency can be the initial frequency, the second counting frequency can be the preset frequency, and the preset frequency can be n times the initial frequency. The value of n can be set according to the working requirements of the conversion module 30, for example but not limited to 18, 32 or 64 and other values, which are not limited here.

[0042] Since there is a certain delay when the conversion module 30 processes the signal, setting the first counting frequency to the initial frequency and setting the second counting frequency to the preset frequency can make the delay time of the delay module 10 easier to match the delay time of the conversion module 30. In other words, the first time can be determined based on the delay time of the conversion module 30, and then the amplitude difference between the amplitude reduction signal and the 0 level can be reduced more quickly, thereby improving the efficiency of reducing the pop noise.

[0043] Furthermore, the first time may include a first sub-time and a second sub-time, and the first sub-time may be determined according to the integer part of the delay of the conversion module 30, and the second sub-time may be determined according to the decimal part of the delay of the conversion module 30. For example, when the delay time of the conversion module 30 is a, and the first counting frequency is b1, and the second counting frequency is b2, the ratio of the integer part of a to b1 is a first ratio, the first sub-time may be set to a value close to the first ratio, the ratio of the decimal part of a to b2 is a second ratio, and the second sub-time may be set to a value close to the second ratio. In this way, the delay time of the delay module 10 may be further matched with the delay time of the conversion module 30.

[0044] Of course, the settings of the first sub-time and the second sub-time can also be other values ​​set based on experience, as long as the delay time of the delay module 10 can match the delay time of the conversion module 30. The specific values ​​of the first sub-time and the second sub-time are not limited here.

[0045] Based on this, the first delay unit and the second delay unit can both be counters. Of course, the first delay unit and the second delay unit can also be set to other structures that are well known to those skilled in the art and can achieve corresponding functions, which is not limited here.

[0046] The first delay unit 11 and the second delay unit 12 are implemented by counting operation when performing delay processing, but are not limited to this, and can also be implemented in other ways, such as by timing operation. At this time, the first delay unit 11 responds to the acquisition of the second enable signal Enable2 with a valid level provided by the outside world and the empty value signal Empty with a valid level, and performs timing at the first timing frequency. The timing is stopped when the time to be counted is greater than or equal to the first sub-time, and outputs the third enable signal Enable3 with a valid level; the second delay unit 12 responds to the acquisition of the third enable signal Enable3 with a valid level and the fixed amplitude digital signal D2, and performs timing at the second timing frequency. The timing is stopped when the time to be counted is greater than or equal to the second sub-time, and outputs the first enable signal Enable1 with a valid level; the first timing frequency is less than the second timing frequency, and the first timing frequency can be determined according to the initial frequency, and the second timing frequency can be determined according to the preset frequency, so that the delay time of the delay module 10 matches the delay time of the conversion module 30. Based on this, the first delay unit 11 and the second delay unit 12 can both be timers.

[0047] 2. Adjustment module:

[0048] When the adjustment module performs a reduction process on the initial value, there are several ways to determine the initial value:

[0049] The method for determining the initial value corresponding to the first amplitude reduction process includes: determining according to a fixed amplitude digital signal corresponding to the start time of outputting a first enable signal with a valid level;

[0050] The method for determining the initial value corresponding to other amplitude reduction processing except the first amplitude reduction processing includes: determining it according to the amplitude reduction signal obtained after the previous amplitude reduction processing.

[0051] For example, the initial value corresponding to the first amplitude reduction processing is represented by a1, and a1 can be the amplitude of the fixed-amplitude digital signal corresponding to the starting moment of outputting the first enable signal with a valid level; if the amplitude reduction signal obtained after the first amplitude reduction processing is represented by m1, then m1 can be used as the initial value corresponding to the second amplitude reduction processing, and the amplitude reduction signal obtained after the second amplitude reduction processing is represented by m2, then m2 can be used as the initial value corresponding to the third amplitude reduction processing, and so on.

[0052] In this way, by collecting the initial value at the first amplitude reduction processing, the amplitude reduction signal obtained after each amplitude reduction processing is used as the initial value for the next amplitude reduction processing, that is, the amplitude reduction signal obtained after each amplitude reduction processing is used as the value required for the next amplitude reduction processing, so that the adjustment module only needs to collect the fixed amplitude digital signal once to perform multiple amplitude reduction processing, making the amplitude reduction processing process simpler and faster; and, because the amplitude reduction signal obtained after each amplitude reduction processing is used as the initial value for the next amplitude reduction processing, the self-attenuation of the collected initial value can be achieved, so that the amplitude of the amplitude reduction signal can be continuously reduced, the amplitude can be greatly reduced, and it can also be continuously close to the 0 level, which is conducive to eliminating pop noise.

[0053] Alternatively, see Figure 2 As shown, the adjustment module 20 is specifically used for: obtaining the adjustment instruction Gain-sel, and determining the adjustment rule according to the adjustment instruction Gain-sel; according to the adjustment rule, according to the operation cycle, the initial value is reduced; the adjustment rule is a fixed step adjustment rule or a variable step adjustment rule.

[0054] Each reduction process can be implemented by shift addition operation. For example, when the step size of each reduction process corresponds to -0.0085dB, -0.0085dB can be expressed as 1-2 -10 -2 -19 , that is, two shift addition operations. In this way, the amplitude reduction processing can be realized through the shift addition operation, which reduces the processing complexity, thereby simplifying the circuit structure and reducing the cost.

[0055] Furthermore, the adjustment instruction Gain-sel may be obtained from the outside, such as from the controller 503. Among them, the adjustment instruction Gain-sel may carry an identifier, and the adjustment module 20 stores a mapping relationship table between the identifier and the adjustment rule. When the adjustment module 20 receives the adjustment instruction Gain-sel, it finds the corresponding adjustment rule from the mapping relationship table based on the extracted identifier, and then uses the found adjustment rule to perform the reduction processing. For example, when the identifier is 1, it corresponds to a fixed step length adjustment rule, and when the identifier is 0, it corresponds to a variable step length adjustment rule, or when the identifier is 0, it corresponds to a fixed step length adjustment rule, and when the identifier is 1, it corresponds to a variable step length adjustment rule, which is not limited here.

[0056] Alternatively, the adjustment instruction Gain-sel may carry a specified adjustment rule, and the adjustment module 20 does not store a mapping relationship table. When receiving the adjustment instruction Gain-sel, the adjustment module 20 may extract the specified adjustment rule, and then use the extracted adjustment rule to perform the reduction processing.

[0057] Alternatively, the adjustment instruction is a specific signal, and a mapping relationship table between the specific signal and the adjustment rule is stored in the adjustment module 20. When the adjustment instruction Gain-sel is received, the adjustment module 20 finds the corresponding adjustment rule from the mapping relationship table based on the specific signal, and then adopts the found adjustment rule to perform the amplitude reduction processing, wherein the specific signal can be a high-level signal or a low-level signal. For example, when the specific signal is a high-level signal, it corresponds to a fixed-step adjustment rule, and when the specific signal is a low-level signal, it corresponds to a variable-step adjustment rule, or when the specific signal is a low-level signal, it corresponds to a fixed-step adjustment rule, and when the specific signal is a high-level signal, it corresponds to a variable-step adjustment rule, and no limitation is made here.

[0058] In this way, an adjustment rule may be determined based on the adjustment instruction Gain-sel, and then the amplitude reduction processing may be performed based on the adjustment rule to reduce the amplitude difference between the amplitude reduction signal and the 0 level.

[0059] It should be understood that the fixed step adjustment rule may include: the reduction amplitude during the amplitude reduction processing in each operation cycle is a fixed value, for example, when the reduction amplitude is G (G is the amplitude corresponding to decibels), the reduction amplitude of each operation cycle is G, so after A operation cycles of amplitude reduction processing, the total reduction amplitude is A×G.

[0060] When the variable step length adjustment rule is an adjustment rule in which the step length changes in stages, the variable step length adjustment rule includes: pre-dividing multiple adjustment stages, each adjustment stage includes at least one operation cycle, the step length remains unchanged in each adjustment stage, and the adjustment stages are arranged in chronological order, and the step length corresponding to the earlier adjustment stage is smaller than the step length corresponding to the later adjustment stage.

[0061] For example, 6000 operation cycles can be divided into three adjustment stages. The first 2000 operation cycles are the first adjustment stage. The step lengths corresponding to the operation cycles in this adjustment stage are the same, such as represented by c1; the middle 2000 operation cycles are the second adjustment stage. The step lengths corresponding to the operation cycles in this adjustment stage are the same, such as represented by c2; the last 2000 operation cycles are the third adjustment stage. The step lengths corresponding to the operation cycles in this adjustment stage are the same, such as represented by c3; at this time, c1, c2 and c3 are arranged in order from small to large: c1, c2, c3. And, assuming that c1 corresponds to -0.005dB, c2 corresponds to -0.01dB, and c3 corresponds to -0.02dB, then the total reduction after the reduction process in the first adjustment stage corresponds to 10dB, the total reduction after the reduction process in the second adjustment stage corresponds to 20dB, and the total reduction after the reduction process in the third adjustment stage corresponds to 40dB. Furthermore, each amplitude reduction process in each adjustment stage can also be implemented by shift addition operation. In this way, the speed of the amplitude reduction process can be accelerated while eliminating the pop noise, so that the playback device can complete the amplitude reduction process faster to prepare for other subsequent operations.

[0062] Of course, when the variable step length adjustment rule is an adjustment rule in which the step length changes at any time, the variable step length adjustment rule may include: as the amplitude reduction process proceeds, the step length corresponding to each operation cycle will also increase accordingly.

[0063] Optionally, the adjustment module 20 is also used to: in response to the absolute value of the amplitude reduction signal D3 being less than the amplitude reduction threshold, stop the amplitude reduction processing, and maintain the output of the amplitude reduction signal D3 obtained after the last amplitude reduction processing. In this way, the amplitude reduction processing can be stopped when the amplitude is reduced to a certain extent, avoiding unnecessary amplitude reduction processing operations, thereby helping to reduce calculations and power consumption; and can also weaken or eliminate pop noise when the audio signal Din provided by the outside world is re-input next time. Among them, the amplitude reduction threshold can be based on the corresponding value when no pop noise is generated when the audio signal Din provided by the outside world is re-input next time, and the specific value is not limited here.

[0064] In addition, the adjustment module 20 is further used to: when the amplitude reduction processing is stopped, output an amplitude reduction end signal Fadeout-done with a valid level to the controller 503 to inform the controller 503 that the amplitude reduction processing has been completed, so that the controller 503 can determine that the pop noise can be weakened when the audio signal Din provided by the outside world is re-input next time; if the controller 503 receives the amplitude reduction end signal Fadeout-done with an invalid level before the audio signal Din provided by the outside world is re-input next time, then the controller 503 can determine that the amplitude reduction processing is not completed, and the equipment can be checked and the fault can be repaired at this time.

[0065] Alternatively, if Figure 3 As shown, the adjustment module 20 may include: a multiplier 201, a trigger 202, a comparator 203, an inverter 204, and an AND logic circuit 205; the input end of the inverter 204 is electrically connected to the output end of the comparator 203, the output end of the inverter 204 is electrically connected to the first input end 1 of the AND logic circuit 205; the second input end 2 of the AND logic circuit 205 is electrically connected to the delay module 10, and the output end of the AND logic circuit 205 is electrically connected to the enable end 3 of the multiplier 201; the first input end of the multiplier 201 4 is electrically connected to the output end of the trigger 202, the second input end 5 of the multiplier 201 is electrically connected to its own output end, and the output end of the multiplier 201 is also electrically connected to the first input end 6 of the comparator 203 and the selection module 40 respectively; the first input end 7 of the trigger 202 is electrically connected to the delay module 10, and the second input end 8 of the trigger 202 is electrically connected to the conversion module 30; the second input end 9 of the comparator 203 is electrically connected to the reference signal end, and the reference signal end can provide a reduction threshold for the comparator 203.

[0066] The trigger 202 is used to: when the first enable signal Enable1 changes from an invalid level to a valid level, collect the fixed amplitude digital signal D2 and output it as an initial value D2';

[0067] The multiplier 201 is used to: determine the adjustment rule according to the adjustment instruction Gain-sel; in response to the control signal D being at an effective level, perform amplitude reduction processing on the received initial value D2' or the amplitude reduction signal D3, and output the amplitude reduction signal D3 to the comparator 203 and the selection module 40 respectively; and, in the first amplitude reduction processing, the initial value D2' is subjected to amplitude reduction processing; in any amplitude reduction processing except the first amplitude reduction processing, the amplitude reduction signal D3 outputted last time is subjected to amplitude reduction processing;

[0068] The comparator 203 is used to: receive the amplitude reduction signal D3; in response to the absolute value of the amplitude reduction signal D3 being greater than or equal to the amplitude reduction threshold, output the amplitude reduction end signal Fadeout-done with an invalid level; in response to the absolute value of the amplitude reduction signal D3 being less than the amplitude reduction threshold, output the amplitude reduction end signal Fadeout-done with a valid level;

[0069] The inverter 204 is used to: perform inverse processing on the level of the received amplitude reduction end signal Fadeout-done and then output it; that is, when the received amplitude reduction end signal Fadeout-done has an invalid level, after being reversely processed by the inverter 204, the invalid level is converted into an effective level, thereby outputting the amplitude reduction end signal Fadeout-done with an effective level; when the received amplitude reduction end signal Fadeout-done has an effective level, after being reversely processed by the inverter 304, the effective level is converted into an invalid level, thereby outputting the amplitude reduction end signal Fadeout-done with an invalid level;

[0070] The AND logic circuit 205 is used to output a control signal D with a valid level in response to the signals output from the two input terminals being both at a valid level or both at an invalid level.

[0071] Among them, the valid levels in the various signals mentioned above may all be high levels, and the invalid levels may all be low levels; or the valid levels in the various signals mentioned above may all be low levels, and the invalid levels may all be high levels.

[0072] For example, taking the case where the effective level in various signals is a high level and the invalid level is a low level, when the first enable signal Enable1 changes from a low level to a high level, the trigger 202 collects a fixed amplitude digital signal D2 once at the rising edge of the first enable signal Enable1 and outputs it as the initial value D2'; since the amplitude reduction processing has not yet started, the amplitude reduction end signal Fadeout-done output by the comparator 203 is a low level, and after being processed by the inverter 204, a high level is output to the first input terminal 1 of the AND logic circuit 205. Since the second input terminal 2 of the AND logic circuit 205 receives the first enable signal Enable1 and is at a high level at this time, the control signal D2 output by the AND logic circuit 205 is a high level; when the control signal D is at a high level, the multiplier 201 performs the first amplitude reduction processing on the received initial value D2' and outputs the amplitude reduction signal D3 after the amplitude reduction processing. This is the first time that a reduction signal is output, so the reduction signal is marked as D31; the comparator 203 compares the absolute value of the reduction signal D31 with the reduction threshold value, and when it is determined that the absolute value of the reduction signal D31 is greater than or equal to the reduction threshold value, it means that the absolute value of the reduction signal D31 has not reached the reduction threshold value, so the output reduction end signal Fadeout-done remains at a low level, and then when the first enable signal Enable1 continues to be at a high level, the control signal D is always at a high level, so the multiplier 201 continues to perform the reduction processing, that is, performs the second reduction processing, at this time, after the reduction processing is performed on the reduction signal D31 as the initial value, the reduction signal is output for the second time and marked as D32; if the comparator 203 determines that the absolute value of the reduction signal D32 has not reached the reduction threshold value, then the multiplier 201 continues to perform the reduction processing, and so on, until the comparator 203 determines that the reduction signal D3 i When the absolute value of (i is an integer greater than 2) reaches the amplitude reduction threshold, the output amplitude reduction end signal Fadeout-done changes to a high level, and then the control signal D changes to a low level, so that the multiplier 201 stops the amplitude reduction process.

[0073] In this way, the function of the amplitude reduction processing of the adjustment module 20 is realized through the combination of the multiplier 201, the trigger 202, the comparator 203, the inverter 204, and the logic circuit 205, so as to achieve the purpose of reducing the pop noise.

[0074] 3. Select module:

[0075] Optionally, the selection module is specifically used to: in response to the external cessation of input audio signals and receiving a first enable signal with an invalid level, output a fixed amplitude digital signal; in response to the external input audio signal and receiving a first enable signal with an invalid level, output a processed audio signal.

[0076] For example, Figure 2 As shown, after the external audio signal Din stops being input, the conversion unit 32 in the conversion module 30 will output the fixed amplitude digital signal D2, and the selection module 40 will output the fixed amplitude digital signal D2 when receiving the first enable signal Enable1 with an invalid level; when the external audio signal Din is normally input, the external audio signal Din is processed by the conversion unit 32 in the conversion module 30 and then output, and the selection module 40 will output the processed signal when receiving the first enable signal Enable1 with an invalid level. In this way, the selection module 40 can output normally when there is no external audio signal input or when there is an external audio signal input, so as to ensure the normal operation of the audio playback control device 501.

[0077] The selection module 40 may be a selector. Of course, the selection module 40 may also be configured as other structures that are well known to those skilled in the art and can realize corresponding functions, which is not limited here.

[0078] In summary, the delay module 10 can be implemented by a counter, the adjustment module 20 can be implemented by a multiplier 201, a trigger 202, a comparator 203, an inverter 204 and an AND logic circuit 205, and the selection module 40 can be implemented by a selector. Thus, in order to reduce the pop noise, it can be achieved through a hardware structure. Compared with software processing, the processing speed is faster and the processing efficiency is higher.

[0079] 4. Conversion module:

[0080] like Figure 2 As shown, the conversion module 30 includes: a cache unit 31 and a conversion unit 32;

[0081] The cache unit 31 is used to: store the audio signal Din input from the outside, and in response to the read pointer and the write pointer being the same, output a null value signal Empty with a valid level;

[0082] The conversion unit 32 is used to process the last audio signal stored in the buffer unit 31 and output a fixed amplitude digital signal D2.

[0083] Among them, the process of processing the last audio signal stored in the cache unit 31 may include: filtering and up-converting the last audio signal stored in the cache unit 31, and the up-converting process may increase the frequency from the initial frequency to a preset frequency, and the preset frequency may be n times the initial frequency.

[0084] In this way, by providing the cache unit 31 and the conversion unit 32 , the conversion module 30 can realize the cache function and the frequency upscaling function.

[0085] In addition, since there is a certain delay from when the conversion unit 32 reads data from the cache unit 31 to when it outputs the fixed-amplitude digital signal D2, the fixed-amplitude digital signal D2 is output after the cache unit outputs the empty signal Empty with a valid level, and the time difference between outputting the fixed-amplitude digital signal D2 and outputting the empty signal Empty with a valid level is related to the delay of the conversion unit 32, which is not limited here. Of course, if the delay from when the conversion unit 32 reads data from the cache unit 31 to when it outputs the fixed-amplitude digital signal D2 is small and can be ignored, the fixed-amplitude digital signal D2 and the empty signal Empty with a valid level can be regarded as being output simultaneously.

[0086] Alternatively, if Figure 2 As shown, the conversion unit 32 may include a volume adjustment circuit 321 and a frequency up-conversion circuit 322, wherein the volume adjustment circuit 321 is electrically connected to the cache unit 31 and the frequency up-conversion circuit 322 respectively, and the frequency up-conversion circuit 322 is also electrically connected to the second delay unit 12, the adjustment module 20 and the selection module 40 respectively.

[0087] The volume adjustment circuit 321 is used to: read the audio signal from the buffer unit 31, and adjust the volume of the read audio signal, and output the volume-adjusted audio signal D1 to the frequency-up circuit 322, and the frequencies of the two audio signals before and after the volume adjustment are the same, and both can be the initial frequency;

[0088] The frequency up-conversion circuit 322 is used to perform filtering and frequency up-conversion processing on the audio signal D1 after the volume is adjusted. When performing the frequency up-conversion processing, the frequency of the audio signal D1 after the volume is adjusted can be increased from the initial frequency to a preset frequency.

[0089] In this way, by providing the volume adjustment circuit 321 and the frequency up-conversion circuit 322 , the conversion unit 32 can perform volume adjustment, filtering and frequency up-conversion processing on the signal read from the cache unit 31 , so as to realize the function of the conversion module 30 .

[0090] 5. Modulation module:

[0091] like Figure 2 As shown, the audio playback control device 501 may further include a modulation module 60, which is electrically connected to the selection module 40 and the player 502 respectively. The modulation module 60 is used to: modulate the audio signal output by the selection module 40 and send it directly to the player 502; or modulate the audio signal output by the selection module 40 and send it to a subsequent circuit (such as an analog circuit, Figure 2 ), and then sent to the player 502 after being processed by subsequent circuits.

[0092] Furthermore, the modulation module can convert the input digital signal into an analog signal. The modulation module 60 can be a Sigma-delta modulator (i.e., SDM). Of course, the modulation module 60 can also be set to other structures that can achieve corresponding functions that are well known to those skilled in the art, and this is not limited here. If the operation rate of the SDM is 64 times fs, and fs is 48KHz, then the operation rate of the SDM is 3MHz. Then, after 6000 operation cycles, the time used to complete the amplitude reduction process is 2ms. In this way, when the audio signal changes abnormally due to the interruption of the external audio signal input, the amplitude of the signal can be reduced in a relatively short time to approach the 0 level. Since the time is short, it is difficult for the human ear to detect, thereby completing the process of eliminating pop noise without affecting the hearing.

[0093] The working process of the above-mentioned audio playback control device provided by the embodiment of the present invention is described below in conjunction with specific embodiments.

[0094] Take the delay processing as counting operation, the effective level as high level, and the invalid level as low level as an example to illustrate, and combine Figure 2 The structure shown.

[0095] When the outside stops inputting the audio signal Din to the cache unit 31 and the read pointer and the write pointer in the cache unit 31 are at the same position (ie, the read pointer and the write pointer are the same), the cache unit 31 outputs a high-level empty signal Empty to the first delay unit 11 .

[0096] After the read pointer and the write pointer in the cache unit 31 are at the same position (i.e., the read pointer and the write pointer are the same), the volume adjustment circuit 321 will continue to read the last audio signal of the external input audio signal Din from the cache unit 31, and after the volume adjustment circuit 321 performs a volume adjustment operation on the last audio signal, it outputs the volume-adjusted audio signal D1 to the up-conversion circuit 322.

[0097] The up-conversion circuit 322 filters and up-converts the volume-adjusted audio signal D1, and outputs a fixed-amplitude digital signal D2 to the selection module 40, the second delay unit 12, and the adjustment module 20, respectively. The amplitude of the fixed-amplitude digital signal D2 may be large or small, which is determined by the last audio signal of the external input audio signal Din.

[0098] During the operation of the audio playback control device, the controller 50 outputs a second enable signal Enable2 with a high level. When the empty value signal Empty is at a high level, the first delay unit 11 starts to work, that is, it starts counting from 0 at a first counting frequency to implement delay processing, until the delay time is greater than or equal to the first sub-time, then stops counting processing, and outputs a third enable signal Enable3 with a high level to the second delay unit 12.

[0099] When the second delay unit 12 receives the third enable signal Enable3 with a high level and the fixed amplitude digital signal D2, it starts counting from 0 at a second counting frequency to implement delay processing until the delay time is greater than or equal to the second sub-time, then stops counting processing and outputs the first enable signal Enable1 with a high level to the adjustment module 20 and the selection module 40.

[0100] At the start time of receiving the first enable signal Enable1 with a high level, the adjustment module 20 collects the amplitude of the fixed amplitude digital signal D2 and uses it as the initial value, determines the adjustment rule according to the adjustment instruction Gain-sel sent by the controller 50, and then outputs the reduced amplitude signal D3 after performing the amplitude reduction processing;

[0101] Among them, assuming that when the adjustment instruction Gain-sel is a low-level signal, the corresponding adjustment rule is a fixed-step adjustment rule, and when the adjustment instruction Gain-sel is a high-level signal, the corresponding adjustment rule is a staged-step adjustment rule; then: when the obtained adjustment instruction Gain-sel is a low-level signal, it means that the current amplitude reduction processing needs to be performed according to the fixed step size, and the audio signal obtained after each amplitude reduction processing will be output as the amplitude reduction signal D3 and used as the initial value of the next amplitude reduction processing; when the absolute value of the amplitude reduction signal D3 is less than the amplitude reduction threshold, the amplitude reduction processing is stopped, and a high-level amplitude reduction end signal Fadeout-done is sent to the controller 50; or, when the obtained adjustment instruction Gain-sel is a high-level signal, it means that the current amplitude reduction processing needs to be performed according to the staged step size, and the signal obtained after each amplitude reduction processing will be output as the amplitude reduction signal D3 and used as the initial value of the next amplitude reduction processing; when the absolute value of the amplitude reduction signal D3 is less than the amplitude reduction threshold, the amplitude reduction processing is stopped, and a high-level amplitude reduction end signal Fadeout-done is sent to the controller 50.

[0102] When the selector 40 receives the first enable signal Enable1 with a high level, the selector 40 outputs the amplitude reduction signal D3. As the amplitude reduction processing of the adjustment module 20 proceeds, the amplitude of the amplitude reduction signal D3 will become smaller and smaller, realizing the self-attenuation of the amplitude. After the amplitude reduction processing is stopped, the amplitude of the amplitude reduction signal D3 may be very small or even close to 0. Therefore, after the amplitude reduction processing is completed, when the external audio signal is re-input, the pop noise can be effectively weakened or even eliminated.

[0103] When the external audio signal Din is ready to be re-input, if the controller 50 receives a Fadeout-done signal with a high level for the end of the amplitude reduction, it indicates that the noise reduction processing of the audio playback control device is normal, and the pop noise can be weakened when the external audio signal is re-input; if the controller 50 receives a Fadeout-done signal with a low level for the end of the amplitude reduction, it indicates that there is an abnormality, and pop noise will most likely be generated when the external audio signal is re-input, and the equipment needs to be checked.

[0104] It should be emphasized that when the conversion module including the cache unit, the volume adjustment circuit and the up-conversion circuit is processing, the delay module including the first delay unit and the second delay unit may also be processing, so the conversion module and the delay module do not work serially when processing, and may work in parallel.

[0105] Based on the same inventive concept, an embodiment of the present invention further provides a playback device, the implementation principle of which is similar to that of the aforementioned audio playback control device. The specific implementation method of the playback device can refer to the embodiment of the aforementioned audio playback control device, and the repeated parts will not be repeated.

[0106] Specifically, an embodiment of the present invention provides a playback device, such as Figure 4 As shown, it includes: an audio playing control device 401, which is used to process the audio signal input from the outside and output it to the player 402 for the player 402 to play.

[0107] Based on the same inventive concept, an embodiment of the present invention further provides an audio playback control method. The implementation principle of the audio playback control method is similar to the implementation principle of the aforementioned audio playback control device. The specific implementation method of the audio playback control method can refer to the embodiment of the aforementioned audio playback control device, and the repeated parts will not be repeated.

[0108] Specifically, an audio playback control method provided by an embodiment of the present invention is as follows: Figure 5 As shown, including:

[0109] S1, in response to the read pointer and the write pointer in the internal cache being the same, outputting a null value signal and a fixed amplitude digital signal having a valid level;

[0110] S2, in response to satisfying a preset condition, outputting a first enable signal with a valid level, the preset condition comprising: receiving a null value signal with a valid level and a fixed amplitude digital signal, and the delay time reaches a first time;

[0111] S3, according to a preset operation cycle, the determined initial value is subjected to a reduction process to obtain a reduction signal and output it; wherein the initial value is determined according to a fixed amplitude digital signal;

[0112] S4. In response to receiving the first enable signal with a valid level, outputting the amplitude reduction signal.

[0113] Optionally, in response to satisfying a preset condition, outputting a first enable signal having a valid level comprises:

[0114] In response to obtaining a second enable signal with a valid level and a null value signal with a valid level provided by the outside, counting is performed at a first counting frequency, counting is stopped when the count value is greater than or equal to a first sub-time corresponding to a first threshold, and a third enable signal with a valid level is output;

[0115] In response to obtaining a third enable signal with an effective level and a fixed amplitude digital signal, counting is performed at a second counting frequency, counting is stopped when the count value is greater than or equal to a second sub-time corresponding to a second threshold, and a first enable signal with an effective level is output;

[0116] The first counting frequency is less than the second counting frequency.

[0117] Optionally, the method for determining the initial value corresponding to the first amplitude reduction process includes: determining according to a fixed amplitude digital signal corresponding to the start time of outputting the first enable signal with a valid level;

[0118] The method for determining the initial value corresponding to other amplitude reduction processing except the first amplitude reduction processing includes: determining it according to the amplitude reduction signal obtained after the previous amplitude reduction processing.

[0119] Optionally, according to a preset operation cycle, the determined initial value is subjected to a reduction process to obtain and output a reduction signal, including:

[0120] Obtain adjustment instructions, determine adjustment rules according to the adjustment instructions; according to the adjustment rules and the operation cycle, perform reduction processing on the initial value;

[0121] The adjustment rule is a fixed step length adjustment rule or a variable step length adjustment rule.

[0122] Optionally, the method further includes: after the amplitude reduction signal is output, in response to the absolute value of the amplitude reduction signal being less than the amplitude reduction threshold, stopping the amplitude reduction processing and maintaining the output of the amplitude reduction signal obtained after the last amplitude reduction processing.

[0123] Optionally, the method further comprises: in response to not meeting a preset condition, outputting a first enable signal having an invalid level;

[0124] In response to receiving the first enable signal with an invalid level, a fixed amplitude digital signal is output or an audio signal input from the outside is processed and then output.

[0125] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. An audio playback control device, characterized in that: include: conversion module, delay module, adjustment module and selection module; The conversion module is used to: process the audio signal input from the outside; in response to the read pointer and the write pointer in the internal cache being the same, output a null value signal with a valid level and a fixed amplitude digital signal; The delay module is used to: in response to satisfying a preset condition, output a first enable signal with a valid level, wherein the preset condition includes: receiving the null value signal with a valid level and the fixed amplitude digital signal, and the delay time reaches a first time; The adjustment module is used to: perform amplitude reduction processing on the determined initial value according to a preset operation cycle, obtain an amplitude reduction signal and output it; wherein the initial value is determined according to the fixed amplitude digital signal; The selection module is used for outputting the amplitude reduction signal in response to receiving the first enable signal having a valid level.

2. The audio playback control device according to claim 1, characterized in that: The delay module is further used for: in response to not meeting the preset condition, outputting a first enable signal with an invalid level; The selection module is further configured to: in response to receiving the first enable signal having an invalid level, output the fixed amplitude digital signal or the processed audio signal.

3. The audio playback control device according to claim 2, characterized in that: The selection module is specifically used for: In response to the external world stopping inputting the audio signal and receiving the first enable signal with an invalid level, outputting the fixed amplitude digital signal; In response to the audio signal being input from the outside and the first enable signal having an invalid level being received, the processed audio signal is output.

4. The audio playback control device according to any one of claims 1 to 3, characterized in that: The selection module is a selector.

5. The audio playback control device according to claim 1, characterized in that: The delay module comprises: a first delay unit and a second delay unit; The first delay unit is used to: in response to obtaining a second enable signal with a valid level provided by the outside and the null value signal with a valid level, count at a first counting frequency, stop counting when the count value is greater than or equal to a first sub-time corresponding to a first threshold, and output a third enable signal with a valid level; The second delay unit is used to: in response to obtaining the third enable signal with a valid level and the fixed amplitude digital signal, count at a second counting frequency, stop counting when the count value is greater than or equal to a second sub-time corresponding to a second threshold, and output the first enable signal with a valid level; The first counting frequency is less than the second counting frequency.

6. The audio playback control device according to claim 5, characterized in that: The conversion module is further used to: increase the frequency of the acquired audio signal from an initial frequency to a preset frequency; The first counting frequency is the initial frequency, and the second counting frequency is the preset frequency.

7. The audio playback control device according to claim 5 or 6, characterized in that: The first delay unit and the second delay unit are both counters.

8. The audio playback control device according to claim 1, characterized in that: The method for determining the initial value corresponding to the first amplitude reduction process includes: determining according to the fixed amplitude digital signal corresponding to the start time of outputting the first enable signal with a valid level; The method for determining the initial value corresponding to other amplitude reduction processing except the first amplitude reduction processing includes: determining according to the amplitude reduction signal obtained after the previous amplitude reduction processing.

9. The audio playback control device according to claim 1, characterized in that: The adjustment module is specifically used to: obtain an adjustment instruction, determine an adjustment rule according to the adjustment instruction; and perform the reduction processing on the initial value according to the adjustment rule and the operation cycle; The adjustment rule is a fixed step length adjustment rule or a variable step length adjustment rule.

10. The audio playback control device according to claim 9, characterized in that: The variable step length adjustment rule includes: pre-dividing a plurality of adjustment stages, each of the adjustment stages includes at least one operation cycle, the step length in each adjustment stage remains unchanged, the adjustment stages are arranged in chronological order, and the step length corresponding to the earlier adjustment stage is smaller than the step length corresponding to the later adjustment stage.

11. The audio playback control device according to claim 1, characterized in that: The regulating module is further used for: in response to the absolute value of the amplitude reduction signal being less than an amplitude reduction threshold, stopping the amplitude reduction processing and maintaining the output of the amplitude reduction signal obtained after the last amplitude reduction processing.

12. The audio playback control device according to claim 11, characterized in that: The regulating module includes: a multiplier, a trigger, a comparator, an inverter, and a logic circuit; The input end of the inverter is electrically connected to the output end of the comparator, and the output end of the inverter is electrically connected to the first input end of the AND logic circuit; The second input terminal of the AND logic circuit is electrically connected to the delay module, and the output terminal of the AND logic circuit is electrically connected to the enable terminal of the multiplier; The first input terminal of the multiplier is electrically connected to the output terminal of the trigger, the second input terminal of the multiplier is electrically connected to its own output terminal, and the output terminal of the multiplier is also electrically connected to the first input terminal of the comparator and the selection module respectively; The first input terminal of the trigger is electrically connected to the delay module, and the second input terminal of the trigger is electrically connected to the conversion module; The second input terminal of the comparator is electrically connected to the reference signal terminal.

13. The audio playback control device according to any one of claims 1 to 12, characterized in that: The conversion module includes: a cache unit and a conversion unit; The cache unit is used to: store the audio signal input from the outside, and in response to the read pointer being the same as the write pointer, output the null value signal with a valid level; The conversion unit is used to: after processing the last audio signal stored in the cache unit, output the fixed amplitude digital signal.

14. An audio playback control method, characterized in that: include: In response to the read pointer and the write pointer in the internal cache being the same, outputting a null value signal and a fixed amplitude digital signal having a valid level; In response to satisfying a preset condition, outputting a first enable signal with a valid level, wherein the preset condition includes: receiving the null value signal with a valid level and the fixed amplitude digital signal, and the delay time reaches a first time; According to a preset operation cycle, the determined initial value is subjected to a reduction processing to obtain a reduction signal and output it; wherein the initial value is determined according to the fixed amplitude digital signal; In response to receiving the first enable signal having an effective level, the amplitude reduction signal is output.

15. A playback device, characterized in that: include: A player, and an audio playback control device as claimed in any one of claims 1 to 13; The audio playback control device is used to process the audio signal input from the outside and then output it to the player for the player to play.

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