JP3918826B2 - Music data playback device - Google Patents

Description

  The present invention relates to a musical sound data reproducing apparatus for reproducing musical sound data compressed and stored in a storage medium.

In recent years, in the audio field, various methods such as MPEG, MP3, AAC, WMA, etc. have been developed as methods (standards) for compressing digital musical tone data. Along with this, various playback devices for reproducing compressed musical tone data have been put into practical use. (See Patent Document 1).
By the way, in the field of game machines such as pachinko machines, loop reproduction is often performed in which the same music is repeatedly reproduced continuously. However, when the above-mentioned compressed musical tone data is used in a game machine, for example, 1152 samples for MPEG and 1024 samples for AAC are used as one frame, and playback processing is performed in units of this frame. Will not contain a specified number of samples, a silence will be included at the rear of the frame. For this reason, there has been a problem that a silent portion is generated between the end portion and the beginning portion of the music piece during repeated reproduction.
Republished patent: WO99 / 59133

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a musical sound data reproducing apparatus that can perform loop reproduction without creating a silent portion.

The present invention has been made in order to solve the above-mentioned problems, and the invention according to claim 1 is characterized in that the musical tone data is stored from a storage medium storing musical tone data composed of compressed musical tone data and non-compressed musical tone data. Is a musical tone data reproducing apparatus for reading out and reproducing compressed musical tone data and non-compressed musical tone data in this order, reading out the non-compressed musical tone data from the storage medium and finishing reading when the reading of the non-compressed musical tone data is completed. A first reading means for outputting a notification; a second reading means for reading the compressed musical sound data from the storage medium; and a decoder for decompressing and outputting the compressed musical sound data read by the second reading means. Switching means for switching between the output of the first reading means and the output of the decoder, the first reading means, the second reading means, and the front Control means for controlling the switching means, the compressed musical sound data has a data size that is an integral multiple of a predetermined reproduction processing unit in the reproduction of the musical sound data, and the control means receives a loop reproduction instruction, A first step of outputting a read command of the compressed musical sound data to the second reading means and switching the switching means to the output of the decoder, and when the decompression and output of the compressed musical sound data by the decoder are completed, A second procedure for outputting a command for reading the non-compressed musical tone data to one reading means and switching the switching means to the output of the first reading means is sequentially executed, and is output from the first reading means. by executing again the first procedure receives the read completion notification tone data, characterized in that for loop playback the musical sound data It is a reproduction apparatus.

According to a second aspect of the present invention, there is provided musical tone data comprising non-compressed musical tone data, compressed musical tone data, and sample number information indicating the total number of data units included in the non-compressed musical tone data and the compressed musical tone data. A musical tone data reproducing apparatus for reading out and reproducing the musical tone data from a stored storage medium, wherein the compressed musical tone data is silence data so that the data size is an integral multiple of a predetermined reproduction processing unit in the reproduction of musical tone data. First reading means for reading out the number-of-samples information from the storage medium, and based on the non-compressed musical tone data and the compressed musical tone data based on the number-of-samples information read by the first reading means Detection means for detecting the end of reproduction of a musical sound; second reading means for reading out the uncompressed musical sound data from the storage medium; and the storage Third reading means for reading the compressed musical tone data from the body, a decoder for decompressing and outputting the compressed musical tone data read by the third reading means, an output of the second reading means, and an output of the decoder Switching means for switching between outputs, a procedure for receiving a loop reproduction instruction, outputting a read command to the first to third reading means, and switching the switching means to the output of the second reading means; A step of switching the switching means to the output of the decoder when reading of the non-compressed musical tone data by the reading means is completed in order, and the detecting means performs a step of switching the musical tone based on the non-compressed musical tone data and the compressed musical tone data. When the end of reproduction is detected, the second and third reading means read the uncompressed musical tone data and the compressed musical tone data again. By starting out a tone data reproducing apparatus characterized by comprising a control means for looping the musical sound data.

According to a third aspect of the present invention, in the musical sound data reproducing apparatus according to the second aspect, the uncompressed musical sound data corresponds to a time required for starting the decompression of the compressed musical sound data and starting the output thereof. It has a data size .

According to a fourth aspect of the present invention, in the musical sound data reproducing apparatus according to any one of the first to third aspects, the compressed musical sound data compressed by the ADPCM method is used instead of the uncompressed musical sound data. It is characterized by .

  According to the present invention, since the uncompressed data is arranged at the end portion of the musical sound data, it is possible to obtain an effect that the compressed musical sound data can be loop-reproduced at an arbitrary place without creating a silent portion. In addition, according to the present invention, since the uncompressed data is arranged at the head portion of the musical tone data, there is an effect that the influence of the delay due to the decoding of the compressed musical tone data can be eliminated and the loop reproduction without the silent portion can be performed.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of a musical tone data reproducing apparatus according to the first embodiment of the present invention. FIG. 2 shows (a) musical tone data format, (b) musical tone data decoding timing, and (c) musical tone data. It is a figure which shows each output timing. As shown in FIG. 2 (a), in this embodiment, the beginning and end of music are PCM (Pulse Code Moduration) musical sound data (hereinafter referred to as PCM data), and the center is compressed. Musical tone data having a configuration called musical tone data (hereinafter referred to as compressed data) is used. The compressed data is compressed according to the MPEG standard.

  FIG. 3 is a flowchart showing a musical sound data generation process shown in FIG. 2A, FIG. 4 is an explanatory diagram of the musical sound data generation process, and FIG. 5 is a block diagram showing a configuration of a circuit for generating compressed data. Hereinafter, the process of generating musical tone data will be described with reference to these drawings. This process is performed by a computer system.

  First, audio data (PCM data) as material is prepared (step S1 in FIG. 3). Next, a phrase (first sample / last sample) is designated (step S2). Next, the total number of samples N (see FIG. 4) is calculated (step S3). Next, the top M sample is stored in a storage medium such as a hard disk by PCM data (step S4). Here, as shown in FIGS. 2B and 2C, the M sample is the number of samples corresponding to the time required from the start of decompression of compressed data until the output of the first decompressed sample. It is. Next, INT {(N−M) / 1152} × 1152 samples following the M samples, that is, the number of samples divisible by 1152 that is the number of samples in one frame are compressed and stored in the storage medium (step S5; (See FIGS. 4 and 5). Next, the last remaining MOD {(NM) / 1152} sample is stored in the storage medium by PCM data. The above is the generation process of the musical sound data. In practical use, the data created in the storage medium in this way is burned into the ROM 11 (see FIG. 4), and the ROM 11 is installed in a game machine or the like for use.

Next, the compressed data generation circuit shown in FIG. 5 will be described.
The PCM audio data Da is framed every 1152 samples by the framing circuit 1 and processed in two paths. First, the subband analysis filter bank 2 in one path divides input data into 32-band subband data having the same bandwidth. In this case, each subband data is downsampled to a sampling frequency of 1/32. The scale factor extraction / normalization circuit 3 detects a sample having the maximum absolute value for each subband data in one frame. The quantized value is called a scale factor. Then, each subband sample is divided by this scale factor, and those values are normalized within a range of ± 1.

On the other hand, the psychoacoustic analysis unit 4 calculates a frequency spectrum by FFT (Fast Fourier Transform), and calculates and outputs a masking threshold for each subband, that is, an allowable quantization noise power based on the frequency spectrum. The bit allocation unit 5 determines the number of quantization bits for each subband by iterative loop processing under the restriction of the number of bits usable in one frame determined by the output of the psychoacoustic analysis unit 4 and the bit rate. The quantization unit 6 quantizes the subband data output from the scale factor extraction / normalization circuit 3 with the number of quantization bits set for each subband. The formatting circuit 7 multiplexes the quantized subband samples, the bit allocation information for each subband, and the scale factor, adds a header to it, creates a bitstream, and outputs it. FIG. 5 shows a bit stream (symbol B) corresponding to one frame.
Note that the compressed data generation circuit described above may be configured by hardware or may be a computer process.

Next, a playback apparatus that plays back the above-described musical sound data will be described with reference to FIGS. 1, 6, and 7. FIG.
FIG. 1 is a block diagram showing the configuration of a musical sound data reproducing apparatus according to an embodiment of the present invention. In this figure, 11 is a ROM in which the above-mentioned musical tone data is stored, 12 is a PCM data reading unit for reading PCM data provided at the beginning and end of musical tone data from the ROM 11, and 13 is compressed from the ROM 11 by the MPEG standard. A compressed data reading unit for reading the compressed data, 14 is a decoder for expanding (decoding) the compressed data read by the compressed data reading unit 13, and 15 is either an output of the PCM data reading unit 12 or an output of the decoder 14 A switching unit that selects and outputs one of them, 16 is a D / A (digital / analog) converter that converts the output of the switching unit 15 into an analog signal, and 17 is a control unit that controls each unit.

  FIG. 6 is a block diagram showing the configuration of the decoder 14. In this figure, 21 is an inverse format circuit, which separates quantized subband samples, bit allocation information, and scale factor from the compressed data output from the compressed data reading unit 13 (see symbol B in FIG. 5). The subband samples are output to the inverse quantization circuit 22 and the bit allocation information is output to the same inverse quantization circuit 22. The scale factor is output to the inverse scaling circuit 23. The inverse quantization circuit 22 inversely quantizes the subband samples using the bit allocation information and outputs the result to the inverse scaling circuit 23. The inverse scaling circuit 23 restores the scale of the output data of the inverse quantization circuit based on the scale factor and outputs it to the subband synthesis filter bank 24. The subband synthesis filter bank 24 synthesizes the subband data output from the inverse scaling circuit 23 and returns the PCM data before compression. The PCM data is temporarily stored in the output buffer 25 and then output to the switching unit 15 in FIG.

Next, the operation of the musical sound data reproducing apparatus shown in FIG. 1 will be described with reference to FIG.
Receiving the loop reproduction instruction, the control unit 17 first outputs the head address of the musical sound data to the PCM data reading unit 12 to instruct reading of the PCM data, and next, the compression data reading unit outputs the head address of the compressed data. 13 to instruct the reading of the compressed data, and then the switching unit 15 is switched to the output of the PCM data reading unit 12 (time t1 in FIG. 7). Upon receiving a read instruction from the control unit 17, the PCM data reading unit 12 sequentially reads the PCM data at the beginning of the musical sound data from the ROM 11 and outputs it to the D / A converter 16 via the switching unit 15. The D / A converter 16 converts the PCM data into an analog musical tone signal and outputs it to a speaker unit (not shown). Thereby, a musical sound based on the PCM data at the leading end of the musical sound data is generated. The PCM data reading unit 12 notifies the control unit 17 of the end of output when all the PCM data at the head of the musical sound data is output (time t2). Upon receiving this end notification, the control unit 17 switches the switching unit 15 to the output of the decoder 14 (see FIG. 7C).

  On the other hand, the compressed data reading unit 13 receives a read instruction from the control unit 17, sequentially reads the compressed data from the ROM 11, and outputs the compressed data to the decoder 14. The decoder 14 decompresses the compressed data and outputs the decompressed data to the switching unit 15. Here, as described above, the number of samples M of the PCM data at the beginning is output as the first decompressed data from the time when the decoder 14 receives the first data from the compressed data reading unit 13. It is decided to coincide with the time until. Therefore, the first decompressed data is output from the decoder 14 at a timing that coincides with the time when the control unit 17 receives the end notification from the PCM data reading unit 12 and switches the switching unit 15. Thereafter, the decompressed data is sequentially output from the decoder 14 and output to the D / A converter 16 via the switching unit 15. The D / A converter 16 converts the decompressed data into an analog musical tone signal and outputs it to the speaker unit. Thereby, a musical sound based on the compressed data in the ROM 11 is generated.

  Next, the compressed data reading unit 13 notifies the control unit 17 of the end of reading when all the compressed data in the ROM 11 is read (time t3). Upon receipt of this notification, the control unit 17 outputs a head address of the PCM data at the rear of the musical sound data to the PCM data reading unit 12 after a predetermined time T has elapsed, and instructs the PCM data to be read. The switching unit 15 is switched to the output of the PCM data reading unit 12 (time t4). Here, the time T is a time from when the last data of the compressed data is read from the ROM 11 and input to the decoder 14 to when the last data is decompressed and output from the decoder 14.

  Upon receiving a read instruction from the control unit 17, the PCM data reading unit 12 sequentially reads out the PCM data at the end of the musical sound data from the ROM 11 and outputs it to the D / A converter 16 via the switching unit 15. As a result, a musical sound based on the PCM data at the end of the musical sound data is generated. When the PCM data reading unit 12 outputs all the PCM data at the end of the musical sound data, the PCM data reading unit 12 notifies the control unit 17 of the end of output (time t5), and then again returns the PCM data at the beginning of the musical sound data. The data are sequentially read and output to the D / A converter 16 via the switching unit 15. As a result, the tone reproduction is performed again in a state where the last tone and the first tone of the tone data are continuous.

  On the other hand, the control unit 17 that has received the PCM data output end notification of the end portion of the musical sound data from the PCM data reading unit 12 outputs a read command to the compressed data reading unit 13. In response to this command, the compressed data reading unit 13 sequentially reads the compressed data again and outputs it to the decoder 14. Then, the control unit 17 receives the notification of the end of reading of the head portion of the musical sound data from the PCM data reading unit 12 and switches the switching unit 15 (time t6). Thereafter, the same operation as described above is repeated, and the musical sound data in the ROM 11 is loop-reproduced.

In the above embodiment, PCM data, that is, uncompressed digital musical sound data, is arranged at the beginning and end of the musical sound data. Instead, for example, compression using a compression method such as ADPCM is performed. Digital musical tone data that can be performed in a short time may be arranged.
Moreover, although the said embodiment has arrange | positioned PCM data in the head part and end part of compression data, it may replace with this and may arrange | position only in an end part. In this case, in order to perform loop reproduction, the control unit 17 needs to instruct the compressed data reading unit 13 to start reading a certain time before the end of reproduction of the rear PCM data.

  Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 8 is a block diagram showing the configuration of the musical sound data reproducing apparatus according to the embodiment, FIG. 9 is a timing diagram for explaining the operation, and FIG. 10 shows the generation process of compressed musical sound data used in the musical sound data reproducing apparatus. FIG. 11 is a flowchart for explaining the generation process of the compressed musical tone data.

First, the generation process of compressed musical tone data will be described with reference to FIGS. First, audio data (material) using PCM data is prepared (step Sa1). Next, a phrase (first sample / final sample) is designated in the prepared audio data (step Sa2). The number of samples (N) is calculated (step Sa3, see FIG. 11). The above processing is the same as steps S1 to S3 in FIG. Next, a phrase header is generated, and the total number of samples N is added to the generated header and stored in a storage medium such as a hard disk (see step Sa4, header H in FIG. 11). Next, the first M sample of the phrase is stored in the storage medium as PCM data (step S5). Here, the M samples are the same as those described in FIG. Next, the remaining (NM) samples are compressed based on the MPEG standard and stored in the storage medium (step Sa6). In this case, since one frame of the MPEG standard is 1152 samples, a silence sample is added to the last frame, and the total number of samples of the compressed data is
INT {(N−M) / 1152} × 1152 + 1152
(See FIG. 11). Each data created in the storage medium is burned into the ROM 31 (FIG. 11).

Next, a musical sound data reproducing apparatus according to the second embodiment of the present invention will be described with reference to FIGS.
FIG. 8 is a block diagram showing the configuration of the musical sound data reproducing apparatus. In this figure, parts corresponding to the respective parts in FIG. In this figure, reference numeral 33 denotes a header reading unit, which receives an instruction from the control unit 17a, reads the header H from the ROM 31, and presets the total number of samples N included in the read header H in the down counter 34. The down counter 34 counts down the clock pulse fs after the time when the total number of samples N is preset. Here, the clock pulse fs is the same clock pulse as the clock pulse that defines the data read timing of the PCM data read unit 12. The count output of the down counter 34 is supplied to the 0 detection circuit 35. When the count output of the down counter 34 becomes “0”, the 0 detection circuit 35 outputs a detection signal to the control unit 17a.

Next, the operation of the musical sound data reproducing apparatus in FIG. 8 will be described.
When a loop reproduction instruction is supplied to the control unit 17a, the control unit 17 sequentially outputs a read command to the header reading unit 33, the PCM data reading unit 12, and the compressed data reading unit 13, and then the switching unit 15 is connected to the PCM. Switch to the data reading unit 12 side. When a read command is output to the header reading unit 33, the header reading unit 33 reads the header H from the ROM 31 and presets the total number of samples N included in the header H to the down counter 34. Thereafter, the down counter 34 counts down the clock pulse fs.

  When a read command is output to the PCM data reading unit 12 and the compressed data reading unit 13, first, a musical sound based on the PCM data in the ROM 31 is generated as in the first embodiment described above (FIG. 9). Next, a musical sound based on the compressed data is generated (time t2 to t3). When a musical sound based on the last sample of the compressed data in the ROM 31 is generated at time t3, a detection signal is output from the 0 detection circuit 35 to the control unit 17a at the same timing. The control unit 17a receives this detection signal, and sequentially outputs a read command to the header reading unit 33, the PCM data reading unit 12 and the compressed data reading unit 13 again, and then switches the switching unit 15 to the PCM data reading unit 12 side. Switch to. Thereafter, musical tone reproduction is performed again in the above process.

  As is apparent from the above description, in the second embodiment, the musical tone reproduction ends just before the silent portion of the final frame, and the musical tone reproduction returns to the beginning of the PCM data. As a result, continuous loop playback is performed.

  Note that, as shown in FIG. 12A, it is possible to place M or more PCM data at the head and feed it back to any position other than the M data. However, in this case, it is necessary to check the reproduction status of the PCM data and output a compressed data read command at the sound generation start time tm of the M data. Also, as shown in FIG. 12B, a plurality of feedback positions may be determined in advance, M pieces of PCM data may be arranged at the feedback positions, and the rest may be compressed data. In this case, it is possible to arbitrarily return to a predetermined feedback position.

  For example, it is used for effect music of game machines such as pachinko.

It is a block diagram which shows the structure of the musical sound data reproducing apparatus by 1st Embodiment of this invention. It is a figure which shows the format and processing timing of the musical sound data used in the embodiment. It is a flowchart which shows the process of music data generation. It is explanatory drawing for demonstrating the process of musical sound data generation. It is a block diagram which shows the structure of the circuit which produces | generates compressed data. It is a block diagram of a decoder that decompresses compressed data. It is a timing diagram for demonstrating operation | movement of the musical sound data reproducing apparatus shown in FIG. It is a block diagram which shows the structure of the musical sound data reproducing apparatus by 2nd Embodiment of this invention. It is a timing diagram for demonstrating operation | movement of the musical sound data reproduction apparatus. It is a flowchart which shows the process of the production | generation of the musical tone data used in the musical tone data reproduction apparatus. It is explanatory drawing for demonstrating the process of musical sound data generation. It is a figure which shows the example of the feedback other than 1st, 2nd embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11, 31 ... ROM, 12 ... PCM data reading part, 13 ... Compressed data reading part, 14 ... Decoder, 15 ... Switching part, 16 ... D / A converter, 17 ... Control part, 33 ... Header reading part, 34 ... Down counter, 35... 0 detection circuit.

Claims (4)

A musical sound data reproducing device that reads out and reproduces the musical sound data in the order of compressed musical data and non-compressed musical sound data from a storage medium storing musical sound data composed of compressed musical sound data and non-compressed musical sound data ,
First reading means for reading out the non -compressed musical tone data from the storage medium and outputting a reading completion notice when reading of the non-compressed musical tone data is completed ;
Second reading means for reading the compressed musical sound data from the storage medium;
A decoder for decompressing and outputting the compressed musical sound data read by the second reading means ;
Switching means for switching between the output of the first reading means and the output of the decoder ;
A control means for controlling the first reading means, the second reading means, and the switching means;
The compressed musical sound data has a data size that is an integral multiple of a predetermined reproduction processing unit in reproduction of musical sound data,
The control means receives the loop reproduction instruction, the second when the outputs read instruction of the compressed musical data to the reading means first steps Ru switched together before Symbol switching means to an output of said decoder, said by the decoder the with stretching and output of compressed musical data outputs said Shi output readings uncompressed music data command Previous Symbol first reading means upon completion switch the switching means to the output of said first reading means The musical sound data is characterized in that the musical sound data is loop-reproduced by executing two steps in order and receiving the reading completion notification output from the first reading means and executing the first procedure again. Playback device. The musical tone data from a storage medium storing musical tone data composed of non-compressed musical tone data, compressed musical tone data, and sample number information indicating the total number of data units included in the non-compressed musical tone data and the compressed musical tone data Is a musical sound data reproducing device for reading out and reproducing
The compressed musical sound data includes silent data so as to have a data size that is an integral multiple of a predetermined reproduction processing unit in the reproduction of musical sound data,
First reading means for reading the sample number information from the storage medium;
Detecting means for detecting the end of reproduction of the musical sound by the non-compressed musical tone data and the compressed musical tone data based on the number-of-samples information read by the first reading means ;
A second reading unit for to read out the uncompressed music data from the storage medium,
Third reading means for reading the compressed musical sound data from the storage medium;
A decoder for decompressing and outputting the compressed musical sound data read by the third reading means;
Switching means for switching between the output of the second reading means and the output of the decoder;
Receiving loop reproduction instruction, the first to third switching procedure step to the output of said second reading means said switching means Shi out readings to reading means together and outputs the command, the second readout means switching procedure step, it was executed in order to pre-Symbol changeover means to the output of the decoder at the time when the uncompressed tone data read is completed by, the tone by the uncompressed tone data and the compressed musical data by the detecting means Control means for causing the second and third reading means to start reading the non-compressed musical tone data and the compressed musical tone data again in response to the detection of the end of reproduction, and to reproduce the musical tone data in a loop ;
A musical sound data reproducing apparatus comprising: The uncompressed musical tone data has a data size corresponding to the time required to start decompressing and outputting the compressed musical tone data.
3. A musical sound data reproducing apparatus according to claim 2, wherein 4. The musical tone data reproducing apparatus according to claim 1, wherein compressed musical tone data compressed by an ADPCM method is used instead of the uncompressed musical tone data .

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