KR950010767B1 - Extention & abstraction system of pcm data - Google Patents

Abstract

The device provides an efficient PCM tone data compression/expansion method by separately storing the sampling data using small amount of data ROM. The device comprises: a tone sampling data ROM(11) which separately stores the upper tone data as increment/decrement(I/D) code and repetition code; initial tone table(12) which performs add/subtract operation according to the restoring parameter input; an original tone restoring unit(13) which processes the upper data I/D code, stores the data to register, and generates output to original tone sampling data; and digital signal processing unit(14) which restores the original sound by using a original tone data and initial tone table(12).

Description

Compression-extension system of PC tone data

1 is a block diagram of a compression extension system of a conventional PC tone data.

A diagram and a quantization waveform diagram showing an example of the tone sampling data structure according to Figs. 2 (a) and 2 (b) or Fig. 1;

3 is a block diagram of a pressure extension system of the present invention's tone data;

4 is a diagram showing an example of the tone sampling data ROM configuration shown in FIG.

* Explanation of symbols for main parts of the drawings

10: address generator 11: tone sampling data ROM

12: initial tone table 13: original tone reproduction unit

14: digital signal processing unit 15: digital / analog converter

The present invention relates to a system for compressing and expanding a PCM tone data. In particular, the upper data and the lower data of the sampling data are left as they are, and the upper data is divided into a sensitization code part and a repetition amount code part, and stored in a sampling ROM. The present invention relates to a system for compressing and expanding a PCM tone data, which enables the restoration of original sampling data while reducing the size of the tone data ROM.

As shown in FIG. 1 of the accompanying drawings, the compressed tone extension system block diagram of the conventional PCM tone data includes the tone sampling data ROM 2 storing a specific tone tone, and the tone sampling data according to input reproduction parameters. An address generator 1 for generating a tone address signal for reading the data of the ROM 2, and tone sample data output from the tone sampling data ROM 2 are processed by a reproduction parameter to obtain the original sound. And a digital / analog converter 4 for converting the digital signal calculated by the digital signal processor 3 into an analog signal and outputting a sound.

The compression extension system of the conventional PMS tone data configured as described above first generates the address of the place where the specific sound is contained by the reproduction parameter inputted by the address generator 1 to make a specific sound, and accordingly the sound sampling. Tone sample data output from the data ROM 2 is sequentially input to the digital signal processing unit 3, and arithmetic operations are performed to reproduce the original sound by the reproduction parameters.

At this time, the tone sampling data stored in the tone sampling data 2 is continuously contained in the 16-bit quantization size as shown in FIG. The digital signal, which has been calculated by the digital signal processor 3, is converted into an original analog signal through the digital / analog converter 4 and output to the sound output terminal.

However, in the conventional compression and expansion system of the PMS data, the sampling data is stored in the tone data ROM as it is, and the types of the tone data are usually hundreds, so the size of the tone data ROM becomes larger and higher quality sampling is possible. In order to obtain the data, the sampling frequency should be increased. However, when the sampling time interval is doubled, the tone data is doubled and the cost of the product increases.

In view of the above-mentioned problems, the present invention maintains the upper data and the lower data of the lower data of the sampling data as it is, and the upper data is divided into an increment code part and a repetition amount code part, and stored in the sampling ROM. By reducing the cost of the original sampling data can be restored while reducing the cost of the product was created a compression extension system of the PSI sound data to reproduce high-quality sound, according to the accompanying drawings of the present invention in detail The explanation is as follows.

3 is a block diagram of a compressed extension system of the PCM tone data. As shown therein, the upper data of a specific sound is divided into an increment / decrease code part and a repeat amount code part, and the lower data is stored as it is. (11) and an address generator (10) for successively generating high / low tone address signals for reading the high / low data of the tone sampling data ROM (11) according to the input reproduction parameters; The upper and lower data of the initial tone table 12 are added to the initial tone table 12 for increasing / decreasing the code and the first addition / subtraction by parameter input, and the upper data increase / decrease code outputted from the tone sampling data ROM 11. The original tone data immediately after the initial tone data after the operation The original sound reproduction unit 13 outputting the play data, the original sound sample data of the original sound reproduction unit 13, and the data of the initial tone table 12 are calculated and processed by the original reproduction parameters. And a digital / analog converter 15 for converting the digital signal computed by the digital signal processor 14 into an analog signal and outputting a sound.

The operation and effects of the present invention configured as described above will be described in detail with reference to FIGS. 3 and 4 as follows.

When a reproduction parameter is input to the address generator 10 and the digital signal processor 14 to reproduce the specific sound sampled first, the address generator 10 according to the address information containing the tone sampling data during the reproduction parameter input. An address of the tone color sampling data ROM 11 is generated, and the output of the tone color sampling data ROM 11 by this address is input to the digital signal processing portion 14 through the original tone reproduction portion 13.

At this time, the configuration of the sampling data stored in the timbre sampling data ROM 11 is divided into upper data and lower data, and upper data means upper bits of the sampled data and lower data means lower bits. As shown in FIG. 2, the lower data shows irregular change while the upper data shows constant change.

Therefore, the upper data showing a constant change may be divided into a data increase / decrease code part and a repeat amount code part as shown in FIG. 4, and may be stored in the tone sampling data ROM 11, and the lower data may be stored as it is.

Therefore, as shown in FIG. 4, the address generator 10 generates the upper address containing the upper data and the lower address containing the lower data in turn. When the first upper address is generated, the first address among all types of tone data is generated. In the initial tone table 12 having only tone data, initial tone data (1FA8: hexadecimal value) corresponding to the tone is output, and at the same time, upper data of the tone sampling data ROM 11 are output.

At this time, the upper data output is divided into a data increase / decrease code part and a repeat amount code part as described above, and each code enters the original tone reproducer 13, and the data increase / decrease code portion in the original tone reproducer 13 Is an addition operation with the upper data (1F) of the initial tone data, and its value is 24 as a hexadecimal value.

This 24 value is stored as a high-order data of the original tone to be used next to the low-order data (DA) by the subsequent low-order address, and used as the tone sampling data immediately after the initial tone data (1FA8). That is, the next tone sampling data is 24DA.

On the other hand, the read repetition amount code generates an upper address refresh signal by the repetition amount counter, and by this signal, the upper address is increased by one, and the next higher data can be output.

That is, the lower address, which is the address of the lower data, is increased by one each time, but the upper address is maintained by the repetition amount code, but is increased by only the upper address refresh signal.

Subsequently, the original tone sample data from the original tone reproducer 13 is input to the digital signal processor 14 to be processed and converted into the original analog signal through the digital / analog converter 15. Sound is output.

As described in detail above, in the present invention, the upper data and the lower data of the sampling data are left as they are, and the upper data is divided into an increase / decrease code part and a repeat amount code part and stored in the sampling ROM to reduce the size of the tone data ROM of the sound generator. In addition, the original sampling data can be restored, thereby reducing the cost of the product and reproducing high quality sound.

Claims (1)

The upper data of a specific timbre is divided into an increase / decrease code portion and a repetition amount code portion, and the lower data is stored as it is. An address generator 10 for continuously generating upper / lower tone address signals for respectively reading / lower data, an initial tone table 12 for first addition / subtraction by increasing / decreasing codes and inputting the reproduction parameters; In addition, the upper data increase / decrease code output from the tone sampling data ROM 11 is added to the upper data of the initial tone data of the initial tone table 12, and then stored in a register together with the lower level data. An original tone reproduction section 13 for outputting the original tone sampling data immediately after the data, and the original tone reproduction section 13 A digital signal processor 14 which calculates the original tone sample data and the data of the initial tone table 12 by the original reproduction parameters and reproduces the original sound, and the digital signal processed by the digital signal processor 14; Compression-extension device of the PMM tone data, characterized by comprising a digital / analog converter 15 for converting the signal into an analog signal to output the sound.