Tone synthesis apparatus and method

#The present invention relates to tone synthesis apparatus, methods and programs for generating waveforms of tones, voices or other desired sounds, for example, on the basis of readout of waveform data from a memory or the like while varying a timbre and rendition style (or articulation) of the tones, voices or other sounds. More particularly, the present invention relates to an improved tone synthesis apparatus, method and program which perform control to reduce a delay in tone generation (i.e., tone generation delay) etc. that may occur during, for example, a real-time performance.

#In recent years, there has been known a tone waveform control technique called “SAEM” (Sound Articulation Element Modeling), which is intended for realistic reproduction and control of various rendition styles (various types of articulation) peculiar to natural musical instruments. Among examples of equipment using the SAEM technique is an apparatus disclosed in Japanese Patent Application Laid-open Publication No. HEI-11-167382 (hereinafter referred to as “patent literature 1”). The conventionally-known apparatus equipped with a tone generator using the SAEM technique, such as the one disclosed in patent literature 1, are arranged to generate a continuous tone waveform by time-serially combining a plurality of ones of rendition style modules prepared in advance for individual portions of tones, such as an attack-related rendition style module defining an attack waveform, release-related rendition style module defining a release waveform, body-related rendition style module defining a body waveform (intermediate waveform) constituting a steady portion of a tone and a joint waveform interconnecting tones. For example, the apparatus can generate a waveform of an entire tone by crossfade-synthesizing waveforms of individual portions of the tone using an attack-related rendition module for an attack portion, i.e. a rise portion, of the tone, one or more body-related rendition modules for a body portion, i.e. a steady portion, of the tone and a release-related rendition style module for a release portion, i.e. a fall portion, of the tone. Also, by using a joint-related rendition style module in place of the release-related rendition style module, the apparatus can also generate a series of waveforms of a plurality of successive tones (or tone portions) connected together by a desired rendition style. Note that, in this specification, the terms “tone waveform” are used to mean a waveform of a voice or any desired sound rather than being limited only to a waveform of a musical tone.

#Further, there have been known apparatus which allow a human player to selectively designate in real time rendition styles to be used, among which is the one disclosed in Japanese Patent Application Laid-open Publication No. 2004-78095 (hereinafter referred to as “patent literature 2”).

#For better understanding of the objects and other features of the present invention, its preferred embodiments will be described hereinbelow in greater detail with reference to the accompanying drawings, in which:

#FIG. 1 is a block diagram showing an exemplary general hardware setup of an electronic musical instrument to which is applied a tone synthesis apparatus in accordance with an embodiment of the present invention;

#FIG. 2 is a conceptual diagram explanatory of rendition style modules to be imparted to various portions of tones;

#FIG. 1 is a block diagram showing an exemplary general hardware setup of an electronic musical instrument to which is applied a tone synthesis apparatus in accordance with an embodiment of the present invention. The electronic musical instrument illustrated here is implemented using a computer, where tone synthesis processing, as typified by the SAEM synthesis technique or method, for sequentially crossfade-synthesizing a plurality of waveforms to output a continuous tone waveform while varying the tone color and rendition style (or articulation) is carried out by the computer executing a predetermined program (software) for realizing the tone synthesis processing of the present invention. Needless to say, the tone synthesis processing may be implemented by microprograms to be executed by a DSP (Digital Signal Processor), rather than by such computer software. Also, the tone synthesis processing may be implemented by a dedicated hardware apparatus having discrete circuits or integrated or large-scale integrated circuit incorporated therein. Further, the equipment to which is applied the tone synthesis apparatus of the present invention may be embodied as an electronic musical instrument, automatic performance apparatus, such as a sequencer, karaoke apparatus, electronic game apparatus, multimedia-related apparatus, personal computer or any other desired form of product. Namely, the tone synthesis apparatus of the present invention may be constructed in any desired manner as long as it can generate tones, imparted with user-desired tone colors and rendition styles (or articulation), in accordance with normal performance information, such as note-on and note-off event information generated in response to operation of, for example, a performance operator unit 5, such as a keyboard, operators of a panel operator unit 6, switch output information, etc. Note that, although the electronic musical instrument employing the tone synthesis apparatus to be described below may include other hardware than the above-mentioned, it will hereinafter be described in relation to a case where only necessary minimum resources are used.

#In the electronic musical instrument of FIG. 1, various processes are carried out under control of a microcomputer including a microprocessor unit (CPU) 1, a read-only memory (ROM) 2 and a random access memory (RAM) 3. The CPU 1 controls operation of the entire electronic musical instrument. To the CPU 1 are connected, via a communication bus (e.g., data and address bus) 1D, the ROM 2, RAM 3, external storage device 4, performance operator unit 5, panel operator unit 6, display device 7, tone generator 8 and interface 9. Also connected to the CPU 1 is a timer 1A for counting various times, for example, to signal interrupt timing for timer interrupt processes. Namely, the timer 1A generates tempo clock pulses for counting a time interval or setting a performance tempo with which to perform a music piece in accordance with given performance information. The frequency of the tempo clock pulses is adjustable, for example, via a tempo-setting switch of the panel operator unit 6. Such tempo clock pulses generated by the timer 1A are given to the CPU 1 as processing timing instructions or as interrupt instructions. The CPU 1 carries out various processes in accordance with such instructions.

#The ROM 2 stores therein various programs for execution by the CPU 1 and various data. The RAM 3 is used as a working memory for temporarily storing various data generated as the CPU 1 executes predetermined programs, as a memory for storing a currently-executed program and data related to the currently-executed program, and for various other purposes. Predetermined address regions of the RAM 3 are allocated to various functions and used as various registers, flags, tables, memories, etc. The external storage device 4 is provided for storing various data, such as rendition style modules for generating tones corresponding to rendition styles specific to various musical instruments, and various control programs to be executed or referred to by the CPU 1. In a case where a particular control program is not prestored in the ROM 2, the control program may be prestored in the external storage device (e.g., hard disk device) 4, so that, by reading the control program from the external storage device 4 into the RAM 3, the CPU 1 is allowed to operate in exactly the same way as in the case where the particular control program is stored in the ROM 2. This arrangement greatly facilitates version upgrade of the control program, addition of a new control program, etc. The external storage device 4 may use any of various removable-type recording media other than the hard disk (HD), such as a flexible disk (FD), compact disk (CD-ROM or CD-RAM), magneto-optical disk (MO) and digital versatile disk (DVD); alternatively, the external storage device 4 may comprise a semiconductor memory. It should be appreciated that other data than the above-mentioned may be stored in the ROM 2, external storage device 4 and RAM 3.