Waveform data analysis method and apparatus suitable for waveform expansion/compression control

A waveform data analysis method comprising:

• a step of performing a filter process for removing components of a predetermined frequency band from original waveform data;
• a step of detecting an envelope of the waveform data having been subjected to the filter process;
• a step of performing an amplitude conversion process on the envelope for reducing an amplitude difference in the envelope;
• and
• a step of determining dividing positions of the original waveform data on the basis of a differentiated result of the envelope having been subjected to the amplitude conversion process.

A waveform data analysis apparatus comprising:

• a storage device that stores original waveform data;
• and
• a processor coupled with said storage device and adapted to:
• designate a waveform type from among a plurality of waveform types, wherein said plurality of waveform types include at least a sustain-sound-related waveform type and a percussion-sound-related waveform type;
• select, in accordance with the designated waveform type, a parameter to be used for a filter process;
• read out an original waveform data from said storage device and perform a filter process for removing, from the read out original waveform data, a predetermined frequency component, wherein said filter process is performed using the selected parameter;
• and
• determine dividing positions of the original waveform data on the basis of envelope levels of the waveform data having been subjected to said filter process.

A waveform data analysis apparatus comprising:

• a storage device that stores original waveform data;
• and
• a processor coupled with said storage device and adapted to:
• read out the original waveform data from said storage device and perform a filter process for removing components of a predetermined frequency band from the original waveform data;
• detect an envelope of the waveform data having been subjected to the filter process;
• perform an amplitude conversion process on the envelope for reducing an amplitude difference in the envelope;
• and
• determine dividing positions of the original waveform data on the basis of a differentiated result of the envelope having been subjected to the amplitude conversion process.

A waveform data analysis method comprising:

• a step of identifying sections of an original waveform data as containing presumed beat positions;
• a step of detecting one or more rise positions in each of the identified sections of the original waveform data;
• and
• a step of, when a plurality of rise positions have been detected in a specific one of the identified sections by said step of detecting, selecting one of the detected rise positions and extracting the selected rise position as a dividing position corresponding to one of the presumed beat positions in the specific section of the original waveform data, and, when only one rise position has been detected in another specific one of the identified sections by said step of detecting, extracting the detected one rise position as a dividing position corresponding to one of the presumed beat positions in the other specific section of the original waveform data.

A waveform data analysis method comprising:

• a step of detecting a plurality of rise positions in an original waveform data;
• a step of determining a presumed beat positions in the original waveform data;
• a step of allocating a plurality of predetermined sections based upon the presumed beat positions in the original waveform data;
• a step of selecting, from among the plurality of rise positions detected by said step of detecting, one or more rise positions within each of the predetermined sections;
• and
• a step of, when a plurality of rise positions have been selected in a specific one of the predetermined sections by said step of selecting, further selecting one of the selected rise positions and extracting the further selected rise position as a dividing position corresponding to one of the presumed beat positions in the specific section of the original waveform data, and when only one rise position has been selected in another specific one of the predetermined sections by said step of selecting, extracting the selected one rise position as a dividing position corresponding to one of the presumed beat positions in the other specific section of the original waveform data.

A waveform data analysis apparatus comprising:

• a storage device that stores original waveform data;
• and
• a processor coupled with said storage device and adapted to:
• identify sections of an original waveform data as containing presumed beat positions;
• detect one or more of rise positions in each of the identified sections of the original waveform data;
• and
• when a plurality of rise positions have been detected in a specific one of the identified sections, select one of the detected rise positions and extract the selected rise position as a dividing position corresponding to one of the presumed beat positions in the specific section of the original waveform data, and, when only one rise position has been detected in another specific one of the identified sections extract the detected one rise position as a dividing position corresponding to one of the presumed beat positions in the other specific section of the original waveform data.

A waveform data analysis apparatus comprising:

• a storage device that stores original waveform data;
• and
• a processor coupled with said storage device and adapted to:
• detect a plurality of rise positions in an original waveform data;
• determine a presumed beat position in the original waveform data;
• allocate a plurality of predetermined sections based upon the presumed beat positions in the original waveform data;
• select, from among the detected plurality of rise positions, one or more rise positions within each of the predetermined sections;
• and
• when a plurality of rise positions have been selected in a specific one of the predetermined sections, further select one of the selected rise positions and extract the further selected rise position as a dividing position corresponding to one of the presumed beat positions in the specific section of the original waveform data, and, when only one rise position has been selected in another specific one of the predetermined sections, extract the selected one rise position as a dividing position corresponding to one of the presumed beat positions in the other specific section of the original waveform data.

A waveform data analysis method comprising:

• a step of generating a tempo clock;
• a step of reproducing automatic performance information synchronously with the tempo clock;
• a step of generating a sound based on the reproduced performance information, wherein a musician can execute a musical performance to generate a waveform in conjunction with the generated sound;
• a step of receiving the waveform and converting the received waveform into waveform data synchronously with the generated sound;
• a step of storing the waveform data in parallel with reproduction of the automatic performance information;
• and
• a step of recording synchronization control data indicative of successive timing relationship between the automatic performance information reproduced successively and the waveform data stored successively, in correspondence with storage of the waveform data, so that the stored waveform data can be associated with timing data of the automatic performance information.

A waveform data analysis apparatus comprising:

• a clock generator that generates a tempo clock;
• a storage device;
• a reproduction device that reproduces automatic performance information synchronously with the tempo clock;
• a sound generator that generates a sound based on the reproduced performance information, wherein a musician can execute a musical performance to generate a waveform in conjunction with the generated sound;
• an input device that receives the waveform and converts the received waveform into waveform data synchronously with the generated sound;
• and
• a control device coupled with said storage device, said reproduction device and said input device, said control device being adapted to:
• store the waveform data in said storage device in parallel with reproduction of the automatic performance information, and perform control to record, in said storage device, synchronization control data indicative of successive timing relationship between the automatic performance information reproduced successively and the waveform data stored successively, in correspondence with storage of the waveform data, so that the stored waveform data can be associated with timing data of the automatic performance information.

A waveform data processing method comprising:

• a step of dividing original waveform data into a plurality of partial waveform data;
• a step of detecting a rise time of each of the partial waveform data;
• a step of adding waveform data of an additional section to each of the partial waveform data divided from the original waveform data by said step of dividing, the waveform data of the additional section attenuating, with passage of time, from an initial value equal to an envelope level at an end of a corresponding one of the partial waveform data;
• a step of storing, in a memory, each of the partial waveform data having the waveform data of the additional section added thereto;
• and
• a step of storing, in the memory, the rise times of the partial waveform data in association with the partial waveform data having the waveform data of the additional section added thereto.

A waveform data processing method comprising:

• a step of dividing original waveform data into a plurality of sections;
• a step of, in correspondence with the sections divided from the original waveform data by said step of dividing, previously generating and storing waveform data of additional sections to be added to individual ones of the divided sections;
• a step of modifying reproduction start timing of the waveform data of individual ones of the divided sections, which is determined by dividing positions of the original waveform data and a reproducing tempo of the waveform data, in accordance with respective rise times of the waveform data and thereby generating the modified reproduction start timing;
• a step of reading out the waveform data of each of the divided sections at the modified reproduction timing and thereby performing waveform reproduction, wherein, when a reproducing tempo for reproduction of the waveform data is faster than a predetermined standard, said step of reading performs the waveform reproduction using the original waveform data of the individual divided sections without using the waveform data of the additional sections;
• and
• a step of reading out the waveform data of each of the divided sections at the modified reproduction timing and thereby performing waveform reproduction, wherein, when the reproducing tempo is slower than the predetermined standard, said step of reading performs the waveform reproduction by adding the waveform data of corresponding ones of the additional sections to the divided sections to follow the waveform data of the divided sections.

A waveform data analysis apparatus comprising:

• a storage device that stores original waveform data;
• and
• a processor coupled with said storage device and adapted to:
• divide original waveform data into a plurality of partial waveform data;
• detect a rise time of each of the partial waveform data;
• add waveform data of an additional section to each of the partial waveform data, the waveform data of the additional section attenuating, with passage of time, from an initial value equal to an envelope level at an end of a corresponding one of the partial waveform data;
• store, in a memory, each of the partial waveform data having the waveform data of the additional section added thereto;
• and
• store, in the memory, the rise times of the partial waveform data in association with the partial waveform data having the waveform data of the additional section added thereto.

A waveform data analysis apparatus comprising:

• a storage device that stores original waveform data;
• and
• a processor coupled with said storage device and adapted to:
• divide original waveform data into a plurality of sections;
• in correspondence with the divided sections, previously generate and store waveform data of additional sections to be added to individual ones of the divided sections;
• modify reproduction start timing of the waveform data of individual ones of the divided sections, which is determined by dividing positions of the original waveform data and a reproducing tempo of the waveform data, in accordance with respective rise times of the waveform data and thereby generating the modified reproduction start timing;
• read out the waveform data of each of the divided sections at the modified reproduction timing thereby to perform waveform reproduction, wherein, when a reproducing tempo for reproduction of the waveform data is faster than a predetermined standard, said waveform reproduction is performed using the original waveform data of the individual divided sections without using the waveform data of the additional sections;
• and
• read out the waveform data of each of the divided sections at the modified reproduction timing thereby to perform waveform reproduction, wherein, when the reproducing tempo is slower than the predetermined standard, said waveform reproduction is performed by adding the waveform data of corresponding ones of the additional sections to the divided sections to follow the waveform data of the divided sections.