摘要:
Systems (100 or 300) and methods (400 or 500) are provided for selecting a post-compression waveform from a post-compression waveform table (106) and supplying it to a synthesis engine (108). The post-compression waveform is based upon a set of post-compression coefficients determined by generating a frequency-domain representation of a periodic signal, the representation including at least one pre-compression frequency-domain sample (204), and performing a threshold-based compression of the pre-compression frequency-domain samples. Systems and methods also include indexing and storing (502) post-compression coefficients in a post-compression coefficient table (102), generating (506) a post-compression waveform based upon the set of post-compression coefficients, and placing (508) the post-compression waveform in the table prior to the selecting (510). The system and method also include performing (504) a read-ahead operation on a sound file before selecting the post-compression waveform, the read-ahead operation indicating the post-compression waveform to be selected and supplied to the synthesis engine.
摘要:
A method of scaling polyphony can include identifying music data to be played (415), wherein the music data indicates instruments to be used and each instrument has an assigned priority. A measure of polyphony needed to play the music data can be compared with polyphony of a sound generating device (425). If the measure of polyphony exceeds the polyphony of the sound generating device, the music data can be played without using one or more instruments indicated by the music data according to the assigned priorities (440, 460).
摘要:
A percussive sound contains both harmonic and non-harmonic frequency spectral content. To reproduce a particular percussive sound, such as the sound of a drum or cymbal or hand clap, for example, the harmonic and non-harmonic content are determined empirically. Also, and tendency of the harmonic content to change over time, and the temporal aspects of attack, sustain, and decay are likewise determined empirically. These attributes are represented in the invention in a percussive sound file which includes a harmonic content profile (502), noise shape filter (504), Doppler shift profile (506), and a time wave shaping profile (508). The harmonic content profile is used by an FM generator (114) to generate a frequency modulated signal (116). The noise shape profile is used by a noise generator (134) to generate and shape the non-harmonic spectral content. While the sound is being generated, the Doppler shift profile is used to adjust the base frequency of the FM signal. The harmonic and non-harmonic signals are scaled (142, 144) and summed (146). The summed signal is then shaped (150) in time to substantially simulate the attack, sustain, and decay properties of the sound. The shaped, summed signal is then played by an audio circuit and converted to an acoustic signal.
摘要:
The invention concerns a communication device (102) and a method (200) for providing a personalized ring-back to a first user of the first communication device (102), when the first user initiates a phone call with a second user of a second communication device (104). In one arrangement, the method can include the steps of detecting (204) reception of a ring-back signal at the first communication device (102) received from a communication network (108), retrieving (206) a multimedia file in the first communication device (102), and playing (208) the multimedia file in the first communication device (102) for at least the duration of the ring-back signal.
摘要:
A sigma delta digital-to-analog (D/A) converter system (10) includes a summing device (35) at an input of a D/A converter (30), and a low frequency low amplitude wave signal (31) injected at an input of the summing device that remains unfiltered and is used to suppress spurious tone artifacts. The D/A converter system can further include an amplitude control and a frequency control for selectively adjusting the frequency and the amplitude of the low frequency low amplitude wave signal being injected. Note, the low frequency low amplitude repeating wave signal generator can take the form of a digital signal processor (DSP) (37) having the appropriate software to generate such signals.
摘要翻译:Σ-Δ数模(D / A)转换器系统(10)包括在D / A转换器(30)的输入处的加法装置(35)和注入的低频低振幅信号(31) 在相加装置的输入端保持未滤波,并用于抑制杂散音伪像。 D / A转换器系统还可以包括用于选择性地调节被注入的低频低振幅信号的频率和振幅的振幅控制和频率控制。 注意,低频低振幅中继波信号发生器可以采用具有适当软件的数字信号处理器(DSP)(37)的形式来产生这样的信号。
摘要:
A system, method and computer readable medium for adjusting volume levels of a Musical Instrument Digital Interface (MIDI) sound file for optimizing play on a sound device. The method on an information processing system includes calculating a first set of loudness levels for each instrument in a MIDI sound file and calculating a second set of loudness levels corresponding to an audio output range of a sound device. The method further includes generating a mapping between the first set of loudness levels and the second set of loudness levels corresponding to the audio output range of the sound device. The method further includes generating a gain term for each note in the MIDI sound file and modifying the MIDI sound file using the second set of loudness levels and the gain term for each note in the MIDI sound file.