臺灣博碩士論文加值系統

本論文為樂器即時演奏合成法之研究，此合成法適用於一般的樂器。依據人耳對音頻感覺的分析，增益較小的頻率會被較大增益的增益所遮蔽掉，故本合成法基本上以加法合成為骨幹，同時為了減少運算時間，本方法亦加入了向量合成和樣本播放的技術，以達到即時性的效能。利用此修正過後的加法合成法技術我們可以針對合成音的各個諧波做獨立的調整，以便更精細的模擬合成音的音高、音長及音量。依據我們的觀察，音長的調整和樂器的種類有絕對的關係。依樂器演奏的方式，音長的調整可用：一、由內插的方法取得包絡曲線；二、以線性預測方式來模擬包絡曲線。利用這兩種方法來做音長的調整可使本合成法更適用於一般的樂器。本合成方法在音色的製作，只須錄下幾個單音透過我們所設計的數位濾波器取得振幅包絡和頻率變化率兩項參數即可，不須要靠經驗上的判斷來取得參數。由於這些參數可藉由電腦的運算取得，大大的提高音色製作上的速度及便利性。任何人皆可利用本合成方法製作出屬於個人特色的樂團，達到其實用方便的目的。

In this thesis, we propose a real time music synthesizer that can be applied to any commercial instruments. According to the variation with frequency of human hearing, a frequency with a small gain will be masked by the frequency with larger gain. Therefore the main idea of the proposed synthesizer is based on the additive method. As for reducing the computation time, we also use the vector synthesis and sample playback techniques to improve the system performance so that it can reach the real time response. Based on the modified additive method, we can individually adjust each harmonic of synthetic sound and simulate elaborately the pitch, duration and volume of it. According to the experiments, there is a strong relationship between the duration of the sound and the types of instruments. To adjust the duration of the sound, we propose two methods to do it. One is to get the scaled envelop by an interpolating method; the other is to simulate the scaled envelop by a linear predicating method. The tone of a sound of an instrument is decided by both the envelop and the drift of the fundamental frequency of the sound. Instead of using human experience, both parameters can be got from the recorded samples of a sound through a digital filter. Therefor, it improves the speed and convenience of making a wavetable of an instrument. Anybody, who is interested in computer music, can use the proposed synthesizer to make its own style of music band.

第一章 緒論
1.1 研究動機及目的
1.2 論文方法概要
1.3 章節大要
第二章 電子合成器
2.1 什麼是電子合成器
2.1.1 類比式合成器
2.1.2 數位式合成器
2.2 合成法的介紹
2.2.1 減法合成( Subtract Synthesis
2.2.2 加法合成( Additive Synthesis
2.2.3 FM合成( Frequency Modulation
2.2.4 樣本播放合成( Sample Playback
2.2.5 削減合成( Waveshaping Synthesis
2.2.6 線性合成( LA Synthesis
2.2.7 向量合成( Vector Synthesis
2.2.8 物理模型( Physical Mode
2.2.9 共振峰合成法( Formant Synthesis
第三章 樂器演奏資訊合成
3.1合成音樂的因素
3.2樂器的類別
3.3音高的合成
3.4音長的調整
3.5音量與力度的關係
3.6演奏技巧的原理與實現
3.7其它可發展的方向
3.8即時合成
第四章 樂曲的合成
4.1樂譜的格式定義
4.2序列器
第五章 實驗與結語
5.1測試方法與結果
5.2結語65
參考文獻

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