12月21日的TfxEcho应用程序分析

TfxEcho is an echo effect AudioUnit Extension plugin. It uses delay lines which are inspired by BBD (bucket brigade device). BBD is used in various analog delay unit and is known for its warm and dark sound. The delay line uses fixed length buffer and an artificial clock to sample input signal in variable sampling rate. When the delay time is changed, the delay line can produce pitch change effect which is similar to the behavior of the BBD based analog delay unit. The delay line is inspired by BBD, but it is not emulation of the any particular BBD. Unlike the typical BBD based delay unit, frequency range of the delay line is not limited. The delay line is capable to capture signal in higher frequency up to about 22KHz. Features AudioUnit Extension - Delay Time: From 20 ms to 1200 ms - Feedback: From 0 % to 100 % - Adjustable lowpass filter and high-pass filter. - Modulation rate: From 0.01 Hz to 10 Hz - Modulation width: From 0 ms to +/- 10 ms - Delay time can be synced to tempo provided by the host application. Host Application Host application uses system audio input as an audio source and processed audio signal is routed to the system audio output.