Fractionally addressed delay lines

While traditional implementations of variable-length digital delay lines ar e based on a circular buffer accessed by two pointers, we propose an implem entation where a single fractional pointer is used both for read and write operations. On modern general-purpose architectures, the proposed method is nearly as efficient as the popular interpolated circular buffer, and it be haves well for delay-length modulations commonly found in digital audio eff ects. The physical interpretation of the new implementation shows that it i s suitable for simulating tension or density modulations in wave-propagatin g media.