core-audio - sub-millisecond latency in Core Audio

Question

Is it possible to play sounds with sub-millisecond latency using Core Audio?

I've tried using AudioQueues with different sizes and numbers of buffers, and I've tried using AudioUnits, but I have been unable to get below 30 ms of latency.

I am using an oscilloscope to measure the time between when a pushbutton on an Arduino is pressed and when sound leaves the audio jack. The Arduino communication never contributes more than 1 ms of delay.

Answer 1

不可以。对于亚毫秒级延迟，不包括 DAC 延迟，音频驱动程序需要以 44.1k 的采样率提取 32 个样本或更少的缓冲区大小，这在当前硬件上似乎不允许输出音频单元。音频队列在音频单元之上运行，因此具有更高的延迟。