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LATENCY, Part III

Output Latency, cont'd

• shortest latency:
  • 2 interrupts per hardware buffer (divides buffer in 2)
  • hardware works on one half
  • software works on other
  • switch at interrupt
• "double buffering" - enforced ASIO design
• ALSA allows other numbers of interrupts/buffer.

Summary

• total output latency: buffer size
• input latency: interrupt interval
• through latency: output latency
• output latency numbers are worst case.

Put differently: we can react to the input within 1 interrupt interval, and deliver audio within 2.