A:

The AIL_digital_latency function can roughly report the current latency. This section will discuss where this latency comes from on each of the Miles platforms.

On Win32/Win64 with DirectSound, the default latency is 64 milliseconds (not counting the OS, sound driver and sound hardware latency which is out of our control). You can reduce or increase the latency by changing the DIG_DS_MIX_FRAGMENT_CNT preference. If you shorten the latency, you increase the chance of skipping. If you lengthen the latency, you can ride out longer thread starvations.

On Win32 with waveOut, the latency depends on the sound card and sound card drivers. Miles calculates the minimum latency that won't cause skipping at runtime. On most cards, this will be 150 ms to 200 ms, but on some sound cards (especially older ISA cards), this latency can rise to as high as 300 ms! These excessive latency times with waveOut environment are due to fundamental design shortcomings in the Microsoft architecture, and cannot be reliably overcome by any external techniques.

However, under waveOut, the MSS architecture does permit a sound effect to be started with essentially zero latency, as long as no other sound effects are currently being played! So, if you have a situation where latency is critical, then you can improve waveOut's performance dramatically by letting all other sounds complete before starting the latency-critical sound effect.

On PS3, the default latency is 40 milliseconds (not counting the OS latency which is out of our control). You can reduce or increase the latency by changing the DIG_DS_MIX_FRAGMENT_CNT preference. If you shorten the latency, you increase the chance of skipping. If you lengthen the latency, you can ride out longer thread starvations.

On Wii, the default latency is 32 milliseconds (not counting the OS latency which is out of our control). You can reduce or increase the latency by changing the DIG_DS_MIX_FRAGMENT_CNT preference. If you shorten the latency, you increase the chance of skipping. If you lengthen the latency, you can ride out longer thread starvations.

On MacOS, the default latency is 64 milliseconds (not counting the OS, sound driver and sound hardware latency which is out of our control). You can reduce or increase the latency by changing the DIG_SM_MIX_FRAGMENT_CNT preference. If you shorten the latency, you increase the chance of skipping. If you lengthen the latency, you can ride out longer thread starvations.

On DOS, the default latency is 100 milliseconds. You can reduce or increase the latency by changing the DIG_LATENCY preference. If you shorten the latency, you increase the chance of skipping. Under DOS, there is little reason to change the default latency.