Subject: Re: [linux-audio-dev] a quick note about latency expectations
From: Tim Goetze (tim_AT_quitte.de)
Date: Sat Dec 08 2001 - 16:10:42 EET
On Dec 6 Tom wrote:
>> >16 frames per cycle! yow! this h/w can really do that?
>>
>>
>> you can even go down to 2 frames/cycle but obviously everything below 64
>> is not really practical with my single-cpu 450 MHz system. 16 can run
>> in perfect sync for a few seconds until the kernel in one of its ignorant
>> moods decides to block the audio thread for a while :(
>
>Since the number of frames/cycle directly determines the amount of time
>the computer has for performing rt dsp, there is probably no reason to
>want to go below 64 frames.
yes, there is. processing audio will take periodic time slices of a
certain length. if you plan to run midi or other processing sensitive
to exact timing along with your audio, you face a tough decision: preempt
audio for midi and take the risk of xrunning, or preempt midi for audio
and have the midi timing jump and jitter because it cannot run during an
audio timeslice.
the third way is go SMP and forget about this problem ;)
tim
This archive was generated by hypermail 2b28 : Sat Dec 08 2001 - 16:55:31 EET