On 9 March 2010 23:48, Ben Klein <shackl...@gmail.com> wrote: > On 10 March 2010 10:01, Avery Pennarun <apenw...@gmail.com> wrote: >> On Tue, Mar 9, 2010 at 9:15 AM, Dan Kegel <d...@kegel.com> wrote: >>> On Tue, Mar 9, 2010 at 2:58 AM, Roderick Colenbrander >>> <thunderbir...@gmail.com> wrote: >>>> I might be able to measure it using my oscilloscope. Somehow I would >>>> need to play lets say the left channel 'without' latency and the other >>>> channel with and compare the two signals. >>> >>> Yes, absolutely, but it'd be good to make this measurement easy >>> to repeat by anybody interested. To do that, let's just loop the >>> audio output back into the audio input. The user will have to >>> provide a loopback cable (or, worst case, put his mike right up >>> to the speaker, and allow for a tiny bit of extra latency >>> from that). >> >> If sound travels at 340m/s, then a one-second sample is 340m long. A >> 1ms delay would therefore be 340mm, or 34 cm. Your mic would have to >> be *quite* far away from the speakers to have a significant impact on >> the delay, unless I'm missing something. > > You are: air pressure ;) hehe. Yeah, I know, it won't make a > noticeable difference either; just being Devil's Advocate. > >> Which is good news, I guess, since it means tests are easier. Hope it >> goes well :)
But if all you are interested in is the relative latency changes, then any additional latency effects should not matter as long as that latency added is constant. What is being checked is that the latency of wine+OpenAL is not noticeably greater than the current wine+ALSA implementation (that is, OpenAL has a latency that is at worst equal to ALSA as used by wine to within a certain tolerance for error). - Reece
