Messages in this thread | | | Date | Sat, 24 Jul 1999 15:43:39 +0200 (CEST) | From | Daniel Kobras <> | Subject | Re: real-time threaded IO with low latency (audio) |
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On Sat, 24 Jul 1999, Gerhard Mack wrote:
> On Fri, 23 Jul 1999, Ingo Molnar wrote: > > > the whole 'why sound skips' problem i think lacks one major necessery > > component: information. Nobody really ever analyzed what the problem > > really is/was. I do have a awe64 soundcard (which i almost never use), if > > you (or anyone else) could point to a method to make sound-playback > > produce bad quality, i'd be happy to analyze the problem. Is running > > mpg123 enough to see the problem? What should i do to make sound skip?
> Mpg123 will skip as the disk usage gets heavy. > > Somewhere between 2.2.8 and 2.3.4 something drastically reduced the sound > dropouts on my system. I used to be able to make the sound skip even with > "mpg123 -b 1024" but that is no longer the case.
In my experience setting the buffer size to a higher value won't do you a blind good as the problem is not input bound but rather on the output side. Heavy disk i/o locks out mpg123's buffer process, therefore audio_play_samples() doesn't get run often enough. So to me it looks like mingos additional schedule()s are certainly in the right ballpark. For a simple test case on sound skippishness, disable DMA on an IDE disk and run a find on it while playing sound. [Or be the proud owner of any IDE chipset that wasn't supported in DMA mode prior to unified ide. :-/]
Daniel.
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