Subject: Re: [linux-audio-dev] tricks wanted for buffer cache optimization
From: David Olofson (audiality_AT_swipnet.se)
Date: su tammi 30 2000 - 15:38:45 EST
On Sun, 30 Jan 2000, Paul Barton-Davis wrote:
> this does work, as i said, but it requires long latency settings for
> the audio interface, and careful tuning of the amount of read-ahead.
> somewhat paradoxically, write-behind is not a problem in the same way
> - i just use an unbounded queue of buffers to keep stuff read from the
> card, and the tape butler thread get to it when it gets to it, so to
> speak.
Well, that's quite logical to me - you have all the critical work in
RAM, and the writing to disk can wait as long as needed. As long as
there is more RAM, you can lag behind w/o problems, but you still
don't have to buffer anything before playback starts.
With playback, the problematic part of the system - the disk - is in
the wrong end of the buffer...
> >Well, you could split the file "the other way around", but that's not
> >as nice and compatible as multiple files...
>
> what's the "other way around" ?
Switch to a new file before the current one blows the 4 GB limit...
:-)
Means trouble if you want to run the file(s) in some editor for
master processing - processing one file at a time won't work, as
there will be a filter state loss resulting in clicks and pops efter
each split.
//David
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