Subject: [linux-audio-dev] Making audio run realtime on older computers
From: Twinkles (dolphin_AT_gargoyle.apana.org.au)
Date: Sun Jul 09 2000 - 13:44:56 EEST
I am using a Linux 486DX66 to play audio but am experiencing the following
problem to which a developer may be able to supply a solution.
I record some music to a WAV file at full cd quality 44100/2/16 and later
save it as a MP3 at the same quality.
I can play back the WAV perfectly. However, when I try to do the same with
a MP3, if the sample rate is above 11025 it starts and stops once or many
times every second. If I happen to be attempting to play the file via my
stereo at a medium volume and forget the command line switch to
downsample, the task switching nearly blows the speakers :(
I know this is because the kernel is multitasking between the audio and
the rest of the applications and the fact that MP3 has to be decoded while
WAV is direct to the card but I am interested to know if there was any way
to wrap the whole thing so the kernal thought it was to run to the
exclusion of (almost) everything else.
To get a mp3 to play I have to use either:
mpg123 -4 file.mp3 (i.e. "-4" means downsampled twice to 11025)
nice -19 mpg123 -4 file.mp3
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