From unslider@balance.wiw.org Thu May 18 23:55:57 2000
Date: Wed, 30 Jun 1999 21:37:22 -0400 (EDT)
From: unslider <unslider@balance.wiw.org>
Subject: a/b test script

here is a cheesy perl script for doing a/b type testing with two mp3
files. perhaps the next mp3 study foo can use something like this.

---cut here---
#!/usr/bin/perl
# Invoke two copies of mpg123 to do "A/B" type testing for encoder quality
# comparisons.
#
# Requires mpg123 and play (part of sox) to be installed. Sound card must
# support 44kHz/16bit/stereo.
#
# To use: run 'abtest.pl file1.mp3 file2.mp3'. To switch streams run
# abtest.pl with no arguments in another xterm (or virtual console, or
# run both on the same terminal like
# 'abtest.pl file1.mp3 file2.mp3 & abtest.pl', etc) and enter 1 whenever you
# want to switch to the first stream and 2 whenever you want to switch to the
# second. Kill both processes when you're done.
#
# Note that because of buffering there is a delay when switching streams,
# typically half a second or so.
#
# 6/30/99 unSlider
# All rights under copyright waived. ABSOLUTELY NO WARRANTY.

$file1=shift || do {
    while(<>) {
        if(/^1/) {
            unlink('/tmp/stream2');
        } elsif(/^2/) {
            symlink('/dev/null','/tmp/stream2');
        } else {
            print "Huh?\n";
        }
    }
    exit;
};
$file2=shift ||die "Read source for usage instructions";

open(OUT,"|play -t sw -r 44100 -c 2 -");
open(STREAM1,"mpg123 -s $file1|");
open(STREAM2,"mpg123 -s $file2|");

$curbuf=2;
for(;;) {
    $buf[1]="";
    $buf[2]="";
    $buf1len=read(STREAM1,$buf[1],1024);
    $buf2len=0;
    while($buf2len<$buf1len) {
        $blah="";
        $buf2len+=read(STREAM2,$blah,$buf1len-$buf2len);
        $buf[2].=$blah;
    }
    $oldbuf=$curbuf;
    if(-e '/tmp/stream2') {
        $curbuf=2;
    } else {
        $curbuf=1;
    }
    if($curbuf!=$oldbuf) {
        print "Switching to stream $curbuf\n";
    }
    print OUT $buf[$curbuf];
}
---cut here---

-- unS.
Below is a plot to destroy the world, cunningly disguised as an irc client.
use IO::Socket;$n=shift;($r=IO::Socket::INET->new(shift.":".shift))*
defined($c=fork)||die;$c&&do{for(;;){print<$r>||die}};do{print$r
"USER $n . . .\nNICK $n\n";while(<>){print$r $_}}