#!/usr/bin/perl
#srchange_pickL.pl
# 2005-05-28 created based on srchange.pl

#Author: Mafuyu Kitahara
#Purpose: sox: sample rate change, and pick Left channel from a stereo file
#Argument: suffix (e.g. wav, aiff) and output sample rate (e.g. 48000, 22500, 8000...)
#Input: all files in the current dir
#Output: [original name][sample rate].[suffix]

die "Usage: perl ~/bin/srchange_pickL.pl [suffix] [sample rate]\n" unless @ARGV;

#message
print "srchange.pl: change sampling rate using sox\n";
print "Usage: perl srchange.pl [suffix] [sample rate]\n";
print "Example: perl srchange.pl wav 48000\n";

$suffix = $ARGV[0];
$sr = $ARGV[1];

#dir
opendir(DIR, ".");
@files = ();
@files = grep(/(\.$suffix$)/, readdir(DIR)); 
closedir(DIR);

# print @files;

# loop
for $file (@files) {
    $basename = `basename $file .$suffix`;
    chomp($base = $basename);
    $out = substr($basename, -5, 4); 
    print "processing $base, sr at $sr\n";
    `sox $file -r $sr -c 1 ${out}.${suffix} pick -l`;
    print "$file .... done\n";
}
print "all done\n";