concat_audio

#!/usr/bin/perl
use strict;
use warnings;
use File::Basename;
use Cwd qw(abs_path getcwd);
use Getopt::Long;

# Add command line option for overwrite
my $overwrite = 0;
GetOptions("overwrite" => \$overwrite) or die "Error in command line arguments\n";

# Check if we have at least two arguments
die "Usage: $0 [--overwrite] <input_file> <number_of_files_to_concat>\n" unless @ARGV >= 2;

my ($input_file, $num_files) = @ARGV;
$input_file = abs_path($input_file);

# Extract prefix, seqnum, phasenum, and extension from the input file
my ($dir, $filename) = $input_file =~ m{^(.+)/([^/]+)$};
my ($prefix, $seqnum, $phasenum, $ext) = $filename =~ /^(.+)_(\d+)-([01])\.(.+)$/;
die "Invalid input filename format\n" unless defined $prefix && defined $ext;

# Determine the width of the seqnum field
my $seqnum_width = length($seqnum);

print "Directory: $dir\n";
print "Prefix: $prefix\n";
print "Starting seqnum: $seqnum (width: $seqnum_width)\n";
print "Phasenum: $phasenum (only processing files with this phase)\n";
print "Extension: $ext\n\n";

my $base_seqnum = $seqnum;

# Array to store input filenames
my @input_files;

# Accumulate input filenames
my $count = 0;
my $last_seqnum = $seqnum;

while ($count < $num_files) {
    my $filename = sprintf("%s/%s_%0*d-%d.%s", $dir, $prefix, $seqnum_width, $seqnum, $phasenum, $ext);
    print "Checking file: $filename\n";
    if (-e $filename) {
        push @input_files, abs_path($filename);
        print "File added: $filename\n";
        $last_seqnum = $seqnum;
        $count++;
    } else {
        print "File not found: $filename\n";
        last;  # Exit the loop when the first missing file is encountered
    }

    # Increment seqnum by 1 (skipping the other phase)
    $seqnum++;
}

if ($count == 0) {
    die "No matching files found to concatenate.\n";
}

# Construct final output filename
my $output_file = sprintf("%s/%s_%0*d-%d_%0*d-%d.%s", $dir, $prefix, $seqnum_width, $base_seqnum, $phasenum, $seqnum_width, $last_seqnum, $phasenum, $ext);

# Create .fnms file in current working directory
my $cwd = getcwd();
my $fnms_file = "$cwd/" . basename($output_file, ".$ext") . ".fnms";

# Write accumulated filenames to the .fnms file
open(my $fh, '>', $fnms_file) or die "Could not open file '$fnms_file' $!";
foreach my $file (@input_files) {
    print $fh "file '$file'\n";
}
close $fh;

print "\nPreparing to concatenate $count files.\n";
print "Output file will be: $output_file\n";
print "File list saved in: $fnms_file\n";

# Check if output file exists and exit if overwrite is not specified
if (-e $output_file && !$overwrite) {
    die "Error: Output file '$output_file' already exists. Use --overwrite to force overwrite.\n";
}

# Construct log filename
my $log_file = $output_file;
$log_file =~ s/\.[^.]+$/.log/;

# Run ffmpeg command
my $ffmpeg_cmd = "ffmpeg -y -f concat -safe 0 -i \"$fnms_file\" -c copy \"$output_file\" 2>&1";
print "\nExecuting command: $ffmpeg_cmd\n";
print "FFmpeg output will be logged to: $log_file\n";

open(my $log_fh, '>', $log_file) or die "Could not open log file '$log_file' $!";
open(my $ffmpeg, "$ffmpeg_cmd |") or die "Could not run ffmpeg: $!";
while (<$ffmpeg>) {
    print $log_fh $_;
}
close $ffmpeg;
close $log_fh;

print "Concatenation complete. Output file: $output_file\n";
print "Number of files concatenated: $count\n";
print "File list saved in: $fnms_file\n";