Video to GIF converter script.

makegif.pl

#!/usr/bin/perl
use strict;
use warnings;

use Math::Round;
use JSON;
use Getopt::Std;

# program paths
my $ffprobePath = "ffprobe";
my $ffmpegPath = "ffmpeg";
my $convertPath = "imconvert";
my $gifsiclePath = "gifsicle";

# subroutines
sub remove_extension {
    my $str = shift;
    $str =~ s{\.[^.]+$}{};
    return $str;
}

sub get_file_size {
    my $file = shift;
    sprintf("%.2f MiB", (-s $file) / 1048576);
}

# argument parsing
my %opts = ();
getopts('ogvrq:f:w:h:s:k:', \%opts);

if (@ARGV < 1) {
    print "usage: makegif.pl <options> <video file> [gif file]\n\n";
    print "-q <float>     Sets the color fuzzing value in percent. Higher values remove more similar pixels from following frames to lower the file size at cost of more artifacts. Default is 2.\n";
    print "-r             Re-use .rgb file from previous call and don't delete it.\n";
    print "-o             Use ordered dithering with reduced colors. Ugly, but reduces file size significantly.\n";
    print "-g             Create GIF file with a global color table.\n";
    print "-w <int>       Override video width.\n";
    print "-h <int>       Override video height.\n";
    print "-s <float>     Override video width and height using this multiplier.\n";
    print "-f <float>     Override video frame rate.\n";
    print "-k <string>    Add comment to GIF file.\n";
    exit;
}

# set options
my $fuzz = defined $opts{q} ? $opts{q} : 2;
my $verbose = defined $opts{v} ? $opts{v} : 0;
my $orderedDither = defined $opts{o} ? $opts{o} : undef;
my $globalColors = defined $opts{g} ? $opts{g} : 0;
my $reuseRGB = defined $opts{r} ? $opts{r} : 0;
my $customFramerate = defined $opts{f} ? $opts{f} : undef;
my $customWidth = defined $opts{w} ? int $opts{w} : undef;
my $customHeight = defined $opts{h} ? int $opts{h} : undef;
my $sizeMulti = defined $opts{s} ? $opts{s} : undef;
my $resize = $customWidth || $customHeight || $sizeMulti;
my $comment = defined $opts{k} ? $opts{k} : undef;
my $colors = 256;

# set files
my $videoFile = $ARGV[0];
my $videoFileName = remove_extension($videoFile);

my $gifFile = defined $ARGV[1] ? $ARGV[1] : $videoFileName . ".gif";
my $gifFileName = remove_extension($gifFile);

my $rgbFile = $videoFileName . ".rgb";

# probe video file
#if (not -f $videoFile) {
#    die "Video file not found";
#}

my $ffprobe = `$ffprobePath -v quiet -print_format json -show_streams "$videoFile" 2>&1`;
my $ffprobeJson = decode_json $ffprobe;
my $videoStream;

# scan for video stream
foreach my $stream (@{$ffprobeJson->{streams}}) {
    if ($stream->{codec_type} eq 'video') {
        $videoStream = $stream;
        last;
    }
}

if (!$videoStream) {
    die "No video stream found in source file";
}

# get final resolution
my $width = $customWidth ? $customWidth : int $videoStream->{width};
my $height = $customHeight ? $customHeight : int $videoStream->{height};
my $framerate = $customFramerate ? $customFramerate : $videoStream->{r_frame_rate};
my $frames = $videoStream->{nb_frames} ? $videoStream->{nb_frames} : $videoStream->{duration_ts};

if ($sizeMulti) {
    $width *= $sizeMulti;
    $height *= $sizeMulti;
}

# convert numerator/denominator to decimal
if ($framerate =~ /^\d+\/\d+$/) {
    $framerate = eval($framerate);
}

my $delay = round (100 / $framerate);

# gif needs at least 1ms delay, most browsers have a minimum of 2ms
if ($delay < 2) {
    $delay = 2;
}

printf "Input: %d frames, %dx%d @ %.2f FPS (%d ms)\n", $frames, $width, $height, $framerate, $delay;

my @args;

# create RGB image array
if (!$reuseRGB || !(-f $rgbFile)) {
    print "Converting video to RGB...\n";

    @args = ();
    push @args, "-loglevel", "quiet" if !$verbose;
    push @args, "-y";
    push @args, "-i", $videoFile;
    push @args, "-pix_fmt", "rgb24";
    push @args, "-s", $width . "x" . $height if $resize;
    push @args, $rgbFile;

    system $ffmpegPath, @args;

    print "RGB size: " . get_file_size($rgbFile) . "\n";
}

print "Converting RGB to GIF...\n";

@args = ();

# memory limits
push @args, "-limit", "memory", "8GiB";
push @args, "-limit", "map", "6GiB";

# output control
push @args, "-verbose" if $verbose;

# animation
push @args, "-delay", $delay;

# input file and control
push @args, "-size", $width . "x" . $height;
push @args, "-depth", "8";
push @args, "rgb:$rgbFile";

# optimization
push @args, "-fuzz", $fuzz . "%" if $fuzz > 0;
push @args, "-layers", "OptimizePlus";
push @args, "-layers", "OptimizeTransparency";

# color reduction and dithering
push @args, "-quantize", "YUV";
push @args, "-dither", "FloydSteinberg";
push @args, "-ordered-dither", "o8x8,32" if $orderedDither;

if ($globalColors) {
    push @args, "-colors", $colors ;
    push @args, "+map";
}

# output file
push @args, $gifFile;

system $convertPath, @args;

print "GIF size: " . get_file_size($gifFile) . " (raw)\n";

unlink $rgbFile if !$reuseRGB;

# optimize and add comment
@args = ();
push @args, "--batch";
push @args, "--optimize=3";
push @args, "--comment", $comment if $comment;
push @args, $gifFile;

system $gifsiclePath, @args;

print "GIF size: " . get_file_size($gifFile) . " (optimized)\n";