add option to create progressive jpeg, close #11

lib/Llavaud/Process/Media/Photo.pm

@@ -174,6 +174,12 @@ sub process {
             carp "[$obj->{'final'}->{$_}->{'path'}] Failed to resize, $err";
             return 0;
         }
+        if (defined $main::OPTIONS{'format'}{$_}{'progressive'} and
+            $main::OPTIONS{'format'}{$_}{'progressive'} eq 'true' and
+            my $err = $image->Set(interlace => 'Plane')) {
+            carp "[$obj->{'final'}->{$_}->{'path'}] Failed to set interlace, $err";
+            return 0;
+        }
         my $err;
         if (defined $main::OPTIONS{'format'}{$_}{'compress'}) {
             $err = $image->Write(filename => $obj->{'final'}->{$_}->{'path'}, quality => $main::OPTIONS{'format'}{$_}{'compress'});

lib/Llavaud/Process/Media/Video.pm

@@ -311,7 +311,7 @@ sub thumbnail {
             carp "[$obj->{'final'}->{$_}->{'dir'}$obj->{'final'}->{'name'}.jpg] Failed to strip, $err";
             return 0;
         }
-        if (my $err = $image->Write(filename => "$obj->{'final'}->{$_}->{'dir'}$obj->{'final'}->{'name'}.jpg", quality => 90)) {
+        if (my $err = $image->Write(filename => "$obj->{'final'}->{$_}->{'dir'}$obj->{'final'}->{'name'}.jpg", interlace => 'Plane', quality => 90)) {
             carp "[$obj->{'final'}->{$_}->{'dir'}$obj->{'final'}->{'name'}.jpg] Failed to write, $err";
             return 0;
         }

process-media

@@ -258,6 +258,7 @@ sub check_conf {
         'compress'      => '^(?:100|[1-9]?[0-9])$',
         'strip'         => '^(?:true|false)$',
         'strip_exclude' => '^(?:orientation|gps|,)+$',
+        'progressive'   => '^(?:true|false)$',
         'resize'        => '^\d+$',
         'vcodec'        => '^x26[45]$',
         'vcodec_params' => '^[\w\:\=]+$',

process-media.yaml

@@ -41,6 +41,9 @@ web_photo:
   # a low value result in a better compression but in a lower quality
   compress: 90
 
+  # create a progressive jpeg
+  progressive: true
+
   # if set to true, all metadata will be removed except ones specified by strip_exclude
   strip: true