diff --git a/core/extension.php b/core/extension.php
index 9761e27e..aa93759d 100644
--- a/core/extension.php
+++ b/core/extension.php
@@ -344,6 +344,8 @@ abstract class FormatterExtension extends Extension
  */
 abstract class DataHandlerExtension extends Extension
 {
+    protected $SUPPORTED_EXT = [];
+
     protected function move_upload_to_archive(DataUploadEvent $event)
     {
         $target = warehouse_path(Image::IMAGE_DIR, $event->hash);
@@ -455,6 +457,13 @@ abstract class DataHandlerExtension extends Extension
         }
     }
 
+    public function onMediaCheckProperties(MediaCheckPropertiesEvent $event)
+    {
+        if ($this->supported_ext($event->ext)) {
+            $this->media_check_properties($event);
+        }
+    }
+
     protected function create_image_from_data(string $filename, array $metadata): Image
     {
         global $config;
@@ -475,10 +484,15 @@ abstract class DataHandlerExtension extends Extension
         return $image;
     }
 
-    abstract protected function supported_ext(string $ext): bool;
+    abstract protected function media_check_properties(MediaCheckPropertiesEvent $event): void;
     abstract protected function check_contents(string $tmpname): bool;
     abstract protected function create_thumb(string $hash, string $type): bool;
 
+    protected function supported_ext(string $ext): bool
+    {
+        return in_array(strtolower($ext), $this->SUPPORTED_EXT);
+    }
+
     public static function get_all_supported_exts(): array
     {
         $arr = [];
diff --git a/ext/handle_flash/main.php b/ext/handle_flash/main.php
index 5dc49fb3..2f8fd1aa 100644
--- a/ext/handle_flash/main.php
+++ b/ext/handle_flash/main.php
@@ -2,23 +2,18 @@
 
 class FlashFileHandler extends DataHandlerExtension
 {
-    public function onMediaCheckProperties(MediaCheckPropertiesEvent $event)
+    protected $SUPPORTED_EXT = ["swf"];
+
+    protected function media_check_properties(MediaCheckPropertiesEvent $event): void
     {
-        switch ($event->ext) {
-            case "swf":
-                $event->image->lossless = true;
-                $event->image->video = true;
+        $event->image->lossless = true;
+        $event->image->video = true;
+        $event->image->image = false;
 
-                $info = getimagesize($event->file_name);
-                if (!$info) {
-                    return null;
-                }
-                $event->image->image = false;
-
-                $event->image->width = $info[0];
-                $event->image->height = $info[1];
-
-                break;
+        $info = getimagesize($event->file_name);
+        if ($info) {
+            $event->image->width = $info[0];
+            $event->image->height = $info[1];
         }
     }
 
@@ -30,12 +25,6 @@ class FlashFileHandler extends DataHandlerExtension
         return true;
     }
 
-    protected function supported_ext(string $ext): bool
-    {
-        $exts = ["swf"];
-        return in_array(strtolower($ext), $exts);
-    }
-
     protected function check_contents(string $tmpname): bool
     {
         $fp = fopen($tmpname, "r");
diff --git a/ext/handle_ico/main.php b/ext/handle_ico/main.php
index a61fec92..f80555d3 100644
--- a/ext/handle_ico/main.php
+++ b/ext/handle_ico/main.php
@@ -2,42 +2,27 @@
 
 class IcoFileHandler extends DataHandlerExtension
 {
-    const SUPPORTED_EXTENSIONS = ["ico", "ani", "cur"];
+    protected $SUPPORTED_EXT = ["ico", "ani", "cur"];
 
-    public function onMediaCheckProperties(MediaCheckPropertiesEvent $event)
+    protected function media_check_properties(MediaCheckPropertiesEvent $event): void
     {
-        if (in_array($event->ext, self::SUPPORTED_EXTENSIONS)) {
-            $event->image->lossless = true;
-            $event->image->video = false;
-            $event->image->audio = false;
-            $event->image->image = ($event->ext!="ani");
+        $event->image->lossless = true;
+        $event->image->video = false;
+        $event->image->audio = false;
+        $event->image->image = ($event->ext!="ani");
 
-            $fp = fopen($event->file_name, "r");
-            try {
-                unpack("Snull/Stype/Scount", fread($fp, 6));
-                $subheader = unpack("Cwidth/Cheight/Ccolours/Cnull/Splanes/Sbpp/Lsize/loffset", fread($fp, 16));
-            } finally {
-                fclose($fp);
-            }
-
-            $width = $subheader['width'];
-            $height = $subheader['height'];
-            $event->image->width = $width == 0 ? 256 : $width;
-            $event->image->height = $height == 0 ? 256 : $height;
+        $fp = fopen($event->file_name, "r");
+        try {
+            unpack("Snull/Stype/Scount", fread($fp, 6));
+            $subheader = unpack("Cwidth/Cheight/Ccolours/Cnull/Splanes/Sbpp/Lsize/loffset", fread($fp, 16));
+        } finally {
+            fclose($fp);
         }
-    }
 
-    protected function supported_ext(string $ext): bool
-    {
-        return in_array(strtolower($ext), self::SUPPORTED_EXTENSIONS);
-    }
-
-    protected function check_contents(string $file): bool
-    {
-        $fp = fopen($file, "r");
-        $header = unpack("Snull/Stype/Scount", fread($fp, 6));
-        fclose($fp);
-        return ($header['null'] == 0 && ($header['type'] == 0 || $header['type'] == 1));
+        $width = $subheader['width'];
+        $height = $subheader['height'];
+        $event->image->width = $width == 0 ? 256 : $width;
+        $event->image->height = $height == 0 ? 256 : $height;
     }
 
     protected function create_thumb(string $hash, string $type): bool
@@ -50,4 +35,12 @@ class IcoFileHandler extends DataHandlerExtension
             return false;
         }
     }
+
+    protected function check_contents(string $file): bool
+    {
+        $fp = fopen($file, "r");
+        $header = unpack("Snull/Stype/Scount", fread($fp, 6));
+        fclose($fp);
+        return ($header['null'] == 0 && ($header['type'] == 0 || $header['type'] == 1));
+    }
 }
diff --git a/ext/handle_mp3/main.php b/ext/handle_mp3/main.php
index 07c54393..1d943b62 100644
--- a/ext/handle_mp3/main.php
+++ b/ext/handle_mp3/main.php
@@ -2,19 +2,17 @@
 
 class MP3FileHandler extends DataHandlerExtension
 {
-    public function onMediaCheckProperties(MediaCheckPropertiesEvent $event)
+    protected $SUPPORTED_EXT = ["mp3"];
+
+    protected function media_check_properties(MediaCheckPropertiesEvent $event): void
     {
-        switch ($event->ext) {
-            case "mp3":
-                $event->image->audio = true;
-                $event->image->video = false;
-                $event->image->lossless = false;
-                $event->image->image = false;
-                $event->image->width = 0;
-                $event->image->height = 0;
-                break;
-        }
-        // TODO: Buff out audio format support, length scanning
+        $event->image->audio = true;
+        $event->image->video = false;
+        $event->image->lossless = false;
+        $event->image->image = false;
+        $event->image->width = 0;
+        $event->image->height = 0;
+        // TODO: ->length = ???
     }
 
     protected function create_thumb(string $hash, string $type): bool
@@ -23,12 +21,6 @@ class MP3FileHandler extends DataHandlerExtension
         return true;
     }
 
-    protected function supported_ext(string $ext): bool
-    {
-        $exts = ["mp3"];
-        return in_array(strtolower($ext), $exts);
-    }
-
     protected function check_contents(string $tmpname): bool
     {
         return getMimeType($tmpname) == 'audio/mpeg';
diff --git a/ext/handle_pixel/main.php b/ext/handle_pixel/main.php
index 3306fe14..c44f7bd0 100644
--- a/ext/handle_pixel/main.php
+++ b/ext/handle_pixel/main.php
@@ -2,9 +2,9 @@
 
 class PixelFileHandler extends DataHandlerExtension
 {
-    const SUPPORTED_EXTENSIONS = ["jpg", "jpeg", "gif", "png", "webp"];
+    protected $SUPPORTED_EXT = ["jpg", "jpeg", "gif", "png", "webp"];
 
-    public function onMediaCheckProperties(MediaCheckPropertiesEvent $event)
+    protected function media_check_properties(MediaCheckPropertiesEvent $event): void
     {
         if (in_array($event->ext, Media::LOSSLESS_FORMATS)) {
             $event->image->lossless = true;
@@ -12,40 +12,30 @@ class PixelFileHandler extends DataHandlerExtension
             $event->image->lossless = Media::is_lossless_webp($event->file_name);
         }
 
-        if (in_array($event->ext, self::SUPPORTED_EXTENSIONS)) {
-            if ($event->image->lossless==null) {
-                $event->image->lossless = false;
-            }
-            $event->image->audio = false;
-            switch ($event->ext) {
-                case "gif":
-                    $event->image->video = Media::is_animated_gif($event->file_name);
-                    break;
-                case "webp":
-                    $event->image->video = Media::is_animated_webp($event->file_name);
-                    break;
-                default:
-                    $event->image->video = false;
-                    break;
-            }
-            $event->image->image = !$event->image->video;
-
-            $info = getimagesize($event->file_name);
-            if (!$info) {
-                return null;
-            }
+        if ($event->image->lossless==null) {
+            $event->image->lossless = false;
+        }
+        $event->image->audio = false;
+        switch ($event->ext) {
+            case "gif":
+                $event->image->video = Media::is_animated_gif($event->file_name);
+                break;
+            case "webp":
+                $event->image->video = Media::is_animated_webp($event->file_name);
+                break;
+            default:
+                $event->image->video = false;
+                break;
+        }
+        $event->image->image = !$event->image->video;
 
+        $info = getimagesize($event->file_name);
+        if ($info) {
             $event->image->width = $info[0];
             $event->image->height = $info[1];
         }
     }
 
-    protected function supported_ext(string $ext): bool
-    {
-        $ext = (($pos = strpos($ext, '?')) !== false) ? substr($ext, 0, $pos) : $ext;
-        return in_array(strtolower($ext), self::SUPPORTED_EXTENSIONS);
-    }
-
     protected function check_contents(string $tmpname): bool
     {
         $valid = [IMAGETYPE_PNG, IMAGETYPE_GIF, IMAGETYPE_JPEG, IMAGETYPE_WEBP];
diff --git a/ext/handle_svg/main.php b/ext/handle_svg/main.php
index 4ffca378..f8c8bef2 100644
--- a/ext/handle_svg/main.php
+++ b/ext/handle_svg/main.php
@@ -3,26 +3,42 @@ use enshrined\svgSanitize\Sanitizer;
 
 class SVGFileHandler extends DataHandlerExtension
 {
+    protected $SUPPORTED_EXT = ["svg"];
+
     /** @var SVGFileHandlerTheme */
     protected $theme;
 
-    public function onMediaCheckProperties(MediaCheckPropertiesEvent $event)
+    public function onPageRequest(PageRequestEvent $event)
     {
-        switch ($event->ext) {
-            case "svg":
-                $event->image->lossless = true;
-                $event->image->video = false;
-                $event->image->audio = false;
-                $event->image->image = true;
+        global $page;
+        if ($event->page_matches("get_svg")) {
+            $id = int_escape($event->get_arg(0));
+            $image = Image::by_id($id);
+            $hash = $image->hash;
 
-                $msp = new MiniSVGParser($event->file_name);
-                $event->image->width = $msp->width;
-                $event->image->height = $msp->height;
+            $page->set_type("image/svg+xml");
+            $page->set_mode(PageMode::DATA);
 
-                break;
+            $sanitizer = new Sanitizer();
+            $sanitizer->removeRemoteReferences(true);
+            $dirtySVG = file_get_contents(warehouse_path(Image::IMAGE_DIR, $hash));
+            $cleanSVG = $sanitizer->sanitize($dirtySVG);
+            $page->set_data($cleanSVG);
         }
     }
 
+    protected function media_check_properties(MediaCheckPropertiesEvent $event): void
+    {
+        $event->image->lossless = true;
+        $event->image->video = false;
+        $event->image->audio = false;
+        $event->image->image = true;
+
+        $msp = new MiniSVGParser($event->file_name);
+        $event->image->width = $msp->width;
+        $event->image->height = $msp->height;
+    }
+
     protected function move_upload_to_archive(DataUploadEvent $event)
     {
         $sanitizer = new Sanitizer();
@@ -49,39 +65,6 @@ class SVGFileHandler extends DataHandlerExtension
         }
     }
 
-    public function onDisplayingImage(DisplayingImageEvent $event)
-    {
-        global $page;
-        if ($this->supported_ext($event->image->ext)) {
-            $this->theme->display_image($page, $event->image);
-        }
-    }
-
-    public function onPageRequest(PageRequestEvent $event)
-    {
-        global $page;
-        if ($event->page_matches("get_svg")) {
-            $id = int_escape($event->get_arg(0));
-            $image = Image::by_id($id);
-            $hash = $image->hash;
-
-            $page->set_type("image/svg+xml");
-            $page->set_mode(PageMode::DATA);
-
-            $sanitizer = new Sanitizer();
-            $sanitizer->removeRemoteReferences(true);
-            $dirtySVG = file_get_contents(warehouse_path(Image::IMAGE_DIR, $hash));
-            $cleanSVG = $sanitizer->sanitize($dirtySVG);
-            $page->set_data($cleanSVG);
-        }
-    }
-
-    protected function supported_ext(string $ext): bool
-    {
-        $exts = ["svg"];
-        return in_array(strtolower($ext), $exts);
-    }
-
     protected function check_contents(string $file): bool
     {
         $msp = new MiniSVGParser($file);
diff --git a/ext/handle_video/main.php b/ext/handle_video/main.php
index e64b5c8c..5b5b3beb 100644
--- a/ext/handle_video/main.php
+++ b/ext/handle_video/main.php
@@ -2,14 +2,14 @@
 
 class VideoFileHandler extends DataHandlerExtension
 {
-    const SUPPORTED_MIME = [
+    protected $SUPPORTED_MIME = [
         'video/webm',
         'video/mp4',
         'video/ogg',
         'video/flv',
         'video/x-flv'
     ];
-    const SUPPORTED_EXT = ["flv", "mp4", "m4v", "ogv", "webm"];
+    protected $SUPPORTED_EXT = ["flv", "mp4", "m4v", "ogv", "webm"];
 
     public function onInitExt(InitExtEvent $event)
     {
@@ -28,75 +28,65 @@ class VideoFileHandler extends DataHandlerExtension
         $event->panel->add_block($sb);
     }
 
-    public function onMediaCheckProperties(MediaCheckPropertiesEvent $event)
+    protected function media_check_properties(MediaCheckPropertiesEvent $event): void
     {
-        if (in_array($event->ext, self::SUPPORTED_EXT)) {
-            $event->image->video = true;
-            $event->image->image = false;
-            try {
-                $data = Media::get_ffprobe_data($event->file_name);
+        $event->image->video = true;
+        $event->image->image = false;
+        try {
+            $data = Media::get_ffprobe_data($event->file_name);
 
-                if (is_array($data)) {
-                    if (array_key_exists("streams", $data)) {
-                        $video = false;
-                        $audio = true;
-                        $streams = $data["streams"];
-                        if (is_array($streams)) {
-                            foreach ($streams as $stream) {
-                                if (is_array($stream)) {
-                                    if (array_key_exists("codec_type", $stream)) {
-                                        $type = $stream["codec_type"];
-                                        switch ($type) {
-                                            case "audio":
-                                                $audio = true;
-                                                break;
-                                            case "video":
-                                                $video = true;
-                                                break;
-                                        }
-                                    }
-                                    if (array_key_exists("width", $stream) && !empty($stream["width"])
-                                        && is_numeric($stream["width"]) && intval($stream["width"]) > ($event->image->width) ?? 0) {
-                                        $event->image->width = intval($stream["width"]);
-                                    }
-                                    if (array_key_exists("height", $stream) && !empty($stream["height"])
-                                        && is_numeric($stream["height"]) && intval($stream["height"]) > ($event->image->height) ?? 0) {
-                                        $event->image->height = intval($stream["height"]);
+            if (is_array($data)) {
+                if (array_key_exists("streams", $data)) {
+                    $video = false;
+                    $audio = true;
+                    $streams = $data["streams"];
+                    if (is_array($streams)) {
+                        foreach ($streams as $stream) {
+                            if (is_array($stream)) {
+                                if (array_key_exists("codec_type", $stream)) {
+                                    $type = $stream["codec_type"];
+                                    switch ($type) {
+                                        case "audio":
+                                            $audio = true;
+                                            break;
+                                        case "video":
+                                            $video = true;
+                                            break;
                                     }
                                 }
+                                if (array_key_exists("width", $stream) && !empty($stream["width"])
+                                    && is_numeric($stream["width"]) && intval($stream["width"]) > ($event->image->width) ?? 0) {
+                                    $event->image->width = intval($stream["width"]);
+                                }
+                                if (array_key_exists("height", $stream) && !empty($stream["height"])
+                                    && is_numeric($stream["height"]) && intval($stream["height"]) > ($event->image->height) ?? 0) {
+                                    $event->image->height = intval($stream["height"]);
+                                }
                             }
-                            $event->image->video = $video;
-                            $event->image->audio = $audio;
-                        }
-                    }
-                    if (array_key_exists("format", $data)&& is_array($data["format"])) {
-                        $format = $data["format"];
-                        if (array_key_exists("duration", $format) && is_numeric($format["duration"])) {
-                            $event->image->length = floor(floatval($format["duration"]) * 1000);
                         }
+                        $event->image->video = $video;
+                        $event->image->audio = $audio;
+                    }
+                }
+                if (array_key_exists("format", $data)&& is_array($data["format"])) {
+                    $format = $data["format"];
+                    if (array_key_exists("duration", $format) && is_numeric($format["duration"])) {
+                        $event->image->length = floor(floatval($format["duration"]) * 1000);
                     }
                 }
-            } catch (MediaException $e) {
-                // a post with no metadata is better than no post
             }
+        } catch (MediaException $e) {
+            // a post with no metadata is better than no post
         }
     }
 
-    /**
-     * Generate the Thumbnail image for particular file.
-     */
     protected function create_thumb(string $hash, string $type): bool
     {
         return Media::create_thumbnail_ffmpeg($hash);
     }
 
-    protected function supported_ext(string $ext): bool
-    {
-        return in_array(strtolower($ext), self::SUPPORTED_EXT);
-    }
-
     protected function check_contents(string $tmpname): bool
     {
-        return in_array(getMimeType($tmpname), self::SUPPORTED_MIME);
+        return in_array(getMimeType($tmpname), $this->SUPPORTED_MIME);
     }
 }