From f926dfe36b5eb21da90bcd6e0196728fe287decc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Julian=20Offenh=C3=A4user?= <offenhaeuser@protonmail.com>
Date: Thu, 27 Oct 2022 20:19:08 +0200
Subject: [PATCH] LibPDF: Implement the DCT filter

This filter basically tells us that we are dealing with a JPEG.
Note that by serializing the resulting image we assume that this filter
is the last one in the chain, everything else would be highly unlikely.
---
 Userland/Libraries/LibPDF/Filter.cpp | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/Userland/Libraries/LibPDF/Filter.cpp b/Userland/Libraries/LibPDF/Filter.cpp
index 5d7da106b4..c184952be0 100644
--- a/Userland/Libraries/LibPDF/Filter.cpp
+++ b/Userland/Libraries/LibPDF/Filter.cpp
@@ -6,6 +6,7 @@
 
 #include <AK/Hex.h>
 #include <LibCompress/Deflate.h>
+#include <LibGfx/JPGLoader.h>
 #include <LibPDF/CommonNames.h>
 #include <LibPDF/Filter.h>
 
@@ -153,10 +154,11 @@ ErrorOr<ByteBuffer> Filter::decode_jbig2(ReadonlyBytes)
     TODO();
 };
 
-ErrorOr<ByteBuffer> Filter::decode_dct(ReadonlyBytes)
+ErrorOr<ByteBuffer> Filter::decode_dct(ReadonlyBytes bytes)
 {
-    // FIXME: Support dct decoding
-    TODO();
+    Gfx::JPGImageDecoderPlugin decoder(bytes.data(), bytes.size());
+    auto frame = TRY(decoder.frame(0));
+    return frame.image->serialize_to_byte_buffer();
 };
 
 ErrorOr<ByteBuffer> Filter::decode_jpx(ReadonlyBytes)