From 6608f6135304fc5c3005615b3d05b45d32e898e2 Mon Sep 17 00:00:00 2001
From: Simon Kammermeier <simon.kammermeier@tum.de>
Date: Tue, 30 Aug 2022 15:38:12 +0200
Subject: [PATCH] Fix starting to read at wrong offset, now skips header

---
 .../imageio/plugins/webp/lossless/VP8LDecoder.java           | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/imageio/imageio-webp/src/main/java/com/twelvemonkeys/imageio/plugins/webp/lossless/VP8LDecoder.java b/imageio/imageio-webp/src/main/java/com/twelvemonkeys/imageio/plugins/webp/lossless/VP8LDecoder.java
index 19e4cf18..f88b04aa 100644
--- a/imageio/imageio-webp/src/main/java/com/twelvemonkeys/imageio/plugins/webp/lossless/VP8LDecoder.java
+++ b/imageio/imageio-webp/src/main/java/com/twelvemonkeys/imageio/plugins/webp/lossless/VP8LDecoder.java
@@ -87,6 +87,11 @@ public final class VP8LDecoder {
     public void readVP8Lossless(final WritableRaster raster, final boolean topLevel) throws IOException {
         //https://github.com/webmproject/libwebp/blob/666bd6c65483a512fe4c2eb63fbc198b6fb4fae4/src/dec/vp8l_dec.c#L1114
 
+        //Skip past already read parts of header (signature, width, height, alpha, version) 5 Bytes in total
+        if (topLevel) {
+            imageInput.seek(imageInput.getStreamPosition() + 5);
+        }
+
         int xSize = raster.getWidth();
         int ySize = raster.getHeight();