From ccf9f2c32cdf99c99c6b654d67b9701b8e41141c Mon Sep 17 00:00:00 2001
From: Michal Maciola <71131832+mmaciola@users.noreply.github.com>
Date: Mon, 19 Jul 2021 07:55:23 +0200
Subject: [PATCH] jpg_loader: decompress header on opening

---
 src/loaders/jpg/tvgJpgLoader.cpp | 11 +++--------
 src/loaders/jpg/tvgJpgLoader.h   |  3 +++
 2 files changed, 6 insertions(+), 8 deletions(-)

diff --git a/src/loaders/jpg/tvgJpgLoader.cpp b/src/loaders/jpg/tvgJpgLoader.cpp
index d92ada1..685819b 100644
--- a/src/loaders/jpg/tvgJpgLoader.cpp
+++ b/src/loaders/jpg/tvgJpgLoader.cpp
@@ -76,7 +76,7 @@ bool JpgLoader::open(const string& path)
 
     if (fread(data, size, 1, jpegFile) < 1) goto failure;
 
-    //FIXME: Decompress header here
+    if (tjDecompressHeader3(jpegDecompressor, data, size, &width, &height, &inSubsamp, &inColorspace) < 0) goto failure;
 
     ret = true;
     freeData = true;
@@ -96,6 +96,8 @@ bool JpgLoader::open(const char* data, uint32_t size, bool copy)
 {
     clear();
 
+    if (tjDecompressHeader3(jpegDecompressor, (unsigned char *) data, size, &width, &height, &inSubsamp, &inColorspace) < 0) return false;
+
     if (copy) {
         this->data = (unsigned char *) malloc(size);
         if (!this->data) return false;
@@ -107,19 +109,12 @@ bool JpgLoader::open(const char* data, uint32_t size, bool copy)
 
     this->size = size;
 
-    //FIXME: Decompress header here
-
     return true;
 }
 
 
 bool JpgLoader::read()
 {
-    //decompress header
-    int width, height;
-    int inSubsamp, inColorspace;
-    if (tjDecompressHeader3(jpegDecompressor, data, size, &width, &height, &inSubsamp, &inColorspace) < 0) return false;
-
     if (image) tjFree(image);
     image = (unsigned char *)tjAlloc(width * height * tjPixelSize[TJPF_BGRX]);
     if (!image) return false;
diff --git a/src/loaders/jpg/tvgJpgLoader.h b/src/loaders/jpg/tvgJpgLoader.h
index 0063da2..91218ba 100644
--- a/src/loaders/jpg/tvgJpgLoader.h
+++ b/src/loaders/jpg/tvgJpgLoader.h
@@ -47,6 +47,9 @@ private:
     unsigned char *image = nullptr;
     unsigned long size = 0;
     bool freeData = false;
+
+    int width, height;
+    int inSubsamp, inColorspace;
 };
 
 #endif //_TVG_JPG_LOADER_H_
-- 
2.7.4