diff --git a/CMakeLists.txt b/CMakeLists.txt
index b255713..6343562 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -2,6 +2,7 @@ cmake_minimum_required(VERSION 3.13)
 project(libdicformat C)
 
 set(CMAKE_C_STANDARD 99)
+add_compile_definitions(__STDC_FORMAT_MACROS=1)
 
 add_library(libdicformat SHARED include/dicformat/consts.h include/dicformat/enums.h include/dic.h include/dicformat.h
             include/dicformat/decls.h include/dicformat/structs.h src/identify.c src/open.c include/dicformat/context.h src/close.c include/dicformat/errors.h)
diff --git a/include/dicformat/context.h b/include/dicformat/context.h
index 7b6ca19..15f7c86 100644
--- a/include/dicformat/context.h
+++ b/include/dicformat/context.h
@@ -10,11 +10,21 @@
 
 typedef struct dicformatContext
 {
-    uint64_t  magic;
-    uint8_t   libraryMajorVersion;
-    uint8_t   libraryMinorVersion;
-    FILE      *imageStream;
-    DicHeader header;
+    uint64_t              magic;
+    uint8_t               libraryMajorVersion;
+    uint8_t               libraryMinorVersion;
+    FILE                  *imageStream;
+    DicHeader             header;
+    struct dataLinkedList *mediaTagsHead;
+    struct dataLinkedList *mediaTagsTail;
 } dicformatContext;
 
+typedef struct dataLinkedList
+{
+    struct dataLinkedList *previous;
+    struct dataLinkedList *next;
+    unsigned char         *data;
+    int                   type;
+} dataLinkedList;
+
 #endif //LIBDICFORMAT_CONTEXT_H
diff --git a/include/dicformat/enums.h b/include/dicformat/enums.h
index b8915a4..6535c07 100644
--- a/include/dicformat/enums.h
+++ b/include/dicformat/enums.h
@@ -183,21 +183,21 @@ typedef enum
 typedef enum
 {
     /** Block containing data */
-            DataBlock                    = 0x4B4C4244,
+            DataBlock          = 0x4B4C4244,
     /** Block containing a deduplication table */
-            DeDuplicationTable           = 0X2A544444,
+            DeDuplicationTable = 0X2A544444,
     /** Block containing the index */
-            Index                        = 0X58444E49,
+            IndexBlock         = 0X58444E49,
     /** Block containing logical geometry */
-            GeometryBlock                = 0x4D4F4547,
+            GeometryBlock      = 0x4D4F4547,
     /** Block containing metadata */
-            MetadataBlock                = 0x4154454D,
+            MetadataBlock      = 0x4154454D,
     /** Block containing optical disc tracks */
-            TracksBlock                  = 0x534B5254,
+            TracksBlock        = 0x534B5254,
     /** Block containing CICM XML metadata */
-            CicmBlock                    = 0x4D434943,
+            CicmBlock          = 0x4D434943,
     /** Block containing contents checksums */
-            ChecksumBlock                = 0x4D534B43,
+            ChecksumBlock      = 0x4D534B43,
     /** TODO: Block containing data position measurements */
             DataPositionMeasurementBlock = 0x2A4D5044,
     /** TODO: Block containing a snapshot index */
diff --git a/include/dicformat/errors.h b/include/dicformat/errors.h
index 574398d..a01323b 100644
--- a/include/dicformat/errors.h
+++ b/include/dicformat/errors.h
@@ -7,6 +7,7 @@
 
 #define DICF_ERROR_NOT_DICFORMAT -1
 #define DICF_ERROR_FILE_TOO_SMALL -2
-#define DICF_ERROR_INCOMPATIBLE_VERSION -2
+#define DICF_ERROR_INCOMPATIBLE_VERSION -3
+#define DICF_ERROR_CANNOT_READ_INDEX -4
 
 #endif //LIBDICFORMAT_ERRORS_H
diff --git a/include/dicformat/structs.h b/include/dicformat/structs.h
index 1ed029b..2a76a14 100644
--- a/include/dicformat/structs.h
+++ b/include/dicformat/structs.h
@@ -104,7 +104,7 @@ typedef struct IndexHeader
 typedef struct IndexEntry
 {
     /**Type of item pointed by this entry */
-    uint32_t uint32_t;
+    uint32_t blockType;
     /**Type of data contained by the block pointed by this entry */
     uint16_t dataType;
     /**Offset in file where item is stored */
diff --git a/src/open.c b/src/open.c
index 4d17914..3a7f933 100644
--- a/src/open.c
+++ b/src/open.c
@@ -34,12 +34,21 @@
 #include <dicformat.h>
 #include <malloc.h>
 #include <errno.h>
+#include <inttypes.h>
+#include <string.h>
 
+// TODO: Check CRC64 on structures
+// TODO: ImageInfo
 void *open(const char *filepath)
 {
     dicformatContext *ctx = malloc(sizeof(dicformatContext));
     int              errorNo;
     size_t           readBytes;
+    long             pos;
+    IndexHeader      idxHeader;
+    IndexEntry       *idxEntries;
+
+    memset(ctx, 0, sizeof(dicformatContext));
 
     if(ctx == NULL)
         return NULL;
@@ -82,14 +91,78 @@ void *open(const char *filepath)
         return NULL;
     }
 
+    fprintf(stderr,
+            "libdicformat: Opening image version %d.%d",
+            ctx->header.imageMajorVersion,
+            ctx->header.imageMinorVersion);
+
+    // Read the index header
+    pos = fseek(ctx->imageStream, ctx->header.indexOffset, SEEK_CUR);
+    if(pos < 0)
+    {
+        free(ctx);
+        errno = DICF_ERROR_CANNOT_READ_INDEX;
+
+        return NULL;
+    }
+
+    pos = ftell(ctx->imageStream);
+    if(pos != ctx->header.indexOffset)
+    {
+        free(ctx);
+        errno = DICF_ERROR_CANNOT_READ_INDEX;
+
+        return NULL;
+    }
+
+    readBytes = fread(&idxHeader, sizeof(IndexHeader), 1, ctx->imageStream);
+
+    if(readBytes != sizeof(IndexHeader) || idxHeader.identifier != IndexBlock)
+    {
+        free(ctx);
+        errno = DICF_ERROR_CANNOT_READ_INDEX;
+
+        return NULL;
+    }
+
+    fprintf(stderr, "libdicformat: Index at %"PRIu64" contains %d entries", ctx->header.indexOffset, idxHeader.entries);
+
+    idxEntries = malloc(sizeof(IndexEntry) * idxHeader.entries);
+
+    if(idxEntries == NULL)
+    {
+        errorNo = errno;
+        free(ctx);
+        errno = errorNo;
+
+        return NULL;
+    }
+
+    memset(idxEntries, 0, sizeof(IndexEntry) * idxHeader.entries);
+    readBytes = fread(idxEntries, sizeof(IndexEntry), idxHeader.entries, ctx->imageStream);
+
+    if(readBytes != sizeof(IndexEntry) * idxHeader.entries)
+    {
+        free(idxEntries);
+        free(ctx);
+        errno = DICF_ERROR_CANNOT_READ_INDEX;
+
+        return NULL;
+    }
+
+    for(int i = 0; i < idxHeader.entries; i++)
+    {
+        fprintf(stderr,
+                "libdicformat: Block type %4s with data type %4s is indexed to be at %"PRIu64"",
+                (char *)&idxEntries[i].blockType,
+                (char *)&idxEntries[i].dataType,
+                idxEntries[i].offset);
+    }
+
     ctx->magic               = DIC_MAGIC;
     ctx->libraryMajorVersion = LIBDICFORMAT_MAJOR_VERSION;
     ctx->libraryMinorVersion = LIBDICFORMAT_MINOR_VERSION;
 
-    fprintf(stderr,
-            "libdicformat: Opened image version %d.%d",
-            ctx->header.imageMajorVersion,
-            ctx->header.imageMinorVersion);
-
+    free(idxEntries);
     return ctx;
 }
\ No newline at end of file