feat: Extract author from XTC/XTCH files

lib/Xtc/Xtc.cpp

@@ -7,7 +7,6 @@
 
 #include "Xtc.h"
 
-#include <FsHelpers.h>
 #include <HardwareSerial.h>
 #include <SDCardManager.h>
 
@@ -87,6 +86,15 @@ std::string Xtc::getTitle() const {
   return filepath.substr(lastSlash, lastDot - lastSlash);
 }
 
+std::string Xtc::getAuthor() const {
+  if (!loaded || !parser) {
+    return "";
+  }
+
+  // Try to get author from XTC metadata
+  return parser->getAuthor();
+}
+
 bool Xtc::hasChapters() const {
   if (!loaded || !parser) {
     return false;

lib/Xtc/Xtc.h

@@ -56,6 +56,7 @@ class Xtc {
 
   // Metadata
   std::string getTitle() const;
+  std::string getAuthor() const;
   bool hasChapters() const;
   const std::vector<xtc::ChapterInfo>& getChapters() const;
 

lib/Xtc/Xtc/XtcParser.cpp

@@ -47,8 +47,21 @@ XtcError XtcParser::open(const char* filepath) {
     return m_lastError;
   }
 
-  // Read title if available
-  readTitle();
+  // Read title & author if available
+  if (m_header.hasMetadata) {
+    m_lastError = readTitle();
+    if (m_lastError != XtcError::OK) {
+      Serial.printf("[%lu] [XTC] Failed to read title: %s\n", millis(), errorToString(m_lastError));
+      m_file.close();
+      return m_lastError;
+    }
+    m_lastError = readAuthor();
+    if (m_lastError != XtcError::OK) {
+      Serial.printf("[%lu] [XTC] Failed to read author: %s\n", millis(), errorToString(m_lastError));
+      m_file.close();
+      return m_lastError;
+    }
+  }
 
   // Read page table
   m_lastError = readPageTable();
@@ -124,24 +137,34 @@ XtcError XtcParser::readHeader() {
 }
 
 XtcError XtcParser::readTitle() {
-  // Title is usually at offset 0x38 (56) for 88-byte headers
-  // Read title as null-terminated UTF-8 string
-  if (m_header.titleOffset == 0) {
-    m_header.titleOffset = 0x38;  // Default offset
-  }
-
-  if (!m_file.seek(m_header.titleOffset)) {
+  constexpr auto titleOffset = 0x38;
+  if (!m_file.seek(titleOffset)) {
     return XtcError::READ_ERROR;
   }
 
   char titleBuf[128] = {0};
-  m_file.read(reinterpret_cast<uint8_t*>(titleBuf), sizeof(titleBuf) - 1);
+  m_file.read(titleBuf, sizeof(titleBuf) - 1);
   m_title = titleBuf;
 
   Serial.printf("[%lu] [XTC] Title: %s\n", millis(), m_title.c_str());
   return XtcError::OK;
 }
 
+XtcError XtcParser::readAuthor() {
+  // Read author as null-terminated UTF-8 string with max length 64, directly following title
+  constexpr auto authorOffset = 0xB8;
+  if (!m_file.seek(authorOffset)) {
+    return XtcError::READ_ERROR;
+  }
+
+  char authorBuf[64] = {0};
+  m_file.read(authorBuf, sizeof(authorBuf) - 1);
+  m_author = authorBuf;
+
+  Serial.printf("[%lu] [XTC] Author: %s\n", millis(), m_author.c_str());
+  return XtcError::OK;
+}
+
 XtcError XtcParser::readPageTable() {
   if (m_header.pageTableOffset == 0) {
     Serial.printf("[%lu] [XTC] Page table offset is 0, cannot read\n", millis());

lib/Xtc/Xtc/XtcParser.h

@@ -67,8 +67,9 @@ class XtcParser {
                              std::function<void(const uint8_t* data, size_t size, size_t offset)> callback,
                              size_t chunkSize = 1024);
 
-  // Get title from metadata
+  // Get title/author from metadata
   std::string getTitle() const { return m_title; }
+  std::string getAuthor() const { return m_author; }
 
   bool hasChapters() const { return m_hasChapters; }
   const std::vector<ChapterInfo>& getChapters() const { return m_chapters; }
@@ -86,6 +87,7 @@ class XtcParser {
   std::vector<PageInfo> m_pageTable;
   std::vector<ChapterInfo> m_chapters;
   std::string m_title;
+  std::string m_author;
   uint16_t m_defaultWidth;
   uint16_t m_defaultHeight;
   uint8_t m_bitDepth;  // 1 = XTC/XTG (1-bit), 2 = XTCH/XTH (2-bit)
@@ -96,6 +98,7 @@ class XtcParser {
   XtcError readHeader();
   XtcError readPageTable();
   XtcError readTitle();
+  XtcError readAuthor();
   XtcError readChapters();
 };
 

lib/Xtc/Xtc/XtcTypes.h

@@ -38,14 +38,16 @@ struct XtcHeader {
   uint8_t versionMajor;      // 0x04: Format version major (typically 1) (together with minor = 1.0)
   uint8_t versionMinor;      // 0x05: Format version minor (typically 0)
   uint16_t pageCount;        // 0x06: Total page count
-  uint32_t flags;            // 0x08: Flags/reserved
-  uint32_t headerSize;       // 0x0C: Size of header section (typically 88)
-  uint32_t reserved1;        // 0x10: Reserved
-  uint32_t tocOffset;        // 0x14: TOC offset (0 if unused) - 4 bytes, not 8!
+  uint8_t readDirection;     // 0x08: Reading direction (0-2)
+  uint8_t hasMetadata;       // 0x09: Has metadata (0-1)
+  uint8_t hasThumbnails;     // 0x0A: Has thumbnails (0-1)
+  uint8_t hasChapters;       // 0x0B: Has chapters (0-1)
+  uint32_t currentPage;      // 0x0C: Current page (1-based) (0-65535)
+  uint64_t metadataOffset;   // 0x10: Metadata offset (0 if unused)
   uint64_t pageTableOffset;  // 0x18: Page table offset
   uint64_t dataOffset;       // 0x20: First page data offset
-  uint64_t reserved2;        // 0x28: Reserved
-  uint32_t titleOffset;      // 0x30: Title string offset
+  uint64_t thumbOffset;      // 0x28: Thumbnail offset
+  uint32_t chapterOffset;    // 0x30: Chapter data offset
   uint32_t padding;          // 0x34: Padding to 56 bytes
 };
 #pragma pack(pop)

src/activities/home/HomeActivity.cpp

@@ -71,6 +71,9 @@ void HomeActivity::onEnter() {
         if (!xtc.getTitle().empty()) {
           lastBookTitle = std::string(xtc.getTitle());
         }
+        if (!xtc.getAuthor().empty()) {
+          lastBookAuthor = std::string(xtc.getAuthor());
+        }
         // Try to generate thumbnail image for Continue Reading card
         if (xtc.generateThumbBmp()) {
           coverBmpPath = xtc.getThumbBmpPath();