Update to version 1.1 with major optimizations

John Sheppard · John Sheppard · commit 16203e78b036 · 2025-10-19T14:46:16.000+01:00
- Rewrote CUE parser to be more robust and efficient
   - Fixed loop sector validation: properly handles REM LOOP (sector 0) vs REM LOOP [sector] vs REM NOLOOP
   - Removed unnecessary CD file size restrictions (MD+ uses WAV/OGG, not CD images)
   - Removed CD sector limits for better compatibility with longer audio files
   - Improved whitespace handling in CUE parsing
   - Streamlined decoder wrapper implementation
   - Enhanced error handling for malformed CUE files
diff --git a/README.md b/README.md
@@ -1,51 +1,78 @@
-# MD+ Audio Player for foobar2000
+# Sega MD+ Audio Player for foobar2000
 
-Seamless loop playback support for MD+ compatible CUE sheets in foobar2000.
+Seamless looped playback for [Sega MD+](#what-is-md) compatible CUE sheets in foobar2000
 
 ## Features
 
-- Seamless audio looping at specified loop points
-- Support for REM LOOP and REM NOLOOP commands
-- Compatible with WAV and OGG files (included because OGG is compatible with emulators such as Genesis Plus GX)
-- Works alongside standard CUE file handling
+- Seamless audio looping at specified loop points in the CUE file via REM LOOP commands
+- Compatible with WAV and OGG files _(as OGG is compatible with MD+ emulators such as Libretro Genesis Plus GX)_
+- Doesn't interfere with foobar2000's standard CUE file handling
 
 ## Installation
 
 1. Download the appropriate DLL for your foobar2000 version:
-   - **32-bit (x86)** (v1.x): [foo_mdplus.dll (x86)](../../releases/latest/download/foo_mdplus_x86.dll)
-   - **64-bit (x64)** (v2.x): [foo_mdplus.dll (x64)](../../releases/latest/download/foo_mdplus_x64.dll)
+   - **32-bit (x86) (v1.x):** [foo_mdplus.dll (x86)](../../releases/latest/download/foo_mdplus_x86.dll)
+   - **64-bit (x64) (v2.x):** [foo_mdplus.dll (x64)](../../releases/latest/download/foo_mdplus_x64.dll)
 
-2. Copy the DLL to your foobar2000 components folder:
-   - Usually (for v1.x): `C:\Program Files (x86)\foobar2000\components\`
-   - (for v2.x): `C:\Program Files\foobar2000\components\`
-   - Or: `%APPDATA%\foobar2000\user-components\`
+2. Copy the DLL to your foobar2000 components folder and **remove "_x86" or "_x64" from the filename** *(it should be named **"foo_mdplus.dll"**)*:
+   - **For foobar2000 versions 1.x:** `C:\Program Files (x86)\foobar2000\components\`
+   - **For foobar2000 versions 2.x:** `C:\Program Files\foobar2000\components\`
+   - **Or:** `%APPDATA%\foobar2000\user-components\`
 
 3. Restart foobar2000
 
+4. Ensure the plugin is activated by checking _"File -> Preferences -> Components"_. It will be displayed as _"MD+ Audio Player"_. You can also check _"View -> Console"_
+
+5. Console will display:
+```
+==========================================
+MD+ Audio Player v1.x initialized
+Usage: Rename .cue files to .mdpcue
+Example: game_name.cue -> game_name.mdpcue
+==========================================
+```
+
 ## Usage
 
-1. Rename your MD+ CUE files from `.cue` to `.mdpcue`
+1. Rename your MD+ CUE files from `.cue` to `.mdpcue`. You can simply make a copy of your existing CUE file and then rename the extension. The data inside the file will remain the same
    - Example: `game_name.cue` -> `game_name.mdpcue`
 
 2. Add the `.mdpcue` file to foobar2000
 
 3. Tracks with `REM LOOP` will loop seamlessly and indefinitely at the specified value in the CUE file
-   - Tracks with `REM NOLOOP` play once and continue to next track
+   - Tracks with `REM NOLOOP` play once and then move on to the next track
 
 ## Example MD+ CUE File Format
 
 ```cue
-FILE "01-Track.wav" WAVE
+FILE "01-Track1.wav" WAVE
   TRACK 01 AUDIO
+    INDEX 01 00:00:00
+    REM LOOP
+
+FILE "02-Track2.wav" WAVE
+  TRACK 02 AUDIO
     INDEX 01 00:00:00
     REM LOOP 12345
     
-FILE "02-Track.wav" WAVE
-  TRACK 02 AUDIO
+FILE "03-Track3.wav" WAVE
+  TRACK 03 AUDIO
     INDEX 01 00:00:00
     REM NOLOOP
 ```
 
+Track 1 will loop from the beginning when it reaches end of file
+
+Track 2 will loop from the specified sector when it reaches end of file _(12345)_
+
+Track 3 will not loop when it reaches end of file, and will move on to the next track on the list
+
+## What is MD+?
+
+MD+ is an open standard developed by neodev/ElSemi of Terraonion for the release of their Sega Mega Drive/Genesis flash cartridge and world's first Sega Mega CD/Sega CD optical drive emulator, the MegaSD, released in June of 2019. It is supported by the aforementioned Terraonion MegaSD, Krikzz's Mega EverDrive PRO _(as of firmware v4.15 from the 24th of June 2022)_ and Mega EverDrive CORE flash cartridges, and can be emulated using Genesis Plus GX and PicoDrive in RetroArch.
+
+It is the 1:1 equivalent of MSU1 on the Super Nintendo, as it allows data streaming, and the original Yamaha YM2612 audio of Sega Mega Drive/Genesis games to be replaced by external PCM wave _(.wav)_ or compressed Ogg Vorbis _(.ogg)_ files to produce something similar to a what a CD version of the game would have been like, but unlike a physical CD unit and CD hardware emulation hacks _(Mode 1/MSU-MD)_, the audio files can be seamlessly looped, resulting in a more professional sounding audio experience and vastly reducing audio file sizes _(even when compared to MSU-MD games that have been converted to CHD)_. There are no inherent seek time delays or other imitations that come with emulating CD drives. Overall, it is a much better, more modern standard for FPGA and emulation platforms than the outdated Mode 1/MSU-MD format.
+
 ## Building from Source
 
 ### Requirements
@@ -54,18 +81,14 @@ FILE "02-Track.wav" WAVE
 
 ### Steps
 1. Clone this repository
-2. Download the foobar2000 SDK and extract to `foobar2000_SDK/` folder
+2. Download the latest foobar2000 SDK and extract to `foobar2000_SDK/` folder
 3. Open `foo_mdplus.sln` in Visual Studio
 4. Select platform: **x86** or **x64**
 5. Build -> Build Solution
-6. DLL will be in `Debug/` or `Release/` folder
+6. DLL will be in `Debug/`, `Release/` or `x64/Release` folder depending on solution configurations and platforms
 
 ## Credits
 
-- Author: Relikk (John Sheppard)
-- Version: 1.0
-- License: MIT License
-
-## Support
-
-For issues or feature requests, please open an issue on GitHub.
+- **Author:** Relikk (John Sheppard)
+- **Version:** 1.0
+- **License:** MIT License
diff --git a/foo_mdplus/foo_mdplus.cpp b/foo_mdplus/foo_mdplus.cpp
@@ -1,19 +1,19 @@
 ﻿// foo_mdplus.cpp - MD+ Audio Player for foobar2000
 // Seamless looping for WAV/OGG files with MD+ compatible CUE metadata
 // Author: Relikk (John Sheppard)
-// Version: 1.0
+// Version: 1.1
 
 #define _CRT_SECURE_NO_WARNINGS
 #include "foobar2000/SDK/foobar2000.h"
 #include "foobar2000/helpers/helpers.h"
 
 DECLARE_COMPONENT_VERSION(
     "MD+ Audio Player",
-    "1.0",
+    "1.1",
     "Seamless loop playback support in foobar2000 for MD+ compatible CUE sheets\n"
     "Handles REM LOOP and REM NOLOOP commands\n\n"
     "Change your MD+ .cue file extension to .mdpcue for intended usage\n"
-    "Standard .cue files remain unaffected\n\n"
+    "Standard .cue file playback remains unaffected\n\n"
     "Author: Relikk (John Sheppard)"
 );
 
@@ -31,6 +31,7 @@ namespace {
         looping_decoder(input_decoder::ptr base, int loop_sector)
             : m_base(base), m_loop_sector(loop_sector)
         {
+            // Convert CD audio sectors (75 per second) to seconds
             m_loop_point = (double)loop_sector / 75.0;
         }
 
@@ -41,8 +42,9 @@ namespace {
         virtual bool run(audio_chunk& chunk, abort_callback& abort) {
             bool result = m_base->run(chunk, abort);
 
-            // If EOF reached and loop is enabled, seek back to loop point
-            if (!result && m_loop_sector > 0) {
+            // When EOF is reached and loop is enabled, seek back to loop point for seamless playback
+            // Loop sector >= 0 means looping is enabled (0 = beginning, >0 = specific sector)
+            if (!result && m_loop_sector >= 0) {
                 m_base->seek(m_loop_point, abort);
                 return m_base->run(chunk, abort);
             }
@@ -87,12 +89,24 @@ namespace {
         }
     };
 
+    // Helper function to skip leading whitespace
+    inline const char* skip_whitespace(const char* ptr) {
+        while (*ptr && (*ptr == ' ' || *ptr == '\t')) ptr++;
+        return ptr;
+    }
+
+    // Helper function to check if line starts with a command (case-insensitive, whitespace-tolerant)
+    inline bool line_starts_with(const char* line, const char* cmd) {
+        line = skip_whitespace(line);
+        return _strnicmp(line, cmd, strlen(cmd)) == 0;
+    }
+
     // Input handler for .mdpcue files
     class input_mdplus : public input_stubs {
     private:
         struct track_info {
             pfc::string8 file_path;
-            int loop_sector;  // >0 = loop sector, -1 = NOLOOP, 0 = no loop info
+            int loop_sector;  // >= 0 = loop at this sector, -1 = no loop (NOLOOP)
         };
 
         pfc::list_t<track_info> m_tracks;
@@ -125,17 +139,19 @@ namespace {
                 filesystem::g_open(cue_file, path, filesystem::open_mode_read, abort);
             }
 
+            // Validate file is not empty
             t_filesize size = cue_file->get_size_ex(abort);
-            if (size == 0 || size > 10485760) {
-                throw exception_io_data();
+            if (size == 0) {
+                throw exception_io_data("MDPCUE file is empty");
             }
 
+            // Read entire CUE file into buffer
             pfc::array_t<char> buffer;
             buffer.set_size(pfc::downcast_guarded<t_size>(size + 1));
             cue_file->read_object(buffer.get_ptr(), size, abort);
-            buffer[size] = 0;
+            buffer[size] = 0;  // Null terminate
 
-            // Get base directory from MDPCUE path
+            // Extract base directory from MDPCUE path for resolving relative audio file paths
             pfc::string8 mdpcue_path = path;
             if (pfc::string_find_first(mdpcue_path, "file://") == 0) {
                 mdpcue_path.remove_chars(0, 7);
@@ -147,65 +163,75 @@ namespace {
                 m_base_path.set_string(mdpcue_path, last_slash - mdpcue_path.get_ptr() + 1);
             }
 
-            // Parse MDPCUE file
+            // Parse MDPCUE file line by line
             const char* ptr = buffer.get_ptr();
             track_info current_track;
-            current_track.loop_sector = 0;
-            int track_number = 0;
+            current_track.loop_sector = -1;  // Default: no looping unless REM LOOP is found
+            int track_count = 0;
             bool track_has_index = false;
 
             while (*ptr) {
+                // Extract one line
                 const char* line_start = ptr;
                 while (*ptr && *ptr != '\n' && *ptr != '\r') ptr++;
 
                 pfc::string8 line(line_start, ptr - line_start);
+
+                // Skip line terminators
                 while (*ptr && (*ptr == '\n' || *ptr == '\r')) ptr++;
 
-                // FILE command - save previous track and start new file
-                if (strstr(line, "FILE ") == line.get_ptr()) {
-                    if (track_has_index && track_number > 0 && current_track.file_path.get_length() > 0) {
+                // Parse CUE commands
+                if (line_starts_with(line, "FILE ")) {
+                    // Save previous track before starting a new file
+                    if (track_has_index && track_count > 0 && current_track.file_path.get_length() > 0) {
                         m_tracks.add_item(current_track);
                     }
 
-                    current_track.loop_sector = 0;
+                    // Reset for new file (default: no looping)
+                    current_track.loop_sector = -1;
                     track_has_index = false;
 
+                    // Extract filename from quotes
                     const char* quote1 = strchr(line, '"');
                     if (quote1) {
                         const char* quote2 = strchr(quote1 + 1, '"');
-                        if (quote2) {
+                        if (quote2 && quote2 > quote1 + 1) {
                             current_track.file_path = m_base_path;
                             current_track.file_path.add_string(quote1 + 1, quote2 - quote1 - 1);
                         }
                     }
                 }
-                // TRACK command
-                else if (strstr(line, "  TRACK ")) {
-                    track_number++;
+                else if (line_starts_with(line, "TRACK ")) {
+                    track_count++;
                 }
-                // INDEX 01 command
-                else if (strstr(line, "    INDEX 01 ")) {
+                else if (line_starts_with(line, "INDEX 01 ")) {
                     track_has_index = true;
                 }
-                // REM LOOP command
-                else if (strstr(line, "    REM LOOP ")) {
-                    const char* sector_str = strstr(line, "LOOP ") + 5;
-                    while (*sector_str == ' ' || *sector_str == '\t') sector_str++;
-                    current_track.loop_sector = atoi(sector_str);
+                else if (line_starts_with(line, "REM LOOP ")) {
+                    // Extract loop sector number
+                    const char* sector_str = strstr(line, "LOOP ");
+                    if (sector_str) {
+                        sector_str = skip_whitespace(sector_str + 5);
+                        current_track.loop_sector = atoi(sector_str); // 0 or positive = loop enabled
+                    }
                 }
-                // REM NOLOOP command
-                else if (strstr(line, "    REM NOLOOP")) {
-                    current_track.loop_sector = -1;
+                else if (line_starts_with(line, "REM LOOP")) {
+                    // "REM LOOP" without sector = loop from beginning (sector 0)
+                    current_track.loop_sector = 0;
+                }
+                else if (line_starts_with(line, "REM NOLOOP")) {
+                    current_track.loop_sector = -1;  // Explicitly disable looping
                 }
             }
 
             // Save last track
-            if (track_has_index && track_number > 0 && current_track.file_path.get_length() > 0) {
+            if (track_has_index && track_count > 0 && current_track.file_path.get_length() > 0) {
                 m_tracks.add_item(current_track);
             }
 
+            // Validate we found at least one track
             if (m_tracks.get_count() == 0) {
-                throw exception_io_data("No tracks found in MDPCUE file");
+                throw exception_io_data("No valid tracks found in MDPCUE file");
             }
         }
 
@@ -224,15 +250,17 @@ namespace {
 
             const track_info& track = m_tracks[subsong];
 
-            // Open audio file and get its metadata
+            // Open audio file and retrieve format information
+            // NOTE: This gets technical audio specs (sample rate, channels, duration)
+            // NOT embedded metadata/tags that could cause loop issues
             service_ptr_t<file> f;
             filesystem::g_open(f, track.file_path, filesystem::open_mode_read, abort);
 
             input_decoder::ptr decoder;
             input_entry::g_open_for_decoding(decoder, f, track.file_path, abort);
             decoder->get_info(0, info, abort);
 
-            // Add track number
+            // Add track number for foobar2000 playlist display
             info.meta_set("tracknumber", pfc::format_int(subsong + 1));
         }
 
@@ -250,12 +278,12 @@ namespace {
 
             const track_info& track = m_tracks[subsong];
 
-            // Open audio file
+            // Open audio file for decoding
             filesystem::g_open(m_file, track.file_path, filesystem::open_mode_read, abort);
             input_entry::g_open_for_decoding(m_decoder, m_file, track.file_path, abort);
 
-            // Wrap decoder with looping if needed
-            if (track.loop_sector > 0) {
+            // Wrap decoder with looping support if track has loop enabled (>= 0)
+            if (track.loop_sector >= 0) {
                 m_decoder = new service_impl_t<looping_decoder>(m_decoder, track.loop_sector);
             }
 
@@ -291,13 +319,15 @@ namespace {
 
     static input_factory_t<input_mdplus> g_input_mdplus_factory;
 
-    // Initialization
+    // Initialization message
     class mdplus_initquit : public initquit {
     public:
         virtual void on_init() {
-            console::print("MD+ Audio Player v1.0 initialized");
-            console::print("Rename your MD+ .cue file extension to .mdpcue for seamless looping audio playback support");
+            console::print("==========================================");
+            console::print("MD+ Audio Player v1.1 initialized");
+            console::print("Usage: Rename .cue files to .mdpcue");
             console::print("Example: game_name.cue -> game_name.mdpcue");
+            console::print("==========================================");
         }
 
         virtual void on_quit() {
