Update

formats/libchdr/libchdr_chd.c

@@ -1682,6 +1682,8 @@ static chd_error hunk_read_into_memory(chd_file *chd, UINT32 hunknum, UINT8 *des
             bytes = read_compressed(chd, blockoffs, blocklen);
             if (bytes == NULL)
                return CHDERR_READ_ERROR;
+            if (!chd->codecintf[rawmap[0]])
+               return CHDERR_UNSUPPORTED_FORMAT;
 				switch (chd->codecintf[rawmap[0]]->compression)
 				{
 					case CHD_CODEC_CD_LZMA:

include/formats/cdfs.h

@@ -31,25 +31,31 @@ RETRO_BEGIN_DECLS
  * of a CD (following the ISO-9660 directory structure definition)
  */
 
+typedef struct cdfs_track_t
+{
+   intfstream_t* stream;
+   unsigned int stream_sector_size;
+   unsigned int stream_sector_header_size;
+   unsigned int pregap_sectors;
+} cdfs_track_t;
+
 typedef struct cdfs_file_t
 {
    int first_sector;
    int current_sector;
    unsigned int current_sector_offset;
    int sector_buffer_valid;
-   unsigned int stream_sector_size;
-   unsigned int stream_sector_header_size;
    unsigned int size;
    unsigned int pos;
-   intfstream_t* stream;
    uint8_t sector_buffer[2048];
+   struct cdfs_track_t* track;
 } cdfs_file_t;
 
 /* opens the specified file within the CD or virtual CD.
  * if path is NULL, will open the raw CD (useful for reading CD without having to worry about sector sizes,
  * headers, or checksum data)
  */
-int cdfs_open_file(cdfs_file_t* file, intfstream_t* stream, const char* path);
+int cdfs_open_file(cdfs_file_t* file, cdfs_track_t* stream, const char* path);
 
 void cdfs_close_file(cdfs_file_t* file);
 
@@ -61,6 +67,8 @@ int64_t cdfs_tell(cdfs_file_t* file);
 
 int64_t cdfs_seek(cdfs_file_t* file, int64_t offset, int whence);
 
+void cdfs_seek_sector(cdfs_file_t* file, unsigned int sector);
+
 /* opens the specified track in a CD or virtual CD file - the resulting stream should be passed to
  * cdfs_open_file to get access to a file within the CD.
  *
@@ -75,11 +83,11 @@ int64_t cdfs_seek(cdfs_file_t* file, int64_t offset, int whence);
  *   MODE1/2048 - untested
  *   MODE2/2336 - untested
  */
-intfstream_t* cdfs_open_track(const char* path, unsigned int track_index);
+cdfs_track_t* cdfs_open_track(const char* path, unsigned int track_index);
 
 /* opens the first data track in a CD or virtual CD file. see cdfs_open_track for supported file formats
  */
-intfstream_t* cdfs_open_data_track(const char* path);
+cdfs_track_t* cdfs_open_data_track(const char* path);
 
 /* opens a raw track file for a CD or virtual CD.
  *
@@ -89,7 +97,10 @@ intfstream_t* cdfs_open_data_track(const char* path);
  *   bin     - path will point to the bin file
  *   iso     - path will point to the iso file
  */
-intfstream_t* cdfs_open_raw_track(const char* path);
+cdfs_track_t* cdfs_open_raw_track(const char* path);
+
+/* closes the CD or virtual CD track and frees the associated memory */
+void cdfs_close_track(cdfs_track_t* track);
 
 RETRO_END_DECLS
 

include/libretro.h

@@ -2524,7 +2524,7 @@ struct retro_core_option_display
 /* Maximum number of values permitted for a core option
  * NOTE: This may be increased on a core-by-core basis
  * if required (doing so has no effect on the frontend) */
-#define RETRO_NUM_CORE_OPTION_VALUES_MAX 192
+#define RETRO_NUM_CORE_OPTION_VALUES_MAX 128
 
 struct retro_core_option_value
 {

include/streams/chd_stream.h

@@ -57,6 +57,8 @@ int64_t chdstream_seek(chdstream_t *stream, int64_t offset, int whence);
 
 ssize_t chdstream_get_size(chdstream_t *stream);
 
+uint32_t chdstream_get_pregap(chdstream_t* stream);
+
 RETRO_END_DECLS
 
 #endif

include/streams/interface_stream.h

@@ -96,6 +96,8 @@ int64_t intfstream_get_size(intfstream_internal_t *intf);
 
 int intfstream_flush(intfstream_internal_t *intf);
 
+uint32_t intfstream_get_chd_pregap(intfstream_internal_t *intf);
+
 intfstream_t* intfstream_open_file(const char *path,
       unsigned mode, unsigned hints);
 

streams/chd_stream.c

@@ -426,5 +426,22 @@ int64_t chdstream_seek(chdstream_t *stream, int64_t offset, int whence)
 
 ssize_t chdstream_get_size(chdstream_t *stream)
 {
-  return stream->track_end;
+   return stream->track_end;
+}
+
+uint32_t chdstream_get_pregap(chdstream_t *stream)
+{
+   metadata_t meta;
+   uint32_t frame_offset = 0;
+   uint32_t i;
+
+   for (i = 0; chdstream_get_meta(stream->chd, i, &meta); ++i)
+   {
+      if (stream->track_frame == frame_offset)
+         return meta.pregap;
+
+      frame_offset += meta.frames + meta.extra;
+   }
+
+   return 0;
 }

streams/interface_stream.c

@@ -421,6 +421,16 @@ void intfstream_putc(intfstream_internal_t *intf, int c)
    }
 }
 
+uint32_t intfstream_get_chd_pregap(intfstream_internal_t *intf)
+{
+#ifdef HAVE_CHD
+   if (intf->type == INTFSTREAM_CHD)
+      return chdstream_get_pregap(intf->chd.fp);
+#endif
+
+   return 0;
+}
+
 intfstream_t* intfstream_open_file(const char *path,
       unsigned mode, unsigned hints)
 {