(cheevos) support for identifying Dreamcast CHDs (#13628)

* support for identifying Dreamcast CHDs

* fix copy/paste error

cheevos/cheevos.c

@@ -1278,7 +1278,7 @@ static void* rc_hash_handle_chd_open_track(
          break;
 
       case RC_HASH_CDTRACK_LARGEST:
-         cdfs_track = cdfs_open_track(path, CHDSTREAM_TRACK_LAST);
+         cdfs_track = cdfs_open_track(path, CHDSTREAM_TRACK_PRIMARY);
          break;
 
       default:
@@ -1304,11 +1304,23 @@ static size_t rc_hash_handle_chd_read_sector(
       void* buffer, size_t requested_bytes)
 {
    cdfs_file_t* file = (cdfs_file_t*)track_handle;
+   uint32_t track_sectors = cdfs_get_num_sectors(file);
+
+   sector -= cdfs_get_first_sector(file);
+   if (sector >= track_sectors)
+      return 0;
 
    cdfs_seek_sector(file, sector);
    return cdfs_read_file(file, buffer, requested_bytes);
 }
 
+static uint32_t rc_hash_handle_chd_first_track_sector(
+   void* track_handle)
+{
+   cdfs_file_t* file = (cdfs_file_t*)track_handle;
+   return cdfs_get_first_sector(file);
+}
+
 static void rc_hash_handle_chd_close_track(void* track_handle)
 {
    cdfs_file_t* file = (cdfs_file_t*)track_handle;
@@ -1337,6 +1349,7 @@ static void* rc_hash_handle_cd_open_track(
       cdreader.open_track = rc_hash_handle_cd_open_track;
       cdreader.read_sector = rc_hash_handle_chd_read_sector;
       cdreader.close_track = rc_hash_handle_chd_close_track;
+      cdreader.first_track_sector = rc_hash_handle_chd_first_track_sector;
       rc_hash_init_custom_cdreader(&cdreader);
 
       return rc_hash_handle_chd_open_track(path, track);

libretro-common/formats/cdfs/cdfs.c

@@ -58,30 +58,31 @@ static void cdfs_determine_sector_size(cdfs_track_t* track)
          track->stream_sector_size = 2352;
          track->stream_sector_header_size = 16;
       }
-      else
-      {
-         /* attempt to determine stream_sector_size from file size */
-         size_t size = intfstream_get_size(track->stream);
+   }
+}
 
-         if ((size % 2352) == 0)
-         {
-            /* raw tracks use all 2352 bytes and have a 24 byte header */
-            track->stream_sector_size = 2352;
-            track->stream_sector_header_size = 24;
-         }
-         else if ((size % 2048) == 0)
-         {
-            /* cooked tracks eliminate all header/footer data */
-            track->stream_sector_size = 2048;
-            track->stream_sector_header_size = 0;
-         }
-         else if ((size % 2336) == 0)
-         {
-            /* MODE 2 format without 16-byte sync data */
-            track->stream_sector_size = 2336;
-            track->stream_sector_header_size = 8;
-         }
-      }
+static void cdfs_determine_sector_size_from_file_size(cdfs_track_t* track)
+{
+   /* attempt to determine stream_sector_size from file size */
+   size_t size = intfstream_get_size(track->stream);
+
+   if ((size % 2352) == 0)
+   {
+      /* raw tracks use all 2352 bytes and have a 24 byte header */
+      track->stream_sector_size = 2352;
+      track->stream_sector_header_size = 24;
+   }
+   else if ((size % 2048) == 0)
+   {
+      /* cooked tracks eliminate all header/footer data */
+      track->stream_sector_size = 2048;
+      track->stream_sector_header_size = 0;
+   }
+   else if ((size % 2336) == 0)
+   {
+      /* MODE 2 format without 16-byte sync data */
+      track->stream_sector_size = 2336;
+      track->stream_sector_header_size = 8;
    }
 }
 
@@ -109,6 +110,23 @@ void cdfs_seek_sector(cdfs_file_t* file, unsigned int sector)
    }
 }
 
+uint32_t cdfs_get_num_sectors(cdfs_file_t* file)
+{
+   uint32_t frame_size = intfstream_get_frame_size(file->track->stream);
+   if (frame_size == 0)
+   {
+      frame_size = file->track->stream_sector_size;
+      if (frame_size == 0)
+         frame_size = 1; /* prevent divide by 0 error if sector size is unknown */
+   }
+   return intfstream_get_size(file->track->stream) / frame_size;
+}
+
+uint32_t cdfs_get_first_sector(cdfs_file_t* file)
+{
+   return file->track->first_sector_index;
+}
+
 static int cdfs_find_file(cdfs_file_t* file, const char* path)
 {
    size_t path_length;
@@ -356,7 +374,7 @@ static void cdfs_skip_spaces(const char** ptr)
 }
 
 static cdfs_track_t* cdfs_wrap_stream(
-      intfstream_t* stream, unsigned first_sector_offset)
+      intfstream_t* stream, unsigned first_sector_offset, unsigned first_sector_index)
 {
    cdfs_track_t* track = NULL;
 
@@ -367,6 +385,7 @@ static cdfs_track_t* cdfs_wrap_stream(
       calloc(1, sizeof(*track));
    track->stream              = stream;
    track->first_sector_offset = first_sector_offset;
+   track->first_sector_index  = first_sector_index;
 
    cdfs_determine_sector_size(track);
 
@@ -507,9 +526,12 @@ static cdfs_track_t* cdfs_open_cue_track(
    if (string_is_empty(track_path))
       return NULL;
 
+   /* NOTE: previous_index_sector_offset will only be valid if all tracks are in the same BIN file.
+    * Otherwise, we need to determine how many tracks are in each previous BIN file, which is not
+    * stored in the CUE file. This will affect cdfs_get_first_sector, which luckily isn't used much. */
    track = cdfs_wrap_stream(intfstream_open_file(
             track_path, RETRO_VFS_FILE_ACCESS_READ,
-            RETRO_VFS_FILE_ACCESS_HINT_NONE), track_offset);
+            RETRO_VFS_FILE_ACCESS_HINT_NONE), track_offset, previous_index_sector_offset);
 
    if (track && track->stream_sector_size == 0)
    {
@@ -537,7 +559,8 @@ static cdfs_track_t* cdfs_open_chd_track(const char* path, int32_t track_index)
       return NULL;
 
    track = cdfs_wrap_stream(intf_stream,
-         intfstream_get_offset_to_start(intf_stream));
+         intfstream_get_offset_to_start(intf_stream),
+         intfstream_get_first_sector(intf_stream));
 
    if (track && track->stream_sector_header_size == 0)
    {
@@ -601,11 +624,15 @@ cdfs_track_t* cdfs_open_raw_track(const char* path)
       intfstream_t* file = intfstream_open_file(path,
          RETRO_VFS_FILE_ACCESS_READ, RETRO_VFS_FILE_ACCESS_HINT_NONE);
 
-      track = cdfs_wrap_stream(file, 0);
+      track = cdfs_wrap_stream(file, 0, 0);
       if (track != NULL && track->stream_sector_size == 0)
       {
-         cdfs_close_track(track);
-         track = NULL;
+         cdfs_determine_sector_size_from_file_size(track);
+         if (track->stream_sector_size == 0)
+         {
+            cdfs_close_track(track);
+            track = NULL;
+         }
       }
    }
    else

libretro-common/include/formats/cdfs.h

@@ -37,6 +37,7 @@ typedef struct cdfs_track_t
    unsigned int stream_sector_size;
    unsigned int stream_sector_header_size;
    unsigned int first_sector_offset;
+   unsigned int first_sector_index;
 } cdfs_track_t;
 
 typedef struct cdfs_file_t
@@ -70,6 +71,10 @@ int64_t cdfs_seek(cdfs_file_t* file, int64_t offset, int whence);
 
 void cdfs_seek_sector(cdfs_file_t* file, unsigned int sector);
 
+uint32_t cdfs_get_num_sectors(cdfs_file_t* file);
+
+uint32_t cdfs_get_first_sector(cdfs_file_t* file);
+
 /* 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.
  *

libretro-common/include/streams/chd_stream.h

@@ -61,6 +61,8 @@ uint32_t chdstream_get_track_start(chdstream_t* stream);
 
 uint32_t chdstream_get_frame_size(chdstream_t* stream);
 
+uint32_t chdstream_get_first_track_sector(chdstream_t* stream);
+
 RETRO_END_DECLS
 
 #endif

libretro-common/include/streams/interface_stream.h

@@ -106,6 +106,8 @@ uint32_t intfstream_get_offset_to_start(intfstream_internal_t *intf);
 
 uint32_t intfstream_get_frame_size(intfstream_internal_t *intf);
 
+uint32_t intfstream_get_first_sector(intfstream_internal_t* intf);
+
 bool intfstream_is_compressed(intfstream_internal_t *intf);
 
 bool intfstream_get_crc(intfstream_internal_t *intf, uint32_t *crc);

libretro-common/streams/chd_stream.c

@@ -163,10 +163,7 @@ chdstream_find_special_track(chd_file *fd, int32_t track, metadata_t *meta)
       if (!chdstream_find_track_number(fd, i, &iter))
       {
          if (track == CHDSTREAM_TRACK_LAST && i > 1)
-         {
-            *meta = iter;
-            return true;
-         }
+            return chdstream_find_track_number(fd, i - 1, meta);
 
          if (track == CHDSTREAM_TRACK_PRIMARY && largest_track != 0)
             return chdstream_find_track_number(fd, largest_track, meta);
@@ -450,3 +447,22 @@ uint32_t chdstream_get_frame_size(chdstream_t *stream)
 {
    return stream->frame_size;
 }
+
+uint32_t chdstream_get_first_track_sector(chdstream_t* stream)
+{
+   uint32_t i;
+   metadata_t meta;
+   uint32_t frame_offset = 0;
+   uint32_t sector_offset = 0;
+
+   for (i = 0; chdstream_get_meta(stream->chd, i, &meta); ++i)
+   {
+      if (stream->track_frame == frame_offset)
+         return sector_offset;
+
+      sector_offset += meta.frames;
+      frame_offset += meta.frames + meta.extra;
+   }
+
+   return 0;
+}

libretro-common/streams/interface_stream.c

@@ -604,6 +604,19 @@ uint32_t intfstream_get_frame_size(intfstream_internal_t *intf)
    return 0;
 }
 
+uint32_t intfstream_get_first_sector(intfstream_internal_t* intf)
+{
+   if (intf)
+   {
+#ifdef HAVE_CHD
+      if (intf->type == INTFSTREAM_CHD)
+         return chdstream_get_first_track_sector(intf->chd.fp);
+#endif
+   }
+
+   return 0;
+}
+
 bool intfstream_is_compressed(intfstream_internal_t *intf)
 {
    if (!intf)