[GNUnet-SVN] r4250 - Extractor/src/plugins

[cyberix]

Author: cyberix
Date: 2007-01-07 07:50:24 -0800 (Sun, 07 Jan 2007)
New Revision: 4250

Modified:
   Extractor/src/plugins/sidextractor.c
Log:
Rewrote the sid extractor for clarity.

Modified: Extractor/src/plugins/sidextractor.c
===================================================================
--- Extractor/src/plugins/sidextractor.c        2007-01-07 15:49:37 UTC (rev 
4249)
+++ Extractor/src/plugins/sidextractor.c        2007-01-07 15:50:24 UTC (rev 
4250)
@@ -1,21 +1,22 @@
 /*
-     This file is part of libextractor.
-     (C) 2006 Toni Ruottu
-
-     libextractor is free software; you can redistribute it and/or modify
-     it under the terms of the GNU General Public License as published
-     by the Free Software Foundation; either version 2, or (at your
-     option) any later version.
-
-     libextractor is distributed in the hope that it will be useful, but
-     WITHOUT ANY WARRANTY; without even the implied warranty of
-     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-     General Public License for more details.
-
-     You should have received a copy of the GNU General Public License
-     along with libextractor; see the file COPYING.  If not, write to the
-     Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-     Boston, MA 02111-1307, USA.
+ * This file is part of libextractor.
+ * (C) 2006, 2007 Toni Ruottu
+ *
+ * libextractor is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published
+ * by the Free Software Foundation; either version 2, or (at your
+ * option) any later version.
+ *
+ * libextractor is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with libextractor; see the file COPYING.  If not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ *
  */
 
 #include "platform.h"
@@ -23,147 +24,206 @@
 #include "convert.h"
 
 
-static struct EXTRACTOR_Keywords *
-addkword(EXTRACTOR_KeywordList *oldhead,
-         const char * phrase,
-         EXTRACTOR_KeywordType type) {
-   EXTRACTOR_KeywordList * keyword;
+#define SID1_HEADER_SIZE 0x76
+#define SID2_HEADER_SIZE 0x7c
 
-   keyword = malloc(sizeof(EXTRACTOR_KeywordList));
-   keyword->next = oldhead;
-   keyword->keyword = strdup(phrase);
-   keyword->keywordType = type;
-   return keyword;
+/* flags */
+
+#define MUSPLAYER_FLAG   0x01
+#define PLAYSID_FLAG     0x02
+#define PAL_FLAG         0x04
+#define NTSC_FLAG        0x08
+#define MOS6581_FLAG     0x10
+#define MOS8580_FLAG     0x20
+
+typedef char sidwrd[ 2 ];
+typedef char sidlongwrd[ 4 ];
+
+struct header
+{
+       char magicid[ 4 ];
+       sidwrd sidversion;
+       sidwrd dataoffset;
+       sidwrd loadaddr;
+       sidwrd initaddr;
+       sidwrd playaddr;
+       sidwrd songs;
+       sidwrd firstsong;
+       sidlongwrd speed;
+       char title[ 32 ];
+       char artist[ 32 ];
+       char copyright[ 32 ];
+       sidwrd flags; /* version 2 specific fields start */
+       char startpage;
+       char pagelength;
+       sidwrd reserved;
+};
+
+int sidword( sidwrd data  )
+{
+       int value =
+               ( unsigned char ) data[ 0 ] * 0x100 +
+               ( unsigned char ) data[ 1 ];
+
+       return( value );
+
 }
 
+static struct EXTRACTOR_Keywords * addkword
+(
+       EXTRACTOR_KeywordList *oldhead,
+       const char * phrase,
+       EXTRACTOR_KeywordType type
+)
+{
+       EXTRACTOR_KeywordList * keyword;
 
+       keyword = malloc( sizeof( EXTRACTOR_KeywordList ) );
+       keyword->next = oldhead;
+       keyword->keyword = strdup( phrase );
+       keyword->keywordType = type;
+       return( keyword );
+}
+
+
 /* "extract" keyword from a SID file
  *
  *  This plugin is based on the nsf extractor
  *
- * */
-struct EXTRACTOR_Keywords *
-libextractor_sid_extract(const char * filename,
-                             char * data,
-                             size_t size,
-                             struct EXTRACTOR_Keywords * prev) {
-  int i, version;
-  char album[33];
-  char artist[33];
-  char copyright[33];
-  char songs[32];
-  char startingsong[32];
+ */
+struct EXTRACTOR_Keywords * libextractor_sid_extract
+(
+       const char * filename,
+       char * data,
+       size_t size,
+       struct EXTRACTOR_Keywords * prev
+)
+{
+       unsigned int flags;
+       int i, version;
+       char album[ 33 ];
+       char artist[ 33 ];
+       char copyright[ 33 ];
+       char songs[ 32 ];
+       char startingsong[ 32 ];
+       char sidversion[ 32 ];
+       struct header *head;
 
+       /* Check header size */
 
-  /* Check header size and "magic" id bytes */
+       if( size < SID1_HEADER_SIZE )
+       {
+               return( prev );
+       }
 
-  if
-  (
-     size < 0x76 ||
-     ( data[0] != 'P' && data[0] != 'R' ) ||
-     data[1] != 'S' ||
-     data[2] != 'I' ||
-     data[3] != 'D'
-  )
-  {
-    return prev;
-  }
+       head = ( struct header * ) data;
 
+       /* Check "magic" id bytes */
 
-  /* Mime-type */
+       if
+       (
+               memcmp( head->magicid, "PSID", 4 ) &&
+               memcmp( head->magicid, "RSID", 4 )
+       )
+       {
+               return( prev );
+       }
 
-  prev = addkword(prev, "audio/prs.sid", EXTRACTOR_MIMETYPE);
 
-  /* Version of SID format */
+       /* Mime-type */
 
-  version = data[4] * 0x100 + data[5];
-  sprintf( startingsong, "%d", version );
-  prev = addkword(prev, startingsong, EXTRACTOR_FORMAT_VERSION);
+       prev = addkword( prev, "audio/prs.sid", EXTRACTOR_MIMETYPE );
 
 
-  /* Get song count */
+       /* Version of SID format */
 
-  sprintf( songs, "%d", data[0x0e] * 0x100 + data[0x0f] );
-  prev = addkword(prev, songs, EXTRACTOR_SONG_COUNT);
+       version = sidword( head->sidversion );
+       sprintf( sidversion, "%d", version );
+       prev = addkword( prev, sidversion, EXTRACTOR_FORMAT_VERSION );
 
 
-  /* Get number of the first song to be played */
+       /* Get song count */
 
-  sprintf( startingsong, "%d", data[0x10] * 0x100 + data[0x11] );
-  prev = addkword(prev, startingsong, EXTRACTOR_STARTING_SONG);
+       sprintf( songs, "%d", sidword( head->songs ) );
+       prev = addkword( prev, songs, EXTRACTOR_SONG_COUNT );
 
 
-  /* Parse album, artist, copyright fields */
+       /* Get number of the first song to be played */
 
-  for( i = 0; i < 32; i++ )
-  {
-    album[i] = data[ 0x16 + i ];
-    artist[i] = data[ 0x36 + i ];
-    copyright[i] = data[ 0x56 + i ];
-  }
+       sprintf( startingsong, "%d", sidword( head->firstsong ) );
+       prev = addkword( prev, startingsong, EXTRACTOR_STARTING_SONG );
 
-  album[32] = '\0';
-  artist[32] = '\0';
-  copyright[32] = '\0';
 
-  prev = addkword(prev, album, EXTRACTOR_ALBUM);
-  prev = addkword(prev, artist, EXTRACTOR_ARTIST);
-  prev = addkword(prev, copyright, EXTRACTOR_COPYRIGHT);
+       /* name, artist, copyright fields */
 
+       memcpy( &album, head->title, 32 );
+       memcpy( &artist, head->artist, 32 );
+       memcpy( &copyright, head->copyright, 32 );
 
-  if( version < 2 || size < 0x7c )
-  {
-    return prev;
-  }
+       album[ 32 ] = '\0';
+       artist[ 32 ] = '\0';
+       copyright[ 32 ] = '\0';
 
-  /* Version 2 specific options follow
-   *
-   * Note: Had some troubles understanding specification
-   * on the flags in version 2. I hope this is correct.
-   *
-   */
+       prev = addkword( prev, album, EXTRACTOR_ALBUM );
+       prev = addkword( prev, artist, EXTRACTOR_ARTIST );
+       prev = addkword( prev, copyright, EXTRACTOR_COPYRIGHT );
 
-  /* PAL or NTSC */
 
-  if( data[0x77] & 16 )
-  {
-    if( data[0x77] & 32 )
-    {
-      prev = addkword(prev, "PAL/NTSC", EXTRACTOR_TELEVISION_SYSTEM);
-    }
-    else
-    {
-      prev = addkword(prev, "PAL", EXTRACTOR_TELEVISION_SYSTEM);
-    }
-  }
-  else
-  {
-    if( data[0x77] & 32 )
-    {
-      prev = addkword(prev, "NTSC", EXTRACTOR_TELEVISION_SYSTEM);
-    }
-  }
+       if( version < 2 || size < SID2_HEADER_SIZE )
+       {
+               return( prev );
+       }
 
-  /* Detect SID Chips suitable for play the files */
+       /* Version 2 specific options follow
+        *
+        * Note: Had some troubles understanding specification
+        * on the flags in version 2. I hope this is correct.
+        *
+        */
 
-  if( data[0x77] & 4 )
-  {
-    if( data[0x77] & 8 )
-    {
-      prev = addkword(prev, "MOS6581/MOS8580", EXTRACTOR_HARDWARE_DEPENDENCY);
-    }
-    else
-    {
-      prev = addkword(prev, "MOS6581", EXTRACTOR_HARDWARE_DEPENDENCY);
-    }
-  }
-  else
-  {
-    if( data[0x77] & 8 )
-    {
-      prev = addkword(prev, "MOS8580", EXTRACTOR_HARDWARE_DEPENDENCY);
-    }
-  }
+       flags = sidword( head->flags );
 
-  return prev;
+       /* PAL or NTSC */
+
+       if( flags & PAL_FLAG )
+       {
+               if( flags & NTSC_FLAG )
+               {
+                       prev = addkword( prev, "PAL/NTSC", 
EXTRACTOR_TELEVISION_SYSTEM );
+               }
+               else
+               {
+                       prev = addkword( prev, "PAL", 
EXTRACTOR_TELEVISION_SYSTEM );
+               }
+       }
+       else
+       {
+               if( flags & NTSC_FLAG )
+               {
+                       prev = addkword( prev, "NTSC", 
EXTRACTOR_TELEVISION_SYSTEM );
+               }
+       }
+
+       /* Detect SID Chips suitable for play the files */
+
+       if( flags & MOS6581_FLAG )
+       {
+               if( flags & MOS8580_FLAG )
+               {
+                       prev = addkword( prev, "MOS6581/MOS8580", 
EXTRACTOR_HARDWARE_DEPENDENCY );
+               }
+               else
+               {
+                       prev = addkword( prev, "MOS6581", 
EXTRACTOR_HARDWARE_DEPENDENCY );
+               }
+       }
+       else
+       {
+               if( flags & MOS8580_FLAG )
+               {
+                       prev = addkword( prev, "MOS8580", 
EXTRACTOR_HARDWARE_DEPENDENCY );
+               }
+       }
+
+       return( prev );
 }