adding test for gif extractor

4 files changed, 187 insertions, 245 deletions

diff --git a/src/plugins/Makefile.am b/src/plugins/Makefile.am
index fe847db..447b674 100644
--- a/src/plugins/Makefile.am
+++ b/src/plugins/Makefile.am
@@ -25,9 +25,15 @@ PLUGIN_MIME=libextractor_mime.la
 TEST_MIME=test_mime
 endif
 
+if HAVE_GIF
+PLUGIN_GIF=libextractor_gif.la
+TEST_GIF=test_gif
+endif
+
 plugin_LTLIBRARIES = \
   $(PLUGIN_OGG) \
-  $(PLUGIN_MIME)
+  $(PLUGIN_MIME) \
+  $(PLUGIN_GIF)
 
 if HAVE_ZZUF
   fuzz_tests=fuzz_default.sh 
@@ -35,7 +41,8 @@ endif
 
 check_PROGRAMS = \
   $(TEST_OGG) \
-  $(TEST_MIME)
+  $(TEST_MIME) \
+  $(TEST_GIF)
 
 TESTS = \
   $(fuzz_tests) \
@@ -81,4 +88,19 @@ test_mime_LDADD = \
   $(top_builddir)/src/plugins/libtest.la
 
 
+libextractor_gif_la_SOURCES = \
+  gif_extractor.c
+libextractor_gif_la_LDFLAGS = \
+  $(PLUGINFLAGS)
+libextractor_gif_la_LIBADD = \
+  $(top_builddir)/src/main/libextractor.la \
+  $(top_builddir)/src/common/libextractor_common.la \
+  -lgif
+
+test_gif_SOURCES = \
+  test_gif.c
+test_gif_LDADD = \
+  $(top_builddir)/src/plugins/libtest.la
+
+
 
diff --git a/src/plugins/gif_extractor.c b/src/plugins/gif_extractor.c
index 055fd9f..1e85f87 100644
--- a/src/plugins/gif_extractor.c
+++ b/src/plugins/gif_extractor.c
@@ -1,10 +1,10 @@
 /*
      This file is part of libextractor.
-     (C) 2002, 2003, 2009 Vidyut Samanta and Christian Grothoff
+     (C) 2012 Vidyut Samanta and Christian Grothoff
 
      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
+     by the Free Software Foundation; either version 3, or (at your
      option) any later version.
 
      libextractor is distributed in the hope that it will be useful, but
@@ -20,261 +20,104 @@
 
 #include "platform.h"
 #include "extractor.h"
-#include "pack.h"
+#include <gif_lib.h>
 
-#define DEBUG_GIF 0
-#if DEBUG_GIF
-#define PRINT(a,b) fprintf(stderr,a,b)
-#else
-#define PRINT(a,b)
-#endif
-
-struct GifHeader
-{
-  char gif[3];
-  char version[3];
-  uint16_t screen_width;
-  uint16_t screen_height;
-  unsigned char flags;
-#define HEADER_FLAGS__SIZE_OF_GLOBAL_COLOR_TABLE 0x07
-#define HEADER_FLAGS__SORT_FLAG 0x08
-#define HEADER_FLAGS__COLOR_RESOLUTION 0x70
-#define HEADER_FLAGS__GLOBAL_COLOR_TABLE_FLAG 0x80
-  unsigned char background_color_index;
-  unsigned char pixel_aspect_ratio;
-};
-
-#define GIF_HEADER_SIZE 13
-#define GIF_HEADER_SPEC "3b3bhhbbb"
-#define GIF_HEADER_FIELDS(p) \
- &(p)->gif,\
- &(p)->version, \
- &(p)->screen_width, \
- &(p)->screen_height, \
- &(p)->flags, \
- &(p)->background_color_index, \
- &(p)->pixel_aspect_ratio
-
-struct GifDescriptor
-{
-  unsigned char image_separator;
-  uint16_t image_left;
-  uint16_t image_top;
-  uint16_t image_width;
-  uint16_t image_height;
-  unsigned char flags;
-#define DESCRIPTOR_FLAGS__PIXEL_SIZE 0x07
-#define DESCRIPTOR_FLAGS__RESERVED 0x18
-#define DESCRIPTOR_FLAGS__SORT_FLAG 0x20
-#define DESCRIPTOR_FLAGS__INTERLACE_FLAG 0x40
-#define DESCRIPTOR_FLAGS__LOCAL_COLOR_TABLE_FLAG 0x80
-};
-
-#define GIF_DESCRIPTOR_SIZE 10
-#define GIF_DESCRIPTOR_SPEC "chhhhc"
-#define GIF_DESCRIPTOR_FIELDS(p) \
- &(p)->image_separator, \
- &(p)->image_left, \
- &(p)->image_top, \
- &(p)->image_width, \
- &(p)->image_height, \
- &(p)->flags
-
-struct GifExtension
-{
-  unsigned char extension_introducer;
-  unsigned char graphic_control_label;
-};
-
-/**
- * Skip a data block.
- * @return the position after the block
- */
-static size_t
-skipDataBlock (const unsigned char *data, size_t pos, const size_t size)
-{
-  while ((pos < size) && (data[pos] != 0))
-    pos += data[pos] + 1;
-  return pos + 1;
-}
 
 /**
- * skip an extention block
- * @return the position after the block
+ * Callback invoked by libgif to read data.
+ *
+ * @param ft the file handle, including our extract context
+ * @param bt where to write the data
+ * @param arg number of bytes to read
+ * @return -1 on error, otherwise number of bytes read
  */
-static size_t
-skipExtensionBlock (const unsigned char *data,
-                    size_t pos, const size_t size, 
-                    const struct GifExtension * ext)
+static int
+gif_read_func (GifFileType *ft,
+               GifByteType *bt,
+               int arg)
 {
-  return skipDataBlock (data, pos + sizeof (struct GifExtension), size);
+  struct EXTRACTOR_ExtractContext *ec = ft->UserData;
+  void *data;
+  ssize_t ret;
+  
+  ret = ec->read (ec->cls,
+                  &data,
+                  arg);
+  if (-1 == ret)
+    return -1;
+  memcpy (bt, data, ret);
+  return ret;
 }
 
-/**
- * @return the offset after the global color map
- */
-static size_t
-skipGlobalColorMap (const unsigned char *data,
-                    const size_t size,
-                    const struct GifHeader * header)
-{
-  size_t gct_size;
-
-  if ((header->flags & HEADER_FLAGS__GLOBAL_COLOR_TABLE_FLAG) > 0)
-    gct_size =
-      3 *
-      (1 << ((header->flags & HEADER_FLAGS__SIZE_OF_GLOBAL_COLOR_TABLE) + 1));
-  else
-    gct_size = 0;
-  return GIF_HEADER_SIZE + gct_size;
-}
 
 /**
- * @return the offset after the local color map
+ * Main entry method for the 'image/gif' extraction plugin.  
+ *
+ * @param ec extraction context provided to the plugin
  */
-static size_t
-skipLocalColorMap (const unsigned char *data,
-                   size_t pos, const size_t size,
-                   const struct GifDescriptor * descriptor)
+void
+EXTRACTOR_gif_extract_method (struct EXTRACTOR_ExtractContext *ec)
 {
-  size_t lct_size;
-
-  if (pos + GIF_DESCRIPTOR_SIZE > size)
-    return size;
-  if ((descriptor->flags & DESCRIPTOR_FLAGS__LOCAL_COLOR_TABLE_FLAG) > 0)
-    lct_size =
-      3 * (1 << ((descriptor->flags & DESCRIPTOR_FLAGS__PIXEL_SIZE) + 1));
-  else
-    lct_size = 0;
-  return pos + GIF_DESCRIPTOR_SIZE + lct_size;
-}
-
-static int
-parseComment (const unsigned char *data,
-              size_t pos, const size_t size, 
-              EXTRACTOR_MetaDataProcessor proc,
-              void *proc_cls)
-{
-  size_t length;
-  size_t off;
-  size_t curr = pos;
-  int ret;
-
-  length = 0;
-  while ( (curr < size) && 
-          (data[curr] != 0) )
+  GifFileType *gif_file;
+  GifRecordType gif_type;
+  GifByteType *ext;
+  int et;
+  char dims[128];
+  
+  if (NULL == (gif_file = DGifOpen (ec, &gif_read_func)))
+    return; /* not a GIF */
+  if (0 !=
+      ec->proc (ec->cls,
+                "gif",
+                EXTRACTOR_METATYPE_MIMETYPE,
+                EXTRACTOR_METAFORMAT_UTF8,
+                "text/plain",
+                "image/gif",
+                strlen ("image/gif") + 1))
+    return;
+  snprintf (dims,
+            sizeof (dims),
+            "%dx%d", 
+            gif_file->SHeight, 
+            gif_file->SWidth);
+  if (0 !=
+      ec->proc (ec->cls,
+                "gif",
+                EXTRACTOR_METATYPE_IMAGE_DIMENSIONS,
+                EXTRACTOR_METAFORMAT_UTF8,
+                "text/plain",
+                dims,
+                strlen (dims) + 1))
+    return;
+  while (1)
     {
-      length += data[curr];
-      curr += data[curr] + 1;
-      if (length > 65536)
+      if (GIF_OK != 
+          DGifGetRecordType (gif_file,
+                             &gif_type))
         break;
-    }
-  if ( (length < 65536) &&
-       (curr < size) )
-    {
-      char comment[length+1];
-
-      curr = pos;
-      off = 0;
-      while ((data[curr] != 0) && (curr < size))
+      if (UNDEFINED_RECORD_TYPE == gif_type)
+        break;
+      if (EXTENSION_RECORD_TYPE != gif_type)
+        continue;
+      if (GIF_OK !=
+          DGifGetExtension (gif_file, &et, &ext))
+        continue;
+      if (COMMENT_EXT_FUNC_CODE == et)
         {
-          if (off + data[curr] >= size)
-            break;
-          memcpy (&comment[off], 
-                  &data[curr] + 1,
-                  data[curr]);
-          off += data[curr];
-          curr += data[curr] + 1;
+          ec->proc (ec->cls,
+                    "gif",
+                    EXTRACTOR_METATYPE_COMMENT,
+                    EXTRACTOR_METAFORMAT_C_STRING,
+                    "text/plain",
+                    (char*) &ext[1],
+                    (uint8_t) ext[0]);
+          break;
         }
-      comment[off] = '\0';
-      ret = proc (proc_cls, 
-                  "gif",
-                  EXTRACTOR_METATYPE_COMMENT,
-                  EXTRACTOR_METAFORMAT_UTF8,
-                  "text/plain",
-                  comment,
-                  length+1);
+      while ( (GIF_ERROR != 
+               DGifGetExtensionNext(gif_file, &ext)) &&
+              (NULL != ext) ) ; /* keep going */
     }
-  else
-    {
-      /* too big */
-      ret = 0;
-    }
-  return ret;
+  DGifCloseFile (gif_file);
 }
 
-
-int 
-EXTRACTOR_gif_extract (const unsigned char *data,
-                       size_t size,
-                       EXTRACTOR_MetaDataProcessor proc,
-                       void *proc_cls,
-                       const char *options)
-{
-  size_t pos;
-  struct GifHeader header;
-  struct GifDescriptor gd;
-  char tmp[128];
-
-  if (size < GIF_HEADER_SIZE)
-    return 0;
-  EXTRACTOR_common_cat_unpack (data, GIF_HEADER_SPEC, GIF_HEADER_FIELDS (&header));
-  if (0 != strncmp (&header.gif[0], "GIF", 3))
-    return 0;
-  if (0 != strncmp (&header.version[0], "89a", 3))
-    return 0;                /* only 89a has support for comments */
-  if (0 != proc (proc_cls, 
-                 "gif",
-                 EXTRACTOR_METATYPE_MIMETYPE,
-                 EXTRACTOR_METAFORMAT_UTF8,
-                 "text/plain",
-                 "image/gif",
-                 strlen ("image/gif")+1))
-    return 1;
-  snprintf (tmp, 
-            sizeof(tmp),
-            "%ux%u", 
-            header.screen_width, header.screen_height);
-  if (0 != proc (proc_cls, 
-                 "gif",
-                 EXTRACTOR_METATYPE_IMAGE_DIMENSIONS,
-                 EXTRACTOR_METAFORMAT_UTF8,
-                 "text/plain",
-                 tmp,
-                 strlen (tmp)+1))
-    return 1;
-  pos = skipGlobalColorMap (data, size, &header);
-  PRINT ("global color map ends at %d\n", pos);
-  while (pos < size)
-    {
-      switch (data[pos])
-        {
-        case ',':              /* image descriptor block */
-          PRINT ("skipping local color map %d\n", pos);
-          EXTRACTOR_common_cat_unpack (&data[pos],
-                                       GIF_DESCRIPTOR_SPEC,
-                                       GIF_DESCRIPTOR_FIELDS (&gd));
-          pos = skipLocalColorMap (data, pos, size, &gd);
-          break;
-        case '!':              /* extension block */
-          PRINT ("skipping extension block %d\n", pos);
-          if (data[pos + 1] == (unsigned char) 0xFE)
-            {
-              if (0 != parseComment (data, pos + 2, size, proc, proc_cls))
-                return 1;
-            }
-          pos = skipExtensionBlock (data, pos, size,
-                                    (const struct GifExtension *) & data[pos]);
-          break;
-        case ';':
-          PRINT ("hit terminator at %d!\n", pos);
-          return 0;        /* terminator! */
-        default:               /* raster data block */
-          PRINT ("skipping data block at %d\n", pos);
-          pos = skipDataBlock (data, pos + 1, size);
-          break;
-        }
-    }
-  PRINT ("returning at %d\n", pos);
-  return 0;
-}
+/* end of gif_extractor.c */
diff --git a/src/plugins/mime_extractor.c b/src/plugins/mime_extractor.c
index 392429a..592ba5f 100644
--- a/src/plugins/mime_extractor.c
+++ b/src/plugins/mime_extractor.c
@@ -4,7 +4,7 @@
 
      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
+     by the Free Software Foundation; either version 3, or (at your
      option) any later version.
 
      libextractor is distributed in the hope that it will be useful, but
diff --git a/src/plugins/test_gif.c b/src/plugins/test_gif.c
new file mode 100644
index 0000000..8fa8185
--- /dev/null
+++ b/src/plugins/test_gif.c
@@ -0,0 +1,77 @@
+/*
+     This file is part of libextractor.
+     (C) 2012 Vidyut Samanta and Christian Grothoff
+
+     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 3, 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.
+*/
+/**
+ * @file plugins/test_gif.c
+ * @brief testcase for ogg plugin
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include "test_lib.h"
+
+
+
+/**
+ * Main function for the GIF testcase.
+ *
+ * @param argc number of arguments (ignored)
+ * @param argv arguments (ignored)
+ * @return 0 on success
+ */
+int
+main (int argc, char *argv[])
+{
+  struct SolutionData gif_image_sol[] =
+    {
+      { 
+        EXTRACTOR_METATYPE_MIMETYPE,
+        EXTRACTOR_METAFORMAT_UTF8,
+        "text/plain",
+        "image/gif",
+        strlen ("image/gif") + 1,
+        0 
+      },
+      { 
+        EXTRACTOR_METATYPE_IMAGE_DIMENSIONS,
+        EXTRACTOR_METAFORMAT_UTF8,
+        "text/plain",
+        "4x4",
+        strlen ("4x4") + 1,
+        0 
+      },
+      { 
+        EXTRACTOR_METATYPE_COMMENT,
+        EXTRACTOR_METAFORMAT_C_STRING,
+        "text/plain",
+        "Testing keyword extraction\n",
+        strlen ("Testing keyword extraction\n"),
+        0 
+      },
+      { 0, 0, NULL, NULL, 0, -1 }
+    };
+  struct ProblemSet ps[] =
+    {
+      { "testdata/gif_image.gif",
+        gif_image_sol },
+      { NULL, NULL }
+    };
+  return ET_main ("gif", ps);
+}
+
+/* end of test_gif.c */