typefinding: move gio-based xdg mime typefinder from -bad to -base

Its purposes is mainly to avoid false positives (e.g. mp3 typefinder
reporting a 20% probability and somesuch). Won't be registered if
the gio plugin has been disabled via ./configure --disable-gio.

configure.ac

@@ -528,7 +528,7 @@ AG_GST_CHECK_FEATURE(GNOME_VFS, [GNOME VFS], gnomevfs, [
 dnl *** libgio ***
 translit(dnm, m, l) AM_CONDITIONAL(USE_GIO, true)
 AG_GST_CHECK_FEATURE(GIO, [GIO library], gio, [
-  PKG_CHECK_MODULES(GIO, gio-2.0 >= 2.15.2, [
+  PKG_CHECK_MODULES(GIO, gio-2.0 >= 2.16, [
     HAVE_GIO="yes"
     GIO_MODULE_DIR="`$PKG_CONFIG --variable=giomoduledir gio-2.0`"
     AC_DEFINE_UNQUOTED(GIO_MODULE_DIR, "$GIO_MODULE_DIR",

gst/typefind/Makefile.am

@@ -1,8 +1,8 @@
 plugin_LTLIBRARIES = libgsttypefindfunctions.la
 
 libgsttypefindfunctions_la_SOURCES = gsttypefindfunctions.c
-libgsttypefindfunctions_la_CFLAGS = $(GST_CFLAGS)
+libgsttypefindfunctions_la_CFLAGS = $(GST_CFLAGS) $(GIO_CFLAGS)
 libgsttypefindfunctions_la_LDFLAGS = $(GST_PLUGIN_LDFLAGS)
-libgsttypefindfunctions_la_LIBADD = $(GST_LIBS)
+libgsttypefindfunctions_la_LIBADD = $(GST_LIBS) $(GIO_LIBS)
 libgsttypefindfunctions_la_LIBTOOLFLAGS = --tag=disable-static
 

gst/typefind/gsttypefindfunctions.c

@@ -1,5 +1,7 @@
 /* GStreamer
  * Copyright (C) 2003 Benjamin Otte <in7y118@public.uni-hamburg.de>
+ * Copyright (C) 2005-2009 Tim-Philipp Müller <tim centricular net>
+ * Copyright (C) 2009 Sebastian Dröge <sebastian.droege@collabora.co.uk>
  *
  * gsttypefindfunctions.c: collection of various typefind functions
  *
@@ -25,6 +27,12 @@
 
 #include <glib.h>
 
+/* don't want to add gio xdgmime typefinder if gio was disabled via configure */
+#ifdef HAVE_GIO
+#include <gio/gio.h>
+#define USE_GIO
+#endif
+
 #include <gst/gsttypefind.h>
 #include <gst/gstelement.h>
 #include <gst/gstversion.h>
@@ -3242,6 +3250,62 @@ vivo_type_find (GstTypeFind * tf, gpointer unused)
   }
 }
 
+/*** XDG MIME typefinder (to avoid false positives mostly) ***/
+
+#ifdef USE_GIO
+static void
+xdgmime_typefind (GstTypeFind * find, gpointer user_data)
+{
+  gchar *mimetype;
+  gsize length = 16384;
+  guint64 tf_length;
+  guint8 *data;
+  gchar *tmp;
+
+  if ((tf_length = gst_type_find_get_length (find)) > 0)
+    length = MIN (length, tf_length);
+
+  if ((data = gst_type_find_peek (find, 0, length)) == NULL)
+    return;
+
+  tmp = g_content_type_guess (NULL, data, length, NULL);
+  if (tmp == NULL || g_content_type_is_unknown (tmp)) {
+    g_free (tmp);
+    return;
+  }
+
+  mimetype = g_content_type_get_mime_type (tmp);
+  g_free (tmp);
+
+  if (mimetype == NULL)
+    return;
+
+  GST_DEBUG ("Got mimetype '%s'", mimetype);
+
+  /* Ignore audio/video types:
+   *  - our own typefinders in -base are likely to be better at this
+   *    (and if they're not, we really want to fix them, that's why we don't
+   *    report xdg-detected audio/video types at all, not even with a low
+   *    probability)
+   *  - we want to detect GStreamer media types and not MIME types
+   *  - the purpose of this xdg mime finder is mainly to prevent false
+   *    positives of non-media formats, not to typefind audio/video formats */
+  if (g_str_has_prefix (mimetype, "audio/") ||
+      g_str_has_prefix (mimetype, "video/")) {
+    GST_LOG ("Ignoring audio/video mime type");
+    g_free (mimetype);
+    return;
+  }
+
+  /* Again, we mainly want the xdg typefinding to prevent false-positives on
+   * non-media formats, so suggest the type with a probability that trumps
+   * uncertain results of our typefinders, but not more than that. */
+  GST_LOG ("Suggesting '%s' with probability POSSIBLE", mimetype);
+  gst_type_find_suggest_simple (find, GST_TYPE_FIND_POSSIBLE, mimetype, NULL);
+  g_free (mimetype);
+}
+#endif /* USE_GIO */
+
 /*** generic typefind for streams that have some data at a specific position***/
 typedef struct
 {
@@ -3688,6 +3752,12 @@ plugin_init (GstPlugin * plugin)
   TYPE_FIND_REGISTER_START_WITH (plugin, "image/vnd.adobe.photoshop",
       GST_RANK_SECONDARY, psd_exts, "8BPS\000\001\000\000\000\000", 10,
       GST_TYPE_FIND_LIKELY);
+
+#ifdef USE_GIO
+  TYPE_FIND_REGISTER (plugin, "xdgmime-base", GST_RANK_MARGINAL,
+      xdgmime_typefind, NULL, NULL, NULL, NULL);
+#endif
+
   return TRUE;
 }