gst/real/gstrealaudiodec.c: Add raversions we can support on the caps.

Original commit message from CVS:
* gst/real/gstrealaudiodec.c: (gst_real_audio_dec_chain),
(close_library), (open_library),
(gst_real_audio_dec_probe_modules), (gst_real_audio_dec_getcaps),
(gst_real_audio_dec_setcaps), (gst_real_audio_dec_init),
(gst_real_audio_dec_change_state), (gst_real_audio_dec_finalize):
Add raversions we can support on the caps.
Refactor the loading of the real codecs like realvideo so that we can
implement probing.
Probe all supported formats by trying to load the .so files, only report
the versions on the caps that we can actually load.
* gst/real/gstrealvideodec.c: (gst_real_video_dec_chain),
(gst_real_video_dec_getcaps), (gst_real_video_dec_setcaps),
(open_library), (close_library),
(gst_real_video_dec_probe_modules),
(gst_real_video_dec_change_state), (gst_real_video_dec_init),
(gst_real_video_dec_finalize), (gst_real_video_dec_class_init):
* gst/real/gstrealvideodec.h:
Change the loading of the library like the audio decoder.
Probe the supported formats by trying to load the .so files and only
report the versions on the caps that we can actually load.

3 files changed, 417 insertions, 180 deletions

diff --git a/gst/real/gstrealaudiodec.c b/gst/real/gstrealaudiodec.c
index 9cb1f5df7..bb07de9dc 100644
--- a/gst/real/gstrealaudiodec.c
+++ b/gst/real/gstrealaudiodec.c
@@ -38,7 +38,9 @@ GST_ELEMENT_DETAILS ("RealAudio decoder",
 
 static GstStaticPadTemplate snk_t =
     GST_STATIC_PAD_TEMPLATE ("sink", GST_PAD_SINK, GST_PAD_ALWAYS,
-    GST_STATIC_CAPS ("audio/x-pn-realaudio; " "audio/x-sipro "));
+    GST_STATIC_CAPS ("audio/x-pn-realaudio, "
+        "raversion = { 3, 4, 5, 6, 8 }; " "audio/x-sipro "));
+
 static GstStaticPadTemplate src_t =
 GST_STATIC_PAD_TEMPLATE ("src", GST_PAD_SRC, GST_PAD_ALWAYS,
     GST_STATIC_CAPS ("audio/x-raw-int, "
@@ -67,25 +69,31 @@ enum
 
 typedef enum
 {
-  GST_REAL_AUDIO_DEC_VERSION_COOK = 8,
   GST_REAL_AUDIO_DEC_VERSION_ATRK = 3,
   GST_REAL_AUDIO_DEC_VERSION_14_4 = 4,
   GST_REAL_AUDIO_DEC_VERSION_28_8 = 5,
-  GST_REAL_AUDIO_DEC_VERSION_SIPR = 6
+  GST_REAL_AUDIO_DEC_VERSION_SIPR = 6,
+  GST_REAL_AUDIO_DEC_VERSION_COOK = 8
 } GstRealAudioDecVersion;
 
 typedef struct
 {
-  guint16 (*RADecode) (gpointer, guint8 *, guint32, guint8 *, guint32 *,
+  /* Hooks */
+  GModule *module;
+
+  /* Used by the REAL library. */
+  gpointer context;
+
+    guint16 (*RADecode) (gpointer, guint8 *, guint32, guint8 *, guint32 *,
       guint32);
-  guint16 (*RACloseCodec) (gpointer);
-  guint16 (*RAFreeDecoder) (gpointer);
-  guint16 (*RAInitDecoder) (gpointer, gpointer);
-  guint16 (*RAOpenCodec2) (gpointer, const gchar *);
-  guint16 (*RASetFlavor) (gpointer, guint16);
+    guint16 (*RACloseCodec) (gpointer);
+    guint16 (*RAFreeDecoder) (gpointer);
+    guint16 (*RAInitDecoder) (gpointer, gpointer);
+    guint16 (*RAOpenCodec2) (gpointer, const gchar *);
+    guint16 (*RASetFlavor) (gpointer, guint16);
   void (*SetDLLAccessPath) (gchar *);
   void (*RASetPwd) (gpointer, gchar *);
-} RealFunctions;
+} GstRADecLibrary;
 
 typedef struct
 {
@@ -108,16 +116,21 @@ struct _GstRealAudioDec
   /* Caps */
   guint width, height, leaf_size;
 
-  /* Hooks */
-  GModule *module;
-  RealFunctions funcs;
-
-  /* Used by the REAL library. */
-  gpointer context;
+  GstRADecLibrary lib;
 
   /* Properties */
-  gchar *real_codecs_path, *racook_names, *raatrk_names, *ra14_4_names,
-      *ra28_8_names, *rasipr_names;
+  gboolean checked_modules;
+  gchar *real_codecs_path;
+  gchar *raatrk_names;
+  gboolean valid_atrk;
+  gchar *ra14_4_names;
+  gboolean valid_ra14_4;
+  gchar *ra28_8_names;
+  gboolean valid_ra28_8;
+  gchar *rasipr_names;
+  gboolean valid_sipr;
+  gchar *racook_names;
+  gboolean valid_cook;
   gchar *pwd;
 };
 
@@ -139,7 +152,7 @@ gst_real_audio_dec_chain (GstPad * pad, GstBuffer * in)
   guint16 res = 0;
   guint len;
 
-  if (G_UNLIKELY (dec->funcs.RADecode == NULL || dec->module == NULL))
+  if (G_UNLIKELY (dec->lib.RADecode == NULL || dec->lib.module == NULL))
     goto not_negotiated;
 
   timestamp = GST_BUFFER_TIMESTAMP (in);
@@ -151,7 +164,7 @@ gst_real_audio_dec_chain (GstPad * pad, GstBuffer * in)
   if (flow != GST_FLOW_OK)
     goto done;
 
-  res = dec->funcs.RADecode (dec->context, GST_BUFFER_DATA (in),
+  res = dec->lib.RADecode (dec->lib.context, GST_BUFFER_DATA (in),
       GST_BUFFER_SIZE (in), GST_BUFFER_DATA (out), &len, -1);
 
   if (res != 0)
@@ -184,47 +197,36 @@ not_negotiated:
   }
 }
 
+static void
+close_library (GstRealAudioDec * dec, GstRADecLibrary * lib)
+{
+  if (lib->context) {
+    GST_LOG_OBJECT (dec, "closing library");
+    if (lib->RACloseCodec)
+      lib->RACloseCodec (lib->context);
+    /* lib->RAFreeDecoder (lib->context); */
+    lib->context = NULL;
+    lib->module = NULL;
+    lib->RACloseCodec = NULL;
+  }
+  if (lib->module) {
+    GST_LOG_OBJECT (dec, "closing library module");
+    g_module_close (lib->module);
+    lib->module = NULL;
+  }
+}
+
 static gboolean
-gst_real_audio_dec_setcaps (GstPad * pad, GstCaps * caps)
+open_library (GstRealAudioDec * dec, gint version, GstRADecLibrary * lib)
 {
-  GstRealAudioDec *dec = GST_REAL_AUDIO_DEC (GST_PAD_PARENT (pad));
-  GstStructure *s = gst_caps_get_structure (caps, 0);
+  gchar *path, *names;
+  gchar **split_names, **split_path;
+  gint i, j;
   gpointer ra_close_codec, ra_decode, ra_free_decoder;
   gpointer ra_open_codec2, ra_init_decoder, ra_set_flavor;
   gpointer set_dll_access_path = NULL, ra_set_pwd = NULL;
-  gchar *path, *names;
-  gchar **split_names, **split_path;
-  gint version, flavor, channels, rate, leaf_size, packet_size, width, height;
-  guint16 res = 0;
-  RAInit data;
-  gboolean bres;
-  const GValue *v;
-  GstBuffer *buf = NULL;
-  const gchar *name = gst_structure_get_name (s);
-  GModule *module = NULL;
-  gpointer context = NULL;
-  RealFunctions funcs = { NULL, };
-  int i, j;
   gchar *tmppath = NULL;
-
-  if (!strcmp (name, "audio/x-sipro"))
-    version = GST_REAL_AUDIO_DEC_VERSION_SIPR;
-  else {
-    if (!gst_structure_get_int (s, "raversion", &version))
-      goto missing_keys;
-  }
-
-  if (!gst_structure_get_int (s, "flavor", &flavor) ||
-      !gst_structure_get_int (s, "channels", &channels) ||
-      !gst_structure_get_int (s, "width", &width) ||
-      !gst_structure_get_int (s, "rate", &rate) ||
-      !gst_structure_get_int (s, "height", &height) ||
-      !gst_structure_get_int (s, "leaf_size", &leaf_size) ||
-      !gst_structure_get_int (s, "packet_size", &packet_size))
-    goto missing_keys;
-
-  if ((v = gst_structure_get_value (s, "codec_data")))
-    buf = g_value_peek_pointer (v);
+  guint16 res = 0;
 
   path = dec->real_codecs_path ? dec->real_codecs_path :
       DEFAULT_REAL_CODECS_PATH;
@@ -249,6 +251,8 @@ gst_real_audio_dec_setcaps (GstPad * pad, GstCaps * caps)
       goto unknown_version;
   }
 
+  GST_LOG_OBJECT (dec, "splitting paths %s, names %s", path, names);
+
   split_path = g_strsplit (path, ":", 0);
   split_names = g_strsplit (names, ":", 0);
 
@@ -256,10 +260,14 @@ gst_real_audio_dec_setcaps (GstPad * pad, GstCaps * caps)
     for (j = 0; split_names[j]; j++) {
       gchar *codec = g_strconcat (split_path[i], "/", split_names[j], NULL);
 
-      module = g_module_open (codec, G_MODULE_BIND_LAZY);
+      GST_LOG_OBJECT (dec, "opening module %s", codec);
+
+      lib->module = g_module_open (codec, G_MODULE_BIND_LAZY);
       g_free (codec);
-      if (module)
+      if (lib->module)
         goto codec_search_done;
+
+      GST_LOG_OBJECT (dec, "failure, try next one...");
     }
   }
 
@@ -267,37 +275,39 @@ codec_search_done:
   /* we keep the path for a while to set the dll access path */
   g_strfreev (split_names);
 
-  if (module == NULL)
+  if (lib->module == NULL)
     goto could_not_open;
 
-  if (!g_module_symbol (module, "RACloseCodec", &ra_close_codec) ||
-      !g_module_symbol (module, "RADecode", &ra_decode) ||
-      !g_module_symbol (module, "RAFreeDecoder", &ra_free_decoder) ||
-      !g_module_symbol (module, "RAOpenCodec2", &ra_open_codec2) ||
-      !g_module_symbol (module, "RAInitDecoder", &ra_init_decoder) ||
-      !g_module_symbol (module, "RASetFlavor", &ra_set_flavor)) {
+  GST_LOG_OBJECT (dec, "finding symbols");
+
+  if (!g_module_symbol (lib->module, "RACloseCodec", &ra_close_codec) ||
+      !g_module_symbol (lib->module, "RADecode", &ra_decode) ||
+      !g_module_symbol (lib->module, "RAFreeDecoder", &ra_free_decoder) ||
+      !g_module_symbol (lib->module, "RAOpenCodec2", &ra_open_codec2) ||
+      !g_module_symbol (lib->module, "RAInitDecoder", &ra_init_decoder) ||
+      !g_module_symbol (lib->module, "RASetFlavor", &ra_set_flavor)) {
     goto could_not_load;
   }
 
-  g_module_symbol (module, "RASetPwd", &ra_set_pwd);
-  g_module_symbol (module, "SetDLLAccessPath", &set_dll_access_path);
+  g_module_symbol (lib->module, "RASetPwd", &ra_set_pwd);
+  g_module_symbol (lib->module, "SetDLLAccessPath", &set_dll_access_path);
 
-  funcs.RACloseCodec = (guint16 (*)(gpointer)) ra_close_codec;
-  funcs.RADecode =
+  lib->RACloseCodec = (guint16 (*)(gpointer)) ra_close_codec;
+  lib->RADecode =
       (guint16 (*)(gpointer, guint8 *, guint32, guint8 *, guint32 *, guint32))
       ra_decode;
-  funcs.RAFreeDecoder = (guint16 (*)(gpointer)) ra_free_decoder;
-  funcs.RAOpenCodec2 = (guint16 (*)(gpointer, const gchar *)) ra_open_codec2;
-  funcs.RAInitDecoder = (guint16 (*)(gpointer, gpointer)) ra_init_decoder;
-  funcs.RASetFlavor = (guint16 (*)(gpointer, guint16)) ra_set_flavor;
-  funcs.RASetPwd = (void (*)(gpointer, gchar *)) ra_set_pwd;
-  funcs.SetDLLAccessPath = (void (*)(gchar *)) set_dll_access_path;
+  lib->RAFreeDecoder = (guint16 (*)(gpointer)) ra_free_decoder;
+  lib->RAOpenCodec2 = (guint16 (*)(gpointer, const gchar *)) ra_open_codec2;
+  lib->RAInitDecoder = (guint16 (*)(gpointer, gpointer)) ra_init_decoder;
+  lib->RASetFlavor = (guint16 (*)(gpointer, guint16)) ra_set_flavor;
+  lib->RASetPwd = (void (*)(gpointer, gchar *)) ra_set_pwd;
+  lib->SetDLLAccessPath = (void (*)(gchar *)) set_dll_access_path;
 
-  if (funcs.SetDLLAccessPath)
-    funcs.SetDLLAccessPath (split_path[i]);
+  if (lib->SetDLLAccessPath)
+    lib->SetDLLAccessPath (split_path[i]);
 
   tmppath = g_strdup_printf ("%s/", split_path[i]);
-  if ((res = funcs.RAOpenCodec2 (&context, tmppath))) {
+  if ((res = lib->RAOpenCodec2 (&lib->context, tmppath))) {
     g_free (tmppath);
     goto could_not_initialize;
   }
@@ -306,6 +316,157 @@ codec_search_done:
   /* now we are done with the split paths, so free them */
   g_strfreev (split_path);
 
+  return TRUE;
+
+  /* ERRORS */
+unknown_version:
+  {
+    GST_DEBUG_OBJECT (dec, "Cannot handle version %i.", version);
+    return FALSE;
+  }
+could_not_open:
+  {
+    g_strfreev (split_path);
+    GST_DEBUG_OBJECT (dec, "Could not find library '%s' in '%s'", names, path);
+    return FALSE;
+  }
+could_not_load:
+  {
+    g_strfreev (split_path);
+    close_library (dec, lib);
+    GST_DEBUG_OBJECT (dec, "Could not load all symbols: %s", g_module_error ());
+    return FALSE;
+  }
+could_not_initialize:
+  {
+    close_library (dec, lib);
+    GST_WARNING_OBJECT (dec, "Initialization of REAL driver failed (%i).", res);
+    return FALSE;
+  }
+}
+
+static void
+gst_real_audio_dec_probe_modules (GstRealAudioDec * dec)
+{
+  GstRADecLibrary dummy = { NULL };
+
+  if ((dec->valid_atrk =
+          open_library (dec, GST_REAL_AUDIO_DEC_VERSION_ATRK, &dummy)))
+    close_library (dec, &dummy);
+  if ((dec->valid_ra14_4 =
+          open_library (dec, GST_REAL_AUDIO_DEC_VERSION_14_4, &dummy)))
+    close_library (dec, &dummy);
+  if ((dec->valid_ra28_8 =
+          open_library (dec, GST_REAL_AUDIO_DEC_VERSION_28_8, &dummy)))
+    close_library (dec, &dummy);
+  if ((dec->valid_sipr =
+          open_library (dec, GST_REAL_AUDIO_DEC_VERSION_SIPR, &dummy)))
+    close_library (dec, &dummy);
+  if ((dec->valid_cook =
+          open_library (dec, GST_REAL_AUDIO_DEC_VERSION_COOK, &dummy)))
+    close_library (dec, &dummy);
+}
+
+static GstCaps *
+gst_real_audio_dec_getcaps (GstPad * pad)
+{
+  GstRealAudioDec *dec = GST_REAL_AUDIO_DEC (GST_PAD_PARENT (pad));
+  GstCaps *res;
+
+  if (dec->checked_modules) {
+    GValue versions = { 0 };
+    GValue version = { 0 };
+
+    GST_LOG_OBJECT (dec, "constructing caps");
+    res = gst_caps_new_empty ();
+
+    g_value_init (&versions, GST_TYPE_LIST);
+    g_value_init (&version, G_TYPE_INT);
+
+    if (dec->valid_atrk) {
+      g_value_set_int (&version, GST_REAL_AUDIO_DEC_VERSION_ATRK);
+      gst_value_list_append_value (&versions, &version);
+    }
+    if (dec->valid_ra14_4) {
+      g_value_set_int (&version, GST_REAL_AUDIO_DEC_VERSION_14_4);
+      gst_value_list_append_value (&versions, &version);
+    }
+    if (dec->valid_ra28_8) {
+      g_value_set_int (&version, GST_REAL_AUDIO_DEC_VERSION_28_8);
+      gst_value_list_append_value (&versions, &version);
+    }
+    if (dec->valid_sipr) {
+      g_value_set_int (&version, GST_REAL_AUDIO_DEC_VERSION_SIPR);
+      gst_value_list_append_value (&versions, &version);
+    }
+    if (dec->valid_cook) {
+      g_value_set_int (&version, GST_REAL_AUDIO_DEC_VERSION_COOK);
+      gst_value_list_append_value (&versions, &version);
+    }
+
+    if (gst_value_list_get_size (&versions) > 0) {
+      res = gst_caps_new_simple ("audio/x-pn-realaudio", NULL);
+      gst_structure_set_value (gst_caps_get_structure (res, 0),
+          "raversion", &versions);
+    } else {
+      res = gst_caps_new_empty ();
+    }
+
+    if (dec->valid_sipr) {
+      gst_caps_append (res, gst_caps_new_simple ("audio/x-sipro", NULL));
+    }
+    g_value_unset (&versions);
+    g_value_unset (&version);
+  } else {
+    GST_LOG_OBJECT (dec, "returning padtemplate caps");
+    res = gst_caps_copy (gst_pad_get_pad_template_caps (pad));
+  }
+  GST_LOG_OBJECT (dec, "returning caps %" GST_PTR_FORMAT, res);
+
+  return res;
+}
+
+static gboolean
+gst_real_audio_dec_setcaps (GstPad * pad, GstCaps * caps)
+{
+  GstRealAudioDec *dec = GST_REAL_AUDIO_DEC (GST_PAD_PARENT (pad));
+  GstStructure *s = gst_caps_get_structure (caps, 0);
+  gint version, flavor, channels, rate, leaf_size, packet_size, width, height;
+  guint16 res = 0;
+  RAInit data;
+  gboolean bres;
+  const GValue *v;
+  GstBuffer *buf = NULL;
+  const gchar *name = gst_structure_get_name (s);
+
+  if (!strcmp (name, "audio/x-sipro")) {
+    version = GST_REAL_AUDIO_DEC_VERSION_SIPR;
+  } else {
+    if (!gst_structure_get_int (s, "raversion", &version))
+      goto missing_keys;
+  }
+
+  if (!gst_structure_get_int (s, "flavor", &flavor) ||
+      !gst_structure_get_int (s, "channels", &channels) ||
+      !gst_structure_get_int (s, "width", &width) ||
+      !gst_structure_get_int (s, "rate", &rate) ||
+      !gst_structure_get_int (s, "height", &height) ||
+      !gst_structure_get_int (s, "leaf_size", &leaf_size) ||
+      !gst_structure_get_int (s, "packet_size", &packet_size))
+    goto missing_keys;
+
+  if ((v = gst_structure_get_value (s, "codec_data")))
+    buf = g_value_peek_pointer (v);
+
+  GST_LOG_OBJECT (dec, "opening code for version %d", version);
+
+  /* first close existing decoder */
+  close_library (dec, &dec->lib);
+
+  if (!open_library (dec, version, &dec->lib))
+    goto could_not_open;
+
+  /* we have the module, no initialize with the caps data */
   data.samplerate = rate;
   data.width = width;
   data.channels = channels;
@@ -315,16 +476,16 @@ codec_search_done:
   data.datalen = buf ? GST_BUFFER_SIZE (buf) : 0;
   data.data = buf ? GST_BUFFER_DATA (buf) : NULL;
 
-  if ((res = funcs.RAInitDecoder (context, &data))) {
+  if ((res = dec->lib.RAInitDecoder (dec->lib.context, &data))) {
     GST_WARNING_OBJECT (dec, "RAInitDecoder() failed");
     goto could_not_initialize;
   }
 
-  if (funcs.RASetPwd) {
-    funcs.RASetPwd (context, dec->pwd ? dec->pwd : DEFAULT_PWD);
+  if (dec->lib.RASetPwd) {
+    dec->lib.RASetPwd (dec->lib.context, dec->pwd ? dec->pwd : DEFAULT_PWD);
   }
 
-  if ((res = funcs.RASetFlavor (context, flavor))) {
+  if ((res = dec->lib.RASetFlavor (dec->lib.context, flavor))) {
     GST_WARNING_OBJECT (dec, "RASetFlavor(%d) failed", flavor);
     goto could_not_initialize;
   }
@@ -343,15 +504,8 @@ codec_search_done:
   dec->width = width;
   dec->height = height;
   dec->leaf_size = leaf_size;
-  if (dec->context) {
-    dec->funcs.RACloseCodec (dec->context);
-    dec->funcs.RAFreeDecoder (dec->context);
-  }
-  dec->context = context;
-  if (dec->module)
-    g_module_close (dec->module);
-  dec->module = module;
-  dec->funcs = funcs;
+
+  GST_LOG_OBJECT (dec, "opened module");
 
   return TRUE;
 
@@ -360,41 +514,21 @@ missing_keys:
     GST_DEBUG_OBJECT (dec, "Could not find all necessary keys in structure.");
     return FALSE;
   }
-unknown_version:
-  {
-    GST_DEBUG_OBJECT (dec, "Cannot handle version %i.", version);
-    return FALSE;
-  }
 could_not_open:
   {
-    g_strfreev (split_path);
-    GST_DEBUG_OBJECT (dec, "Could not find library '%s' in '%s'", names, path);
-    return FALSE;
-  }
-could_not_load:
-  {
-    g_module_close (module);
-    g_strfreev (split_path);
-    GST_DEBUG_OBJECT (dec, "Could not load all symbols: %s", g_module_error ());
+    GST_DEBUG_OBJECT (dec, "Could not find decoder");
     return FALSE;
   }
 could_not_initialize:
   {
-    if (context) {
-      funcs.RACloseCodec (context);
-      funcs.RAFreeDecoder (context);
-    }
-    g_module_close (module);
+    close_library (dec, &dec->lib);
     GST_WARNING_OBJECT (dec, "Initialization of REAL driver failed (%i).", res);
     return FALSE;
   }
 could_not_set_caps:
   {
-    if (context) {
-      funcs.RACloseCodec (context);
-      funcs.RAFreeDecoder (context);
-    }
-    g_module_close (module);
+    /* should normally not fail */
+    close_library (dec, &dec->lib);
     GST_DEBUG_OBJECT (dec, "Could not convince peer to accept caps.");
     return FALSE;
   }
@@ -406,6 +540,8 @@ gst_real_audio_dec_init (GstRealAudioDec * dec, GstRealAudioDecClass * klass)
   dec->snk = gst_pad_new_from_static_template (&snk_t, "sink");
   gst_pad_set_setcaps_function (dec->snk,
       GST_DEBUG_FUNCPTR (gst_real_audio_dec_setcaps));
+  gst_pad_set_getcaps_function (dec->snk,
+      GST_DEBUG_FUNCPTR (gst_real_audio_dec_getcaps));
   gst_pad_set_chain_function (dec->snk,
       GST_DEBUG_FUNCPTR (gst_real_audio_dec_chain));
   gst_element_add_pad (GST_ELEMENT (dec), dec->snk);
@@ -430,10 +566,25 @@ gst_real_audio_dec_change_state (GstElement * element,
     GstStateChange transition)
 {
   GstStateChangeReturn ret;
+  GstRealAudioDec *dec = GST_REAL_AUDIO_DEC (element);
+
+  switch (transition) {
+    case GST_STATE_CHANGE_NULL_TO_READY:
+      gst_real_audio_dec_probe_modules (dec);
+      dec->checked_modules = TRUE;
+      break;
+    default:
+      break;
+  }
 
   ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
+
   switch (transition) {
     case GST_STATE_CHANGE_PAUSED_TO_READY:
+      close_library (dec, &dec->lib);
+      break;
+    case GST_STATE_CHANGE_READY_TO_NULL:
+      dec->checked_modules = FALSE;
       break;
     default:
       break;
@@ -446,19 +597,7 @@ gst_real_audio_dec_finalize (GObject * object)
 {
   GstRealAudioDec *dec = GST_REAL_AUDIO_DEC (object);
 
-  if (dec->context) {
-    dec->funcs.RACloseCodec (dec->context);
-    /* Calling RAFreeDecoder seems to randomly cause SEGFAULTs.
-     * All other implementation (xine, mplayer) have also got this function call
-     * commented. So until we know more, we comment it too. */
-
-    /*     dec->funcs.RAFreeDecoder (dec->context); */
-    dec->context = NULL;
-  }
-  if (dec->module) {
-    g_module_close (dec->module);
-    dec->module = NULL;
-  }
+  close_library (dec, &dec->lib);
 
   if (dec->real_codecs_path) {
     g_free (dec->real_codecs_path);
diff --git a/gst/real/gstrealvideodec.c b/gst/real/gstrealvideodec.c
index 3c471f5d9..275584266 100644
--- a/gst/real/gstrealvideodec.c
+++ b/gst/real/gstrealvideodec.c
@@ -65,8 +65,8 @@ GST_BOILERPLATE (GstRealVideoDec, gst_real_video_dec, GstElement,
     GST_TYPE_ELEMENT);
 
 static gboolean open_library (GstRealVideoDec * dec,
-    GstRealVideoDecHooks * hooks, GstRealVideoDecVersion version);
-static void close_library (GstRealVideoDecHooks hooks);
+    GstRealVideoDecVersion version, GstRVDecLibrary * lib);
+static void close_library (GstRealVideoDec * dec, GstRVDecLibrary * lib);
 
 typedef struct
 {
@@ -103,7 +103,7 @@ gst_real_video_dec_chain (GstPad * pad, GstBuffer * in)
 
   dec = GST_REAL_VIDEO_DEC (GST_PAD_PARENT (pad));
 
-  if (G_UNLIKELY (dec->hooks.transform == NULL || dec->hooks.module == NULL))
+  if (G_UNLIKELY (dec->lib.Transform == NULL || dec->lib.module == NULL))
     goto not_negotiated;
 
   data = GST_BUFFER_DATA (in);
@@ -162,9 +162,9 @@ gst_real_video_dec_chain (GstPad * pad, GstBuffer * in)
   /* jump over the frag table to the fragments */
   data += frag_size;
 
-  result = dec->hooks.transform (
+  result = dec->lib.Transform (
       (gchar *) data,
-      (gchar *) GST_BUFFER_DATA (out), &tin, &tout, dec->hooks.context);
+      (gchar *) GST_BUFFER_DATA (out), &tin, &tout, dec->lib.context);
   if (result)
     goto could_not_transform;
 
@@ -243,10 +243,51 @@ could_not_push:
   }
 }
 
-static gboolean
-gst_real_video_dec_activate_push (GstPad * pad, gboolean active)
+static GstCaps *
+gst_real_video_dec_getcaps (GstPad * pad)
 {
-  return TRUE;
+  GstRealVideoDec *dec = GST_REAL_VIDEO_DEC (GST_PAD_PARENT (pad));
+  GstCaps *res;
+
+  if (dec->checked_modules) {
+    GValue versions = { 0 };
+    GValue version = { 0 };
+
+    GST_LOG_OBJECT (dec, "constructing caps");
+    res = gst_caps_new_empty ();
+
+    g_value_init (&versions, GST_TYPE_LIST);
+    g_value_init (&version, G_TYPE_INT);
+
+    if (dec->valid_rv20) {
+      g_value_set_int (&version, GST_REAL_VIDEO_DEC_VERSION_2);
+      gst_value_list_append_value (&versions, &version);
+    }
+    if (dec->valid_rv30) {
+      g_value_set_int (&version, GST_REAL_VIDEO_DEC_VERSION_3);
+      gst_value_list_append_value (&versions, &version);
+    }
+    if (dec->valid_rv40) {
+      g_value_set_int (&version, GST_REAL_VIDEO_DEC_VERSION_4);
+      gst_value_list_append_value (&versions, &version);
+    }
+
+    if (gst_value_list_get_size (&versions) > 0) {
+      res = gst_caps_new_simple ("video/x-pn-realvideo", NULL);
+      gst_structure_set_value (gst_caps_get_structure (res, 0),
+          "rmversion", &versions);
+    } else {
+      res = gst_caps_new_empty ();
+    }
+    g_value_unset (&versions);
+    g_value_unset (&version);
+  } else {
+    GST_LOG_OBJECT (dec, "returning padtemplate caps");
+    res = gst_caps_copy (gst_pad_get_pad_template_caps (pad));
+  }
+  GST_LOG_OBJECT (dec, "returning caps %" GST_PTR_FORMAT, res);
+
+  return res;
 }
 
 static gboolean
@@ -259,7 +300,6 @@ gst_real_video_dec_setcaps (GstPad * pad, GstCaps * caps)
   gchar data[36];
   gboolean bres;
   const GValue *v;
-  GstRealVideoDecHooks hooks = { 0, 0, 0, 0, 0, 0 };
 
   if (!gst_structure_get_int (s, "rmversion", &version) ||
       !gst_structure_get_int (s, "width", (gint *) & width) ||
@@ -272,8 +312,10 @@ gst_real_video_dec_setcaps (GstPad * pad, GstCaps * caps)
 
   GST_LOG_OBJECT (dec, "Setting version to %d", version);
 
-  if (!open_library (dec, &hooks, version))
-    return FALSE;
+  close_library (dec, &dec->lib);
+
+  if (!open_library (dec, version, &dec->lib))
+    goto open_failed;
 
   /* Initialize REAL driver. */
   GST_WRITE_UINT16_LE (data + 0, 11);
@@ -285,8 +327,7 @@ gst_real_video_dec_setcaps (GstPad * pad, GstCaps * caps)
   GST_WRITE_UINT32_LE (data + 16, 1);
   GST_WRITE_UINT32_LE (data + 20, format);
 
-  res = hooks.init (&data, &hooks.context);
-  if (res)
+  if ((res = dec->lib.Init (&data, &dec->lib.context)))
     goto could_not_initialize;
 
   if ((v = gst_structure_get_value (s, "codec_data"))) {
@@ -328,7 +369,7 @@ gst_real_video_dec_setcaps (GstPad * pad, GstCaps * caps)
     for (i = 0; i < bufsize; i++)
       msgdata[i + 2] = 4 * (guint32) bufdata[i];
 
-    res = hooks.custom_message (&msg, hooks.context);
+    res = dec->lib.Message (&msg, dec->lib.context);
 
     g_free (msgdata);
     if (res)
@@ -344,8 +385,6 @@ gst_real_video_dec_setcaps (GstPad * pad, GstCaps * caps)
   if (!bres)
     goto could_not_set_caps;
 
-  close_library (dec->hooks);
-  dec->hooks = hooks;
   dec->version = version;
   dec->width = width;
   dec->height = height;
@@ -361,34 +400,35 @@ missing_keys:
     GST_ERROR_OBJECT (dec, "Could not find all necessary keys in structure.");
     return FALSE;
   }
-
+open_failed:
+  {
+    GST_ERROR_OBJECT (dec, "failed to open library");
+    return FALSE;
+  }
 could_not_initialize:
   {
-    close_library (hooks);
     GST_ERROR_OBJECT (dec, "Initialization of REAL driver failed (%i).", res);
+    close_library (dec, &dec->lib);
     return FALSE;
   }
-
 could_not_allocate:
   {
-    close_library (hooks);
     GST_ERROR_OBJECT (dec, "Could not allocate memory.");
+    close_library (dec, &dec->lib);
     return FALSE;
   }
-
 could_not_send_message:
   {
-    close_library (hooks);
     GST_ERROR_OBJECT (dec, "Failed to send custom message needed for "
         "initialization (%i).", res);
+    close_library (dec, &dec->lib);
     return FALSE;
   }
-
 could_not_set_caps:
   {
-    close_library (hooks);
     GST_ERROR_OBJECT (dec, "Could not convince peer to accept dimensions "
         "%i x %i.", dec->width, dec->height);
+    close_library (dec, &dec->lib);
     return FALSE;
   }
 }
@@ -396,8 +436,8 @@ could_not_set_caps:
 /* Attempts to open the correct library for the configured version */
 
 static gboolean
-open_library (GstRealVideoDec * dec, GstRealVideoDecHooks * hooks,
-    GstRealVideoDecVersion version)
+open_library (GstRealVideoDec * dec, GstRealVideoDecVersion version,
+    GstRVDecLibrary * lib)
 {
   gpointer rv_custom_msg, rv_free, rv_init, rv_transform;
   GModule *module = NULL;
@@ -464,11 +504,11 @@ codec_search_done:
     goto could_not_load;
   }
 
-  hooks->init = (GstRealVideoDecInitFunc) rv_init;
-  hooks->free = (GstRealVideoDecFreeFunc) rv_free;
-  hooks->transform = (GstRealVideoDecTransformFunc) rv_transform;
-  hooks->custom_message = (GstRealVideoDecMessageFunc) rv_custom_msg;
-  hooks->module = module;
+  lib->Init = rv_init;
+  lib->Free = rv_free;
+  lib->Transform = rv_transform;
+  lib->Message = rv_custom_msg;
+  lib->module = module;
 
   dec->error_count = 0;
 
@@ -479,44 +519,93 @@ unknown_version:
     GST_ERROR_OBJECT (dec, "Cannot handle version %i.", version);
     return FALSE;
   }
-
 could_not_open:
   {
     GST_ERROR_OBJECT (dec, "Could not open library '%s' in '%s': %s", names,
         path, g_module_error ());
     return FALSE;
   }
-
 could_not_load:
   {
-    close_library (*hooks);
+    close_library (dec, lib);
     GST_ERROR_OBJECT (dec, "Could not load all symbols: %s", g_module_error ());
     return FALSE;
   }
 }
 
 static void
-close_library (GstRealVideoDecHooks hooks)
+close_library (GstRealVideoDec * dec, GstRVDecLibrary * lib)
+{
+  if (lib->context) {
+    GST_LOG_OBJECT (dec, "closing library");
+    if (lib->Free)
+      lib->Free (lib->context);
+  }
+  if (lib->module) {
+    GST_LOG_OBJECT (dec, "closing library module");
+    g_module_close (lib->module);
+    lib->module = NULL;
+  }
+  memset (lib, 0, sizeof (*lib));
+}
+
+static void
+gst_real_video_dec_probe_modules (GstRealVideoDec * dec)
+{
+  GstRVDecLibrary dummy = { NULL };
+
+  if ((dec->valid_rv20 =
+          open_library (dec, GST_REAL_VIDEO_DEC_VERSION_2, &dummy)))
+    close_library (dec, &dummy);
+  if ((dec->valid_rv30 =
+          open_library (dec, GST_REAL_VIDEO_DEC_VERSION_3, &dummy)))
+    close_library (dec, &dummy);
+  if ((dec->valid_rv40 =
+          open_library (dec, GST_REAL_VIDEO_DEC_VERSION_4, &dummy)))
+    close_library (dec, &dummy);
+}
+
+static GstStateChangeReturn
+gst_real_video_dec_change_state (GstElement * element,
+    GstStateChange transition)
 {
-  if (hooks.context && hooks.free)
-    hooks.free (hooks.context);
+  GstStateChangeReturn ret;
+  GstRealVideoDec *dec = GST_REAL_VIDEO_DEC (element);
 
-  if (hooks.module) {
-    g_module_close (hooks.module);
-    hooks.module = NULL;
+  switch (transition) {
+    case GST_STATE_CHANGE_NULL_TO_READY:
+      gst_real_video_dec_probe_modules (dec);
+      dec->checked_modules = TRUE;
+      break;
+    default:
+      break;
+  }
+
+  ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
+
+  switch (transition) {
+    case GST_STATE_CHANGE_PAUSED_TO_READY:
+      close_library (dec, &dec->lib);
+      break;
+    case GST_STATE_CHANGE_READY_TO_NULL:
+      dec->checked_modules = FALSE;
+      break;
+    default:
+      break;
   }
+  return ret;
 }
 
 static void
 gst_real_video_dec_init (GstRealVideoDec * dec, GstRealVideoDecClass * klass)
 {
   dec->snk = gst_pad_new_from_static_template (&snk_t, "sink");
+  gst_pad_set_getcaps_function (dec->snk,
+      GST_DEBUG_FUNCPTR (gst_real_video_dec_getcaps));
   gst_pad_set_setcaps_function (dec->snk,
       GST_DEBUG_FUNCPTR (gst_real_video_dec_setcaps));
   gst_pad_set_chain_function (dec->snk,
       GST_DEBUG_FUNCPTR (gst_real_video_dec_chain));
-  gst_pad_set_activatepush_function (dec->snk,
-      GST_DEBUG_FUNCPTR (gst_real_video_dec_activate_push));
   gst_element_add_pad (GST_ELEMENT (dec), dec->snk);
 
   dec->src = gst_pad_new_from_static_template (&src_t, "src");
@@ -542,8 +631,7 @@ gst_real_video_dec_finalize (GObject * object)
 {
   GstRealVideoDec *dec = GST_REAL_VIDEO_DEC (object);
 
-  close_library (dec->hooks);
-  memset (&dec->hooks, 0, sizeof (dec->hooks));
+  close_library (dec, &dec->lib);
 
   if (dec->real_codecs_path) {
     g_free (dec->real_codecs_path);
@@ -641,11 +729,14 @@ static void
 gst_real_video_dec_class_init (GstRealVideoDecClass * klass)
 {
   GObjectClass *object_class = G_OBJECT_CLASS (klass);
+  GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
 
   object_class->set_property = gst_real_video_dec_set_property;
   object_class->get_property = gst_real_video_dec_get_property;
   object_class->finalize = gst_real_video_dec_finalize;
 
+  element_class->change_state = gst_real_video_dec_change_state;
+
   g_object_class_install_property (object_class, PROP_REAL_CODECS_PATH,
       g_param_spec_string ("real-codecs-path",
           "Path where to search for RealPlayer codecs",
diff --git a/gst/real/gstrealvideodec.h b/gst/real/gstrealvideodec.h
index d3ac5391d..e80b6f468 100644
--- a/gst/real/gstrealvideodec.h
+++ b/gst/real/gstrealvideodec.h
@@ -35,11 +35,6 @@ typedef struct _GstRealVideoDec GstRealVideoDec;
 typedef struct _GstRealVideoDecClass GstRealVideoDecClass;
 typedef enum _GstRealVideoDecVersion GstRealVideoDecVersion;
 
-typedef guint32 (*GstRealVideoDecMessageFunc) (gpointer, gpointer);
-typedef guint32 (*GstRealVideoDecFreeFunc) (gpointer);
-typedef guint32 (*GstRealVideoDecInitFunc) (gpointer, gpointer);
-typedef guint32 (*GstRealVideoDecTransformFunc) (gchar *, gchar *, gpointer, gpointer, gpointer);
-
 enum _GstRealVideoDecVersion
 {
   GST_REAL_VIDEO_DEC_VERSION_2 = 2,
@@ -50,13 +45,21 @@ enum _GstRealVideoDecVersion
 typedef struct {
   GModule *module;
 
+  gpointer context;
+
+  guint32 (*Init) (gpointer, gpointer);
+  guint32 (*Free) (gpointer);
+  guint32 (*Transform) (gchar *, gchar *, gpointer, gpointer, gpointer);
+  guint32 (*Message) (gpointer, gpointer);
+
+  /*
   GstRealVideoDecMessageFunc custom_message;
   GstRealVideoDecFreeFunc free;
   GstRealVideoDecInitFunc init;
   GstRealVideoDecTransformFunc transform;
+  */
 
-  gpointer context;
-} GstRealVideoDecHooks;
+} GstRVDecLibrary;
 
 struct _GstRealVideoDec
 {
@@ -72,14 +75,18 @@ struct _GstRealVideoDec
 
   gint error_count;
 
-  /* Hooks */
-  GstRealVideoDecHooks hooks;
+  /* Library functions */
+  GstRVDecLibrary lib;
 
   /* Properties */
   gchar *real_codecs_path;
+  gboolean checked_modules;
   gchar *rv20_names;
+  gboolean valid_rv20;
   gchar *rv30_names;
+  gboolean valid_rv30;
   gchar *rv40_names;
+  gboolean valid_rv40;
   gint max_errors;
 };