Bring the plugins in sync with the new core capsnego system.

Original commit message from CVS:
Bring the plugins in sync with the new core capsnego system.
Added some features, enhancements...

ext/ffmpeg/gstffmpegdec.c

@@ -114,12 +114,15 @@ gst_ffmpegdec_class_init (GstFFMpegDecClass *klass)
   gobject_class->get_property = gst_ffmpegdec_get_property;
 }
 
-static void
-gst_ffmpegdec_newcaps (GstPad *pad, GstCaps *caps)
+static GstPadConnectReturn
+gst_ffmpegdec_sinkconnect (GstPad *pad, GstCaps *caps)
 {
   GstFFMpegDec *ffmpegdec = (GstFFMpegDec *)(gst_pad_get_parent (pad));
   GstFFMpegDecClass *oclass = (GstFFMpegDecClass*)(G_OBJECT_GET_CLASS (ffmpegdec));
 
+  if (!GST_CAPS_IS_FIXED (caps))
+    return GST_PAD_CONNECT_DELAYED;
+
   ffmpegdec->context->width = gst_caps_get_int (caps, "width");
   ffmpegdec->context->height = gst_caps_get_int (caps, "height");
   ffmpegdec->context->pix_fmt = PIX_FMT_YUV420P;
@@ -129,11 +132,14 @@ gst_ffmpegdec_newcaps (GstPad *pad, GstCaps *caps)
   /* FIXME bug in ffmpeg */
   if (avcodec_open (ffmpegdec->context, avcodec_find_encoder(CODEC_ID_MPEG1VIDEO)) <0 ) {
     g_warning ("ffmpegdec: could not open codec");
+    return GST_PAD_CONNECT_REFUSED;
   }
 
   if (avcodec_open (ffmpegdec->context, oclass->in_plugin) < 0) {
     g_warning ("ffmpegdec: could not open codec");
+    return GST_PAD_CONNECT_REFUSED;
   }
+  return GST_PAD_CONNECT_OK;
 }
 
 static void
@@ -145,7 +151,7 @@ gst_ffmpegdec_init(GstFFMpegDec *ffmpegdec)
 
   ffmpegdec->sinkpad = gst_pad_new_from_template (
 		  GST_PADTEMPLATE_GET (gst_ffmpegdec_sink_factory), "sink");
-  gst_pad_set_newcaps_function (ffmpegdec->sinkpad, gst_ffmpegdec_newcaps);
+  gst_pad_set_connect_function (ffmpegdec->sinkpad, gst_ffmpegdec_sinkconnect);
 
   if (oclass->in_plugin->type == CODEC_TYPE_VIDEO) {
     ffmpegdec->srcpad = gst_pad_new_from_template (
@@ -210,7 +216,7 @@ gst_ffmpegdec_chain_video (GstPad *pad, GstBuffer *inbuf)
       height = ffmpegdec->context->height;
 
       if (!GST_PAD_CAPS (ffmpegdec->srcpad)) {
-        gst_pad_set_caps (ffmpegdec->srcpad, 
+        gst_pad_try_set_caps (ffmpegdec->srcpad, 
 		      GST_CAPS_NEW (
 			"ffmpegdec_src",
 			"video/raw",

ext/ffmpeg/gstffmpegenc.c

@@ -174,12 +174,15 @@ gst_ffmpegenc_class_init (GstFFMpegEncClass *klass)
   gobject_class->get_property = gst_ffmpegenc_get_property;
 }
 
-static void
-gst_ffmpegenc_newcaps (GstPad *pad, GstCaps *caps)
+static GstPadConnectReturn
+gst_ffmpegenc_sinkconnect (GstPad *pad, GstCaps *caps)
 {
   GstFFMpegEnc *ffmpegenc = (GstFFMpegEnc *) gst_pad_get_parent (pad);
   GstFFMpegEncClass *oclass = (GstFFMpegEncClass*)(G_OBJECT_GET_CLASS(ffmpegenc));
 
+  if (!GST_CAPS_IS_FIXED (caps))
+    return GST_PAD_CONNECT_DELAYED;
+
   if (strstr (gst_caps_get_mime (caps), "audio/raw")) {
     ffmpegenc->context->sample_rate = gst_caps_get_int (caps, "rate");
     ffmpegenc->context->channels = gst_caps_get_int (caps, "channels");
@@ -207,10 +210,12 @@ gst_ffmpegenc_newcaps (GstPad *pad, GstCaps *caps)
   }
   else {
     g_warning ("ffmpegenc: invalid caps %s\n", gst_caps_get_mime (caps));
+    return GST_PAD_CONNECT_REFUSED;
   }
 
   if (avcodec_open (ffmpegenc->context, oclass->in_plugin) < 0) {
     g_warning ("ffmpegenc: could not open codec\n");
+    return GST_PAD_CONNECT_REFUSED;
   }
 
   if (oclass->in_plugin->type == CODEC_TYPE_AUDIO) {
@@ -218,6 +223,7 @@ gst_ffmpegenc_newcaps (GstPad *pad, GstCaps *caps)
 		  ffmpegenc->context->channels);
     ffmpegenc->buffer_pos = 0;
   }
+  return GST_PAD_CONNECT_OK;
 }
 
 static void
@@ -245,7 +251,7 @@ gst_ffmpegenc_init(GstFFMpegEnc *ffmpegenc)
     ffmpegenc->context->sample_rate = -1;
   }
 
-  gst_pad_set_newcaps_function (ffmpegenc->sinkpad, gst_ffmpegenc_newcaps);
+  gst_pad_set_connect_function (ffmpegenc->sinkpad, gst_ffmpegenc_sinkconnect);
   gst_element_add_pad (GST_ELEMENT (ffmpegenc), ffmpegenc->sinkpad);
 
   ffmpegenc->srcpad = gst_pad_new_from_template (