diff --git a/ChangeLog b/ChangeLog
index 9bcc87dd84..9ebb44a0fa 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,35 @@
+2005-06-02  Wim Taymans  <wim@fluendo.com>
+
+	* ext/ogg/README:
+	* ext/ogg/gstoggdemux.c: (gst_ogg_pad_submit_packet),
+	(gst_ogg_demux_activate_chain), (gst_ogg_demux_clear_chains):
+	* ext/ogg/gstoggmux.c: (gst_ogg_mux_buffer_from_page):
+	* ext/theora/theoradec.c: (theora_dec_src_query),
+	(theora_handle_data_packet):
+	* ext/theora/theoraenc.c: (theora_buffer_from_packet),
+	(theora_enc_chain):
+	* ext/vorbis/vorbisdec.c: (vorbis_dec_sink_event),
+	(vorbis_handle_data_packet):
+	* gst/audioconvert/bufferframesconvert.c:
+	(buffer_frames_convert_chain):
+	* gst/ffmpegcolorspace/gstffmpegcolorspace.c:
+	(gst_ffmpegcsp_getcaps), (gst_ffmpegcsp_configure_context),
+	(gst_ffmpegcsp_setcaps), (gst_ffmpegcsp_bufferalloc),
+	(gst_ffmpegcsp_chain):
+	* gst/videorate/gstvideorate.c: (gst_videorate_transformcaps),
+	(gst_videorate_getcaps), (gst_videorate_setcaps),
+	(gst_videorate_event), (gst_videorate_chain):
+	* gst/videotestsrc/gstvideotestsrc.c: (gst_videotestsrc_activate),
+	(gst_videotestsrc_src_query), (gst_videotestsrc_loop):
+	* sys/ximage/ximagesink.c: (gst_ximagesink_ximage_new),
+	(gst_ximagesink_setcaps), (gst_ximagesink_buffer_alloc):
+	* sys/xvimage/xvimagesink.c: (gst_xvimage_buffer_destroy),
+	(gst_xvimage_buffer_finalize), (gst_xvimage_buffer_free),
+	(gst_xvimage_buffer_class_init), (gst_xvimage_buffer_get_type),
+	(gst_xvimagesink_xvimage_new), (gst_xvimagesink_xvimage_put),
+	(gst_xvimagesink_show_frame), (gst_xvimagesink_buffer_alloc):
+	Cleanups and buffer alloc.
+
 2005-05-31  Wim Taymans  <wim@fluendo.com>
 
 	* gst-libs/gst/audio/gstringbuffer.c: (gst_ringbuffer_delay):
diff --git a/ext/ogg/README b/ext/ogg/README
index 1343fa4b2d..7c76b3aaac 100644
--- a/ext/ogg/README
+++ b/ext/ogg/README
@@ -187,3 +187,31 @@ TODO
 
 - use the OFFSET field in the GstBuffer to store/read the granulepos as 
   opposed to the OFFSET_END field.
+
+
+Ogg media mapping
+-----------------
+
+Ogg defines a mapping for each media type that it embeds.
+
+For Vorbis:
+
+  - 3 header pages, with granulepos 0.
+     - 1 page with 1 packet header identification
+     - N pages with 2 packets comments and codebooks
+  - granulepos is samplenumber of next page
+  - one packet can contain a variable number of samples
+  
+For Theora
+     
+  - 3 header pages, with granulepos 0.
+     - 1 page with 1 packet header identification
+     - N pages with 2 packets comments and codebooks
+  - granulepos is framenumber of last packet in page, where framenumber
+    is a combination of keyframe number and p frames since keyframe.
+  - one packet contains 1 frame
+  
+  
+
+
+
diff --git a/ext/ogg/gstoggdemux.c b/ext/ogg/gstoggdemux.c
index d3d6e4da30..e28da68498 100644
--- a/ext/ogg/gstoggdemux.c
+++ b/ext/ogg/gstoggdemux.c
@@ -625,34 +625,18 @@ gst_ogg_pad_submit_packet (GstOggPad * pad, ogg_packet * packet)
   if (pad->packetno == 0) {
     gst_ogg_pad_typefind (pad, packet);
   }
-#if 0
-  if (ogg->state != OGG_STATE_STREAMING) {
-    GST_DEBUG_OBJECT (ogg, "%p collecting headers, state %d", pad, ogg->state);
-
-    buf = gst_buffer_new_and_alloc (packet->bytes);
-    memcpy (GST_BUFFER_DATA (buf), packet->packet, packet->bytes);
-    gst_buffer_set_caps (buf, GST_PAD_CAPS (pad));
-    GST_BUFFER_OFFSET (buf) = -1;
-    GST_BUFFER_OFFSET_END (buf) = packet->granulepos;
-
-    /* we are collecting the chain info, just need to queue the buffers */
-    pad->headers = g_list_append (pad->headers, buf);
-
-    goto done;
-  }
-#endif
 
   /* stream packet to peer plugin */
   if (pad->mode == GST_OGG_PAD_MODE_STREAMING) {
-    buf =
+    ret =
         gst_pad_alloc_buffer (GST_PAD (pad), GST_BUFFER_OFFSET_NONE,
-        packet->bytes, GST_PAD_CAPS (pad));
+        packet->bytes, GST_PAD_CAPS (pad), &buf);
 
     GST_DEBUG_OBJECT (ogg,
         "%p streaming to peer serial %08lx, packetno %lld", pad, pad->serialno,
         pad->packetno);
 
-    if (buf) {
+    if (ret == GST_FLOW_OK) {
       memcpy (buf->data, packet->packet, packet->bytes);
 
       pad->offset = packet->granulepos;
@@ -678,11 +662,8 @@ gst_ogg_pad_submit_packet (GstOggPad * pad, ogg_packet * packet)
     }
   } else {
     /* initialize our internal decoder with packets */
-    if (!pad->elem_pad) {
-      GST_WARNING_OBJECT (ogg,
-          "pad %08lx does not have elem_pad, no decoder ?", pad);
-      return GST_FLOW_OK;
-    }
+    if (!pad->elem_pad)
+      goto no_decoder;
 
     GST_DEBUG_OBJECT (ogg,
         "%p init decoder serial %08lx, packetno %lld", pad, pad->serialno,
@@ -696,13 +677,16 @@ gst_ogg_pad_submit_packet (GstOggPad * pad, ogg_packet * packet)
 
     ret = gst_pad_chain (pad->elem_pad, buf);
   }
-
-#if 0
-done:
-#endif
   pad->packetno++;
 
   return ret;
+
+no_decoder:
+  {
+    GST_WARNING_OBJECT (ogg,
+        "pad %08lx does not have elem_pad, no decoder ?", pad);
+    return GST_FLOW_OK;
+  }
 }
 
 /* submit a page to an oggpad, this function will then submit all
diff --git a/ext/ogg/gstoggmux.c b/ext/ogg/gstoggmux.c
index 333274892e..e31e3b86cf 100644
--- a/ext/ogg/gstoggmux.c
+++ b/ext/ogg/gstoggmux.c
@@ -473,8 +473,7 @@ gst_ogg_mux_buffer_from_page (GstOggMux * mux, ogg_page * page, gboolean delta)
   GstBuffer *buffer;
 
   /* allocate space for header and body */
-  buffer = gst_pad_alloc_buffer (mux->srcpad, GST_BUFFER_OFFSET_NONE,
-      page->header_len + page->body_len, NULL);
+  buffer = gst_buffer_new_and_alloc (page->header_len + page->body_len);
   memcpy (GST_BUFFER_DATA (buffer), page->header, page->header_len);
   memcpy (GST_BUFFER_DATA (buffer) + page->header_len,
       page->body, page->body_len);
diff --git a/ext/theora/theoradec.c b/ext/theora/theoradec.c
index 63fb58e30d..ffd7266aae 100644
--- a/ext/theora/theoradec.c
+++ b/ext/theora/theoradec.c
@@ -825,16 +825,16 @@ theora_handle_data_packet (GstTheoraDec * dec, ogg_packet * packet,
 
   /* now copy over the area contained in offset_x,offset_y,
    * frame_width, frame_height */
-  out = gst_pad_alloc_buffer (dec->srcpad, GST_BUFFER_OFFSET_NONE, out_size,
-      GST_PAD_CAPS (dec->srcpad));
-  if (out == NULL)
+  result = gst_pad_alloc_buffer (dec->srcpad, GST_BUFFER_OFFSET_NONE, out_size,
+      GST_PAD_CAPS (dec->srcpad), &out);
+  if (result != GST_FLOW_OK)
     goto no_buffer;
 
   /* copy the visible region to the destination. This is actually pretty
    * complicated and gstreamer doesn't support all the needed caps to do this
    * correctly. For example, when we have an odd offset, we should only combine
    * 1 row/column of luma samples with one chroma sample in colorspace conversion. 
-   * We compensate for this by adding a block border around the image when the
+   * We compensate for this by adding a black border around the image when the
    * offset or size is odd (see above).
    */
   {
diff --git a/ext/theora/theoraenc.c b/ext/theora/theoraenc.c
index cc05eca264..7c7a898925 100644
--- a/ext/theora/theoraenc.c
+++ b/ext/theora/theoraenc.c
@@ -365,9 +365,13 @@ theora_buffer_from_packet (GstTheoraEnc * enc, ogg_packet * packet,
     GstClockTime timestamp, GstClockTime duration)
 {
   GstBuffer *buf;
+  GstFlowReturn ret;
+
+  ret = gst_pad_alloc_buffer (enc->srcpad,
+      GST_BUFFER_OFFSET_NONE, packet->bytes, GST_PAD_CAPS (enc->srcpad), &buf);
+  if (ret != GST_FLOW_OK)
+    goto no_buffer;
 
-  buf = gst_pad_alloc_buffer (enc->srcpad,
-      GST_BUFFER_OFFSET_NONE, packet->bytes, GST_PAD_CAPS (enc->srcpad));
   memcpy (GST_BUFFER_DATA (buf), packet->packet, packet->bytes);
   GST_BUFFER_OFFSET (buf) = enc->bytes_out;
   GST_BUFFER_OFFSET_END (buf) = packet->granulepos;
@@ -381,10 +385,14 @@ theora_buffer_from_packet (GstTheoraEnc * enc, ogg_packet * packet,
   } else {
     GST_BUFFER_FLAG_SET (buf, GST_BUFFER_FLAG_DELTA_UNIT);
   }
-
   enc->packetno++;
 
   return buf;
+
+no_buffer:
+  {
+    return NULL;
+  }
 }
 
 /* push out the buffer and do internal bookkeeping */
@@ -482,8 +490,6 @@ theora_enc_chain (GstPad * pad, GstBuffer * buffer)
 
   in_time = GST_BUFFER_TIMESTAMP (buffer);
 
-  GST_STREAM_LOCK (pad);
-
   /* no packets written yet, setup headers */
   if (enc->packetno == 0) {
     GstCaps *caps;
@@ -576,8 +582,11 @@ theora_enc_chain (GstPad * pad, GstBuffer * buffer)
       dst_y_stride = enc->info_width;
       dst_uv_stride = enc->info_width / 2;
 
-      newbuf = gst_pad_alloc_buffer (enc->srcpad,
-          GST_BUFFER_OFFSET_NONE, y_size * 3 / 2, GST_PAD_CAPS (enc->srcpad));
+      ret = gst_pad_alloc_buffer (enc->srcpad,
+          GST_BUFFER_OFFSET_NONE, y_size * 3 / 2, GST_PAD_CAPS (enc->srcpad),
+          &newbuf);
+      if (ret != GST_FLOW_OK)
+        goto no_buffer;
 
       dest_y = yuv.y = (guint8 *) GST_BUFFER_DATA (newbuf);
       dest_u = yuv.u = yuv.y + y_size;
@@ -681,7 +690,6 @@ theora_enc_chain (GstPad * pad, GstBuffer * buffer)
     }
     gst_buffer_unref (buffer);
   }
-  GST_STREAM_UNLOCK (pad);
 
   return ret;
 
@@ -689,13 +697,16 @@ theora_enc_chain (GstPad * pad, GstBuffer * buffer)
 header_push:
   {
     gst_buffer_unref (buffer);
-    GST_STREAM_UNLOCK (pad);
+    return ret;
+  }
+no_buffer:
+  {
+    gst_buffer_unref (buffer);
     return ret;
   }
 data_push:
   {
     gst_buffer_unref (buffer);
-    GST_STREAM_UNLOCK (pad);
     return ret;
   }
 }
diff --git a/ext/vorbis/vorbisdec.c b/ext/vorbis/vorbisdec.c
index 1d1d9173d1..7406a9bd44 100644
--- a/ext/vorbis/vorbisdec.c
+++ b/ext/vorbis/vorbisdec.c
@@ -662,11 +662,11 @@ vorbis_handle_data_packet (GstVorbisDec * vd, ogg_packet * packet)
   if (sample_count > 0) {
     GstBuffer *out;
 
-    out = gst_pad_alloc_buffer (vd->srcpad, GST_BUFFER_OFFSET_NONE,
+    result = gst_pad_alloc_buffer (vd->srcpad, GST_BUFFER_OFFSET_NONE,
         sample_count * vd->vi.channels * sizeof (float),
-        GST_PAD_CAPS (vd->srcpad));
+        GST_PAD_CAPS (vd->srcpad), &out);
 
-    if (out != NULL) {
+    if (result == GST_FLOW_OK) {
       float *out_data = (float *) GST_BUFFER_DATA (out);
 
       copy_samples (out_data, pcm, sample_count, vd->vi.channels);
diff --git a/gst/audioconvert/bufferframesconvert.c b/gst/audioconvert/bufferframesconvert.c
index e760ee1665..b1ad70534a 100644
--- a/gst/audioconvert/bufferframesconvert.c
+++ b/gst/audioconvert/bufferframesconvert.c
@@ -299,6 +299,8 @@ buffer_frames_convert_chain (GstPad * pad, GstBuffer * buf)
   gfloat *data_out;
   gint i, samples_in, samples_in_remaining, samples_out_remaining,
       out_buffer_samples;
+  GstFlowReturn ret;
+
 
   this = (BufferFramesConvert *) GST_OBJECT_PARENT (pad);
 
@@ -358,9 +360,13 @@ buffer_frames_convert_chain (GstPad * pad, GstBuffer * buf)
   } else {
     /* otherwise make a leftover buffer if it's necessary */
     if (samples_in_remaining) {
-      buf_out =
+      ret =
           gst_pad_alloc_buffer (this->srcpad, 0,
-          out_buffer_samples * sizeof (gfloat), GST_PAD_CAPS (this->srcpad));
+          out_buffer_samples * sizeof (gfloat), GST_PAD_CAPS (this->srcpad),
+          &buf_out);
+      if (ret != GST_FLOW_OK)
+        goto done;
+
       data_out = (gfloat *) GST_BUFFER_DATA (buf_out);
       this->buf_out = buf_out;
       this->samples_out_remaining = out_buffer_samples - samples_in_remaining;
@@ -368,8 +374,10 @@ buffer_frames_convert_chain (GstPad * pad, GstBuffer * buf)
         *(data_out++) = *(data_in++);
     }
   }
+  ret = GST_FLOW_OK;
 
+done:
   gst_buffer_unref (buf_in);
 
-  return GST_FLOW_OK;
+  return ret;
 }
diff --git a/gst/ffmpegcolorspace/gstffmpegcolorspace.c b/gst/ffmpegcolorspace/gstffmpegcolorspace.c
index 3778d87372..c46f2cdab2 100644
--- a/gst/ffmpegcolorspace/gstffmpegcolorspace.c
+++ b/gst/ffmpegcolorspace/gstffmpegcolorspace.c
@@ -98,8 +98,8 @@ static void gst_ffmpegcsp_set_property (GObject * object,
 static void gst_ffmpegcsp_get_property (GObject * object,
     guint prop_id, GValue * value, GParamSpec * pspec);
 
-static GstBuffer *gst_ffmpegcsp_bufferalloc (GstPad * pad, guint64 offset,
-    guint size, GstCaps * caps);
+static GstFlowReturn gst_ffmpegcsp_bufferalloc (GstPad * pad, guint64 offset,
+    guint size, GstCaps * caps, GstBuffer ** buf);
 static GstFlowReturn gst_ffmpegcsp_chain (GstPad * pad, GstBuffer * buffer);
 static GstElementStateReturn gst_ffmpegcsp_change_state (GstElement * element);
 
@@ -385,22 +385,23 @@ gst_ffmpegcsp_init (GstFFMpegCsp * space)
   space->palette = NULL;
 }
 
-static GstBuffer *
+static GstFlowReturn
 gst_ffmpegcsp_bufferalloc (GstPad * pad, guint64 offset, guint size,
-    GstCaps * caps)
+    GstCaps * caps, GstBuffer ** buf)
 {
-  GstBuffer *buf;
+  GstFlowReturn ret;
   GstFFMpegCsp *space;
 
   space = GST_FFMPEGCSP (GST_PAD_PARENT (pad));
 
   if ((space->from_pixfmt == space->to_pixfmt) &&
       space->from_pixfmt != PIX_FMT_NB) {
-    buf = gst_pad_alloc_buffer (space->srcpad, offset, size, caps);
+    ret = gst_pad_alloc_buffer (space->srcpad, offset, size, caps, buf);
   } else {
-    buf = NULL;
+    *buf = NULL;
+    ret = GST_FLOW_OK;
   }
-  return buf;
+  return ret;
 }
 
 static GstFlowReturn
@@ -426,9 +427,9 @@ gst_ffmpegcsp_chain (GstPad * pad, GstBuffer * buffer)
         avpicture_get_size (space->to_pixfmt, space->width, space->height);
 
     /* get buffer in prefered format, setcaps will be called when it is different */
-    outbuf = gst_pad_alloc_buffer (space->srcpad, GST_BUFFER_OFFSET_NONE, size,
-        space->src_prefered);
-    if (outbuf == NULL)
+    res = gst_pad_alloc_buffer (space->srcpad, GST_BUFFER_OFFSET_NONE, size,
+        space->src_prefered, &outbuf);
+    if (res != GST_FLOW_OK)
       goto no_buffer;
 
     /* fill from from with source data */
@@ -452,6 +453,8 @@ gst_ffmpegcsp_chain (GstPad * pad, GstBuffer * buffer)
     /* copy timestamps */
     GST_BUFFER_TIMESTAMP (outbuf) = GST_BUFFER_TIMESTAMP (buffer);
     GST_BUFFER_DURATION (outbuf) = GST_BUFFER_DURATION (buffer);
+    GST_BUFFER_OFFSET (outbuf) = GST_BUFFER_OFFSET (buffer);
+    GST_BUFFER_OFFSET_END (outbuf) = GST_BUFFER_OFFSET_END (buffer);
 
     /* we don't need source anymore */
     gst_buffer_unref (buffer);
@@ -462,11 +465,6 @@ gst_ffmpegcsp_chain (GstPad * pad, GstBuffer * buffer)
   return res;
 
   /* ERRORS */
-no_buffer:
-  {
-    gst_buffer_unref (buffer);
-    return GST_FLOW_ERROR;
-  }
 unkown_format:
   {
     GST_ELEMENT_ERROR (space, CORE, NOT_IMPLEMENTED, (NULL),
@@ -474,6 +472,11 @@ unkown_format:
     gst_buffer_unref (buffer);
     return GST_FLOW_NOT_NEGOTIATED;
   }
+no_buffer:
+  {
+    gst_buffer_unref (buffer);
+    return res;
+  }
 }
 
 static GstElementStateReturn
diff --git a/gst/videorate/gstvideorate.c b/gst/videorate/gstvideorate.c
index 9dcebe71c0..7ade9fa277 100644
--- a/gst/videorate/gstvideorate.c
+++ b/gst/videorate/gstvideorate.c
@@ -414,8 +414,6 @@ gst_videorate_chain (GstPad * pad, GstBuffer * buffer)
   if (videorate->to_fps == 0)
     return GST_FLOW_NOT_NEGOTIATED;
 
-  GST_STREAM_LOCK (pad);
-
   /* pull in 2 buffers */
   if (videorate->prevbuf == NULL) {
     /* We're sure it's a GstBuffer here */
@@ -514,7 +512,6 @@ gst_videorate_chain (GstPad * pad, GstBuffer * buffer)
     videorate->prevbuf = buffer;
   }
 done:
-  GST_STREAM_UNLOCK (pad);
 
   return res;
 }
diff --git a/gst/videotestsrc/gstvideotestsrc.c b/gst/videotestsrc/gstvideotestsrc.c
index 21d8d4e45b..49cb72a6e4 100644
--- a/gst/videotestsrc/gstvideotestsrc.c
+++ b/gst/videotestsrc/gstvideotestsrc.c
@@ -318,29 +318,14 @@ gst_videotestsrc_activate (GstPad * pad, GstActivateMode mode)
     case GST_ACTIVATE_PULL:
       break;
     case GST_ACTIVATE_PUSH:
-      /* if we have a scheduler we can start the task */
-      if (GST_ELEMENT_SCHEDULER (videotestsrc)) {
-        GST_STREAM_LOCK (pad);
-        GST_RPAD_TASK (pad) =
-            gst_scheduler_create_task (GST_ELEMENT_SCHEDULER (videotestsrc),
-            (GstTaskFunction) gst_videotestsrc_loop, pad);
-
-        gst_task_start (GST_RPAD_TASK (pad));
-        GST_STREAM_UNLOCK (pad);
-        result = TRUE;
-      }
+      result = gst_pad_start_task (pad,
+          (GstTaskFunction) gst_videotestsrc_loop, pad);
       break;
     case GST_ACTIVATE_NONE:
       /* step 1, unblock clock sync (if any) */
 
       /* step 2, make sure streaming finishes */
-      GST_STREAM_LOCK (pad);
-      /* step 3, stop the task */
-      gst_task_stop (GST_RPAD_TASK (pad));
-      gst_object_unref (GST_OBJECT (GST_RPAD_TASK (pad)));
-      GST_STREAM_UNLOCK (pad);
-
-      result = TRUE;
+      result = gst_pad_stop_task (pad);
       break;
     default:
       result = FALSE;
@@ -602,6 +587,7 @@ gst_videotestsrc_loop (GstPad * pad)
   GstVideotestsrc *videotestsrc;
   gulong newsize;
   GstBuffer *outbuf;
+  GstFlowReturn res;
 
   videotestsrc = GST_VIDEOTESTSRC (GST_PAD_PARENT (pad));
   GST_LOG_OBJECT (videotestsrc, "get");
@@ -660,18 +646,11 @@ gst_videotestsrc_loop (GstPad * pad)
   GST_LOG_OBJECT (videotestsrc, "creating buffer of %ld bytes for %dx%d image",
       newsize, videotestsrc->width, videotestsrc->height);
 
-  outbuf =
+  res =
       gst_pad_alloc_buffer (pad, GST_BUFFER_OFFSET_NONE, newsize,
-      GST_RPAD_CAPS (pad));
-
-  if (GST_BUFFER_CAPS (outbuf) != GST_PAD_CAPS (pad)) {
-    if (!gst_pad_set_caps (pad, GST_BUFFER_CAPS (outbuf))) {
-      GST_ELEMENT_ERROR (videotestsrc, CORE, NEGOTIATION, (NULL),
-          ("format wasn't accepted"));
-      gst_pad_push_event (pad, gst_event_new (GST_EVENT_EOS));
-      goto need_pause;
-    }
-  }
+      GST_PAD_CAPS (pad), &outbuf);
+  if (res != GST_FLOW_OK)
+    goto need_pause;
 
   videotestsrc->make_image (videotestsrc, (void *) GST_BUFFER_DATA (outbuf),
       videotestsrc->width, videotestsrc->height);
@@ -695,7 +674,7 @@ gst_videotestsrc_loop (GstPad * pad)
 
 need_pause:
   {
-    gst_task_pause (GST_RPAD_TASK (pad));
+    gst_task_pause (GST_PAD_TASK (pad));
   }
 }
 
diff --git a/sys/ximage/ximagesink.c b/sys/ximage/ximagesink.c
index e9eda218ab..bf6babdcff 100644
--- a/sys/ximage/ximagesink.c
+++ b/sys/ximage/ximagesink.c
@@ -1088,12 +1088,8 @@ gst_ximagesink_setcaps (GstBaseSink * bsink, GstCaps * caps)
   /* if the caps contain pixel-aspect-ratio, they have to match ours,
    * otherwise linking should fail */
   par = gst_structure_get_value (structure, "pixel-aspect-ratio");
-  if (par) {
-    if (gst_value_compare (par, ximagesink->par) != GST_VALUE_EQUAL) {
-      GST_INFO_OBJECT (ximagesink, "pixel aspect ratio does not match");
-      return FALSE;
-    }
-  }
+  if (par && gst_value_compare (par, ximagesink->par) != GST_VALUE_EQUAL)
+    goto wrong_aspect;
 
   /* Creating our window and our image */
   g_assert (GST_VIDEOSINK_WIDTH (ximagesink) > 0);
@@ -1123,6 +1119,14 @@ gst_ximagesink_setcaps (GstBaseSink * bsink, GstCaps * caps)
       GST_VIDEOSINK_WIDTH (ximagesink), GST_VIDEOSINK_HEIGHT (ximagesink));
 
   return TRUE;
+
+  /* ERRORS */
+wrong_aspect:
+  {
+    g_mutex_unlock (ximagesink->stream_lock);
+    GST_INFO_OBJECT (ximagesink, "pixel aspect ratio does not match");
+    return FALSE;
+  }
 }
 
 static GstElementStateReturn
@@ -1291,9 +1295,9 @@ gst_ximagesink_buffer_free (GstBuffer * buffer)
 }
 #endif
 
-static GstBuffer *
+static GstFlowReturn
 gst_ximagesink_buffer_alloc (GstBaseSink * bsink, guint64 offset, guint size,
-    GstCaps * caps)
+    GstCaps * caps, GstBuffer ** buf)
 {
   GstXImageSink *ximagesink;
   GstXImageBuffer *ximage = NULL;
@@ -1305,7 +1309,7 @@ gst_ximagesink_buffer_alloc (GstBaseSink * bsink, guint64 offset, guint size,
    * we should not just reconfigure ourselves yet */
   if (caps && caps != GST_PAD_CAPS (GST_VIDEOSINK_PAD (ximagesink))) {
     if (!gst_ximagesink_setcaps (bsink, caps)) {
-      return NULL;
+      return GST_FLOW_NOT_NEGOTIATED;
     }
   }
 
@@ -1342,7 +1346,9 @@ gst_ximagesink_buffer_alloc (GstBaseSink * bsink, guint64 offset, guint size,
         GST_VIDEOSINK_WIDTH (ximagesink), GST_VIDEOSINK_HEIGHT (ximagesink));
   }
 
-  return GST_BUFFER (ximage);
+  *buf = GST_BUFFER (ximage);
+
+  return GST_FLOW_OK;
 }
 
 /* Interfaces stuff */
diff --git a/sys/xvimage/xvimagesink.c b/sys/xvimage/xvimagesink.c
index 2761b892fa..96d73c5719 100644
--- a/sys/xvimage/xvimagesink.c
+++ b/sys/xvimage/xvimagesink.c
@@ -1562,9 +1562,9 @@ gst_xvimagesink_buffer_free (GstBuffer * buffer)
 }
 #endif
 
-static GstBuffer *
+static GstFlowReturn
 gst_xvimagesink_buffer_alloc (GstBaseSink * bsink, guint64 offset, guint size,
-    GstCaps * caps)
+    GstCaps * caps, GstBuffer ** buf)
 {
   GstXvImageSink *xvimagesink;
   GstXvImageBuffer *xvimage = NULL;
@@ -1575,7 +1575,7 @@ gst_xvimagesink_buffer_alloc (GstBaseSink * bsink, guint64 offset, guint size,
    * we should not just reconfigure ourselves yet */
   if (caps && caps != GST_PAD_CAPS (GST_VIDEOSINK_PAD (xvimagesink))) {
     if (!gst_xvimagesink_setcaps (bsink, caps)) {
-      return NULL;
+      return GST_FLOW_NOT_NEGOTIATED;
     }
   }
 
@@ -1617,7 +1617,9 @@ gst_xvimagesink_buffer_alloc (GstBaseSink * bsink, guint64 offset, guint size,
   if (xvimage) {
     gst_buffer_set_caps (GST_BUFFER (xvimage), caps);
   }
-  return GST_BUFFER (xvimage);
+  *buf = GST_BUFFER (xvimage);
+
+  return GST_FLOW_OK;
 }
 
 /* Interfaces stuff */