GstOverlay and gtk : Display without padding (Black strips) - c++

Question

I render my streaming in a wxWidget ImagePanel (m_renderwindow in my code) like in the picture : Image. The problem is that I have padding at top and bottom and I don't succeed to remove it. I Try gst_video_overlay_set_render_rectangle but the area stay black and don't display the stream. Does anyone have an idea?
GstState state;
GstState pending;
GstPad* pad = nullptr;
GError* error = NULL;
GstElement* source;
GstElement* clocktime;
GstElement* textoverlay;
GstCaps* caps = gst_caps_new_simple("application/x-rtp",
"media", G_TYPE_STRING, "video",
"payload", G_TYPE_INT, 96,
"encoding-name", G_TYPE_STRING, "H264",
NULL);
(*ptrstats).pipeline = gst_parse_launch("udpsrc name=source !rtph264depay !h264parse !avdec_h264 ! videoconvert !d3dvideosink name=mysink sync=false ", &error);
if (!(*ptrstats).pipeline) {
outfile << "Load video : ", error->message, "\n";
exit(1);
}
source = gst_bin_get_by_name(GST_BIN((*ptrstats).pipeline), "source");
g_object_set(G_OBJECT(source), "caps", caps, NULL);
g_object_set(G_OBJECT(source), "port", m_port, NULL);
pad = gst_element_get_static_pad(source, "src");
gst_pad_add_probe(pad, GST_PAD_PROBE_TYPE_BUFFER, (GstPadProbeCallback)buffer_out_cb, ptrstats, NULL);
gst_object_unref(pad);
#ifdef __WXGTK__
outfile << "__WXGTK__\n";
GstElement* sink = gst_bin_get_by_name((GstBin*)(*ptrstats).pipeline, "mysink");
gst_video_overlay_set_window_handle(GST_VIDEO_OVERLAY(sink), m_xid);
#elif defined __WXMSW__
GstElement* sink = gst_bin_get_by_name((GstBin*)(*ptrstats).pipeline, "mysink");
WXWidget hwnd = m_renderWindow->GetHandle();
//gst_video_overlay_set_render_rectangle(GST_VIDEO_OVERLAY(sink), 0, 0, 1224, 1024);
gst_video_overlay_set_window_handle(GST_VIDEO_OVERLAY(sink),
reinterpret_cast<guintptr>(hwnd));
#endif
gst_element_set_state((*ptrstats).pipeline, GST_STATE_PLAYING);
SOLUTION : add d3dvideosink force-aspect-ratio=false