Problems with text_overlay

[John Hanks]

I'm trying to overlay text on video.  I have successfully added static 
text but I need the text to change over time. I'm using an app_src to 
generate the text.

It looks like I have an incompatibility between my app_src and text_overlay.

I've coded this to flow as follows:

app_src -> queue -> text_overlay

I've tried to create a caps for this and using the caps in the link (it 
has worked me with KLV data):

textsrccaps =gst_caps_new_simple("text/x-raw", "format", G_TYPE_STRING, 
"pango-markup, utf8", NULL);
text_link_ok=gst_element_link_filtered(data.tqueue,data.text_overlay,textsrccaps); 


When I run with DEBUG, my output is showing this:

GST_CAPS gstutils.c:3065:gst_pad_query_caps: query returned text/x-raw, 
format=(string)"pango-markup\,\ utf8"

and text_overlay is showing this:

GST_CAPS gstutils.c:3065:gst_pad_query_caps: query returned text/x-raw, 
format=(string){ pango-markup, utf8 }

How do I set the caps so it is compatible?  I've tried "... 
G_TYPE_STRING, "{ pango-markup, utf8 }"..." but that did not help.

Thanks in advance,

John