<div dir="ltr">Thanks, it works! </div> <div class="gmail_quote"><div dir="ltr">On Fri, Aug 24, 2018 at 12:47 AM Antonio Ospite <<a href="mailto:ao2@ao2.it">ao2@ao2.it</a>> wrote: </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">On Thu, 23 Aug 2018 23:59:37 +0800 kk <<a href="mailto:pinganddu90@gmail.com" target="_blank">pinganddu90@gmail.com</a>> wrote: > gst-launch-1.0 videotestsrc ! video/x-raw, format=RGB, width=300, height=300 ! ximagesink Add videoconvert before ximagesink. For data to pass from one element to the others they have to support the same format (caps) to complete the negotiation step successfully, if they don't a conversion is needed. Use "gst-launch-1.0 -v" to see more negotiation details. You can see the caps of an element with "gst-inspect-1.0 elementname". Some elements do not show all the caps properties here as they may be discovered at runtime. Look up some info about GStreamer caps and negotiation. Ciao, Antonio -- Antonio Ospite <a href="https://ao2.it" rel="noreferrer" target="_blank">https://ao2.it</a> <a href="https://twitter.com/ao2it" rel="noreferrer" target="_blank">https://twitter.com/ao2it</a> A: Because it messes up the order in which people normally read text. See <a href="http://en.wikipedia.org/wiki/Posting_style" rel="noreferrer" target="_blank">http://en.wikipedia.org/wiki/Posting_style</a> Q: Why is top-posting such a bad thing? </blockquote></div>