Le vendredi 01 mars 2019 à 11:19 +0100, Hans Verkuil a écrit : > > $ gst-launch-1.0 videotestsrc num-buffers=120 ! video/x-raw,format=RGB,width=322,height=200 ! v4l2video0convert disable-passthrough=1 ! video/x-raw,width=428,height=400 ! videoconvert ! xvimagesink > > But you explicitly set different resolutions for source and sink. > What happens in gstreamer if the driver doesn't support scaling? Will > gstreamer continue with wrong values? Give an error? It will post an error or type NOT_NEGOTIATED after failing to set the OUTPUT or CAPTURE format. It does assume your converter driver do scaling though, the caps negotiation is written in a way that it will first try to avoid it. So if it's unavoidable, and your driver does not support scaling, it's also unavoidable that negotiation will fail. In the case of this test pipeline, you cannot test scaling without forcing the width/height on both side of it. Because videotestsrc can produce frames at any raw video format mapped into GStreamer. Then xvimagesink does scaling, so it would accept any given videotestsrc resolution without the need for scaling. Nicolas
