如何使用Gstreamer硬解码rtsp流?

我尝试使用命令:gst-launch-1.0 rtspsrc location=rtsp://192.168.0.134:554/test ! rtph264depay ! decodebin ! videoconvert ! videoscale ! video/x-raw,width=1280,height=720 ! autovideosink
但此时的延迟是两秒多。
将命令中的decodebin替换为mppvideodec后则打不开流:

setting pipeline to NuLL 
Freeing pipeline 

请问想要使用Gstreamer硬解码rtsp H264流应该如何正确搭建pipeline?

试试这个?

gst-launch-1.0 rtspsrc location=rtsp://192.168.0.134:554/test ! rtph264depay ! h264parse ! mppvideodec ! videoconvert ! videoscale ! video/x-raw,width=1280,height=720 ! autovideosink