help!!!the problem about gstreamer

[guoyuehua]

My tutor wants to me for programming for capturing the picture from
webcam. I use v4l for realizing the function . serverl days age , I look the webpags from the websites .I found the gstreamer can realize this function just running some command line .
As following :
on the sender :
gst-launch -v v4lsrc ! ffenc_mpeg4 ! rtpmp4vpay ! udpsink host =127.0.0.1 port=10000

on the reciver:
gst-launch udpsrc port=10000 caps="application/x-rtp, media=(string)video, payload=(int)96, clock-rate=(int)90000, encoding-name=(string)MP4V-ES, ssrc=(guint)316354176, clock-base=(guint)1519933345, seqnum-base=(guint)7963, profile-level-id=(string)1, config=(string)000001b001000001b589130000010000000 12000c48d8800ce18102030a31f000001b24c61766335312e3 1342e30 " ! rtpmp4vdepay ! ffdec_mpeg4 ! xvimagesink

The result is that there is the black screen in my desktop.
I donot kown the reason ~~~
If i can get your reply , I am very appreciate it ~(by the way ,my english is very poor )

[flo77]

It seems correct, have you tried with the option sync=false on xvimagesink? (just add this to the last command)

[guoyuehua]

Firstly,thank you very much for your reply~
Now, I use the "tcpclientsink" and "tcpserversrc",this can realize the function , and "sync=false" can reduce the time delay caused by the loss packages.
How should i use rtp and udp to realize the function?
Thanks~~~

[argesino]

I have also a similar problem: if i do this:

Server side: gst-launch tcèserversrc host=127.0.0.1 port=3000 ! decodebin ! ffmpegcolorspace ! videorate !videoscale ! capsfilter caps=video/x-raw-rgb,bpp=24,width=640,height=480 ! autovideosink

Client side: gst-launch filesrc location="/home/argesino" ! tcpclientsink host=127.0.0.1 port=3000

It works well !

But if I try to do the same with udpsrc and udpsink encoding the video taken with v4l with theora in this manner (as written in the documentation http://gstreamer.freedesktop.org/dat...session.html):
Server side: gst-launch videotestsrc ! theoraenc ! rtptheorapay ! .send_rtp_sink gstrtpsession .send_rtp_src ! udpsink port=5000
Client side: gst-launch udpsrc port=5000 caps="application/x-rtp" ! .recv_rtp_sink gstrtpsession .recv_rtp_src ! rtptheoradepay ! theoradec ! autovideosink

it give me this error:
ERRORE: from element /pipeline0/udpsrc0: internal errore in the low of dates.
Additive debug information:
gstbasesrc.c(2099): gst_base_src_loop (): /pipeline0/udpsrc0:
streaming task paused, reason not-negotiated (-4)
Execution ended after 23170198000 ns.

Any suggestion? Could be the problem related with the version of the libraries? I had other problems that I have resolves so. But in this case probably there is a problem in the pipeline's construction.