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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 ...
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  1. #1
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    help!!!the problem about gstreamer


    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 )

  2. #2
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    It seems correct, have you tried with the option sync=false on xvimagesink? (just add this to the last command)

  3. #3
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    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~~~

  4. #4
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    similar problem

    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.

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