a question about rtph263pdepay caps

[Aaron]

Hi,all!

   I have some questions about the rtph263pdepay.I have the command like this:gst-launch udpsrc port=5000 caps="application/x-rtp,media=(string)video,clock-rate=(int)90000,encoding-name=(string)H263-1998"  ! rtph263pdepay  ! omx_h263dec  !  surfaceflingersink  sync=0 . It reports that the negorate failed when  rtph263pdepay negotiate with omx_h263dec . I find that the width and height are 0 when the two plugins are negorating. In the gstrtph263pdepay.c  gst_rtp_h263p_depay_parse_width_height()
function  will  parse width and height from caps.So  i want to know ,How the rtph263pdepay get the caps which gst_rtp_h263p_depay_parse_width_height function parsed ? Dose it from the command  or the sdp or the coming video stream ?
I find the note in the gstrtph263pdepay.c is "//a-framesize:<payload type number><width>-<height>,indicates FrameWidth and FrameHeight as defined in SDP."  and " //a-Width=(string)"integer\;720", a-Height=(string)"integer\;576"  ." And i set the a-Width and a-Height like the note but the command report error.What should i do for this mistake? Thank you!

Soft versions:

Factory Details:
  Long name:    RTP H263 depayloader
  Class:        Codec/Depayloader/Network/RTP
  Description:  Extracts H263/+/++ video from RTP packets (RFC 4629)
  Author(s):    Wim Taymans <[e-mail]>
  Rank:         secondary (128)

Plugin Details:
  Name:                 rtp
  Description:          Real-time protocol plugins
  Filename:             /system/plugins/libgstrtp.so
  Version:              0.10.30
  License:              LGPL
  Source module:        gst-plugins-good
  Source release date:  2011-06-15
  Binary package:       GStreamer Good Plug-ins source release
  Origin URL:           Unknown package origin

GObject
 +----GstObject
       +----GstElement
             +----GstBaseRTPDepayload
                   +----GstRtpH263PDepay

Pad Templates:
  SINK template: 'sink'
    Availability: Always
    Capabilities:
      application/x-rtp
                  media: video
                payload: [ 96, 127 ]
             clock-rate: [ 1, 2147483647 ]
          encoding-name: H263-1998
      application/x-rtp
                  media: video
                payload: [ 96, 127 ]
             clock-rate: [ 1, 2147483647 ]
          encoding-name: H263-2000

  SRC template: 'src'
    Availability: Always
    Capabilities:
      video/x-h263
                variant: itu


Element Flags:
  no flags set

Element Implementation:
  Has change_state() function: 0x403f9451

Element has no clocking capabilities.
Element has no indexing capabilities.
Element has no URI handling capabilities.

Pads:
  SRC: 'src'
    Implementation:
      Has getcapsfunc(): gst_pad_get_fixed_caps_func
      Has acceptcapsfunc(): gst_pad_acceptcaps_default
    Pad Template: 'src'
  SINK: 'sink'
    Implementation:
      Has chainfunc(): 0x4044e361
      Has custom eventfunc(): 0x4044e315
      Has setcapsfunc(): 0x4044ea61
      Has acceptcapsfunc(): gst_pad_acceptcaps_default
    Pad Template: 'sink'

Element Properties:
  name                : The name of the object
                        flags: readable, writable
                        String. Default: null Current: "rtph263pdepay0"
  queue-delay         : Amount of ms to queue/buffer, deprecated
                        flags: readable, writable
                        Unsigned Integer. Range: 0 - 4294967295 Default: 0 Current: 0


BR

Aaron