+++ This bug was initially created as a clone of Bug #433491 +++

# gst-launch -v filesrc location=/MEDIA/test_qcif.m4v ! ffdec_mpeg4 ! identity ! ffmpegcolorspace ! videoscale ! autovideosink

--> LOG
..........................
[gstffmpegdec.c:1666] [gst_ffmpegdec_sink_event]
/pipeline0/identity0: last-message = "event   ******* (identity0:sink) E (type: 102, GstEventNewsegment, update=(boolean)false, rate=(double)1, applied_rate=(double)1, format=(GstFormat)GST_FORMAT_TIME, start=(gint64)0, stop=(gint64)-1, position=(gint64)0) 0x9fc20a0"
[gstffmpegdec.c:1806] [gst_ffmpegdec_chain]
ERROR: from element /pipeline0/ffdec_mpeg40: Internal GStreamer error: negotiation problem.  Please file a bug at http://bugzilla.gnome.org/enter_bug.cgi?product=GStreamer.
Additional debug info:
gstffmpegdec.c(2010): gst_ffmpegdec_chain (): /pipeline0/ffdec_mpeg40:
ffdec_mpeg4: input format was not set before data start
ERROR: pipeline doesn't want to preroll.
Setting pipeline to NULL ...
[gstffmpegdec.c:2025] [gst_ffmpegdec_change_state]
[gstffmpegdec.c:445] [gst_ffmpegdec_close]
[gstffmpegdec.c:2025] [gst_ffmpegdec_change_state]
FREEING pipeline ...
.....

 
??? Questions!!
1) Why error occured? please tell me, solution of this ploblem.
2) What is pipeline for MPEG 4 video play?
   < What do i using element or plug-in? >

-- please help me.


ah.. using playbin plug-in, mpeg 4 video play. so command-line(gst-launch), 
manual pipeline can't play.