Missing videoconvert before autovideosink

[oopch]

Some of the pipelines do not work unless videoconvert is added before autovideosink. I assume that this issue does not reproduce in all the systems.

gst-launch-1.0     uridecodebin uri=$PIC !     imagefreeze !     videoconvert  !  autovideosink

If I try the original recipe:

gst-launch-1.0     uridecodebin uri=$PIC !     imagefreeze   !  autovideosink

I get:
"""
Setting pipeline to PAUSED ...
Pipeline is PREROLLING ...
Got context from element 'source': gst.soup.session=context, session=(GstSoupSession)NULL;
Setting pipeline to PLAYING ...
WARNING: from element /GstPipeline:pipeline0/GstURIDecodeBin:uridecodebin0: Delayed linking failed.
Additional debug info:
gst/parse/grammar.y(540): gst_parse_no_more_pads (): /GstPipeline:pipeline0/GstURIDecodeBin:uridecodebin0:
failed delayed linking some pad of GstURIDecodeBin named uridecodebin0 to some pad of GstImageFreeze named imagefreeze0
ERROR: from element /GstPipeline:pipeline0/GstURIDecodeBin:uridecodebin0/GstQueue2:queue2-0: Internal data stream error.
Additional debug info:
../plugins/elements/gstqueue2.c(3242): gst_queue2_loop (): /GstPipeline:pipeline0/GstURIDecodeBin:uridecodebin0/GstQueue2:queue2-0:
streaming stopped, reason not-linked (-1)
Execution ended after 0:00:00.003506309
Setting pipeline to NULL ...
Freeing pipeline ...
"""