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Bug 747555 - python -c 'from gi.repository import Gst; Gst.Caps.from_string("video/x-raw,format=RGB")' crashes
python -c 'from gi.repository import Gst; Gst.Caps.from_string("video/x-raw,f...
Status: RESOLVED FIXED
Product: GStreamer
Classification: Platform
Component: gst-python
1.x
Other Linux
: Normal normal
: git master
Assigned To: GStreamer Maintainers
GStreamer Maintainers
Depends on:
Blocks:
 
 
Reported: 2015-04-09 12:39 UTC by Tobias Mueller
Modified: 2015-04-24 07:24 UTC
See Also:
GNOME target: ---
GNOME version: ---


Description Tobias Mueller 2015-04-09 12:39:12 UTC 
This may be more gobject-introspection's fault, feel free to re-assign.

python -c 'from gi.repository import Gst; Gst.Caps.from_string("video/x-raw,format=RGB")'
crashes for me.

Caps.from_string("image/png") too.
Comment 1 Tobias Mueller 2015-04-09 12:40:48 UTC 



+
Trace
    234951






    

  • 
#0
gst_mini_object_init

    
                from
                /usr/lib/x86_64-linux-gnu/libgstreamer-1.0.so.0

    

    • 

  • 
#1
gst_caps_new_empty

    
                from
                /usr/lib/x86_64-linux-gnu/libgstreamer-1.0.so.0

    

    • 

  • 
#2
gst_caps_from_string

    
                from
                /usr/lib/x86_64-linux-gnu/libgstreamer-1.0.so.0

    

    • 

  • 
#3
ffi_call_unix64

    
                from
                /usr/lib/x86_64-linux-gnu/libffi.so.6

    

    • 

  • 
#4
ffi_call

    
                from
                /usr/lib/x86_64-linux-gnu/libffi.so.6

    

    • 

  • 
#5
??

    
                from
                /usr/lib/python2.7/dist-packages/gi/_gi.so

    

    • 

  • 
#6
??

    
                from
                /usr/lib/python2.7/dist-packages/gi/_gi.so

    

    • 

  • 
#7
PyObject_Call

    
                at ../Objects/abstract.c
                  line
                  2529

    

    • 

  • 
#8
do_call

    
                at ../Python/ceval.c
                  line
                  4251

    

    • 

  • 
#9
call_function

    
                at ../Python/ceval.c
                  line
                  4056

    

    • 

  • 
#10
PyEval_EvalFrameEx

    
                at ../Python/ceval.c
                  line
                  2679

    

    • 









also:  https://bugs.launchpad.net/ubuntu/+source/python2.7/+bug/1442051
....






Comment 2


Tim-Philipp Müller





          2015-04-09 12:52:35 UTC
        



Have you tried calling Gst.Init(None,None) ?






Comment 3


Tobias Mueller





          2015-04-09 12:53:14 UTC
        



nope.






Comment 4


Tim-Philipp Müller





          2015-04-09 13:03:26 UTC
        



Please try it then!

$ python -c 'from gi.repository import Gst; Gst.Caps.from_string("video/x-raw,format=RGB")'
Segmentation fault

$ python -c 'from gi.repository import Gst; Gst.init(None); print Gst.Caps.from_string("video/x-raw,format=RGB")'
<GstCaps at 0x135f590>






Comment 5


Tobias Mueller





          2015-04-09 13:39:55 UTC
        



Right. It works for me with the init.

It's annoying when the ipython shell crashes, though.






Comment 6


Olivier Crête





          2015-04-09 16:49:31 UTC
        



I wonder if we could do a clever thing with the overrides to either emit an exception if Gst.init() hasn't been called, or maybe just call it?






Comment 7


Tobias Mueller





          2015-04-09 17:15:40 UTC
        



It's certainly possible to "hide" the real API until init() has been called. In Python at least.  And I think it's way better than to crash.

I don't know much about pygi in order to assess whether this is feasible, though.






Comment 8


Thibault Saunier





          2015-04-10 09:00:07 UTC
        



(In reply to Olivier Crête from comment #6)
> I wonder if we could do a clever thing with the overrides to either emit an
> exception if Gst.init() hasn't been called, or maybe just call it?

I implemented that here: http://phabricator.freedesktop.org/D87






Comment 9


Tim-Philipp Müller





          2015-04-23 23:57:28 UTC
        



> I implemented that here: http://phabricator.freedesktop.org/D87

So what's happening with that? Now we have two bugs in two bug trackers... can we close this one (it's a WONTFIX for me for the C API).






Comment 10


Thibault Saunier





          2015-04-24 07:13:39 UTC
        



Ah, sorry forgot to close the bug.

So now if the user forget to init Gst we raise an issue like:

$ python3 -c "from gi.repository import Gst; print(Gst.Structure.from_string('video/x-raw,framerate=10/1')[0]['framerate'])"               
Traceback (most recent call last):




+
Trace
    234997






    

  • 
          File "<string>",
          line 1
            in <module>

    • 

  • 
          File "/home/thiblahute/devel/pitivi/1.0-uninstalled/gst-python/gi/overrides/Gst.py",
          line 347
            in fake_method

    raise NotInitalized("Please call Gst.init(argv) before using GStreamer") gi.overrides.Gst.NotInitalized: Please call Gst.init(argv) before using GStreamer
    

    • 













Comment 11


Thibault Saunier





          2015-04-24 07:14:20 UTC
        



commit 44931ffd9b77f0a591858bc54a104dedff3cce98
Author: Thibault Saunier <tsaunier@gnome.org>
Date:   Wed Apr 15 19:55:16 2015 +0200

    overrides: Disable all GStreamer APIs until Gst has been initialized
    
    Summary:
    And throw an exception if the user tries to call any Gst API without
    initializing gst.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=747555
    
    Reviewers: Mathieu_Du
    
    Differential Revision: http://phabricator.freedesktop.org/D87






Comment 12


Thibault Saunier





          2015-04-24 07:24:59 UTC
        



Actually I had not pushed those commit, it is done now:

commit d97662ad41e4506b4df29d66bc23607ab091aa4a
Author: Thibault Saunier <tsaunier@gnome.org>
Date:   Wed Apr 15 19:57:43 2015 +0200

    test: Bring back the testsuite and test if the initialization override works
    
    Summary:
    Simplify the Makefile taking example on pitivi and copy several pitivi
    testing files, simplifying them a bit for our use case
    
    Reviewers: Mathieu_Du
    
    Differential Revision: http://phabricator.freedesktop.org/D97

commit 6b32ccbbb250f7516f36a1ea82c0fbba8925af09
Author: Thibault Saunier <tsaunier@gnome.org>
Date:   Wed Apr 15 19:55:16 2015 +0200

    overrides: Disable all GStreamer APIs until Gst has been initialized
    
    Summary:
    And throw an exception if the user tries to call any Gst API without
    initializing gst.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=747555
    
    Reviewers: Mathieu_Du
    
    Differential Revision: http://phabricator.freedesktop.org/D87