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Bug 758943 - SEGV using rtpj2kdepay & openjpegdec
SEGV using rtpj2kdepay & openjpegdec
Product: GStreamer
Classification: Platform
Component: gst-plugins-good
Other Linux
: Normal normal
: 1.6.3
Assigned To: GStreamer Maintainers
GStreamer Maintainers
Depends on:
Reported: 2015-12-02 10:43 UTC by Pierre Lamot
Modified: 2015-12-18 10:10 UTC
See Also:
GNOME target: ---
GNOME version: ---

Test without buffer list in the RTP payloader (1.62 KB, patch)
2015-12-17 14:27 UTC, Vincent Dehors
committed Details | Review

Description Pierre Lamot 2015-12-02 10:43:09 UTC
The element rtpj2kpay raise a SIGSEGV signal with Gstreamer 1.6.1 (tested on Arch 4.2.5 and Debian testing). This bug is not present on Gstreamer 1.4.4

The pipeline used for test is: 
gst-launch-1.0 videotestsrc do-timestamp=true is-live=true ! video/x-raw,format=I420,framerate=10/1 !openjpegenc ! rtpj2kpay ! rtpj2kdepay ! openjpegdec ! fakesink

0:00:00.012015892 10449      0x23eb6d0 FIXME                default gstutils.c:3766:gst_pad_create_stream_id_internal:<videotestsrc0:src> Creating random stream-id, consider implementing a deterministic way of creating a stream-id
Passage du pipeline à la phase PLAYING…
0:00:00.012153310 10449      0x23eb6d0 FIXME           videodecoder gstvideodecoder.c:1057:gst_video_decoder_drain_out:<openjpegdec0> Sub-class should implement drain()
New clock: GstSystemClock
Spinning.  Please run 'gdb gst-launch-1.0 10449' to continue debugging, Ctrl-C to quit, or Ctrl-\ to dump core.

This might be an interaction between rtpj2kdepay and openjpegdec since theses pipelines doesn't crash

videotestsrc do-timestamp=true  is-live=true ! video/x-raw,format=I420,framerate=10/1 !  openjpegenc ! openjpegdec ! fakesink

videotestsrc do-timestamp=true  is-live=true ! video/x-raw,format=ARGB,framerate=10/1 !  openjpegenc !  rtpj2kpay ! rtpj2kdepay ! fakesink

This problem might be linked to bug 756422
Comment 1 Vincent Dehors 2015-12-17 14:24:13 UTC
I got the same problem with gstreamer 1.6.2.

The following pipeline causes a SEGFAULT while processing the first image in the element "openjpegdec" :
gst-launch-1.0 videotestsrc ! video/x-raw, format=I420 ! openjpegenc ! rtpj2kpay ! rtpj2kdepay ! openjpegdec ! videoconvert ! autovideosink sync=false

BUT the following one does not crash :
gst-launch-1.0 videotestsrc ! video/x-raw, format=I420 ! openjpegenc ! openjpegdec ! videoconvert ! autovideosink sync=false

The RTP deplayloader pushed buffer list but openjpegdec does not seem to be able to handle "parted" frame.

For example, the "rtpj2kdepay" use "gst_rtp_base_depayload_push_list (depayload, buflist);" to push several small buffer. The concatenation of all small buffer of the buffer list corresponds to a video frame. The element "openjpegdec" has a callback for frame processing : "gst_openjpeg_dec_handle_frame()". But the buffer "frame->input_buffer" in this callback is not the whole frame, this is only "one" buffer of the buffer list pushed by the depayloader.

If I changed the depayloader to push whole buffer, the first commande is working fine (see patch).

Why does buffer list have been introduced in this depayloader ? Should we do something in the decoder to continue to use buffer list ?
Comment 2 Vincent Dehors 2015-12-17 14:27:37 UTC
Created attachment 317564 [details] [review]
Test without buffer list in the RTP payloader
Comment 3 Sebastian Dröge (slomo) 2015-12-17 14:59:45 UTC
This fixes the crash at least, we shouldn't crash on decoding errors. But the RTP payloader or depayloader is somehow generating broken data here.

commit 9b4611ccae8df20b70644be82efbeab026374a6b
Author: Sebastian Dröge <>
Date:   Thu Dec 17 15:56:57 2015 +0100

    openjpegdec: Don't crash when decoding returns NULL data for any component
Comment 4 Sebastian Dröge (slomo) 2015-12-17 15:03:29 UTC
Your patch is correct, I was just starting to do the same :) Using a buffer list here doesn't make sense. We need one JPEG2000 frame per buffer.
Comment 5 Sebastian Dröge (slomo) 2015-12-17 15:05:42 UTC
commit c1b66a63acd3b9eaa638ca322b4b52a55085aa53
Author: Vincent Dehors <>
Date:   Thu Dec 17 16:03:04 2015 +0100

    rtpj2kdepay: Push one JPEG2000 frame per buffer, not a buffer list with multiple buffers
Comment 6 Sebastian Dröge (slomo) 2015-12-17 15:08:14 UTC
I'll backport both fixes to 1.6 later. Thanks!