Trying to diagnose a READY --> PAUSED transition bug

David Ing ding at
Tue Mar 26 16:08:48 UTC 2019

Keith -- I'm afraid I don't know anything about segments, but the log does
say that the filesink ignored the message.  So I am guessing that it isn't
the problem, but I will investigate that further.

Thibault -- It does look like there was an issue with caps negotiation
(from the diagram).  I will definitely investigate that further.

Nicolas -- An excellent suggestion.  I may need to go down that road.

Also:  I just learned that when I use a different muxer (qtmux) and encoder
(voaacenc), the pipeline does enter the PLAYING state ... but the job takes
a very long time (2:53) to create the audio composition (only 1:16 of audio

I will keep investigating.  Thanks for all your suggestions so far.

On Tue, Mar 26, 2019 at 6:20 AM Nicolas Dufresne <nicolas at>

> Le lun. 25 mars 2019 17 h 26, David Ing <ding at> a écrit :
>> I am using Gstreamer 1.14.4.  I am having an issue with one of my
>> pipelines on Windows.  I attached an SVG file which shows my pipeline at
>> the point in time when it gets stuck.  The issue occurs when I try to move
>> my pipeline from READY to PAUSED.  I do this by calling
>> gst_element_set_state(gstPipeline, GST_STATE_PAUSED), and after that call
>> is made, I see all elements within the pipeline transition to PAUSED except
>> the *GstFileSink which remains stuck in READY*.
>> Also:
>>    - The issue does not repro on Linux (only Windows).
>>    - I use the same basic code to render many other kinds of jobs and I
>>    never have a problem with the GstFileSink.  It is only for this one
>>    specific pipeline that I have the problem.
>>    - I am 100% certain that this isn't some kind of file system issue
>>    (e.g. folder permissions).
>> For logging I set the the "filesink" category to TRACE and this is the
>> entirety of what it shows me:
>> Pipeline is in NULL state, as I connect the muxer to the filesink I see
>> this:
>> 19-03-25T20:44:19.420327 INFO    filesink gstfilesink.c:294 filename :
>> C:\dev\github\panopto\panopto-core\Debug\x64\test-scratch\2019-03-25T20-44-11.942351\CompositionTests\Debug\0ed40ba8-7d3d-4569-8294-aa02017efdfc-9531e8a6-d94f-44ed-a79a-aa0b0008a713.mp4
>> 19-03-25T20:44:19.420327 INFO    filesink gstfilesink.c:295 uri      :
>> file:///C:/dev/github/panopto/panopto-core/Debug/x64/test-scratch/2019-03-25T20-44-11.942351/CompositionTests/Debug/0ed40ba8-7d3d-4569-8294-aa02017efdfc-9531e8a6-d94f-44ed-a79a-aa0b0008a713.mp4
>> Immediately after I call  gst_element_set_state(gstPipeline,
>> GST_STATE_READY)  , I see:
>> 19-03-25T20:44:19.458327 DEBUG   filesink gstfilesink.c:516 Seeking to
>> offset 0 using fseeko
>> 19-03-25T20:44:19.458327 DEBUG   filesink gstfilesink.c:416 opened file
>> C:\dev\github\panopto\panopto-core\Debug\x64\test-scratch\2019-03-25T20-44-11.942351\CompositionTests\Debug\0ed40ba8-7d3d-4569-8294-aa02017efdfc-9531e8a6-d94f-44ed-a79a-aa0b0008a713.mp4,
>> seekable 1
>> 6.3 seconds after I call  gst_element_set_state(gstPipeline,
>> GST_STATE_PAUSED)  , I see:
>> 19-03-25T20:44:25.853308 DEBUG   filesink gstfilesink.c:586 Ignored
>> SEGMENT event of format 3 (time)
>> My best guess is that it's some kind of rare timing bug within gstreamer
>> (which most pipelines are lucky to avoid).
>> I am looking for tips about how to diagnose the exact cause of this bug:
>> But keep in mind that I have no debug symbols because I'm on Windows.
> Windows build have debug symbols, but only gdb format. You can download
> gdb for Windows in order to trace. Best experience is if you have made your
> own build, since then it will be able to map to the source code. Another
> note, there has been load of work done to support a subset of the build,
> using msvc, that is currently in GStreamer master of cerbero as a variant
> (-v msvc iirc)
> _______________________________________________
>> gstreamer-devel mailing list
>> gstreamer-devel at
> _______________________________________________
> gstreamer-devel mailing list
> gstreamer-devel at
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <>

More information about the gstreamer-devel mailing list