Caps Negotiation Confusion.

[Stirling Westrup]

Even more info: If I run my pipeline under valgrind's helgrind tool,
it works. I do get a bunch of errors reported by helgrind though. I'm
hoping one or more of them will shed some light on things.

On Tue, Jan 29, 2013 at 2:05 PM, Stirling Westrup <swestrup at gmail.com> wrote:
> Reading through the above log, I am more confused than ever. As far as
> I can tell, full caps negotiation does take place (although it happens
> far later than I expected) and all the elements *seem* to accept the
> caps event they get (I say seems because I'm not 100% sure what all
> the debug statements actually mean).
>
> However my graph dump once in the playing state still doesn't show
> correctly negotiated caps. I don't get it.
>
>
> On Mon, Jan 28, 2013 at 4:20 PM, Stirling Westrup <swestrup at gmail.com> wrote:
>> Okay, here's some more info. I'm working on a project to display video
>> content on a video wall made up of a rectangular array of monitors.
>> Right now it works fine if I just play video files, but my boss would
>> like me to be able to show live content as well, such as a video
>> camera feed, or a capture from an X session. This latter is what I
>> chose to implement first, and its what I'm now trying to debug. To
>> simplify the tests, this example just reads from a single source and
>> outputs it to a single monitor, but the program is intended to be able
>> to handle multiple video and audio channels and to dynamically
>> reconfigure things while a source is playing, hence the complexity of
>> the pipeline.
>>
>> Alas I cannot just upload my code to a public forum as this thing will
>> eventually be commercial. However I can upload selected portions if
>> need be.
>>
>> In the meantime, here's a pair of .png graphs. One from launch showing
>> what shape I expect the pipeline to be in, and one from my program
>> (named 'vaal') showing the actual state of things once I enter the
>> PAUSED state.
>>
>> https://docs.google.com/file/d/0BwCOnjTaGreOOHlUVW5WcEQtelU/edit
>> https://docs.google.com/file/d/0BwCOnjTaGreOZWVnbElzOEtxYmM/edit
>>
>> And finally, here's a full-blown debug trace of me running the program
>> and it getting all the way into the playing state without actually
>> ever delivering any data to the output screen:
>>
>> https://docs.google.com/file/d/0BwCOnjTaGreOTFRUUGhESGtZZE0/edit
>>
>> On Mon, Jan 28, 2013 at 1:31 PM, Tim-Philipp Müller <t.i.m at zen.co.uk> wrote:
>>> On Mon, 2013-01-28 at 11:41 -0500, Stirling Westrup wrote:
>>>
>>>> Right now I have an interesting problem in that caps negotiation is
>>>> not completing in my pipeline. This has to be a side effect of
>>>> dynamically building the pipeline in stages as caps negotiation
>>>> completes and gives the expected results if I build and run an exact
>>>> copy of the pipeline via gst-launch.
>>>>
>>>> For background, my pipeline can either run in pull or push mode. It
>>>> runs in pull mode when I supply a file video source, and in push mode
>>>> when I supply a live video source (like an X session capture).
>>>>
>>>> In pull mode, everything works fine. In push mode, the pipeline
>>>> successfully gets into the PAUSED state and a gst_pad_query_caps of
>>>> source pad at the end of the video processing chain returns a fixed
>>>> set of caps, as I would hope. However a call to
>>>> gst_pad_get_current_caps at that same location always returns ANY. A
>>>> dot-dump of the pipeline at that point shows that essentially no
>>>> negotiation has taken place, at all.
>>>>
>>>> I can't figure out what I need to do to ensure the pipeline completes
>>>> negotiation.
>>>
>>> It would be easier to help with some more information, such as:
>>>
>>>  - pipeline
>>>  - code
>>>  - png graph
>>>
>>> Otherwise one can just say: check backwards which pads get negotiated
>>> and not, somewhere a caps event (1.0) or buffer (0.10) must not have
>>> gone through.
>>>
>>>  Cheers
>>>   -Tim
>>>
>>>
>>> _______________________________________________
>>> gstreamer-devel mailing list
>>> gstreamer-devel at lists.freedesktop.org
>>> http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel
>>
>>
>>
>> --
>> Stirling Westrup
>> Programmer, Entrepreneur.
>> https://www.linkedin.com/e/fpf/77228
>> http://www.linkedin.com/in/swestrup
>> http://technaut.livejournal.com
>> http://sourceforge.net/users/stirlingwestrup
>
>
>
> --
> Stirling Westrup
> Programmer, Entrepreneur.
> https://www.linkedin.com/e/fpf/77228
> http://www.linkedin.com/in/swestrup
> http://technaut.livejournal.com
> http://sourceforge.net/users/stirlingwestrup



-- 
Stirling Westrup
Programmer, Entrepreneur.
https://www.linkedin.com/e/fpf/77228
http://www.linkedin.com/in/swestrup
http://technaut.livejournal.com
http://sourceforge.net/users/stirlingwestrup