Pull mode and queue2

[Tim Müller]

On Wed, 2014-09-24 at 13:44 +0000, Demeyer Jonathan wrote:

Hi Jonathan,

I think you need to set some properties on queue2 to make it support
pull mode. Try: queue2 ring-buffer-max-size=1048576

But it only really makes sense (or is likely to work) if upstream is
seekable or your filter pulls buffers sequentially. And doesn't fakesrc
send 0-sized buffers by default?

Cheers
 -Tim

>  
> I'm trying to do an application using pull mode in some elements.
>  
> For testing purpose, I wrote two filters. One filter "pullfilter" uses
> pull mode for its sink and push mode for its source. The other is a
> dispenser (wrongly named "mdispatch", based on tee), source pad on
> requests and giving buffers as pullfilter requests them.
>  
> This pipeline works like expected :
> gst-launch-1.0 fakesrc can-activate-push=false ! pullfilter ! fakesink
> 
> This one also works :
> gst-launch-1.0 fakesrc ! queue2 ! pullfilter ! fakesink
>  
> With two branches, no problem :
> gst-launch-1.0 --gst-debug-level=3 fakesrc can-activate-push=false !
> mdispatch has-chain=false name=t ! pullfilter ! fakesink t. !
> pullfilter ! fakesink
> 
> But when I put a queue2 in the previous pipeline, it fails :
> gst-launch-1.0 --gst-debug=pullfilter:5 fakesrc ! queue2 ! mdispatch
> has-chain=false name=t ! pullfilter ! fakesink t. ! pullfilter !
> fakesink
> Setting pipeline to PAUSED ...
> mdispatch: Pull mode not supported by peer
> mdispatch: Push mode activated
> mdispatch: Pull mode not supported by peer
> mdispatch: Push mode activated
> 0:00:00.011082003 11673  0x80958c0 WARN                GST_PADS
> gstpad.c:974:gst_pad_set_active:<t:sink> Failed to activate pad
> ERROR: Pipeline doesn't want to pause.
> Setting pipeline to NULL ...
> Freeing pipeline ...
> 
> I doesn't see why it fails when setting a queue2 to the pipeline (I
> tested in previous pipeline if "queue2" in pull mode can works with
> fakesrc in push mode).
>  
> Is there a problem with the design ?
>  
> Thanks,
> Jonathan DEMEYER
> Software engineer
> 
> Description : MACQ Traffic &
> Automation
> 
> 
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> 
>  
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-- 
Tim Müller, Centricular Ltd - http://www.centricular.com