mirrors/gstreamer
mirrors/gstreamer
1
1
Fork 0
mirror of https://gitlab.freedesktop.org/gstreamer/gstreamer.git synced 2024-09-29 15:22:17 +00:00
Code Issues 1 Projects Releases Wiki Activity

basesink: Document the interaction between unlock() and wait_preroll()

Browse source 
This was totally non-obvious, the kind of big problem is that subclasses must
be able to unblock their streaming thread and continue exactly where they left off
on unpause!

https://bugzilla.gnome.org/show_bug.cgi?id=773912
This commit is contained in:
Olivier Crête 2016-11-04 18:54:10 -04:00
parent 5216322d39
commit e6febb5bc1
2 changed files with 12 additions and 2 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

7
libs/gst/base/gstbasesink.c
View file

@ -2239,6 +2239,13 @@ no_clock:
* against the clock it must unblock when going from PLAYING to the PAUSED state
* and call this method before continuing to render the remaining data.
*
* If the #GstBaseSinkClass.render() method can block on something else than
* the clock, it must also be ready to unblock immediately on
* the #GstBaseSinkClass.unlock() method and cause the
* #GstBaseSinkClass.render() method to immediately call this function.
* In this case, the subclass must be prepared to continue rendering where it
* left off if this function returns %GST_FLOW_OK.
*
* This function will block until a state change to PLAYING happens (in which
* case this function returns %GST_FLOW_OK) or the processing must be stopped due
* to a state change to READY or a FLUSH event (in which case this function

7
libs/gst/base/gstbasesink.h
View file

@ -122,9 +122,12 @@ struct _GstBaseSink {
* @start: Start processing. Ideal for opening resources in the subclass
* @stop: Stop processing. Subclasses should use this to close resources.
* @unlock: Unlock any pending access to the resource. Subclasses should
* unblock any blocked function ASAP
* unblock any blocked function ASAP and call gst_base_sink_wait_preroll()
* @unlock_stop: Clear the previous unlock request. Subclasses should clear
* any state they set during unlock(), such as clearing command queues.
* any state they set during #GstBaseSinkClass.unlock(), and be ready to
* continue where they left off after gst_base_sink_wait_preroll(),
* gst_base_sink_wait() or gst_wait_sink_wait_clock() return or
* #GstBaseSinkClass.render() is called again.
* @query: perform a #GstQuery on the element.
* @event: Override this to handle events arriving on the sink pad
* @wait_event: Override this to implement custom logic to wait for the event