mirror of
https://gitlab.freedesktop.org/gstreamer/gstreamer.git
synced 2024-12-22 08:17:01 +00:00
89 lines
1.3 KiB
Text
89 lines
1.3 KiB
Text
|
The clock
|
||
|
|
---------
|
||
|
|
|
||
|
|
The clock always returns reference time
|
||
|
|
|
||
|
|
Element State change
|
||
|
|
--------------------
|
||
|
|
|
||
|
|
Each element receives the current clock reference time
|
||
|
|
in the state change function.
|
||
|
|
|
||
|
|
On PAUSED to PLAYING
|
||
|
|
|
||
|
|
An element starts sending buffers with timestamp
|
||
|
|
reftime + internal counter
|
||
|
|
|
||
|
|
After a seek, the element sets internal counters to 0
|
||
|
|
|
||
|
|
|
||
|
|
Bin state change
|
||
|
|
----------------
|
||
|
|
|
||
|
|
PAUSED to PLAYING
|
||
|
|
|
||
|
|
bin propagates clock time to children
|
||
|
|
|
||
|
|
|
||
|
|
Toplevel bin state change
|
||
|
|
-------------------------
|
||
|
|
|
||
|
|
PAUSED to PLAYING
|
||
|
|
|
||
|
|
start time is set to ref time
|
||
|
|
stream time is thus 0
|
||
|
|
|
||
|
|
start time is sent to state change of children
|
||
|
|
|
||
|
|
|
||
|
|
use case 1
|
||
|
|
----------
|
||
|
|
|
||
|
|
filesrc ! mad ! osssink
|
||
|
|
|
||
|
|
pipeline PAUSED to PLAYING:
|
||
|
|
|
||
|
|
start time = ref time
|
||
|
|
|
||
|
|
filesrc state change gets starttime
|
||
|
|
mad state change gets starttime
|
||
|
|
osssink state change gets starttime
|
||
|
|
|
||
|
|
mad sends buffers with timestamp starttime + internal counter
|
||
|
|
osssink syncs these samples against the clock with starttime + timestamp
|
||
|
|
|
||
|
|
PLAYING to PAUSED
|
||
|
|
|
||
|
|
nothing happens
|
||
|
|
|
||
|
|
use case 2
|
||
|
|
----------
|
||
|
|
|
||
|
|
{ filesrc ! mad ! queue } ! osssink
|
||
|
|
|
||
|
|
let it play for a while
|
||
|
|
PAUSE the thread
|
||
|
|
PLAY the thread
|
||
|
|
thread is not the toplevel bin, use same starttime as when
|
||
|
|
it first started.
|
||
|
|
do state change on elements with same starttime
|
||
|
|
|
||
|
|
use case 3
|
||
|
|
----------
|
||
|
|
|
||
|
|
filesrc ! mad ! mixer ! osssink
|
||
|
|
|
||
|
|
!
|
||
|
|
filesrc ! mad !-^
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
|