diff options
author | Wim Taymans <wim.taymans@collabora.co.uk> | 2010-09-01 11:34:01 +0200 |
---|---|---|
committer | Wim Taymans <wim.taymans@collabora.co.uk> | 2010-09-01 11:34:34 +0200 |
commit | 70617be38e9767c4209c7e877f31402ca492b776 (patch) | |
tree | 1e22edef92187d5c57bfbae1392e1581896139c6 | |
parent | 0107c7e793fed42eecf2797c7837c1f8f2059180 (diff) |
manual: improve clock docs a little
-rw-r--r-- | docs/manual/advanced-clocks.xml | 20 |
1 files changed, 13 insertions, 7 deletions
diff --git a/docs/manual/advanced-clocks.xml b/docs/manual/advanced-clocks.xml index 0435091312..2ab1350bc3 100644 --- a/docs/manual/advanced-clocks.xml +++ b/docs/manual/advanced-clocks.xml @@ -51,9 +51,10 @@ <function>gst_clock_get_time ()</function>. The clock-time does not need to start at 0. The pipeline, which contains the global clock that all elements in the pipeline will use, in addition has a <quote>base - time</quote>, which is the clock time at the the point where media time - is starting from zero. This timestamp is subtracted from the clock - time, and that value is returned by <function>_get_time ()</function>. + time</quote>, which is the clock time at the the point where the + pipeline went to the PLAYING state. Each element can subtract the + <quote>base time</quote> from the clock-time to know the current + running time. </para> <para> The clock provider is responsible for making sure that the clock time @@ -70,10 +71,15 @@ Clock slaves get assigned a clock by their containing pipeline. Their task is to make sure that media playback follows the time progress as represented by this clock as closely as possible. For most elements, - that will simply mean to wait until a certain time is reached before - playing back their current sample; this can be done with the function - <function>gst_clock_id_wait ()</function>. Some elements may need to - support dropping samples too, however. + that will simply mean to wait until the buffer running-time is reached + before playing back their current sample. + </para> + <para> + The buffer running-time is derived from the buffer timestamp and the + newsegment event preceeding the buffer. A buffer is played synchronized + with the clock when the clock's running-time has reached exactly the + buffer running-time; this can be done with the function + <function>gst_clock_id_wait ()</function>. </para> <para> For more information on how to write elements that conform to this |