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| author | Thibault Saunier <tsaunier@gnome.org> | 2016-12-05 18:16:34 -0300 |
|---|---|---|
| committer | Thibault Saunier <tsaunier@gnome.org> | 2016-12-06 14:08:14 -0300 |
| commit | d1c79fc1774c80873b956bfb187ad57042deedbb (patch) | |
| tree | 3f9a620c1d9acbcd516bbf5e8fa314b6dcf352c0 /docs/design/part-live-source.txt | |
| parent | dbe3d2b328113b468e19adc2ff39acc22e151069 (diff) | |
docs: Remove design doc as they have been moved to gst-docs
https://bugzilla.gnome.org/show_bug.cgi?id=775667
Diffstat (limited to 'docs/design/part-live-source.txt')
| -rw-r--r-- | docs/design/part-live-source.txt | 60 |
1 files changed, 0 insertions, 60 deletions
diff --git a/docs/design/part-live-source.txt b/docs/design/part-live-source.txt deleted file mode 100644 index 47055a5a9e..0000000000 --- a/docs/design/part-live-source.txt +++ /dev/null @@ -1,60 +0,0 @@ -Live sources ------------- - -A live source is a source that cannot be arbitrarily PAUSED without losing -data. - -A live source such as an element capturing audio or video need to be handled -in a special way. It does not make sense to start the dataflow in the PAUSED -state for those devices as the user might wait a long time between going from -PAUSED to PLAYING, making the previously captured buffers irrelevant. - -A live source therefore only produces buffers in the PLAYING state. This has -implications for sinks waiting for a buffer to complete the preroll state -since such a buffer might never arrive. - -Live sources return NO_PREROLL when going to the PAUSED state to inform the -bin/pipeline that this element will not be able to produce data in the -PAUSED state. NO_PREROLL should be returned for both READY->PAUSED and -PLAYING->PAUSED. - -When performing a get_state() on a bin with a non-zero timeout value, the -bin must be sure that there are no live sources in the pipeline because else -the get_state() function would block on the sinks. - -A gstbin therefore always performs a zero timeout get_state() on its -elements to discover the NO_PREROLL (and ERROR) elements before performing -a blocking wait. - - -Scheduling -~~~~~~~~~~ - -Live sources will not produce data in the paused state. They block in the -getrange function or in the loop function until they go to PLAYING. - - -Latency -~~~~~~~ - -The live source timestamps its data with the time of the clock at the -time the data was captured. Normally it will take some time to capture -the first sample of data and the last sample. This means that when the -buffer arrives at the sink, it will already be late and will be dropped. - -The latency is the time it takes to construct one buffer of data. This latency -is exposed with a LATENCY query. - -See part-latency.txt. - - -Timestamps -~~~~~~~~~~ - -Live sources always timestamp their buffers with the running_time of the -pipeline. This is needed to be able to match the timestamps of different live -sources in order to synchronize them. - -This is in contrast to non-live sources, which timestamp their buffers starting -from running_time 0. - |