mirrors/gstreamer
mirrors/gstreamer
1
1
Fork 0
mirror of https://gitlab.freedesktop.org/gstreamer/gstreamer.git synced 2025-06-05 15:08:53 +00:00
Code Issues 1 Projects Releases Wiki Activity

Update pipeline-manipulation.md: fix local link; fix a typo in “see”; fix “appsink” and “min-percent” formatting; fix “and/or” punctuation; improve wording (“replace”, “sink pad”, etc).

Browse source
This commit is contained in:
R Kh 2019-01-24 00:19:48 +00:00
parent b3bf274f1d
commit 182f4ed973
1 changed files with 10 additions and 10 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

20
markdown/application-development/advanced/pipeline-manipulation.md
View file

@ -77,9 +77,9 @@ Probe types:
Blocking probes are used to temporarily block pads because they are Blocking probes are used to temporarily block pads because they are
unlinked or because you are going to unlink them. If the dataflow is unlinked or because you are going to unlink them. If the dataflow is
not blocked, the pipeline would go into an error state if data is not blocked, the pipeline would go into an error state if data is
pushed on an unlinked pad. We will se how to use blocking probes to pushed on an unlinked pad. We will see how to use blocking probes to
partially preroll a pipeline. See also [Play a region of a media partially preroll a pipeline. See also [Play a section of a media
file](#play-a-region-of-a-media-file). file](#play-a-section-of-a-media-file).
- Be notified when no activity is happening on a pad. You install this - Be notified when no activity is happening on a pad. You install this
probe with the `GST_PAD_PROBE_TYPE_IDLE` flag. You can specify probe with the `GST_PAD_PROBE_TYPE_IDLE` flag. You can specify
@ -482,10 +482,10 @@ how to statically embed plugins in your application.
There are two possible elements that you can use for the above-mentioned There are two possible elements that you can use for the above-mentioned
purposes: `appsrc` (an imaginary source) and `appsink` (an imaginary sink). The purposes: `appsrc` (an imaginary source) and `appsink` (an imaginary sink). The
same method applies to these elements. We will discuss how to use them to insert same method applies to these elements. We will discuss how to use them to insert
(using `appsrc`) or to grab (using appsink) data from a pipeline, and how to set (using `appsrc`) or to grab (using `appsink`) data from a pipeline, and how to set
negotiation. negotiation.
Both `appsrc` and appsink provide 2 sets of API. One API uses standard Both `appsrc` and `appsink` provide 2 sets of API. One API uses standard
`GObject` (action) signals and properties. The same API is also available `GObject` (action) signals and properties. The same API is also available
as a regular C API. The C API is more performant but requires you to as a regular C API. The C API is more performant but requires you to
link to the app library in order to use the elements. link to the app library in order to use the elements.
@ -570,7 +570,7 @@ When `appsrc` is configured in push mode (`stream-type` is stream or
seekable), the application repeatedly calls the `push-buffer` method with seekable), the application repeatedly calls the `push-buffer` method with
a new buffer. Optionally, the queue size in the `appsrc` can be controlled a new buffer. Optionally, the queue size in the `appsrc` can be controlled
with the `enough-data` and `need-data` signals by respectively with the `enough-data` and `need-data` signals by respectively
stopping/starting the `push-buffer` calls. The value of the min-percent stopping/starting the `push-buffer` calls. The value of the `min-percent`
property defines how empty the internal `appsrc` queue needs to be before property defines how empty the internal `appsrc` queue needs to be before
the `need-data` signal is issued. You can set this to some positive value the `need-data` signal is issued. You can set this to some positive value
to avoid completely draining the queue. to avoid completely draining the queue.
@ -1071,7 +1071,7 @@ pipelines:
pipeline is removed, a new clock has to be selected. pipeline is removed, a new clock has to be selected.
- Adding and removing elements might cause upstream or downstream - Adding and removing elements might cause upstream or downstream
elements to renegotiate caps and or allocators. You don't really elements to renegotiate caps and/or allocators. You don't really
need to do anything from the application, plugins largely adapt need to do anything from the application, plugins largely adapt
themselves to the new pipeline topology in order to optimize their themselves to the new pipeline topology in order to optimize their
formats and allocation strategy. formats and allocation strategy.
@ -1099,7 +1099,7 @@ element1 | | element2 | | element3
``` ```
We want to change element2 by element4 while the pipeline is in the We want to replace element2 by element4 while the pipeline is in the
PLAYING state. Let's say that element2 is a visualization and that you PLAYING state. Let's say that element2 is a visualization and that you
want to switch the visualization in the pipeline. want to switch the visualization in the pipeline.
@ -1107,7 +1107,7 @@ We can't just unlink element2's sinkpad from element1's source pad
because that would leave element1's source pad unlinked and would cause because that would leave element1's source pad unlinked and would cause
a streaming error in the pipeline when data is pushed on the source pad. a streaming error in the pipeline when data is pushed on the source pad.
The technique is to block the dataflow from element1's source pad before The technique is to block the dataflow from element1's source pad before
we change element2 by element4 and then resume dataflow as shown in the we replace element2 by element4 and then resume dataflow as shown in the
following steps: following steps:
- Block element1's source pad with a blocking pad probe. When the pad - Block element1's source pad with a blocking pad probe. When the pad
@ -1125,7 +1125,7 @@ following steps:
- Put an event probe on element2's source pad. - Put an event probe on element2's source pad.
- Send `EOS` to element2's sinkpad. This makes sure the all the data - Send `EOS` to element2's sink pad. This makes sure that all the data
inside element2 is forced out. inside element2 is forced out.
- Wait for the `EOS` event to appear on element2's source pad. When - Wait for the `EOS` event to appear on element2's source pad. When