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design: schedulling: drop manual padding from figures & add missing markup

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Reynaldo H. Verdejo Pinochet 2016-12-29 14:43:26 -08:00
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commit 939bfc3034
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markdown/design/scheduling.md
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@ -20,7 +20,7 @@ producer produces a constant stream of data.
## Pulling
Pads that operate in pulling mode can only pull data from a pad that
exposes the pull\_range function. In this case, the sink pad exposes a
exposes the `pull_range()` function. In this case, the sink pad exposes a
loop function that will be called repeatedly until the task is stopped.
After pulling data from the peer pad, the loop function will typically
@ -28,7 +28,7 @@ call the push function to push the result to the peer sinkpad.
## Deciding the scheduling mode
When a pad is activated, the \_activate() function is called. The pad
When a pad is activated, the `_activate()` function is called. The pad
can then choose to activate itself in push or pull mode depending on
upstream capabilities.
@ -38,23 +38,23 @@ is no activate function for the pad.
## The chain function
The chain function will be called when a upstream element performs a
\_push() on the pad. The upstream element can be another chain based
`_push()` on the pad. The upstream element can be another chain based
element or a pushing source.
## The getrange function
The getrange function is called when a peer pad performs a
\_pull\_range() on the pad. This downstream pad can be a pulling element
or another \_pull\_range() based element.
`_pull_range()` on the pad. This downstream pad can be a pulling element
or another `_pull_range()` based element.
## Scheduling Query
A sinkpad can ask the upstream srcpad for its scheduling attributes. It
does this with the SCHEDULING query.
does this with the `SCHEDULING` query.
* (out) **`modes`**: G_TYPE_ARRAY (default NULL): an array of GST_TYPE_PAD_MODE enums. Contains all the supported scheduling modes.
* (out) **`modes`**: `G_TYPE_ARRAY` (default NULL): an array of `GST_TYPE_PAD_MODE` enums. Contains all the supported scheduling modes.
* (out) **`flags`**, GST_TYPE_SCHEDULING_FLAGS (default 0):
* (out) **`flags`**, `GST_TYPE_SCHEDULING_FLAGS` (default 0):
```c
typedef enum {
@ -79,16 +79,16 @@ typedef enum {
operations might be slow as well so downstream elements should take this into
consideration.
* (out) **`minsize`**: G_TYPE_INT (default 1): the suggested minimum size of pull requests
* (out) **`maxsize`**: G_TYPE_INT (default -1, unlimited): the suggested maximum size of pull requests
* (out) **`align`**: G_TYPE_INT (default 0): the suggested alignment for the pull requests.
* (out) **`minsize`**: `G_TYPE_INT` (default 1): the suggested minimum size of pull requests
* (out) **`maxsize`**: `G_TYPE_INT` (default -1, unlimited): the suggested maximum size of pull requests
* (out) **`align`**: `G_TYPE_INT` (default 0): the suggested alignment for the pull requests.
## Plug-in techniques
### Multi-sink elements
Elements with multiple sinks can either expose a loop function on each
of the pads to actively pull\_range data or they can expose a chain
of the pads to actively `pull_range` data or they can expose a chain
function on each pad.
Implementing a chain function is usually easy and allows for all
@ -98,7 +98,7 @@ possible scheduling methods.
If the chain based sink wants to wait for one of the pads to receive a buffer, just
implement the action to perform in the chain function. Be aware that the action could
be performed in different threads and possibly simultaneously so grab the STREAM_LOCK.
be performed in different threads and possibly simultaneously so grab the `STREAM_LOCK`.
# Collect pads
@ -168,11 +168,11 @@ by the pads:
* (c) - (c): impossible
```
+---------+ +------------+ +-----------+
| filesrc | | mp3decoder | | audiosink |
| src--sink src--sink |
+---------+ +------------+ +-----------+
(l-g) (c) () (c)
+---------+ +------------+ +-----------+
| filesrc | | mp3decoder | | audiosink |
| src--sink src--sink |
+---------+ +------------+ +-----------+
(l-g) (c) () (c)
```
When activating the pads:
@ -184,11 +184,11 @@ When activating the pads:
created to call the srcpad loop function.
```
+---------+ +------------+ +----------+
| filesrc | | avidemuxer | | fakesink |
| src--sink src--sink |
+---------+ +------------+ +----------+
(l-g) (l) () (c)
+---------+ +------------+ +----------+
| filesrc | | avidemuxer | | fakesink |
| src--sink src--sink |
+---------+ +------------+ +----------+
(l-g) (l) () (c)
```
- fakesink has a chain function and the peer pad has no loop function,
@ -198,11 +198,11 @@ When activating the pads:
created to call the sinkpad loop function.
```
+---------+ +----------+ +------------+ +----------+
| filesrc | | identity | | avidemuxer | | fakesink |
| src--sink src--sink src--sink |
+---------+ +----------+ +------------+ +----------+
(l-g) (c) () (l) () (c)
+---------+ +----------+ +------------+ +----------+
| filesrc | | identity | | avidemuxer | | fakesink |
| src--sink src--sink src--sink |
+---------+ +----------+ +------------+ +----------+
(l-g) (c) () (l) () (c)
```
- fakesink has a chain function and the peer pad has no loop function,
@ -212,11 +212,11 @@ When activating the pads:
pipeline is not schedulable.
```
+---------+ +----------+ +------------+ +----------+
| filesrc | | identity | | avidemuxer | | fakesink |
| src--sink src--sink src--sink |
+---------+ +----------+ +------------+ +----------+
(l-g) (c-l) (g) (l) () (c)
+---------+ +----------+ +------------+ +----------+
| filesrc | | identity | | avidemuxer | | fakesink |
| src--sink src--sink src--sink |
+---------+ +----------+ +------------+ +----------+
(l-g) (c-l) (g) (l) () (c)
```
- fakesink has a chain function and the peer pad has no loop function,
@ -229,11 +229,11 @@ When activating the pads:
avidemux to getrange data from filesrc.
```
+---------+ +----------+ +------------+ +----------+
| filesrc | | identity | | oggdemuxer | | fakesink |
| src--sink src--sink src--sink |
+---------+ +----------+ +------------+ +----------+
(l-g) (c) () (l-c) () (c)
+---------+ +----------+ +------------+ +----------+
| filesrc | | identity | | oggdemuxer | | fakesink |
| src--sink src--sink src--sink |
+---------+ +----------+ +------------+ +----------+
(l-g) (c) () (l-c) () (c)
```
- fakesink has a chain function and the peer pad has no loop function,