[v14,01/34] media: Documentation: mc: add definitions for stream and pipeline
Commit Message
The doc talks about streams and pipelines, but doesn't really define
them. This is an attempt to define them according to my understanding.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
---
Documentation/driver-api/media/mc-core.rst | 12 ++++++++++++
1 file changed, 12 insertions(+)
@@ -214,6 +214,18 @@ Link properties can be modified at runtime by calling
Pipelines and media streams
^^^^^^^^^^^^^^^^^^^^^^^^^^^
+A media stream is a stream of pixels or metadata originating from one or more
+source devices (such as a sensors) and flowing through media entity pads
+towards the final sinks. The stream can be modified on the route by the
+devices (e.g. scaling or pixel format conversions), or it can be split into
+multiple branches, or multiple branches can be merged.
+
+A media pipeline is a set of media streams which are interdependent. This
+interdependency can be caused by the hardware (e.g. configuration of a second
+stream cannot be changed if the first stream has been enabled) or by the driver
+due to the software design. Most commonly a media pipeline consists of a single
+stream which does not branch.
+
When starting streaming, drivers must notify all entities in the pipeline to
prevent link states from being modified during streaming by calling
:c:func:`media_pipeline_start()`.