From b558ce56b434d8ca633ccc31a4acfee79a29a7a5 Mon Sep 17 00:00:00 2001 From: Tomi Valkeinen Date: Wed, 31 Aug 2022 16:13:24 +0200 Subject: media: Documentation: mc: add definitions for stream and pipeline 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 Reviewed-by: Laurent Pinchart Signed-off-by: Sakari Ailus Signed-off-by: Mauro Carvalho Chehab --- Documentation/driver-api/media/mc-core.rst | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'Documentation/driver-api/media') diff --git a/Documentation/driver-api/media/mc-core.rst b/Documentation/driver-api/media/mc-core.rst index 84aa7cdb5341..4bb062d5c2e7 100644 --- a/Documentation/driver-api/media/mc-core.rst +++ b/Documentation/driver-api/media/mc-core.rst @@ -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()`. -- cgit v1.2.1