chore: add documentation for infinites

Author: justandras

…nt-developers/part-and-piece-timings.mdx …elopers/part-and-piece-timings/index.mdxpackages/documentation/docs/for-developers/for-blueprint-developers/part-and-piece-timings.mdx renamed to packages/documentation/docs/for-developers/for-blueprint-developers/part-and-piece-timings/index.mdx packages/documentation/docs/for-developers/for-blueprint-developers/part-and-piece-timings.mdx renamed to packages/documentation/docs/for-developers/for-blueprint-developers/part-and-piece-timings/index.mdx

@@ -1,4 +1,8 @@
-import { PartTimingsDemo } from './_part-timings-demo'
+---
+sidebar_position: 7
+---
+
+import { PartTimingsDemo } from '../_part-timings-demo'
 
 # Part and Piece Timings
 
@@ -134,6 +138,8 @@ Pieces with an infinite lifespan (ie, not `lifespan: PieceLifespan.WithinPart`)
 Only one pieceGroup is created for an infinite Piece which is present in multiple of the current, next and previous Parts.  
 The Piece calculates and tracks its own started playback times, which is preserved and reused in future takes. On the timeline it lives outside of the partGroups, but still gets the same caps applied when appropriate.
 
+For a deep understanding on how infinites work, read [the full documentation on infinites](infinites.md).
+
 ### Interactive timings demo
 
 Use the sliders below to see how various Preroll and In & Out Transition timing properties interact with each other.

packages/documentation/docs/for-developers/for-blueprint-developers/part-and-piece-timings/infinites.md

@@ -0,0 +1,64 @@
+# Infinites
+
+An **Infinite** is a timeline object that has no predefined end in the context of the piece, rather it's context determines when they are terminated.
+
+- Infinites are governed by:
+  - Type
+  - Activation order
+  - Playhead progression
+  - Level
+    - Showstyle
+    - Rundown
+    - Segment
+    - Part
+
+![Infinite hierarchy](/img/docs/for-developers/timing/infinites/infinite-hierarchy.png)
+
+## Types of infinites and their lifecycle
+
+There are two types of infinites in Sofie:
+
+- OnEnd
+  - Mainly used for planned content and most of the time originates form NRCS
+  - Resolved at ingest (1, 3)
+    - It's resulting state is known before we enter the piece (1, 3)
+  - It only propagates forward until the end of it's content level. (5, 7)
+- OnChange (also referred to as playhead tracking infinite)
+  - Mainly used for unplanned content and most of the time originates form AdLibs
+  - It can only be resolved when it's triggered which happens when the original piece is entered (2, 4, 6)
+    - It propagates forward from the playhead, it's lifecycle is dependent on playout order, therefore it's resulting state is unknown at ingest.
+      - This means that it can propagate before and after the triggering piece depending on where the next take will be.(6, 8)
+
+Both types can only live within their content level.
+
+![Infinite lifecycle](/img/docs/for-developers/timing/infinites/infinite-lifecycle.png)
+![Infinite lifecycle between parents](/img/docs/for-developers/timing/infinites/infinite-lifecycle-levels.png)
+
+## Infinites inserted by AdLibs
+
+The infinite activates when it's entered in the AdLib part, then it behaves identically to it's default behavior.
+![Infinite AdLibs](/img/docs/for-developers/timing/infinites/infinite-adlibs.png)
+
+## Piece priority
+
+- Normal pieces or lower level infinites can temporarily override a higher level infinite.
+  - OnEnd behavior:
+    - After the higher priority pieces end the higher level infinite resumes.
+  - OnChange behavior:
+    - After the higher priority pieces end the infinite is terminated until it's starting point is entered again.
+
+![Infinite priority](/img/docs/for-developers/timing/infinites/infinite-priority.png)
+
+## Permanently terminating an infinite
+
+An infinite piece can be permanently terminated by another infinite that has the same or higher content level.
+In this case the latest infinite overrides the previous one, because it has the same or higher lifecycle and takes priority like any piece as described above.
+
+Instead of overriding it with a new state terminating an infinite can be achieved by inserting a new infinite with an empty or baseline state.
+
+![Infinite Termination](/img/docs/for-developers/timing/infinites/infinite-termination.png)
+
+## Comprehensive infinites cheat sheet
+
+Everything we outlined in this document can also be found on this cheat sheet for easy reference during development:
+![Infinites cheat sheet](/img/docs/for-developers/timing/infinites/cheat-sheet.png)