Ad Marker / SCTE-35

What is it?

An ad marker is a signal embedded in a video stream that says "an ad can go here" — marking the exact points where ad breaks are allowed to be inserted. SCTE-35 is the industry-standard format for these markers (a technical standard from the cable/broadcast world, now universal in streaming). When an ad-insertion system (SSAI/DAI) decides to place ads, it places them at these markers — the markers are the pre-designated "ad goes here" signposts the automated systems look for.

Practical example

A live sports stream needs ads inserted at the natural breaks (timeouts, between innings) — not mid-play. The production inserts SCTE-35 markers into the stream at those exact moments, signaling "ad break opportunity here, this long." The ad-insertion system reads the markers and stitches ads precisely there, so ads land at the timeout (good) rather than over the winning goal (catastrophic). For pre-recorded content, markers are placed at the intended break points. The marker is the bridge between the editorial decision (where ads belong) and the automated insertion (the system filling them): humans (or rules) place the markers; machines fill them. Without markers, automated ad systems wouldn't know where it's acceptable to interrupt.

Key things to know (non-technical)

• An ad marker is the "ad allowed here" signal in the stream; SCTE-35 is the standard format — the signposts that tell automated ad systems where breaks can go.
• It separates the where decision from the insertion: markers encode the editorially-acceptable break points (placed by humans/rules), and ad systems insert at them (automated) — bridging editorial intent and machine execution.
• Placement matters enormously for live: markers at natural breaks (timeouts, segment ends) preserve the experience; markers mid-action ruin it — getting marker placement right is getting ad-break placement right, encoded for machines.
• It's the standard that makes ad systems interoperable: because SCTE-35 is universal, content, ad servers, and insertion systems from different vendors all understand the same markers — the shared language of automated ad insertion.

In Tupic Live

Ad markers are the technical mechanism connecting Tupic Live's rundown (where the creator/show defines break points) to its ad-insertion system: the rundown's designated break slots become SCTE-35-style markers in the stream, telling the SSAI/DAI system exactly where it may place ads — so ads land at the creator's intended seams (segment breaks, not mid-sentence), the editorial placement craft preserved and automated rather than left to a system guessing where to interrupt.