SCTE-35 is the standard for signalling ad break opportunities in video streams. Messages are embedded in the video transport stream at break points — typically 4–6 seconds before the actual break begins. SSAI (server-side ad insertion) systems watch for these markers in real time and use them as the trigger to run an ad auction and stitch ads into the stream before delivery.
Without correct SCTE-35 markers, an SSAI platform cannot detect that a break is coming — and defaults to no-fill. For India publishers running live sports or news streams, missing or malformed SCTE-35 signals are a direct cause of lost ad revenue.
SCTE-35 in live vs on-demand content
SCTE-35 is most important for live and linear OTT streaming, where broadcast break signals need to be passed through the encoding pipeline to the SSAI platform. On-demand content typically uses VMAP (pre-defined ad break positions in the manifest) or in-app triggers rather than SCTE-35, since break positions can be defined at encoding time.
Common SCTE-35 issues in India CTV
The most frequent problems are marker loss in transcoding (some encoders strip SCTE-35), timing drift, and duration mismatches between the SCTE-35 signal and the actual ad pod configured in the ad server. Each causes either missed ad breaks or dead air.