Test for Video Quality

What telecine artefacts are

Telecine is the process of converting film-rate content (24 fps) to broadcast-rate video (29.97 fps or 25 fps). The most common method, 3:2 pulldown, duplicates and interleaves frames to fill the higher frame rate. When this process is applied incorrectly, reversed improperly, or stacked across multiple conversions, the result is visible artefacts: stuttering playback from duplicate frames, or combing lines from interlaced fields blended into a progressive stream.

These artefacts are common in creatives that were mastered for broadcast and then repurposed for digital or CTV delivery without proper deinterlacing. The video file may pass codec, resolution, and bitrate checks while still containing visible quality defects that only show up during playback.

Two checks in one

Advalidation runs two separate analyses under this test, each with its own pass/fail result:

• Duplicate frames: The video is divided into ten equal sections. Each section is analyzed for the percentage of frames that are duplicates of the preceding frame. A duplicate frame percentage of 10% or higher in the most prevalent section triggers a fail. Percentages in the 10-30% range suggest 3:2 pulldown processing.
• Interlaced frames: Each frame is analyzed using both single-frame and multi-frame detection to identify top-field-first (TFF) or bottom-field-first (BFF) interlacing. The single-frame and multi-frame ratios are averaged. An interlace ratio above 15% triggers a fail.

Both checks are indicative rather than conclusive. Static text screens and single-color pause frames can increase the duplicate frame percentage without being an actual quality issue. Results that fall near the threshold should be reviewed visually.

Why this matters for CTV and streaming

Broadcast delivery historically handled telecine artefacts at the playout stage. CTV and streaming platforms receive the file as-is and play it back directly. There is no playout processor to clean up a bad pulldown. A creative with combing artefacts or stuttering playback looks broken on a living room screen, and the viewer blames the platform.

For broadcasters transitioning to hybrid delivery (linear + streaming), this check catches creatives that were acceptable for traditional broadcast playout but need reprocessing before digital delivery.

How to use this check

Enable the telecine artefact check in your video ad specification. No threshold configuration is needed since the detection thresholds are based on the established patterns for pulldown artefacts. Each media file in a VAST rotation is analyzed independently. Results show the duplicate frame percentage and interlace ratio, along with a per-section breakdown in the detailed view.

Related checks

• Scan Type validates whether a video is progressive or interlaced at the container level
• Video Frame Rate checks declared frame rate against your specification

See all checks on the video tests page.