Read the whole format label
A height such as 1080 describes only part of a picture format. The following i or p distinguishes interlaced from progressive scanning, and the rate completes the description. EBU’s European HDTV production reference distinguishes 1080i/25 from 1080p/25 and 1080p/50. These examples show why the resolution number by itself cannot explain how motion was sampled or how a player should present it.
Keep fields distinct from complete frames
Interlaced material divides the picture into alternating line fields. Progressive material presents complete frames. Labels in product menus and technical reports do not always use the same rate convention, so inspect whether a number refers to fields or frames. A report of 50 updates is not automatically proof of 50 independently captured full progressive pictures. Retaining the complete scanning notation prevents that ambiguity in a support discussion.
Recognise the deinterlacing task
A progressive display needs an appropriate way to present interlaced source material. If moving edges show comb-like artefacts, inspect how the application identifies and handles the source before changing the network connection. A problem visible only during motion can differ from a delivery stall. An authorised clip with both motion and still detail is a more useful comparison than a static menu screen.
Avoid a universal quality ranking
Higher frame rate, scanning method and spatial detail answer different questions. Source production, processing and encoding still affect the result. Compare the same scene under controlled conditions instead of declaring every interlaced source worse than every progressive one. This reference describes the format distinction; it does not identify the production format of a named channel or establish UK IPTV’s actual output.
Questions, answered
Does 1080i/25 mean 25 progressive pictures each second?
No. The i identifies interlaced scanning. Keep fields, frames and the rate convention distinct when interpreting a device or stream report.