QC: An Inside Job?

Thursday, June 30, 2011

The requirement for quality control grew up in the early days of television and depended on measurement instruments to check the video and audio going to air. This T&M made prefect sense when equipment was analogue and, to an extent, has continued into the digital era, however the needs of the digital file based workflow environment are very different. For example digital signals do not ‘drift’ and the structure of modern digital playout systems is very different to analogue. Add in the huge increase in the number of digital channels now on-air, with many running on slender budgets, and it’s clear that a fresh approach to playout QC is needed.

Today file-based workflows are popular and these fit perfectly with PlayBox Technology’s playout solutions, which are inherently file-based. These run a series of real-time functions for ingest, playout, graphics, text, playlists, subtitles, traffic management, etc... Such a collection is often referred to as a ‘channel in a box’ and users have, over the years, continually asked for more to be bundled into the ‘box’. So, at NAB 2011, QCBox was added to provide a series of checks of the media prior to going to air.

QCBox offers automatic QC, giving an assessment of the technical quality of the media to guarantee successful playout via an AirBox playout server. The checks, applied to relevant media files in a playlist, folder or to selected files, test for the correct duration, continuity (no missing or overlapped frames), blocking, frozen and black frames as well as audio tests, including level and loudness. All test results are stored in a metadata file accompanying the media file. Then, prior to the file’s subsequent playout, the AirBox reads the QC metadata and may be set up to skip, show a warning before playing, or play the file depending on the quality results. In addition the audio data from QCBox can be used to automatically control the audio level.

These tests are designed to fit with the needs of PlayBox Technology’s playout operation. They fit inside the ‘box’ and add no extra space, require virtually zero additional power and are fully automated. QCBox provides the vital QC functions with little, or no, extra operator effort – so keeping the overheads and running costs low and still fitting within those ever stretched slender budgets.