Compressing a convention the size of NAB 2008 into a few paragraphs of comment requires a very tight angle of focus. Mine this year was on new approaches to automating the quality control aspect of our multichannel playout operations.
Like most modern playout service-providers, we ingest all incoming video and audio content to digital files before playing to air.
Although I would be the last to entrust quality control entirely to automated devices, these technologies obviously have a place in modern broadcasting. But how big a place?
Failure autosensing devices are common throughout the electronics business but Tektronix appear to have been the earliest to pick up on this market niche within the broadcast test and measurement area. They introduced Cerify several years ago and have been gradually adding extra bells and whistles. Cerify was claimed (correctly, so far as I can determine) to be the world's first fully automated system for checking file based content prior to broadcast transmission.
Controlled via a web-browser, Cerify was designed to replace the manual process of visually inspecting video content. Aspects of broadcast file content that can be checked by Cerify include video and audio standards conformity, resolution, bit-rate and adherence to transmission system limits.
Also overall video and audio quality factors such as black frames, blockiness and audio silence. Cerify is designed to be used at ingest, prior to post production, before playout and for post-transmission archive validation. User-definable templates can be constructed as verification references.
Signal types handled include QCIF, CIF, SD, 720p, 1080I, MPEG-2, MPEG-4, H.264 and VC-1. Introduced in prototype this year, Cerify 5.0 includes applications for Dolby DP600 and Dolby-E support, additional audio/video codecs including .wma, and enhanced baseband tests.
Harris responded at NAB this year with the latest version of its Videotek QuiC media analysis server. It combines loudness monitoring technology from TC Electronic with the QuiC system's automated quality control and correction tools.
Quic is intended for use with Harris' Nexio server. The server generates a flag that allows a file to be placed automatically in the analysis queue on ingest or alteration (edit).
Following analysis of a media file, QuiC tracks the file's status and creates a database of test results along with any changes made to the file. The information is then summarised in the header of the file's MXF wrapper and can be viewed as a relatively user-friendly GUI display.
Coupled to a legaliser, QuiC Media Analysis corrects out-of-spec baseband audio and video content without requiring the file to be returned to the content-provider for re-editing. Harris originally introduced QuiC in April 2006 and currently claims an installed based of more than 100 customers.
The third contender in this product category at NAB2008 was Hamlet's Reel-Check video and audio offline test and measurement system.
Designed to run entirely in software on a PC under Microsoft Windows, Reel-Check provides a variety automated monitoring tools including video and audio error checking video and audio waveform monitoring, video and audio vectorscope and surround sound checking, all with logging.
Video and audio errors can be continuously monitored and used to trigger a pre-set alarm flag. Errors can be logged, along with other relevant data, into a text document. Reel-Check can also be used in an auto mode to process content arriving as a file rather than as baseband video, making it suitable for conformance checking as well as rushes logging.
When the audio and video industry began to go seriously digital in the 1980s, quite a lot of people assumed that test and measurement routines would soon become irrelevant.
Nearly 30 years on, it is more relevant than ever and looks likely to stay that way. The increasing use of file-based technology for programme acquisition and for intermediate delivery from channel-source to playout service-provider suggests to me that broadcasting could eventually be totally file-based so technologies like Cerify, QuiC and Reel-Check merit very serious attention.
The current trend towards screens of 40 inch diagonal size and upwards - plus higher line rates - means many defects in a video feed are much easier to see than they ever were on a typical 20 to 27 inch CRT.
Whether human, automated or (as I suspect) a mix of the two, quality control is here to stay.
Sass Jahani is the managing director ofAdvanced Broadcast Services
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