In recent weeks, a growing number of viewers of the BBC HD service in London have voiced complaints about what they perceive as a distinct degradation of picture quality — with several viewers charging the BBC with intentionally lowering bitrates in order to save money with different encoders.
The BBC's official online blogger for viewer complaints, Danielle Nagler, is in the process of responding to the protests, which began soon after the broadcast service introduced new transmission encoders for BBC HD in August. "There was an extensive process of assessment in advance of the selection of new encoders for the BBC HD service, using both objective and subjective criteria," Nagler wrote. "The encoders which were chosen…went through further testing in advance of operational use, not only for picture quality but for compatibility with the Sky [DBS] and Freesat platforms and their ability to deliver other services such as subtitling and surround-sound successfully."
Nagler said the new encoders (which she did not identify by brand or model) were intended to handle a wide range of material which the BBC broadcasts in HD, and "to help to improve the picture quality of some of our most challenging programs" — such as combining progressive and interlaced footage, or where the BBC has limited control over some aspects of the broadcast chain.
Nagler acknowledges that following the introduction of the new encoders, "There were some issues around the handling of some pictures — primarily mixes and fades — which we acknowledged through the BBC HD blog [online] on picture quality almost immediately. We have worked with our encoder supplier to address these issues in the long-term, and also put in place interim changes to minimize the difficulties," she said.
