The FCC released a Notice of Proposed Rulemaking (FCC 11-36) proposing rules to reinstate the requirement that broadcaster and multichannel video programming distributors (MVPDs) provide and distribute "video descriptions." These are narrative descriptions of the TV programs key visual elements inserted during silence in the main dialog. The NPRM mostly deals with the type and amount of programming that will require video description and who will be required to carry it.
There is one technical change proposed. The NPRM notes that current rules incorporate the ATSC digital broadcast standard by reference, but have not been updated to reflect the 2010 revisions to the A/53 standard. The FCC proposes to update the rules to incorporate A/53 Part 5:2010, which drops an option for transmitting video description that is rarely implemented and retains the option that's compatible with all DTV tuners. The option remaining is for transmitting a complete audio service with the video description narrative included. The rarely-used option is for transmitting the video description only on an audio PID, and depends on the television receiver to mix it with program audio.
The NPRM notes that with the transition to digital, broadcasters are no longer limited to transmitting one primary audio channel along with a secondary audio channel. While broadcasters can add a video description channel simply by adding an audio encoder for it and assigning the audio to a separate PID described as a "VI" (Visually Impaired) service, once the signal leaves the broadcast plant, things become more complicated. Many, if not most, cable set-top boxes only support two audio channels. Off-air DTV receivers may support more audio choices, but they may not be properly identified as video description channels. Broadcasters, cable companies and device manufacturers are working together to resolve these issues, but it will take a long time to replace existing receivers and set-top boxes. The industry will need to educate viewers on how to receive video description audio on their cable set-top boxes and off-air receivers.
