Note: the current PBS Closed Caption format supported by COVE 2.0 is SAMI. We are actively working to implement the standards defined below over the next few months.
PBS Closed Captioning Requirements
Guided by the new FCC regulations, PBS Interactive is adopting Society of Motion Picture and Television Engineers Timed Text (SMPTE-TT) as the format for online closed captioning. To support a broad range of producer toolchains and workflows, we will also accept Synchronized Accessible Media Interchange (SAMI) and Scenarist Closed Caption (SCC) files during video ingest into COVE 2.0. If one of these "legacy" formats is provided, the COVE 2.0 system will automatically convert it to SMPTE-TT for storage and online display.
Closed Caption assets should be delivered in sync with the final output media, including any edits made prior to the encoding process (e.g. for the removal of funder messages).
PBS' Media Operations Center will provide SMPTE-TT captioning files for all output media that has captioning encoded (Line 21 - CEA608) on the source material.
New FCC Regulation
Full text of the regulation:FCC regulations
All prerecorded and unedited (not live) full-length video programming shown with captions on TV after September 30, 2012 must have captions when streamed online via IP.
Captions of IP-delivered video programming must be at least the same quality as the captions shown on TV.
File Extension: .xml (or .ttml or .dfxp)
In a nutshell: SMPTE-TT = TTML = DFXP
File extension: .scc
See the SCC Tools documentation for details of this format: http://www.theneitherworld.com/mcpoodle/SCC_TOOLS/DOCS/SCC_FORMAT.HTML
File Extension: .sami
For up to date resources on SAMI generation, see the SAMI article on Wikipedia or visit the WGBH National Center for Accessible Media website. Specifications for the format can be found through the Microsoft Developer Network site.
For even more information about exactly what a SAMI file is and how it can be generated please visit page: http://webaim.org/techniques/captions/windows/sami