[ivtv-users] is VBI (closed captioning) supported on ATSC(Digital) program?

[faginbagin]

Hi Steve,

Andy Walls wrote:
> On Fri, 2009-07-31 at 00:56 -0700, Steve Chui wrote:
>> I've a HVR1600 card with cx18 driver. Currently, I'm able to record
>> analog programs with VBI embedded. Recently, I enabled the digital
>> tuner on HVR1600 to start recording digital programs. The recording
>> works great but no VBI. I wonder is VBI supported on digital
>> recordings?
> 
> As far as digital broadcasts are concerned, the CX23418 and cx18 driver
> act simply as a passthrough from the broadcaster.
> 
> There are captioning and other information encoded in the digital ATSC
> or QAM streams from the broadcaster. (I can't recall the standards right
> now.)  Getting captioning from an ATSC or QAM stream is up to the
> application.
> 
> I have no idea what applications currently support displaying captions
> from ATSC and North American QAM digital broadcasts.

I can confirm that MythTV can display captions embedded in ATSC streams. MythTV supports both EIA-608 captions (the older standard) and EIA-708 (newer standard with more features like user's ability to choose fonts & font sizes). The ATSC standard specifies that both types of captions should be provided by broadcasters. I should also mention that MythTV's support for EIA-708 leaves a lot to be desired. Fortunately, you can tell MythTV to favor EIA-608 captions.

Helen