[mythtv-users] ATSC caption question

Yeechang Lee ylee at pobox.com
Wed Dec 23 00:18:12 UTC 2009

Devin Heitmueller <dheitmueller at kernellabs.com> says:
> I don't doubt the points you are raising are visible - but I do wonder
> whether they are really because of differences in the actual
> broadcast, or whether they are bugs in MythTV's EIA-708
> implementation.

Yes I should have been clearer on this issue. Assuming Clayton's
patches fix all remaining MythTV issues with EIA-708 compliance--and
based on his commentary for #7775 I have no reason to think not--my
message really boils down to whether there is any practical reason to
prefer ATSC over VBI captions outside of their level of support within
MythTV. I know VBI is supposed to be the past, but are ATSC's support
for colors and markups ever actually used in the real world? If so,
that would be a reason for using it even with the occasional VBI
virtue of the kind I mentioned.

Looking over the Wikipedia page for EIA-608 I see that the VBI
standard also supports "controls for the color of the foreground and
background of the text, underlining, blinking, and italics," so there
are deficiencies in MythTV's VBI support, too. Now that the last
remaining (?) holes in MythTV's EIA-708 implementation are filled
filling in the VBI gaps aren't so important, of course.

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