[MEncoder-users] ATSC closed captioning

[Reimar Döffinger]

On Sun, Nov 07, 2010 at 09:14:12PM -0800, Scott W. Larson wrote:
> > Yes, it worked really badly for me, and as said I couldn't really
> > find a way to reconcile it with any specs or anything I could find.
> 
> I can see how normal EIA_608 captions wouldn't have worked very well
> without rollup support.

Roll-up support exists in SVN, on top of what your patch does also
4-line roll-up and roll-on mode.

> > I suspect the reordering code etc. is likely to not be in a way
> > I'd like to have for maintainabilty reasons, however the bugfixes
> > would be interesting, should make it easier for me to figure out
> > which parts of the code I just don't get vs. where the code is broken.
> 
> Are you talking about the code in cc_decode_EIA608()? It looks like I
> added some channel selecting code, added some code to poorly handle
> italics (I just enclosed them between '<>'), and added support for two
> line and and three line rollup captions.

Unfortunately the channel selection code has no way to be reset e.g.
on channel change.
And btw. the second channel is in the second field, which both your
and SVN code discard.
However the biggest problem I have is the subcc_decode function in
SVN which claims to do EIA-708 but has not resemblance at all with it.
I suspect it might be CC-subs for DVDs and maybe they are different,
but it seems we do not have a single sample for that...