[mythtv] How to burn DVDs with NTSC closed captions

faginbagin mythtv at hbuus.com
Sun Jan 20 04:56:29 UTC 2008


Hi Mike,

Thanks for the background info. I'm not quite sure how it's relevant to 
being able to burn DVDs with NTSC closed captions.

What I gleaned from the links is that there's an issue with 
mythtranscode (or the libraries) getting confused about primary and 
secondary audio tracks where the secondary tracks provide descriptive 
audio for those who are vision impaired. Apparently these tracks are 
available in DVB (European & UK) transmissions and are therefore in 
mythtv recordings. And these recordings also have subtitle tracks, which 
are bitmaps, not the ASCII-like captions found in line 21 NTSC 
transmissions. I can certainly appreciate the value of supporting both 
the descriptive audio track and subtitles and that it is desirable to 
include them when burning DVDs for both the visual and hearing impaired. 
It's a shame that the DVB-SUB subtitle stream is apparently not 
compatible with the DVD (MPEG2-PS) standards for subtitles (at least 
that's what I got from mythtv0368's comments).

If I develop some expertise in this area, I will certainly keep 
accessibility features in mind.

I have found some specs from the late 1990's, some are North American, 
some are European. I have no idea if they're relevant or hopelessly out 
of date.

Anyway, I'm still looking for answers to the questions I posed in my 
original post:
http://mythtv.org/pipermail/mythtv-dev/2008-January/059675.html

Thanks



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