[FFmpeg-devel] Question on line 21 data in wtv

Carlos Fernandez cfs at nova.es
Sat Oct 20 22:15:22 CEST 2012

On Sat, Oct 20, 2012 at 6:05 PM, Reimar Döffinger
<Reimar.Doeffinger at gmx.de> wrote:
> Uh, this is _not_ the data in the wtv file, or more precisely that is not the data that Windows Media Center will use to display the CC data (though it should match for normally created files).

> Instead, that seems to be the data that Media Center left in the video stream (it itself does not use that, it uses the data in the subtitle streams), which you then let the video code mangle (which also means completely pointless processing since the wtv file already contains the reordered data in the subtitle streams).

This is quite interesting info :-) To be honest the reason I didn't
want to deal with the wtv in code and preferred the 'let the codecs do
it' was I that I had the hope that I would be able to get the CC data
from encrypted wtv. This was based on the assumption (proved
incorrect) that the standard filters would be able to open an
encrypted wtv provided it had been recorded in the same machine (so
keys would be present, etc) - so I was willing to sacrifice
portability for that benefit.

I'm at a point where my code "works" (in the 7 samples I have,
anyway), so since windows in general isn't my cup of tea I think I'm
going to focus on the rest of the CEA-708 support which is long

But I'll stick around since I've always wanted to dip my toes on
ffmpeg and never had the guts for it.


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