[FFmpeg-devel] [PATCH] avcodec: add minimal teletext subtitle decoder

[Carl Eugen Hoyos]

Am So., 14. Juni 2020 um 17:40 Uhr schrieb Marton Balint <cus at passwd.hu>:
>
>
>
> On Sun, 14 Jun 2020, Carl Eugen Hoyos wrote:
>
> > Am So., 14. Juni 2020 um 16:26 Uhr schrieb Marton Balint <cus at passwd.hu>:
> >>
> >>
> >>
> >> On Sun, 14 Jun 2020, Carl Eugen Hoyos wrote:
> >>
> >> > Am So., 14. Juni 2020 um 12:05 Uhr schrieb Paul B Mahol <onemda at gmail.com>:
> >> >>
> >> >> [...] this patch should be merged.
> >> >
> >> > I still believe this is one of the most important missing
> >> > features
> >>
> >> Which one? As far as I remember I integrated all the features (including
> >> colorized ass output) to libzvbi-teletextdec, so I am curious what is the
> >> feature that you still miss from that.
> >
> > You mean apart from the fact that this project was always about
> > re-inventing the wheel (like it or not)?
> >
> > Since this morning, I (very seriously) wonder if you have ever used
> > the existing teletext decoder (and how): Both "ffplay file.ts" and
> > "ffmpeg -i file.ts out.mkv" do not work as expected, and even if you
> > know that you have to specify "-txt_format ass" the output is still
> > completely unusable.
>
> Are implying that the default txt_page should be changed to "subtitle"
> from "*"? Beacuse that is all it takes to make it a regular subtitle from
> a list of all the pages (if that is what you mean when you write
> *unusable*)

No.

I am implying that FFmpeg needs an internal teletext decoder that
does not produce the specified graphical output as libzvbi allows
but decodes teletext to usable text subtitles (including automatic
page detection) without an external dependency (that we should
of course keep for the valid usecase of overlaying the intended
graphics).
Fixes to the existing external decoder are probably welcome,
but this is imo completely unrelated.

Carl Eugen