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

Marton Balint cus at passwd.hu
Sun Jun 14 18:40:04 EEST 2020



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*)

Regards,
Marton

>
> I believe the external library makes sense if you want "correct"
> display of the ugly original teletext subtitles as overlay (which is
> a 100% valid usecase) but there is no reason whatsoever for
> the need of an external library to decode the text subtitles to
> something that a subtitle encoder can use, even more so if a
> patch exists.
>
> It is likely that the patch needs a little more work but I find
> the fact that you are blocking it very difficult to understand,
> actually a little appalling.


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