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

Marton Balint cus at passwd.hu
Wed Apr 25 22:32:43 EEST 2018

On Tue, 24 Apr 2018, Aman Gupta wrote:

> From: Aman Gupta <aman at tmm1.net>
> Based largely on VLC's modules/codec/telx.c.
> Processes only teletext pages marked as subtitles, so depending
> on the stream it might not produce any output.
> Subtitles are rendered directly to ASS, with support for background
> colors and a best-effort at screen positioning. The ASS packets
> are emitted in real time (similar to ccaption_dec's real_time
> option), with -1 durations. The decoder expects that the player
> will remove all existing subtitles whenever a new packet arrives.
> The teletext clear command is implemented using an empty subtitle,
> which removes existing subtitles but does not render anything new.

Why don't you add the ASS styling functionality to the existing 
libzvbi-teletextdec.c instead? You're duplicating lot's of code and doing 
teletext parsing which is hard to do properly so using libzvbi for it 
seems a better choice.


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