[FFmpeg-devel] [PATCH] dvbsubenc: add a disable_2bpp option to work around some decoders.

[Ronan Waide]

> On 1 Mar 2025, at 11:43, Waider <waider at waider.ie> wrote:
> 
> As noted in the code in several places, some DVB subtitle decoders
> don't handle 2bpp color. This patch adds a disable_2bpp option which
> disables the 2bpp format; subtitles which would use 2bpp will be bumped
> up to 4bpp.


I'm a first-time patcher so apologies in advance if I've missed anything here. The patch is as described: I have a TV that will not correctly render 2bpp DVB subtitles, but is happy enough with 4bpp+, and this patch has allowed me to transcode DVDs into MPEG-TS with subtitles which work on the TV. I've kept the change as small as I can without sacrificing clarity - if I'd carried the `disable_2bpp` option through as-is then I'd have to have each use of it first check if it's set and then tweak the size of the colour table, and the layout of the current code is such that it relies more on the number of colours than the bits-per-pixel so that would have been a more intrusive change.

Cheers,
Waider.
-- 
Ronan Waide
waider at waider.ie