[FFmpeg-devel] [FFmpeg-devel, v2] dvbsub.c, change segment order to be in line with spec

[John Stebbins]

On Tue, 2020-04-14 at 10:29 +0200, Paul B Mahol wrote:
> On 4/14/20, Alen Vrečko <alen.vrecko at fora.si> wrote:
> > Hello, everyone.
> > 
> > Looks like this patch got forgotten. I'd very much like to see it
> > applied.
> > 
> > In our testing. This patch doesn't break any existing players. But
> > it does
> > allow for older STBs to play subtitles.
> > 
> > If you don't like the patch, feel free to change the order
> > yourself. The
> > current dvb structure order in dvbsub.c is not in line with ETSI EN
> > 300 743
> > (any version).
> > 
> > Spec order: display definition segment > page composition segment >
> > region
> > composition segment > CLUT
> > Your order: display definition segment > page composition segment >
> > *CLUT* >
> > region composition segment
> 
> Is specification freely available?
> 
> > 

I can answer that since I've been poking around in that code lately...
https://www.etsi.org/deliver/etsi_en/300700_300799/300743/01.03.01_60/en_300743v010301p.pdf

The relevant information is in section 4.3

Within a display set the sequence of segments (when present) is:
•display definition segment; 
•page composition; 
•region composition; 
•CLUT definition; 
•object data; 
•end of display set segment.