[mythtv] [dvb] subtitling

Stuart Auchterlonie stuarta at squashedfrog.net
Thu Apr 28 17:21:00 UTC 2005


On Thu, Apr 28, 2005 at 06:26:40PM +0200, Jesper Sörensen wrote:
> 
> Yes, and that is intentional. Certain descriptors will override the 
> stream types since they are more reliable than the stream types. I think 
> this setup is pretty flexible and should work with most DVB feeds, even 
> though they sometimes don't follow the specs to 100%.

Fair enough. There had to be a reason for it....

> 
> BTW, it is not a "descriptor byte" either, it's a descriptor loop. Each 
> stream can have one or several descriptors (or none) so just checking 
> the fifth byte or whatever won't help. If you're not sure how it works, 
> please look up the PMT & descriptor format in the MPEG-2 system standard 
> (section 2.4.4.8 "Program Map Table" in ITU-T H.222.0, or in the 
> original ISO doc if you have access to that).

I'd love to be able to read the specs, would save me asking silly
questions, but both of those require $$, so I'm having to work things
out from how code has been implemented...

> 
> It probably would be possible to only look for certain descriptors for 
> certain stream types but it's hard to work out the exact relationship 
> and it would create a big mess of if:s or switch:es so I don't think 
> it's something we need or want to do. I think it's a non-issue and 
> simplicity is better than complexity. :-)

Think for now I'll leave it how it is....

> 
> You're welcome to send a patch if you think you can clean it up or make 
> it better somehow though. I don't have CVS access but if it looks good 
> I'll vote for getting it committed.
> 

Stuart



More information about the mythtv-dev mailing list