[mythtv] DSM-CC object carousel parser and storage patch for 0.18.1

Daniel Kristjansson danielk at cuymedia.net
Sat Oct 1 01:08:48 UTC 2005


On Sat, 2005-10-01 at 00:00 +0100, Stuart Auchterlonie wrote:
> On Fri, Sep 23, 2005 at 11:39:09AM +0300, John Papaioannou wrote:
> There are two method we could use to implement live tv.
> 
> 1. Decode the DSMCC on the backend, and then pass bits and pieces
> through to the frontend for interpretation and display. This would
> require the frontend to then talk to the backend to request data
> out of the Object Carousel Cache. (This is how John's done it)
> 
> 2. Pass the whole stream through to the frontend and do the decoding
> and caching at the frontend. This could be implemented as an avcodec
> much like the subtitles are done at the moment.
>
> My favoured approach would be to implement #2. It should be cleaner
> and easier to maintain in the long run.
> Comments everyone?

Passing the whole stream to the frontend would be much cleaner,
recorder wise. It also allow you to record one of the programs
and do the interactive stuff later, right?

> We can still use all the parsing and caching stuff John's written,
> we will just have to tie it all together in a different way.
Yes, my main reason for wanting to integrate this sooner rather
than later is that I don't want the code to become impossible
to merge. But then once merged I would like to move it to 
DVBStreamData & dvbtables. The xStreamData/xtables stuff was
written with frontend decoding in mind.

Making #2 work with avlib would probably be a major PITA. But if
you are up for it, it would be insanely cool. :)

Also the xtables "parsers" are all C++ and avlib is all C. Since you
would basically just be requesting certain streams I don't think it
would be a huge headache, but I might be wrong. The "parsers" is in
quotes because these are really just wrappers around the raw tables.
They do the absolute minimum amount of parsing needed for quick
extraction of data from the tables.

-- Daniel



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