[mythtv] Fw: DVB Big PATCH, Part I - for CVS pls

Ben Bucksch linux.news at bucksch.org
Tue Aug 5 01:24:02 EDT 2003


Ramon Roca wrote:

>After this patch you will have a clear way to identify which are the AC3 PID if they are, something that wasn't before, so now you can write a patch to use them.
>
AC3 should work without your patch already (of course, I couldn't test 
it). Isaac said the frontend supports it, and there's nothing specific 
to be done in the backend. No need to change anything or write any code.

>Note: Not sure, I do suspect that the subtitles are coming in the text pids.
>Anyway I didn't find such PIDs anywhere, just let me know where I can grab
>them.
>
I don't know, but here's what I found using Google:

<http://www.dba.org.au/index.asp?sectionID=16>
*"Captions on Digital Television *
The DVB standard provides for captioning using two different systems - 
DVB Teletext and DVB Subtitles.
DVB Teletext resembles World System Teletext used in analog broadcasting 
in that only text information is carried in the datastream. This makes 
it an efficient way to carry captions as it has low bandwidth 
requirements. The trade-off, though, is that fonts are limited and 
dictated by the display device.
DVB Subtitles are bit-mapped graphics. Their appearance is controlled by 
the author in the same way as subtitles on DVDs. While a higher data 
overhead is required, the readability of DVB Subtitles is far superior 
to DVB Teletext."

<http://webapp.etsi.org/workprogram/Report_WorkItem.asp?WKI_ID=15155>



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