[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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