[mythtv] DVB: Teletext & Subtitles

[mian]

> I started reading through my archive of docs, but could not find a clear
description of how the subtitle and teletext data is coded. Has someone
encountered such documentation? If so, could you point me in the right
direction, please?
>

libmpsys is a good start as modifying the XML to generate parser code is
very fast and flexible, the following relevant structures can be found
pasted below, this PDF also seems very elaborate at first glance, just go
down to chapter 4..
http://webapp.etsi.org/action%5COP/OP20021004/en_300743v010201o.pdf

<struct name="subtitling">
	<constant name="descriptor_tag" bits="8" value="0x59"/>
	<length   name="descriptor_length" bits="8">
		<repeat      name="subtitles">
			<isolang name="language_code"/>
			<int     name="subtitling_type" bits="8"/>
			<int     name="composition_page_id" bits="16"/>
			<int     name="ancillary_page_id" bits="16"/>
		</repeat>
	</length>
</struct>

<struct name="vbi_data">
	<constant name="descriptor_tag" bits="8" value="0x45"/>
	<length   name="descriptor_length" bits="8">
		<repeat name="services">
			<int name="data_service_id" bits="8"/>
			<length name="data_service_descriptors_length" bits="8">
				<!-- cheating: avoiding if -->
				<data name="descriptors"/>
			</length>
		</repeat>
	</length>
</struct>

<struct name="vbi_teletext">
	<constant name="descriptor_tag" bits="8" value="0x46"/>
	<length   name="descriptor_length" bits="8">
		<repeat      name="teletexts">
			<isolang name="language_code"/>
			<int     name="teletext_type" bits="5"/>
			<int     name="teletext_magazine_number" bits="3"/>
			<int     name="teletext_page_number" bits="8"/>
		</repeat>
	</length>
</struct>

<struct name="teletext">
	<constant name="descriptor_tag" bits="8" value="0x56"/>
	<length   name="descriptor_length" bits="8">
		<repeat      name="teletexts">
			<isolang name="language_code"/>
			<int     name="teletext_type" bits="5"/>
			<int     name="teletext_magazine_number" bits="3"/>
			<int     name="teletext_page_number" bits="8"/>
		</repeat>
	</length>
</struct>