[linux-dvb] Re: Frontend IP based

[Ralph Metzler <rjkm@metzlerbros.de>]

sf writes:
 > Ralph Metzler wrote:
 > ...
 > > Of course most cards do not deliver time stamps for the incoming TS
 > > packets (but some do). So, most RTP servers programs derive the 
 > > time from the PCR and interpolation which kind of defeats their purpose.
 > 
 > Which cards do deliver time stamps? How can I get at them from user space?


The newer DVB chips by ST do deliver a TS with timestamps. But those
are only used in STBs.

The only card I know of is still under development by a customer of
us. I cannot reveal any details without checking with them.

For this card we added a DMX_OUT_TS_TAP_OSIZE mode to the frontend
and the demux layer. It will deliver all packets in their original size
as delivered by the hardware. In this case, 4 bytes timestamp plus the
actual TS packet. To the demux layer you can now deliver all kind of
packet sizes. You just have to tell it the total packet size and where
the actual 188 byte TS packet starts.
We already comitted patches to mplayer and xine to handle these kinds
of packets (it also fixes the broken 204 byte packet support) but they
currently only skip the timestamp and do not use them for time recovery. 


Ralph