Re: [Redbutton-devel] Problem after retuning with Freesat

[John W. <jo...@po...>]

On Mon, 28 Feb 2011 12:44:45 +0000
Simon Kilvington <s.k...@er...> wrote:

> just got a quick question - I don't have access to FreeSat, so I can't
> test this, but what happens to the video stream when the channel
> changes with your patch? Does the video carry on playing?

No. In fact the new channel is on a completely different transponder
(12.441GHz instead of 10.773GHz), it has a different SID, different
VPID and APID etc etc. The video just freezes.

The spec says "any prepared MHEG-5 Stream objects shall be re-evaluated
according to the context of the new service as if a SetData action had
occurred". I would *guess* that this means that, if it was playing the
default video/audio for the service before the tune, it should start
playing the video/audio of the new service after the tune. This would
require some code to change the PES filters to the new VPID and APID,
which doesn't exist at the moment. Also, I think I've sometimes
seem a StreamClass SetData action, which isn't implemented: perhaps
this is setting some details of the new service?

If I navigate to the menu option that takes me back to the original
program on BBC1, then the video comes back to life again. So the PES
filters must still be working OK, they are just filtering the wrong PIDs
for the new service.

Actually, I've built the code of rb-download into a plugin for the
"vdr" program, so that rb-download uses vdr to do the tuning; this
means that the new channel appears on my TV after the tune. Now the
rb-browser program doesn't show any video at all, because vdr has got
control of the dvr0 device; but my plan is to make rb-browser into a
vdr plugin too, so that its text output will appear overlayed on top of
the video output from vdr.

Regards,
John