Hartmut Hackmann wrote:
Hi,
Michael Krufky wrote:
Hartmut Hackmann wrote:
There is a driver for the DVB-S channel decoder of this
card available now. The problem is: how to select the frontends.
Hello Hartmut,
I changed the list cc from v4l to dvb, as that would be more appropriate.
I'm just curious... Will saa713x with multiple frontends be able to use
both frontends at once? Or just one at a time? (I would assume the latter)
In the case of the cx2388x cards, Hauppauge has an HVR3000 card that has
both DVB-T and DVB-S demods on it. Only one can be used at a time, as
they would share a single transport to move the ts data.
Steve Toth has been working on the 8802-mpeg port functionality of the
cx88 driver, and he has created this device_acquire method, that allows
the driver to select which frontend has access to a bus at any given moment.
You might want to take a look at his tree for ideas:
http://linuxtv.org/hg/~stoth/hvr1300-final?cmd=changeset;node=4b846f1d939b;style=gitweb
This tree doesnt yet deal with multiple DVB frontends, but it does deal
with MPEG Encoder vs. DVB-T demod. I believe the multiple frontend
support is coming next, but I havent asked him about that.
Of course, if the saa713x will allow both demods to function
simultaneously, then the suggestion above will not apply at all.
I'm just shooting ideas around, and asking for my curiousity... Dont
feel pressured to act on this immediately. ;-)
Thanks that you pointed me to this, i will have a look. Your assumption
is right, the saa173x have only 1 TS interface, so both decoders can't
be active simultanously.
The easiest solution is to select the demodulator with an insmod option,
it can be done with a very simple hack.
I've been working on some generic patches for the cx88 and saa7134
drivers to add support for multiple frontends on a single adapter.
Specifically, I'm defining some generic videobuf_dvb_X structures which
move the struct videobuf_dvb member from the cx8802_dev and
(saa7134_dev?) core structures down into a list with some other
elements. (This can be extended for multiple adapters multiple frontends)
I'm also changing the dvb_register functions. Instead of calling
videobuf_dvb_register (which implicitly creates a single adapter with a
single frontend), I'm calling a new function videobuf_dvb_register_bus
which registers a single adapter and any number of frontends.
Based on replies to my earlier question, my feeling is that cx88 boards
are a single adapter with multiple frontends. Other bridges could be
multiple adapters and multiple frontends (MD8800).
The saa7134 framework will also need it's own version of
cx88_hw_bus_ctrl() and will need to override feops.hw_bus_ctrl to ensure
all the frontends call and try to determine whether access is available.
This mechanism stops two different frontends from trying to
access/configure the same hardware. <---- I'm _NOT_ working on these
patches. The cx88 framework is a good reference for this.
The patches are done but I need to test. If everything goes well I'll
post the patches fore review later this week.
Steve
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