Hi All,

I am working on the AVStream minidriver. When I use GraphEdit to select
input between cable and antenna on TV tuner filter properties window,
GraphEdit doesn't inform the driver (not call Set_tunerInput in
KSPROPERTY_TUNER_INPUT). I've set the number of inputs to 2 in tuner mode cap
request. How does the driver know if the input is cable or antenna? The
driver needs to know the current tuning spaces ecause the hardware has
different mapping tables for air and cable.

Thanks in advance,

Jen Zhang

DDK documentation is a bit confusing.

KSPROPERTY_TUNER_INPUT is designed for switching between different physical
inputs on the tuner device. Frequently analog tuners have multiple inputs.
This allows the user to connect multiple cables to it. People usually use it
to hook up the signal that is coming from antenna on one input and from
cable on the other one. That makes it possible to receive signal from both
antenna and cable without reconnecting wires. All the hardware does is it
switches from one input to the other.

Switching frequency map tables between cable and terrestrial is done at the
higher level (usually by components in middleware). Drivers operate
frequencies, which means that they don't care about channel-to-frequency
mapping.

If all you want to do is to support both terrestrial and cable, then you
don't have to do anything else as DirectShow does it for you automatically.

-- Max.




"Jen Zhang" <Jen Zhang@discussions.microsoft.com> wrote in message
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