[pvrusb2] pvrusb2-mci-20070114 radio support - stereo?

[Pantelis]

Rick Macdonald wrote:
> I'm writing to ask if pvrusb2-mci-20070114 supports stereo FM.
> I tried to make this short, but...
>
> Two years ago I bought a PVR USB2, really just wanting FM stereo radio.
> I _believe_ the unit is stereo but I guess I don't know for sure.

I think I found the bug that caused the FM radio not being stereo in 29xxx
devices. The bug was (not so) surprisingly in the msp3400 module. Thankfully,
this bug is already fixed by Hans Verkuil's commit

ec5a9f0bca164ccf62399b37394d7a98f7e9be3d

in v4l-dvb repository. If you have a recent kernel (say >= 2.6.18/19) and
you don 't want the whole v4l-dvb repo, you can isolate this patch using

hg export 4982 

From the commit log of this:

"The wrong matrix was used when an external input was selected instead of
the tuner input. The rxsubchans field was also not initialized to STEREO
for an external input. And finally the msp34xxg_detect_stereo() should
not try to detect stereo for an external input, that code is for the
tuner input only.

Together these bugs made it hit 'n miss whether you ever got stereo out
of the msp3400 for an external input."

This, together with the fact that as far as msp3400 is concerned, radio
is just an external input (SCART2 IIRC), explain why this bugfix resolves
the radio problem.

Thanks Hans for fixing this :-)

-Pantelis

P.S., I also applied the "mplayer pan" test to tv input and (un)surprisingly
I found this to be mono as well. That could be the station though, but I 'm
sure I 'll have to investigate more :-(