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

[Mike Isely]

On Thu, 25 Jan 2007, Rick Macdonald wrote:

> Rick Macdonald wrote:
> > Pantelis wrote:
> >   
> >> What you can try:
> >> Have the two computers close enough, so that whether you connect to one
> >> or the other, the antenna stays on the same place.
> >>
> >> Tune to *exactly* the same station. If you still hear mono+hiss to one while
> >> it is stereo in the other, then play with stereo_threshold to see if that 
> >> changes anything.
> >>   
> >>     
> > The laptop and desktop are side-by-side, so I don't have to touch 
> > anything except the USB cable (and my headphones) when I switch 
> > back-and-forth.  Same station. The PVR-USB2 plays stereo when the USB 
> > cable goes to the laptop, so the signal strength would seem to be OK.
> >
> > On the desktop, the pvrusb2 gets mono+hiss when I echo Stereo to the 
> > ctl_audio_mode, and mono+nohiss when I echo Mono to ctl_audio_mode.
> >
> > On the laptop, the pvrusb2 gets stereo+hiss when I echo Stereo to the 
> > ctl_audio_mode, and mono+nohiss when I echo Mono to ctl_audio_mode.
> >   
> OK, finally something interesting.
> 
> I installed the same kernel on the laptop as on the desktop, Debian 
> pre-built linux-image-2.6.18-3-686, and now the laptop now longer plays 
> stereo. It behaves the same as the desktop. I can boot back and forth 
> between the two kernels, and the old one comes back stereo; the new one 
> mono. In both cases (and on the desktop) I haven't updated anything to 
> with video/sound except for the pvrusb2 snapshot.
> 
> Mike - what kernel version do you run when you test your 29xxx device?

I've been running under 2.6.18.1 here for a while.

I did try both 29xxx and 24xxx devices, however I'll listen to them 
again with a more critical ear.  A little later though - in the midst of 
some long overdue encoder control cleanups right now.


> 
> In light of this, what is the next step?

The modules you are working with (msp3400, tuner, tda9887) have been 
evolving quite a bit since 2.6.15.  Quite likely something has been 
busted along the way.  I do know that msp3400 underwent a bunch of 
changes after 2.6.15 in order to fix problems with stereo / SAP decoding 
in NTSC.  (However don't get your hopes up with that because in radio 
mode msp3400 is not the part decoding the audio.)

I will listen to things here again and see if I can discern any problems 
using my 2.6.18.1 kernel build.

  -Mike

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