On Sun, 2009-07-19 at 00:30 +0530, Ravi A wrote:
> On Sat, Jul 18, 2009 at 6:19 AM, Andy Walls<[email protected]> wrote:
> > On Fri, 2009-07-17 at 19:16 -0400, Andy Walls wrote:
> >> On Sat, 2009-07-18 at 02:35 +0530, Ravi A wrote:
> >> > On Tue, Jul 14, 2009 at 6:07 AM, Andy Walls<[email protected]> wrote:
> >
> >> > It so happens the driver/utility is setting the input back to Y0
> >> > (default, white connector) whenever video format is changed -
> >> >
> >> > $sudo v4l2-ctl -s pal
> >> > sets MUX input to Y0 from wherever it was. However -
> >> > $sudo v4l2-ctl --log-status
> >> > still shows the input to be Line-In!
> >> >
> >> > $sudo v4l2-ctl -i1
> >> > $sudo v4l2-ctl -i2
> >> > sets the input back to Y1 and sound re-appears.
> >> >
> >> > Is this how the behavior should be?
> >>
> >> Nope.  Good observation, this is the bug.  I checked the source code of
> >> ivtv-gpio.c and the version history, and it's a bug that's been in the
> >> ivtv driver since before it was in the mainline kernel.
> >>
> >> It should be striaght-forward to fix the behavior, but I'll have to take
> >> a look and make sure there's not some odd board that needs something
> >> special.  I'll have a patch ready soon.
> >
> > Ravi,
> >
> > I have pushed a patch to
> >
> > http://linuxtv.org/hg/~awalls/ivtv
> >
> >
> > The bug was ancient.  It looks like it arose from an old method of
> > setting the tuner back to TV when exiting from FM radio mode.  It had
> > the side effect of changing the audio input of a GPIO audio mux back to
> > the tuner whenever the video standard was changed when you were not in
> > radio mode.
> >
> > Apparently no one with a card with a GPIO audio mux ever changed the
> > standard when set to Composite or SVideo.
> >
> >
> >
> >> > When MUX is set properly and sound is present, the volume was still a
> >> > bit low and it seemed very noisy - something like zero-crossing
> >> > distortion. I could improve it a bit by setting volume all the way
> >> > high.
> >> > sudo v4l2-ctl -c volume=65535
> >> > Setting bass and treble to '0' helped to reduce the distortion/noise
> >> > significantly although the volume still seemed low
> >> > sudo v4l2-ctl -c bass=0
> >> > sudo v4l2-ctl -c treble=0
> >> >
> >> > If I can get v4l2-dbg to read/set registers maybe I can try more
> >> > experiments for the audio quality.
> >
> > Yes, it will give you the flexibility to experiment will all sorts of
> > audio settings.
> >
> > Regards,
> > Andy
> >
> >
> 
> 
> Hi Andy,
> 
> With the latest patch, the MUX control becomes stable and the audio
> stays put with video standard changes!
> 
> Now that the audio is stable, I notice some possible issue with the
> PLL VCO center frequency adjustment patch. Both e8fcd13e4ae7 and
> d7e1eb4b17d8 show some skips/gaps in both video and audio (Composite
> input). After 10 seconds of playing with mplayer the following is
> output -
> "Your system is too SLOW to play this! .. blah"
> and after another 10 seconds a continuous stream of "Too many video
> packets in the buffer: (4096 in 8007268 bytes)... blah" appear.
> Patches 82a264ea2784 and 7ea3e7b9a657 do not show this, both video and
> audio are smooth.

Oops.  The CX23416 firmware seems to be assuming a crystal value of
28.636363 MHz for the CX2584x, where the CX23418 firmware assumes a
crystal value of 28.636360 MHz for it's internal A/V decoder.

(I wish they had both assumed the correct value of  28.63636363... MHz.)

I'll have to get out my spreadsheet and recompute the values.  I'll push
a patch tonight.  I'll also try to test with my PVR-150 (but might not
get to testing it tonight).

Regards,
Andy

> I was able to finally read some registers after compiling the latest
> v4l2-dbg. I will try tweaking audio registers using 82a264ea2784 next.
> 
> Regards
> Ravi



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