[linux-dvb] ASUSTEK P7131 Dual TV dvb mode?

hermann pitton hermann-pitton at arcor.de
Sun Oct 1 01:01:52 CEST 2006

Am Samstag, den 30.09.2006, 17:45 +0300 schrieb Ville Herva:
> On Sat, Sep 30, 2006 at 02:20:27PM +0300, you [v+dvb at iki.fi] wrote:
> > > For now with the above modification card=78 seems fine, but for example
> > > still no report for radio function. 
> > 
> > I can't get any sound out of analog tv (picture works) nor fm radio (seems
> > to tune, though), but I'm likely missing the cable. Or is analog sound
> > supposed to work without the cable from the card to sound card input?
> After fiddling around, I got analog tv sound and radio sort of working.
> It needed this to .mplayer/config
>   tv=driver=v4l2:norm=PAL:input=0:alsa=yes:adevice=hw.1,0:forceaudio=yes:immediatemode=0:audiorate=32000:amode=1:width=768:height=576:device=/dev/video1:outfmt=yuy2:chanlist=europe-west
> crucial bit being "adevice=hw.1,0".
> For radio, this seems to do something:
>   arecord -D hw:1,0 -r 32000 -c 2 -f S16_LE | aplay &
>   gnomeradio
> (I also tried fmtools-1.0 "fm" utility, I need to do 
> "while true; do fm 103.7 32000; done" as fm seems to exit after a second for
> some reason.)
> The radio sound is not perfect, though, there's constant crackling (which
> *sounded* more like sound prosessing artifact or internal electric
> interference rather than just weak fm signal), and after a few minutes,
> arecord|aplay seemed to get out of sync (somekind of stutter at ~0.5s
> frequency) and I needed to restart arecord|aplay.
> But it works :).

Hi Ville,

thanks for reporting the radio functionality!

The radio misses signal strength and stereo detection, so autotuning
doesn't work yet, but sound should be perfect with the above.

The bundled rabbit ears antenna is very poor in a room with known bad
reception conditions here, even for strong stations I had to adjust it
per station, but with the DVB-T roof antenna and radio from cable-tv it
has totally clear sound.

The bundled DVB-T antenna is unusable for radio, it produces distortions
and whistling noise.

You could also enable debug=1 for saa7134-alsa, maybe your system
produces buffer over/underuns. Not the case for me.

To connect a analog audio cable is always fine too. The two pins in the
middle of the connector are ground.

Even the card has a totally new layout and misses the firmware eeprom,
the rest seems to be like on the older one. Maybe Hartmut has a
suggestion, how we should further proceed with it now, to avoid that the
users have to adjust code themselves.

Yeah, the remote is still unconfirmed for that one and Marc just posted
a new and further cleaned up version of his patch. Maybe we could need
some dummy device for testing unknown remotes just for keydown/up and
further gpio events in the beginning.

To avoid using radio first in order to get the FM/RF input active for
DVB-T, you could either use the cable-tv antenna input for it or apply
the patch I previously linked to.

After that patch the ability to use the cable-tv antenna input for DVB-T
and the FM/RF antenna input with a dedicated radio antenna at once is
lost. Also we would have to change gpio for Composite1 and S-Video to
0x0200000 to keep the ability to watch/record DVB-T and input from an
external tuner at once. For somebody with only this single card it is
really a feature I guess. Comments or other suggestions?


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