[linux-dvb] typhoon usb dvb-t card low signal

Bertrand Marquis bertrand.marquis at gmail.com
Sat Feb 25 14:07:18 CET 2006


Hi,

i did some research and find out that the front end register for my device is 
not a typhoon but a wideview. Here a the kernel logs during pluging device 
and then starting mplayer:

Feb 25 14:04:21 localhost kernel: usb 2-1: new full speed USB device using 
uhci_hcd and address 6
Feb 25 14:04:21 localhost kernel: dvb-usb: found a 
'WideView/Yuan/Yakumo/Hama/Typhoon DVB-T USB2.0 (WT-200U)' in cold state, 
will try to load a firmware
Feb 25 14:04:21 localhost kernel: dvb-usb: downloading firmware from file 
'dvb-usb-dtt200u-01.fw' to the 'Cypress FX2'
Feb 25 14:04:22 localhost kernel: dvb-usb: WideView/Yuan/Yakumo/Hama/Typhoon 
DVB-T USB2.0 (WT-200U) successfully initialized and connected.
Feb 25 14:04:23 localhost kernel: usb 2-1: USB disconnect, address 6
Feb 25 14:04:23 localhost kernel: dvb-usb: generic DVB-USB module successfully 
deinitialized and disconnected.
Feb 25 14:04:24 localhost kernel: usb 2-1: new full speed USB device using 
uhci_hcd and address 7
Feb 25 14:04:24 localhost kernel: dvb-usb: found a 
'WideView/Yuan/Yakumo/Hama/Typhoon DVB-T USB2.0 (WT-200U)' in warm state.
Feb 25 14:04:24 localhost kernel: dvb-usb: will use the device's hardware PID 
filter (table count: 15).
Feb 25 14:04:24 localhost kernel: DVB: registering new adapter 
(WideView/Yuan/Yakumo/Hama/Typhoon DVB-T USB2.0 (WT-200U)).
Feb 25 14:04:24 localhost kernel: DVB: registering frontend 0 (WideView USB 
DVB-T)...
Feb 25 14:04:24 localhost kernel: dvb-usb: could not initialize remote 
control.
Feb 25 14:04:24 localhost kernel: dvb-usb: WideView/Yuan/Yakumo/Hama/Typhoon 
DVB-T USB2.0 (WT-200U) successfully initialized and connected.
Feb 25 14:04:27 localhost pam_console.dev[10632]: Restoring console 
permissions for /dev/dvb/adapter0/demux0
Feb 25 14:04:28 localhost pam_console.dev[10643]: Restoring console 
permissions for /dev/dvb/adapter0/dvr0
Feb 25 14:04:28 localhost pam_console.dev[10679]: Restoring console 
permissions for /dev/dvb/adapter0/frontend0
Feb 25 14:04:28 localhost pam_console.dev[10665]: Restoring console 
permissions for /dev/dvb/adapter0/net0
Feb 25 14:04:39 localhost lircd-0.7.1[8236]: accepted new client on /dev/lircd
Feb 25 14:05:00 localhost lircd-0.7.1[8236]: removed client

Could the wrong frontend be the source of my problems ?


Le Samedi 25 Février 2006 12:34, Bertrand Marquis a écrit :
> Hi Patrick
>
> Sorry for the last two messages, mistake in the address
>
> Le Samedi 25 Février 2006 12:05, vous avez écrit :
> > Hi Bertrand,
> >
> > On Sat, 25 Feb 2006, Bertrand Marquis wrote:
> > > I am trying to make a Typhoon dvb-t usb to work under linux.
> > >
> > > When i plug the card, the kernel detects it correctly as a typhoon
> > > card, load the firmware i downloaded in linuxtv and then the led is on.
> > > I am then able to look for channels using scandvb and i can found all
> > > channels available in my area.
> >
> > Very good.
> >
> > > The problem is that i have a really low signal:
> >
> > Actually the signal strength should give a value of the Signal power
> > before any tuner/LNA/AGC of the board. A lot of boards currently
> > supported don't give that value or it cannot be calculation due to the
> > lack of floating point operations at kernel level.
> >
> > Furthermore your board has everyhting "hidden" in a firmware and the
> > value you read from it is "pre-calculated". From the information we have
> > we just assumed that it is a percent value, but we might be wrong.
> >
> > However, in DVB the signal strength is not so important. If BER and UNC
> > is zero everything is OK and you will not have any bad video or
> > something. I would not recommend this device and using its signal
> > strength to find a good position for the antenna.
> >
> > > Under windows the typhoon application says that i have a signal of
> > > about 95% and the same for the snr and then i can look television
> > > without problems.
> > >
> > > But under linux i can see practically nothing and kaffeine says that my
> > > signal is only 20%.
> >
> > And there is no TV visible?
>
> i can see part of the images from time to time but then the player
> (mplayer, xine or kaffeine) give an error saying that i have a lack of
> resources.
>
> Here is the output of mplayer:
>            ************************************************
>            **** Your system is too SLOW to play this!  ****
>            ************************************************
>
> Possible reasons, problems, workarounds:
> - Most common: broken/buggy _audio_ driver
>   - Try -ao sdl or use the OSS emulation of ALSA.
>   - Experiment with different values for -autosync, 30 is a good start.
> - Slow video output
>   - Try a different -vo driver (-vo help for a list) or try -framedrop!
> - Slow CPU
>   - Don't try to play a big DVD/DivX on a slow CPU! Try some of the
> lavdopts, e.g. -vfm ffmpeg -lavdopts lowres=1:fast:skiploopfilter=all.
> - Broken file
>   - Try various combinations of -nobps -ni -forceidx -mc 0.
> - Slow media (NFS/SMB mounts, DVD, VCD etc)
>   - Try -cache 8192.
> - Are you using -cache to play a non-interleaved AVI file?
>   - Try -nocache.
> Read DOCS/HTML/en/video.html for tuning/speedup tips.
> If none of this helps you, read DOCS/HTML/en/bugreports.html.
>
> In fact it seems like i have only part of the image and due to this the
> player is not able to decode the video.
>
> There are only noises from time to time
> for the sound and every 10 seconds xine is redoing buffering to end saying
> that i have an error messaying that there are too much dropped frame. My
> processor is only between 10 and 20% use.
>
> > > Does anyone has this problem and knows how to solve it ?
> >
> > What is the problem?
> >
> > regards,
> > Patrick.
> >
> > --
> >    Mail: patrick.boettcher at desy.de
> >    WWW:  http://www.wi-bw.tfh-wildau.de/~pboettch/
>
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