[mythtv] Problems with Hauppauge Nova TD Dual Tuner USB Stick and Mythtv, no problems in Windows!

Edward Peckham edward at peckham.me.uk
Sun Apr 14 15:56:18 UTC 2013


Stephen, Roger,

On Monday 15 Apr 2013 01:26:17 Stephen Worthington wrote:
> On Sun, 14 Apr 2013 10:32:50 +0100, you wrote:
> >On Sun, 14 Apr 2013 02:31:18 +0100, Stephen Worthington
> >
> ><stephen_agent at jsw.gen.nz> wrote:
> >> On Sat, 13 Apr 2013 23:23:35 +0100, you wrote:
> >>> Another data point. I've been fighting my Nova TD ever since I upgraded
> >>> to
> >>> Ubuntu 12.10 with MythTV 0.25.2. Well actually I've been fighting my TD
> >>> ever
> >>> since I bought it, but before 12.10 I felt like I was winning.
> >>> 
> >>> My memory fades, but I think the magic fix in the past was setting the
> >>> bandwidth to auto. With 12.10/0.25 my MythTV log was full of auto
> >>> bandwidth
> >>> not being a valid setting, so I changed to using 8MHz bandwidth and can
> >>> now
> >>> occasionally get a lock, but mostly just end up with partial locks.
> >>> 
> >>> Interestingly, tzap has no trouble tuning:
> >>> 
> >>> $ head -n1 channels.conf
> >>> BBC ONE Scot:522000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_AUTO:FEC_AUTO:
> >>> QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_32:HIERARCHY_NONE:101:102:4
> >>> 220
> >>> 
> >>> $ tzap -c channels.conf "BBC ONE Scot"
> >>> using '/dev/dvb/adapter0/frontend0' and '/dev/dvb/adapter0/demux0'
> >>> reading channels from file 'channels.conf'
> >>> tuning to 522000000 Hz
> >>> video pid 0x0065, audio pid 0x0066
> >>> status 0f | signal f9ee | snr 00d1 | ber 001fffff | unc 00000000 |
> >>> status 1f | signal ffff | snr 010f | ber 00000000 | unc 00000000 |
> >>> FE_HAS_LOCK
> >>> ^C
> >>> 
> >>> So something changed, but I'm still struggling to find out what.
> >>> 
> >>> Good luck,
> >>> Ed
> >> 
> >> There are options on drivers that can affect things. You set them
> >> from the /etc/modprobe.d directory. My Hauppauge WinTV Nova TD-500
> >> PCI dual tuner card has one that turns on the low noise amplifier. It
> >> is supposed to work automatically now, in current driver versions, but
> >> in older drivers it had to be set manually, and caused problems
> >> exactly like yours. So maybe it is not turning on automatically and
> >> needs to be forced on.
> >> 
> >> You can find the options for drivers by using the modinfo command. You
> >> need to know the name of the driver - in my case, it is
> >> dvb_usb_dib0700 so the command:
> >> 
> >> modinfo dvb_usb_dib0700
> >> 
> >> produces a big listing with these "parm" values at the end:
> >> 
> >> parm: force_lna_activation:force the activation of
> >> Low-Noise-Amplifyer(s) (LNA), if applicable for the device (default:
> >> 0=automatic/off). (int)
> >> parm: debug:set debugging level (1=info,2=fw,4=fwdata,8=data
> >> (or-able)). (int)
> >> parm: nb_packet_buffer_size:Set the dib0700 driver data
> >> buffer size. This parameter corresponds to the number of TS packets.
> >> The actual size of the data buffer corresponds to this parameter
> >> multiplied by 188 (def ault: 21) (int)
> >> parm: adapter_nr:DVB adapter numbers (array of short)
> >> 
> >> So putting a line like this in a file in /etc/modeprobe.d (eg
> >> options-dvb.conf) would force my LNA on:
> >> 
> >> options dvb_usb_dib0700 force_lna_activation=1
> >> 
> >> Your driver name may be different - you can find a list of all the
> >> driver names using a command like:
> >> 
> >> modprobe -l | grep dvb-usb
> >> 
> >> There is probably a way of finding driver names from /proc or /sys
> >> somewhere (I have never figured that out), and the driver name should
> >> show up in dmesg and kern.log when it is loaded. This is from my
> >> dmesg:
> >> 
> >> [ 19.287457] usbcore: registered new interface driver
> >> dvb_usb_dib0700
> >> 
> >> Some drivers also have debug options there that you can use to make
> >> them tell you more about what they are doing.
> >
> >Also experiment with the tuning delay set in mythtv-setup/Capture Cards.
> >That affects Partial Lock issues. Maybe the upgrade upset the Myth/tuner
> >synchronisation.
> 
> Yes, my Hauppauge WinTV Nova TD-500 PCI card is supposed to need a 500
> ms tuning delay.  I set it to that and it worked, so I never tried
> smaller delays.  Your Nova TD USB stick sounds as though it may be
> using very similar hardware and might well need that delay too.

Thanks very much for the suggestions guys.  It's much appreciated.

I had another round of playing with the module params for my dib0700

$ ls /sys/module/dvb_usb_dib0700/parameters/
adapter_nr  debug  force_lna_activation  nb_packet_buffer_size

It turned out I'd already set  force_lna_activation=1 on a previous occasion, 
so I tried with it off again.  I also set my tuning delay up to 1000ms without 
success:

mysql> update capturecard set dvb_tuning_delay = 1000;

It just seems very strange that tzap is rock solid and gets FE_HAS_LOCK every 
time, whereas my mythtv-backend  really struggles to get anything other than a 
partial lock.

With tzap succeeding, My feeling is that it has to be something on the 
userland side rather than kernel modules as their param configuration is common 
to both MythTV and tzap.

Cheers,
Edward

ps. Sorry for continuing to clutter -dev with this discussion rather than -
users, but my list fu is not really up to moving it.



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