[mythtv-users] KWorld UB499-2T usb dvt-t twin-tuner device
J.Pilk at tesco.net
Thu Dec 8 12:52:04 UTC 2011
I got one of these some time ago but had no success and put it away.
Recently I've been setting up Scientific Linux 6, one of the RHEL6 near
clones, on a laptop, and I wanted to find out what media support is
available with it. I was really thinking about HD stuff, and in
particular dvb-t2 as used here in the UK. I came across the
'media_build' script on the linux-media site, and eventually ran it
successfully on SL6. The actual build took around a quarter of an hour.
Then, needing some hardware to try it on, I retrieved this device.
I had to get firmware from the Windows driver, as detailed in the
linux-media wiki, but once that was installed the device was recognised,
as a 'KWorld UB499-2T T09(IT9137)', and I was able to run a mythtvsetup
scan and record simultaneously from two muxes. 0.24-fixes.
There are still some problems and I wouldn't recommend this as a
five-star purchase, but the recordings seem fine; projectx finds a few
packets out of order, more than I get with my pci cards, but this
doesn't seem to be important.
Probably the worst feature is that dmesg reports a hardware PID filter
with a table count of 31: it may not pass on the complete data as
received. On the BBC SD mux this may cause backend error messages about
demuxing once every second, which obscures the other content of the
backend log. I've seen this with another similarly-but-worse-crippled
old Freecom usb pen, and Mike Dean suggested using an inverse grep to
cope with it. This limitation isn't mentioned in the device's wiki
page, and it appears that there are other similar pens with an IT9135
that may not work as twin-tuners.
Some channels also appear to myth with channel numbers above 25000
instead of eg 15; that may be related to the PID filter too.
Another peculiarity is that myth status now believes I have 22 tuners,
mostly inaccessible; I've 'deleted all tuners' several times.
At present my feeling is that I have it and I may use it as a
low-priority device to provide extra cover. Last time I was in Maplin
they had it at about 20 GBP.
The new v4l kmdl from ATrpms may support this - and the dvb-t2 usb
device - too; I haven't tried it.
More ramblings here:
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