[mythtv-users] UK DVB-T Mendip Tuning Fails with Error: Wrong PMT
Alex Butcher
mythlist at assursys.co.uk
Wed Jul 6 20:23:42 UTC 2011
On Wed, 6 Jul 2011, Nigel Jewell wrote:
> Up until about 2 months ago I was able to receive all Freeview channels
> on my MythTV box without any issues using a Hauppage Nova-T DVB card
> from the Mendip transmitter, however at the end of May I noticed that
> all channels on a single multiplex were failing to tune.
ISTR that coincided with a change in the broadcasting parameters and/or
frequencies. A quick Google can't confirm that, however.
> If I plug the aerial directly into my TV (which also has a Freeview
> tuner) I receive all channels with good quality, so I can safely assume
> that I should be able to pick it up.
>
> Using dvbscan as:
>
> /usr/bin/scandvb -u -vvv uk-Mendip
The tuning files aren't being kept up-to-date, in my experience.
On Fedora 14, as of dvb-apps-1.1.1-22.fc14, that file contains:
$ cat /usr/share/dvb-apps/dvb-t/uk-Mendip# UK, Mendip
# Auto-generated from http://www.dtg.org.uk/retailer/dtt_channels.html
# and http://www.ofcom.org.uk/static/reception_advice/index.asp.html
# T freq bw fec_hi fec_lo mod transmission-mode guard-interval hierarchy
T 778167000 8MHz 3/4 NONE QAM16 2k 1/32 NONE
T 746167000 8MHz 2/3 NONE QAM64 2k 1/32 NONE
T 802167000 8MHz 2/3 NONE QAM64 2k 1/32 NONE
T 826167000 8MHz 3/4 NONE QAM16 2k 1/32 NONE
T 754167000 8MHz 3/4 NONE QAM16 2k 1/32 NONE
T 842000000 8MHz 3/4 NONE QAM16 2k 1/32 NONE
I make it should be:
# UK, Mendip
# Manually generated 06 July 2011 from
# http://www.digitaluk.co.uk/postcodechecker/ and
# http://www.ukfree.tv/mapsofsignal.php?c=61&a=1 etc.
# C61
T 794000000 8MHz 2/3 NONE QAM64 8k 1/32 NONE
# C54
T 738000000 8MHz 2/3 NONE QAM64 8k 1/32 NONE
# C58 (HD)
T 770000000 8MHz 2/3 NONE QAM256 32k 1/32 NONE
# C62+
T 802167000 8MHz 2/3 NONE QAM64 2k 1/32 NONE
# C56+
T 754167000 8MHz 3/4 NONE QAM16 2k 1/32 NONE
# C67
T 842000000 8MHz 2/3 NONE QAM64 8k 1/32 NONE
The digitaluk.co.uk site is the best I've found, if you tick the "I am in
the aerial installation trade" checkbox. :-)
Hover over the channel numbers to get the DVB parameters, and Use queries
like <http://www.ukfree.tv/mapsofsignal.php?c=61&a=1> to get the
frequencies.
> Any ideas? I'm not sure where to begin with this as it could be a fault
> of the signal, of the kernel drivers, or of MythTV ... or maybe my
> channel configuration data ...
You will need to adjust the contents of your dtv_multiplex table.
MythTV doesn't (as far as I know) use the 'seed' files under
/usr/share/dvb-apps/. Instead, it scans the entire spectrum and tries to
fill in the parameters automatically. Furthermore, I had difficulties with
it losing multiplexes with some of those parameters set to auto, so I used
the digitaluk and ukfree.tv data to fill in my dtv_multiplex table as per
<http://pastebin.com/raw.php?i=WqmtTJW4>.
Note that you will need to make further changes to the dtv_multiplex table
(and /usr/share/dvb-apps/dvb-t/uk-Mendip, if you use it with other
applications) on both 28 September 2011 and 28 March 2012, so put these
dates in your diary now.
> I've pasted the channel configuration from the database below.
>
> Kind Regards,
> Nige.
>
> mysql> select * from channel inner join dtv_multiplex on channel.mplexid
> = dtv_multiplex.mplexid where callsign = 'ITV4'\G
> *************************** 1. row ***************************
> chanid: 160024
> channum: 24
> freqid: NULL
> sourceid: 1
> callsign: ITV4
> name: ITV4
> icon: /mythtv/icon/ITV4.png
> finetune: NULL
> videofilters:
> xmltvid: itv4.itv.co.uk
> recpriority: 0
> contrast: 32768
> brightness: 32768
> colour: 32768
> hue: 32768
> tvformat: Default
> visible: 1
> outputfilters:
> useonairguide: 0
> mplexid: 16
> serviceid: 28032
> tmoffset: 0
> atsc_major_chan: 0
> atsc_minor_chan: 0
> last_record: 2011-06-11 20:55:02
> default_authority:
> commmethod: -1
> mplexid: 16
> sourceid: 1
> transportid: 24576
> networkid: 9018
> frequency: 842000000
> inversion: a
> symbolrate: 0
> fec: auto
> polarity: v
> modulation: qam_64
> bandwidth: 8
> lp_code_rate: 3/4
> transmission_mode: 2
> guard_interval: 1/32
> visible: 0
> constellation: qam_16
> hierarchy: n
> hp_code_rate: 3/4
> mod_sys: UNDEFINED
> rolloff: 0.35
> sistandard: dvb
> serviceversion: 8
> updatetimestamp: 2010-05-31 19:29:14
> default_authority:
For reference:
mysql> select * from channel inner join dtv_multiplex on channel.mplexid =
dtv_multiplex.mplexid where callsign = 'ITV4'\G
*************************** 1. row ***************************
chanid: 1024
channum: 24
freqid:
sourceid: 1
callsign: ITV4
name: ITV4
icon: /etc/mythtv/channels/itv4.jpg
finetune: 0
videofilters:
xmltvid: itv4.itv.co.uk
recpriority: 0
contrast: 32768
brightness: 32768
colour: 32768
hue: 32768
tvformat:
visible: 1
outputfilters:
useonairguide: 0
mplexid: 19
serviceid: 28032
tmoffset: 0
atsc_major_chan: 0
atsc_minor_chan: 0
last_record: 2011-07-06 20:42:38
default_authority: www.itv.com
commmethod: -1
mplexid: 19
sourceid: 1
transportid: 24640
networkid: 9018
frequency: 842000000
inversion: a
symbolrate: 0
fec: auto
polarity: v
modulation: qam_64
bandwidth: 8
lp_code_rate: 1/2
transmission_mode: 8
guard_interval: 1/32
visible: 0
constellation: qam_64
hierarchy: n
hp_code_rate: 2/3
mod_sys: UNDEFINED
rolloff: 0.35
sistandard: dvb
serviceversion: 33
updatetimestamp: 2011-01-24 00:41:50
default_authority:
HTH,
Alex
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