Mailing List Archive

Slave backend part 2
So I built my slave backend, loaded it with Debian Buster and added the deb-multimedia repo.

Installing the backend is a pain, since it insists on installing a database server, which of course
is not required for a slave. (This also happened when updating the master; it mucks about with the
database password in config.sys. Beware.)

Added my Hauppauge Nova-T USB tuner, created a source and attempted to scan. Nothing! I can see on
the display that there is signal but the message is always the same, whatever the channel: Timed
out, no signal.

Adding in some debug tracing gives me a stream of which the following is a snippet:

2020-10-23 15:28:07.492726 I DVBSigMon[16](/dev/dvb/adapter0/frontend0): Stop() -- end
2020-10-23 15:28:07.492790 I ChannelScanSM(/dev/dvb/adapter0/frontend0): ScanTransport Tuning to
Channel 39 mplexid(0)
2020-10-23 15:28:07.492883 I DVBChan[16](/dev/dvb/adapter0/frontend0):
Old Params: 599500000 auto 0 auto auto 7 8 auto n v fec: auto msys: UNDEFINED rolloff: 0.35
New Params: 606500000 auto 0 auto auto 7 8 auto n v fec: auto msys: UNDEFINED rolloff: 0.35
2020-10-23 15:28:07.492899 I DVBChan[16](/dev/dvb/adapter0/frontend0): Tune(): Tuning to 606500000Hz
2020-10-23 15:28:08.326998 I DVBChan: wait_for_backend: Status: Signal,
2020-10-23 15:28:08.327022 I DVBChan[16](/dev/dvb/adapter0/frontend0): Tune(): Frequency tuning
successful.
2020-10-23 15:28:08.327072 I DTVSigMon[16](/dev/dvb/adapter0/frontend0)::SetChannel(-1, -1):
2020-10-23 15:28:11.332313 I ChannelScanSM(/dev/dvb/adapter0/frontend0): ScanTransport Tuning to
Channel 39 offset 1 mplexid(0)
2020-10-23 15:28:11.587085 I DVBChan[16](/dev/dvb/adapter0/frontend0):
Old Params: 606500000 auto 0 auto auto 7 8 auto n v fec: auto msys: UNDEFINED rolloff: 0.35
New Params: 606625000 auto 0 auto auto 7 8 auto n v fec: auto msys: UNDEFINED rolloff: 0.35
2020-10-23 15:28:11.587102 I DVBChan[16](/dev/dvb/adapter0/frontend0): Tune(): Frequency tuning
successful.
2020-10-23 15:28:11.587151 I DTVSigMon[16](/dev/dvb/adapter0/frontend0)::SetChannel(-1, -1):
2020-10-23 15:28:14.590891 I ChannelScanSM(/dev/dvb/adapter0/frontend0): transport_tune_complete:
wait_until_complete 0
2020-10-23 15:28:14.591025 I ChannelScanSM(/dev/dvb/adapter0/frontend0): Channel 39 offset 1 --
Timed out, no signal
2020-10-23 15:28:14.591045 I DVBSigMon[16](/dev/dvb/adapter0/frontend0): Stop() -- begin
2020-10-23 15:28:14.884806 I DVBSigMon[16](/dev/dvb/adapter0/frontend0): Stop() -- end
2020-10-23 15:28:14.884864 I ChannelScanSM(/dev/dvb/adapter0/frontend0): ScanTransport Tuning to
Channel 40 mplexid(0)
2020-10-23 15:28:14.884975 I DVBChan[16](/dev/dvb/adapter0/frontend0):
Old Params: 606500000 auto 0 auto auto 7 8 auto n v fec: auto msys: UNDEFINED rolloff: 0.35
New Params: 613500000 auto 0 auto auto 7 8 auto n v fec: auto msys: UNDEFINED rolloff: 0.35
2020-10-23 15:28:14.884998 I DVBChan[16](/dev/dvb/adapter0/frontend0): Tune(): Tuning to 613500000Hz
2020-10-23 15:28:15.715051 I DVBChan: wait_for_backend: Status: Signal,
2020-10-23 15:28:15.715082 I DVBChan[16](/dev/dvb/adapter0/frontend0): Tune(): Frequency tuning
successful.
2020-10-23 15:28:15.715137 I DTVSigMon[16](/dev/dvb/adapter0/frontend0)::SetChannel(-1, -1):
2020-10-23 15:28:18.721037 I ChannelScanSM(/dev/dvb/adapter0/frontend0): ScanTransport Tuning to
Channel 40 offset 1 mplexid(0)
2020-10-23 15:28:18.991130 I DVBChan[16](/dev/dvb/adapter0/frontend0):
Old Params: 613500000 auto 0 auto auto 7 8 auto n v fec: auto msys: UNDEFINED rolloff: 0.35
New Params: 613625000 auto 0 auto auto 7 8 auto n v fec: auto msys: UNDEFINED rolloff: 0.35
2020-10-23 15:28:18.991148 I DVBChan[16](/dev/dvb/adapter0/frontend0): Tune(): Frequency tuning
successful.
2020-10-23 15:28:18.991197 I DTVSigMon[16](/dev/dvb/adapter0/frontend0)::SetChannel(-1, -1):
2020-10-23 15:28:21.994333 I ChannelScanSM(/dev/dvb/adapter0/frontend0): transport_tune_complete:
wait_until_complete 0
2020-10-23 15:28:21.994455 I ChannelScanSM(/dev/dvb/adapter0/frontend0): Channel 40 offset 1 --
Timed out, no signal
2020-10-23 15:28:21.994474 I DVBSigMon[16](/dev/dvb/adapter0/frontend0): Stop() -- begin
2020-10-23 15:28:22.284838 I DVBSigMon[16](/dev/dvb/adapter0/frontend0): Stop() -- end
2020-10-23 15:28:22.284900 I ChannelScanSM(/dev/dvb/adapter0/frontend0): ScanTransport Tuning to
Channel 41 mplexid(0)
2020-10-23 15:28:22.284988 I DVBChan[16](/dev/dvb/adapter0/frontend0):
Old Params: 613500000 auto 0 auto auto 7 8 auto n v fec: auto msys: UNDEFINED rolloff: 0.35
New Params: 620500000 auto 0 auto auto 7 8 auto n v fec: auto msys: UNDEFINED rolloff: 0.35
2020-10-23 15:28:22.285003 I DVBChan[16](/dev/dvb/adapter0/frontend0): Tune(): Tuning to 620500000Hz
2020-10-23 15:28:22.285178 I DVBChan: wait_for_backend: Status:
2020-10-23 15:28:22.285198 I DVBChan[16](/dev/dvb/adapter0/frontend0): Tune(): Frequency tuning
successful.
2020-10-23 15:28:22.285248 I DTVSigMon[16](/dev/dvb/adapter0/frontend0)::SetChannel(-1, -1):
2020-10-23 15:28:25.289546 I ChannelScanSM(/dev/dvb/adapter0/frontend0): ScanTransport Tuning to
Channel 41 offset 1 mplexid(0)
2020-10-23 15:28:25.289627 I DVBChan[16](/dev/dvb/adapter0/frontend0):
Old Params: 620500000 auto 0 auto auto 7 8 auto n v fec: auto msys: UNDEFINED rolloff: 0.35
New Params: 620625000 auto 0 auto auto 7 8 auto n v fec: auto msys: UNDEFINED rolloff: 0.35
2020-10-23 15:28:25.289641 I DVBChan[16](/dev/dvb/adapter0/frontend0): Tune(): Frequency tuning
successful.
2020-10-23 15:28:25.289686 I DTVSigMon[16](/dev/dvb/adapter0/frontend0)::SetChannel(-1, -1):
2020-10-23 15:28:28.293252 I ChannelScanSM(/dev/dvb/adapter0/frontend0): transport_tune_complete:
wait_until_complete 0
2020-10-23 15:28:28.293378 I ChannelScanSM(/dev/dvb/adapter0/frontend0): Channel 41 offset 1 --
Timed out, no signal
2020-10-23 15:28:28.293399 I DVBSigMon[16](/dev/dvb/adapter0/frontend0): Stop() -- begin
2020-10-23 15:28:28.321404 I DVBSigMon[16](/dev/dvb/adapter0/frontend0): Stop() -- end
2020-10-23 15:28:28.321477 I ChannelScanSM(/dev/dvb/adapter0/frontend0): ScanTransport Tuning to
Channel 42 mplexid(0)
2020-10-23 15:28:28.321590 I DVBChan[16](/dev/dvb/adapter0/frontend0):
Old Params: 620500000 auto 0 auto auto 7 8 auto n v fec: auto msys: UNDEFINED rolloff: 0.35
New Params: 627500000 auto 0 auto auto 7 8 auto n v fec: auto msys: UNDEFINED rolloff: 0.35
2020-10-23 15:28:28.321606 I DVBChan[16](/dev/dvb/adapter0/frontend0): Tune(): Tuning to 627500000Hz
2020-10-23 15:28:29.163021 I DVBChan: wait_for_backend: Status: Signal,
2020-10-23 15:28:29.163046 I DVBChan[16](/dev/dvb/adapter0/frontend0): Tune(): Frequency tuning
successful.
2020-10-23 15:28:29.163097 I DTVSigMon[16](/dev/dvb/adapter0/frontend0)::SetChannel(-1, -1):
2020-10-23 15:28:32.166000 I ChannelScanSM(/dev/dvb/adapter0/frontend0): ScanTransport Tuning to
Channel 42 offset 1 mplexid(0)
2020-10-23 15:28:32.431106 I DVBChan[16](/dev/dvb/adapter0/frontend0):
Old Params: 627500000 auto 0 auto auto 7 8 auto n v fec: auto msys: UNDEFINED rolloff: 0.35
New Params: 627625000 auto 0 auto auto 7 8 auto n v fec: auto msys: UNDEFINED rolloff: 0.35
2020-10-23 15:28:32.431123 I DVBChan[16](/dev/dvb/adapter0/frontend0): Tune(): Frequency tuning
successful.
2020-10-23 15:28:32.431173 I DTVSigMon[16](/dev/dvb/adapter0/frontend0)::SetChannel(-1, -1):
2020-10-23 15:28:35.434978 I ChannelScanSM(/dev/dvb/adapter0/frontend0): transport_tune_complete:
wait_until_complete 0
2020-10-23 15:28:35.435110 I ChannelScanSM(/dev/dvb/adapter0/frontend0): Channel 42 offset 1 --
Timed out, no signal
2020-10-23 15:28:35.435131 I DVBSigMon[16](/dev/dvb/adapter0/frontend0): Stop() -- begin
2020-10-23 15:28:35.716704 I DVBSigMon[16](/dev/dvb/adapter0/frontend0): Stop() -- end

Sorry about the length, but the selection is important. I /know/ that there are transmissions (here)
on channels, 39, 40 and 42, yet the scanner finds NOTHING. (My MBE is using these channels!)

A close look at the channel frequencies reveals the problem: they are nothing like the published
values. Channel 39 is being scanned at 606500000Hz but I know that it should be 618200000Hz. Channel
42 is scanned at 627500000Hz whereas it should be 642000000Hz.

I am using the Europe-west table as I am in the UK. My master backend has been successfully tuned
this way in the recent past. Has something recently changed?

--

Mike Perkins

_______________________________________________
mythtv-users mailing list
mythtv-users@mythtv.org
http://lists.mythtv.org/mailman/listinfo/mythtv-users
http://wiki.mythtv.org/Mailing_List_etiquette
MythTV Forums: https://forum.mythtv.org
Re: Slave backend part 2 [ In reply to ]
The whole scanning process is documented in reasonable detail in
https://www.mythtv.org/wiki/Channel_Scanning .
I guess that you are doing a DVB-T/T2 ¨Full Scan" but that you have not
selected the country and in that case it can default to Australia. Which
has a different list of frequencies. Details are in
https://www.mythtv.org/wiki/Channel_Scanning#Full_Scan and please note that
you have use the left arrow key to return from the country selection back
to the Full Scan selection otherwise the selection is lost..... and you are
in Australia again.

Hope this helps,
Klaas.
Re: Slave backend part 2 [ In reply to ]
On 23/10/2020 15:49, Mike Perkins wrote:
> So I built my slave backend, loaded it with Debian Buster and added the
> deb-multimedia repo.
>
> Installing the backend is a pain, since it insists on installing a
> database server, which of course is not required for a slave. (This also
> happened when updating the master; it mucks about with the database
> password in config.sys. Beware.)
>
> Added my Hauppauge Nova-T USB tuner, created a source and attempted to
> scan. Nothing! I can see on the display that there is signal but the
> message is always the same, whatever the channel: Timed out, no signal.
>
> Adding in some debug tracing gives me a stream of which the following is
> a snippet:
>
...
>
> Sorry about the length, but the selection is important. I /know/ that
> there are transmissions (here) on channels, 39, 40 and 42, yet the
> scanner finds NOTHING. (My MBE is using these channels!)
>
> A close look at the channel frequencies reveals the problem: they are
> nothing like the published values. Channel 39 is being scanned at
> 606500000Hz but I know that it should be 618200000Hz. Channel 42 is
> scanned at 627500000Hz whereas it should be 642000000Hz.
>
> I am using the Europe-west table as I am in the UK. My master backend
> has been successfully tuned this way in the recent past. Has something
> recently changed?
>

You should do a full scan and select UK for DVB-T/T2 and then it has
the correct frequency list.


Regards
Stuart

_______________________________________________
mythtv-users mailing list
mythtv-users@mythtv.org
http://lists.mythtv.org/mailman/listinfo/mythtv-users
http://wiki.mythtv.org/Mailing_List_etiquette
MythTV Forums: https://forum.mythtv.org