[mythtv-users] known issues related to DVB-T in Australia (was: Channel tuning broken in 0.24)

Igor Cicimov icicimov at gmail.com
Thu Jun 7 01:16:59 UTC 2012 

On Thu, Jun 7, 2012 at 10:59 AM, Igor Cicimov <icicimov at gmail.com> wrote:

> On Thu, Jun 7, 2012 at 9:39 AM, Igor Cicimov <icicimov at gmail.com> wrote:
>
>> On Wed, Jun 6, 2012 at 8:22 PM, Vincent McIntyre <
>> vincent.mcintyre at gmail.com> wrote:
>>
>>> curiosity got the better of me...
>>>
>>>
>>> http://git.linuxtv.org/media_tree.git/commitdiff/f0ef7c88ca919912011593d2392a59c2fde04748?hp=4911085fa3342d2ccb04f84c2987305b86785ebf
>>>
>>> Perhaps this module needs checking for issues like the one in
>>> tuners-xc2028.c?
>>>
>>> Might be worth trying to load the driver module with the debug
>>> parameter turned on
>>> and doing a scan?
>>> _______________________________________________
>>> mythtv-users mailing list
>>> mythtv-users at mythtv.org
>>> http://www.mythtv.org/mailman/listinfo/mythtv-users
>>>
>>
>>
>> Hi Vincent,
>>
>> Thanks for your input. I believe that Leadtek card I use is based on
>> cx2388x chip. This is the l4v support page and the card, pay attention to
>> revision J detail, is listed as card 82:
>>
>>
>> http://git.linuxtv.org/media_tree.git/blob/HEAD:/Documentation/video4linux/CARDLIST.cx88#l83
>>
>> and is being properly recognized as card=82 in the kernel module during
>> boot.
>>
>> From the driver change log you sent me we can see some work was done for
>> DTV2000H Plus card support which is different one from the one I have.
>>
>> To answer the question about channel 9 ... It's really a roulet with this
>> channel, sometimes its terrible and locks the frontend same as GO and GEM
>> but sometimes liveTV is fine. But the recordings are always horrible ... go
>> figure. I noticed that 7 is also bad but 7two is perfect. For the rest of
>> them the LiveTV works fine and the recording are good quality.
>>
>> Someone, I think it was Nick, asked me about channel tuning setup in the
>> backend more specifically about fast channel tuning. I had that option set
>> to "Always" but had to switch it to "Never" because of the tuning issues I
>> have. This way I can skip the channels I know are broken without freezing
>> the frontend in case of auto channel change.
>>
>> It really sucks that, as Karl says at the beginning of the thread,
>> channel import doesn't work properly too for Australia. Can someone confirm
>> that this is being fixed? I really can't see any more options for me except
>> for channel import after dvbscan.
>>
>> I have an old channels.conf in Mplayer from 13/09/2008 so will try that
>> one with Mplayer/xine first before I create a new one.
>>
>> Thanks,
>> Igor
>>
>
>
> Ok, I shutdown the mythbackend and did a scan. This is the result of the
> initial scan with w_scan (with terrestrial TV channels option only):
>
> $ cat initial-tuning-data.txt
>
> #------------------------------------------------------------------------------
> # file automatically generated by w_scan
> # (http://wirbel.htpc-forum.de/w_scan/index2.html)
> #! <w_scan> 20091230 1 0 OFDM AU </w_scan>
>
> #------------------------------------------------------------------------------
> # location and provider: <add description here>
> # date (yyyy-mm-dd)    : 2012-06-07
> # provided by (opt)    : <your name or email here>
> #
> # T[2] <freq> <bw> <fec_hi> <fec_lo> <mod> <tm> <guard> <hi> [# comment]
>
> #------------------------------------------------------------------------------
> T 177500000 7MHz  3/4 NONE    QAM64   8k 1/16 NONE    # Seven Network
> T 219500000 7MHz  3/4 NONE    QAM64   8k 1/16 NONE    # Network TEN
> T 226500000 7MHz  3/4 NONE    QAM64   8k 1/16 NONE    # ABC Sydney
> T 536625000 7MHz  2/3 NONE     QPSK   8k  1/8 NONE    # CTV
> T 571500000 7MHz  2/3 NONE    QAM64   8k  1/8 NONE    # SBS Sydney
>
>
> And for comparison this is what I have in MythTV database:
>
> mysql> select mplexid,sourceid,transportid,networkid,frequency,sistandard
> from dtv_multiplex;
> +---------+----------+-------------+-----------+-----------+------------+
> | mplexid | sourceid | transportid | networkid | frequency | sistandard |
> +---------+----------+-------------+-----------+-----------+------------+
> |       1 |        1 |        1538 |      4116 | 219500000 | dvb        |
> |       2 |        1 |           2 |        57     | 536500000 |
> dvb        |
> |      12 |        1 |         768 |     12802 | 571500000 | dvb        |
> |      11 |        1 |         545 |      4112  | 226500000 | dvb        |
> |      10 |        1 |        1056 |      4114 | 191500000 | dvb        |
> |       9 |        1 |        1282 |      4115  | 177500000 | dvb        |
> +---------+----------+-------------+-----------+-----------+------------+
>
> Looks like Myth did even better tuning job than w_scan and found one more
> transponder with frequency of 191500000 :). Maybe that's the
> channel9/GO/GEM carrier?
>
> After using scan to turn this initial file to channels.conf this is what I
> get:
>
>
> $ cat .tzap/channels.conf
> 7
> Digital:177500000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_3_4:FEC_3_4:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:513:514:1312
> 7 Digital
> 1:177500000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_3_4:FEC_3_4:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:513:514:1313
>
> 7TWO:177500000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_3_4:FEC_3_4:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:545:546:1314
>
> 7mate:177500000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_3_4:FEC_3_4:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:561:0:1315
> 7
> Digital:177500000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_3_4:FEC_3_4:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:513:514:1316
>
> TV4ME:177500000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_3_4:FEC_3_4:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:625:626:1319
>
> ONE:219500000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_3_4:FEC_1_2:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:514:0:1569
> TEN
> Digital:219500000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_3_4:FEC_1_2:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:512:650:1573
>
> ONE:219500000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_3_4:FEC_1_2:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:514:0:1575
>
> ELEVEN:219500000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_3_4:FEC_1_2:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:516:681:1576
> ABC News
> 24:226500000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_3_4:FEC_1_2:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:2314:0:544
>
> ABC1:226500000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_3_4:FEC_1_2:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:512:650:545
> ABC2 /
> ABC4:226500000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_3_4:FEC_1_2:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:2307:2308:546
>
> ABC1:226500000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_3_4:FEC_1_2:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:512:650:547
>
> ABC3:226500000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_3_4:FEC_1_2:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:2311:2312:548
>
> TVS:536625000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_2_3:FEC_1_2:QPSK:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_8:HIERARCHY_NONE:100:101:44
> SBS
> ONE:571500000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_2_3:FEC_1_2:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_8:HIERARCHY_NONE:161:81:769
> SBS
> TWO:571500000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_2_3:FEC_1_2:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_8:HIERARCHY_NONE:162:83:770
> SBS
> 3:571500000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_2_3:FEC_1_2:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_8:HIERARCHY_NONE:161:81:772
> SBS
> 4:571500000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_2_3:FEC_1_2:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_8:HIERARCHY_NONE:161:81:773
> SBS
> HD:571500000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_2_3:FEC_1_2:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_8:HIERARCHY_NONE:102:103:774
>
> so no channel9, GO and GEM as we can see.
>
> From this I would say it is obvious that the tuning problem is not in
> MythTV since both scans yield practically same results.. If there is an
> issue with the frequency offset in AUS then both w_scan and Myth behave
> same and fail to lock to the offset frequency of +125KHz of our carriers.
>
> What I'm going to do next is add the channel9 frequencies that Vincent
> posted into my channel.conf and check if Mplayer can tune to this channels
> at all.
>
> Igor
>
>
>
>
Ok, after adding the channel9 frequencies I tried Mplayer and it crashed
when trying to tune to channel9. So same problem as MythTV.

CONCLUSION: For some reason my card can't tune to channel9 frequency any
more and probably this is related to the dvb driver in Lucid. I didn't have
any issues at all with these channels on 8.04 and Myth 0.20. I'll do some
investigation and try to find the exact reason. Maybe building the latest
v4l modules from git will help.

Igor
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.mythtv.org/pipermail/mythtv-users/attachments/20120607/74e674b0/attachment.html>

More information about the mythtv-users mailing list