[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 01:23:21 UTC 2012


On Thu, Jun 7, 2012 at 11:16 AM, Igor Cicimov <icicimov at gmail.com> wrote:

> 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
>

Just for completnes, this is my dtv_multiplex table (after adding
additional 125KHz to the frequencies as suggested by Karl):

mysql> select mplexid,sourceid,transportid,networkid,frequency,sistandard
from dtv_multiplex;
+---------+----------+-------------+-----------+-----------+------------+
| mplexid | sourceid | transportid | networkid | frequency | sistandard |
+---------+----------+-------------+-----------+-----------+------------+
|       1 |        1 |        1538 |      4116 | 219625000 | dvb        |
|       2 |        1 |           2 |        57     | 536625000 | dvb
|
|      12 |        1 |         768 |     12802 | 571625000 | dvb        |
|      11 |        1 |         545 |      4112  | 226625000 | dvb        |
|      10 |        1 |        1056 |      4114 | 191625000 | dvb        |
|       9 |        1 |        1282 |      4115  | 177625000 | dvb        |
+---------+----------+-------------+-----------+-----------+------------+
6 rows in set (0.00 sec)

Would love to see what other Aussies have in their multiplex table.

Igor
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