[mythtv-users] Channel scanner won't find a specific channel

[David Parker]

On Feb 4, 2016 4:12 PM, "John Pilkington" <J.Pilk at tesco.net> wrote:
>
> On 04/02/16 20:39, David Parker wrote:
>>
>> I do know that the signal strength dropped from 92% to 87% when it hit
>> QAM-256 channel 115 in the scan, then went back up on the next channel.
>> When I actually tune to the channel in Live TV mode, it shows a signal
>> strength of 91%.
>>
>> mythffmpeg reports the following:
>>
>> # mythffmpeg -i hd_test_1.dat
>> ffmpeg version 1.2.7 Copyright (c) 2000-2014 the FFmpeg developers
>>    built on Feb  2 2016 10:27:10 with gcc 4.9.2 (Debian 4.9.2-10)
>>    configuration: --prefix=/usr/local/mythtv-0.27-2255patch
>>    libavutil      52. 18.100 / 52. 18.100
>>    libavcodec     54. 92.100 / 54. 92.100
>>    libavformat    54. 63.104 / 54. 63.104
>>    libavdevice    54.  3.103 / 54.  3.103
>>    libavfilter     3. 42.103 /  3. 42.103
>>    libswscale      2.  2.100 /  2.  2.100
>>    libswresample   0. 17.102 /  0. 17.102
>>    libpostproc    52.  2.100 / 52.  2.100
>> [mpeg2video @ 0x1372000] 0x0 is invalid
>>      Last message repeated 9 times
>> [mpegts @ 0x136fa20] Stream #0: not enough frames to estimate rate;
>> consider increasing probesize
>> [mpegts @ 0x136fa20] PES packet size mismatch
>> Input #0, mpegts, from 'hd_test_1.dat':
>>    Duration: 00:00:37.09, start: 13266.651322, bitrate: 15013 kb/s
>> Codec 0x20000 is not in the full list.
>>      Stream #0:0[0x0]: Data: unknown_codec, 18399 kb/s
>>      Stream #0:1[0x6f]: Video: mpeg2video (Main), yuv420p, 1280x720 [SAR
>> 1:1 DAR 16:9], 59.94 fps, 59.94 tbr, 90k tbn, 119.88 tbc
>>      Stream #0:2[0x70]: Audio: ac3, 48000 Hz, 5.1(side), fltp, 384 kb/s
>> At least one output file must be specified
>
>
> Hmm.  Don't know what stream #0:0 might be, but that looks like the
likely problem.   Do your other myth recordings have something similar?
Have you tried 'lossless transcode', mythtranscode -m ?
> That might remove it.
>
> mythtv 0.28-pre now has mythffmpeg v 2.8.5.   Maybe your mplayer is more
up-to-date than your mythffmpeg.   But if we're comparing similar channels
that wouldn't explain the difference you see.
>
>
>>
>> And I got an error when I tried to run a conversion:
>
>
> It's an mpeg2-ts file anyway.  I'm not sure what you hoped for :-)
>
>>
>> # mythffmpeg hd_test_1.dat
>> ffmpeg version 1.2.7 Copyright (c) 2000-2014 the FFmpeg developers
>>    built on Feb  2 2016 10:27:10 with gcc 4.9.2 (Debian 4.9.2-10)
>>    configuration: --prefix=/usr/local/mythtv-0.27-2255patch
>>    libavutil      52. 18.100 / 52. 18.100
>>    libavcodec     54. 92.100 / 54. 92.100
>>    libavformat    54. 63.104 / 54. 63.104
>>    libavdevice    54.  3.103 / 54.  3.103
>>    libavfilter     3. 42.103 /  3. 42.103
>>    libswscale      2.  2.100 /  2.  2.100
>>    libswresample   0. 17.102 /  0. 17.102
>>    libpostproc    52.  2.100 / 52.  2.100
>> [NULL @ 0x2285a20] Unable to find a suitable output format for
>> 'hd_test_1.dat'
>> hd_test_1.dat: Invalid argument
>>

I haven't had a chance to try the lossless transcode yet, but I did verify
that this is only a MythTV issue.  I recorded a program from this
troublesone channel, and it has consistently had choppy audio and video
every time I've watched the recording in MythTV.  I copied the mpeg file
from the "recorded" directory to another PC with far worse hardware and an
older version of Debian.  The video played flawlessly in Xine on the other
PC.

What's really got me scratching my head is the fact that this one single
channel is choppy when I watch it live through MythTV, too.  So for some
reason, MythTV is having issues with the data coming from the tuner for
this one particular channel.  Same channel which MythTV couldn't even find
until I told it where to look.

The channel is crystal clear on the TV.

Thanks!
Dave
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mythtv.org/pipermail/mythtv-users/attachments/20160204/065f63e6/attachment.html>