[mythtv-users] UK DVB-T Channels 4, 5; multiple video streams

[Roger Siddons]

On Sat, 22 Jun 2013 14:53:04 +0100, John Pilkington <J.Pilk at tesco.net>  
wrote:

> On 05/06/13 11:03, John Pilkington wrote:
>> On 04/06/13 19:46, John Pilkington wrote:
>>> On 04/06/13 12:26, John Pilkington wrote:
>>>> Last week the BBC mux from my local transmitter was moved to clear G4
>>>> spectrum.  Since then my recordings from Channels 4 and 5 have
>>>> apparently included multiple video streams.  This breaks my cutting
>>>> script.  A simple edit ought to fix that, but has anything else  
>>>> changed
>>>> too?
>>>>
>>>> $ ionice -c3 mythffmpeg -i  1005_20130603185800.mpg
>>>> ffmpeg version 0.10.2.git Copyright (c) 2000-2012 the FFmpeg  
>>>> developers
>>>>    built on Apr 27 2013 17:23:40 with gcc 4.7.2 20120921 (Red Hat
>>>> 4.7.2-2)
>>>
>>> <snip>
>>>
>>>> Input #0, mpegts, from '1005_20130603185800.mpg':
>>>>    Duration: 01:07:58.37, start: 51087.044133, bitrate: 2824 kb/s
>>>>      Stream #0:0[0xb22]: Video: mpeg2video (Main), yuv420p, 704x576  
>>>> [SAR
>>>> 16:11 DAR 16:9], 15000 kb/s, 25 fps, 25 tbr, 90k tbn, 50 tbc
>>>>      Stream #0:1[0xb23](eng): Audio: mp2, 48000 Hz, stereo, s16, 192
>>>> kb/s
>>>>      Stream #0:2[0xb25](eng): Audio: mp2, 48000 Hz, mono, s16, 64 kb/s
>>>>      Stream #0:3[0xb24](eng): Subtitle: dvb_subtitle
>>>>      Stream #0:4[0x806]: Video: mpeg2video, 90k tbr, 90k tbn, 90k tbc
>>>>      Stream #0:5[0x8cb]: Video: mpeg2video, 90k tbr, 90k tbn, 90k tbc
>>>>      Stream #0:6[0x8cc]: Video: mpeg2video, 90k tbr, 90k tbn, 90k tbc
>>>
>>> mediainfo --version
>>> MediaInfo Command line,
>>> MediaInfoLib - v0.7.52
>>>
>>> mediainfo sees only the expected first four streams, with nothing
>>> conspicuously wrong.  I guess mythffmpeg just picked a bad sampling
>>> region, but I don't remember seeing results like this before.
>>>
>>
>> I'm seeing the same results on my ScientificLinux6 laptop, and on
>> Channel 3 (ITV), which is on the same mux as Channels 4 and 5.  It looks
>> as if my script should now grep 'mpeg2video (Main)' instead of just
>> 'Video' in the section aimed at selecting the video and audio PIDs.  The
>> same change was needed a few months ago in MythArchive to allow DVD
>> creation from DVB-T recordings without re-encoding.
>>
>
> I'm still seeing this, and this transmitter-specific page has several  
> Media Center etc users who appear to be affected by it or something  
> related to it.
>
> http://www.ukfree.tv/txdetail.php?a=SK809233&PGSTART=1700#pagebar
>
> I can think of no reason why this change, on the PSB2 mux,  should be  
> linked to the retune of the PSB1 mux and I have no idea if the change  
> affects other DVB-T transmitters.  It might help if people outside the  
> East Midlands could run mythffmpeg -i <filename> on raw recordings from  
> Channels 3,4,or 5.  Do you see multiple Video streams reported too?
>
> Thanks,
>
> John P
>

I'm not sure how the ffmpeg version compars but all my Ch 4 & 5 recordings  
 from Winter Hill (North West) are similar to this;

$ mythffmpeg -i /media/tv1/recordings/1004_20130619213400.mpg
ffmpeg version git-2013-02-12-ac8d780 Copyright (c) 2000-2012 the FFmpeg  
developers
   built on Feb 13 2013 11:28:57 with gcc 4.6.3
   configuration: --prefix=/usr --enable-proc-opt --disable-vdpau
   libavutil      51. 56.100 / 51. 56.100
   libavcodec     54. 23.100 / 54. 23.100
   libavformat    54.  6.101 / 54.  6.101
   libavdevice    54.  0.100 / 54.  0.100
   libavfilter     2. 77.100 /  2. 77.100
   libswscale      2.  1.100 /  2.  1.100
   libswresample   0. 15.100 /  0. 15.100
   libpostproc    52.  0.100 / 52.  0.100
[dvbsub @ 0x183abe0] Invalid extradata, subtitle streams may be combined!
[mpegts @ 0x1836100] max_analyze_duration 5000000 reached at 5000000
[mpegts @ 0x1836100] Could not find codec parameters (Audio: mp3, 0  
channels, s16)
[NULL @ 0x183a260] start time is not set in estimate_timings_from_pts
[NULL @ 0x183abe0] start time is not set in estimate_timings_from_pts
[mpegts @ 0x1836100] PES packet size mismatch
Input #0, mpegts, from '/media/tv1/recordings/1004_20130619213400.mpg':
   Duration: 01:03:56.25, start: 56829.674600, bitrate: 3121 kb/s
     Stream #0:0[0xb0d]: Video: mpeg2video (Main), yuv420p, 704x576 [SAR  
16:11 DAR 16:9], 15000 kb/s, 25 fps, 25 tbr, 90k tbn, 50 tbc
     Stream #0:1[0xb0e](eng): Audio: mp2, 48000 Hz, stereo, s16, 192 kb/s
     Stream #0:2[0xb10](eng): Audio: mp3, 0 channels, s16
     Stream #0:3[0xb0f](eng): Subtitle: dvb_subtitle
At least one output file must be specified