[MPlayer-users] Garbled/distorted video with MPEG-2 transportstream playback (DVB)

[Falck Kenneth]

Nico Sabbi wrote:
> Falck Kenneth wrote:
> >My problem is that sometimes, certain programmes on certain channels
> >cannot be played back. The video image is distorted, as if the
> >vertical/horizontal sync had been somehow lost. The picture looks the
> >same as an old CRT monitor with invalid frequencies, but this happens
> >"within" mplayer, inside the video window. (My screens are 
> TFT anyway)
> >
> >To be more specific, it happens at least with "Dr. Phil" on channel 4
> >here in Finland. The beginning commercials play fine, but when the
> >actual programme starts, the picture becomes distorted. At the same
> >time, mplayer prints out this, apparently detecting some 
> change in the
> >MPEG2 encoding parameters:
> 
> if you can upload a sample somewhere someone can give it a look
> incoming isn't usable atm.

I captured a 20 second clip that seems to reproduce this bug
consistently. It can be downloaded from
http://www.kfalck.net/pub/mpegbug.ts (9 MB)

The format is what mplayer records from a DVB-C card using -dumpstream,
cropped with dd.

When this file is played back with mplayer, the first 5 seconds plays OK
and then the display is garbled. I noticed that there is a change of
resolution involved. The first 5 seconds are:

VDec: vo config request - 720 x 576 (preferred csp: Planar YV12)
VDec: using Planar YV12 as output csp (no 0)
Movie-Aspect is 1.33:1 - prescaling to correct movie aspect.
VO: [directx] 720x576 => 768x576 Planar YV12

And after that, the stream changes to:

VDec: vo config request - 704 x 576 (preferred csp: Planar YV12)
VDec: using Planar YV12 as output csp (no 0)
Movie-Aspect is 1.33:1 - prescaling to correct movie aspect.
VO: [directx] 720x576 => 768x576 Planar YV12

In fact, if the file is cropped so that the resolution change is
eliminated from the beginning, it plays back fine.

-- 
Kenneth Falck, SWelcom Oy, Ludviginkatu 6-8, 00130 Helsinki, Finland
Private: kennu at iki.fi  Business: kennu at swelcom.fi  GSM: +358405103121
               Balance is the essential component.