[vdr] Re: DVB-T, moving parts blocky.

[Seppo Ingalsuo <seppo.ingalsuo@iki.fi>]

I wasn't too verbose about my setup. It is VDR 1.1.20, Dxr3 plugin 
0.1.3. Ffmpeg is a couple of weeks old CVS version, I need to update it 
to 0.4.6 release. DVB driver is 3.1.2003 CVS. My Nova-T card is 
TT-Budget/WinTV-NOVA-T Grundig 29504-401. There is a print of v1.2. My 
PC has a 950 Mhz K7 Athlon & Asus K7M mb so it should be sufficient for 
this application.

Marko Myllymäki wrote:
>>I have also quite bad block artefact problems with VDR with some (but
>>not all) Finnish DVB-T channels. The recordings at first sight seem to
>>have dropped the corrupted frames. With Mplayer SW decoding the picture
>>quality is OK with all channels.
> 
> 
> So does this mean, that you have block artefacts only when playing the
> strean with VDR (or live) and by using dvbstream, they do not exist?

Yes, picture quality is good with dvbstream and mplayer (both SW and 
DXR3 HW decoding).

If mplayer has some MPEG error concealment (e.g. for (S)VCD playback) it 
could also cause something like this (I'm not familiar with internals of 
  mplayer).

> 
> Do your blocks exist only on moving parts, as example a background which is
> not mowing is fine and moving parts are blocky and leave a blocky trails for
> a short while?

With VDR & DXR3 viewing the moving picture content gets blocked and the 
frames freeze sometimes. The blocks are rather big so clear trails are 
not visible. The non-moving content is OK. It is not a total disaster in 
quality sense but e.g. in my DVB-S receiver Nokia 9800S this type of 
errors are very rare.

With Finnish "Nelonen D" the problem seems to be only occasional frame 
freezes (~ 1 times in a minute). I haven't watched it much so I'm not 
definitely sure about this.

With Finnish "YLE *" channels there is both blocking artefacts and frame 
freezes. Now when I watched some channels this morning the problems were 
smaller compared to yesterday evening.

Tzap reports for YLE TV1:
status 1f | signal 3232 | snr b9b9 .. bcbc | ber 00002ac7 .. 0000345f

Stream parameters reported by Mplayer:

VIDEO:  MPEG2  720x576  (aspect 2)  25,00 fps  12500,0 kbps (1562,5 kbyte/s)
AUDIO: 48000 Hz, 2 ch, 16 bit (0x10), ratio: 28000->192000 (224,0 kbit)

And for "Nelonen D" tzap:
status 1f | signal 3131 | snr 9e9e .. 9f9f | ber 00006e37 .. 00007190

Mplayer:

VIDEO:  MPEG2  720x576  (aspect 2)  25,00 fps  12500,0 kbps (1562,5 kbyte/s)
AUDIO: 48000 Hz, 2 ch, 16 bit (0x10), ratio: 28000->192000 (224,0 kbit)

I guess smaller BER figure is better. How is it with signal and SNR 
figures, how are they converted to dBs? I could try to tune home antenna 
amplifier gains (with BER or SNR information) and check later if it helped.

> 
> 
>>I'm not sure my Finland/Tampere channels.conf is perfectly set up. It is
>>here in case it could give a clue. I ignored the last three parameters
>>for tzap channels.conf. This one was made with dvbtune and xml2vdr.
> 
> 
> They seem to be fine by me, but I am the one having problems also ;).

OK!

Cheers,
Seppo

> 
> Br,
> Marko
> 
> 
> 





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