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Old 01-26-10, 12:46 PM   #11
MarkG
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Join Date: Jun 2008
Posts: 29
Default Re: Myth recording video breaks up with VDPAU

Quote:
Originally Posted by cehoyos View Post
Note that FFmpeg has been known for a long time for its advanced error-concealment. I may be wrong, but I think it is unlikely to implement something similar in a hardware decoder.
You should really try to improve your reception, did you also try to record with szap and cat, just in case it is not a reception probem?

Carl Eugen
I've got a rooftop antenna with line of sight to the transmitters, with the best HD frequency only, sub 2 dB noise figure, high overload amp i could find. My tuner cards don't report accurately, but they show zero bit error rate and the TV that is also split off the feed shows the high 90s for signal strength. I think the reception is as good as I can get it.

I am concerned that they now allow adjacent channels for digital stations. The station with the problem does happen to have an occupied adjacent channel. I've attached the output of a spectrum analyzer. The problem station is the highest frequency one on the right. It looks strong and well above the noise to me, but my analyzer can't evaluate the bit error rate of ATSC signals. I can't tell if the problem is a reception problem or too short a set of errors to not be corrected by the ECC. Most reception problems I've seen are larger and cause breakup in both the picture and sound.

I uploaded a sample of the bad video to Nvidia in the hopes that someone with an mpeg bitstream analyzer could tell. I am thinking that it may be possible that the station's encoder is not quite right and it is just covered up by most receivers and the rest just accept it. I get the same issues with any of my three tuner cards, which are two different models. I've not tried recording with szap and cat.

Mark
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