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From: "Thomas Börkel" <thomas@boerkel.de>
To: linux-dvb <linux-dvb@linuxtv.org>
Subject: Re: [linux-dvb] A/V sync issues with DVB-S
Date: Wed, 20 Aug 2008 06:52:25 +0200	[thread overview]
Message-ID: <48ABA309.30906@boerkel.de> (raw)
In-Reply-To: <1219113106.4107.21.camel@pc10.localdom.local>

HI!

hermann pitton wrote:

Thanks for the informations.

>> Is it normal, that every now and then (1-2 of 10 recordings), I get one
>> serious (suddenly 30 frames off) A/V sync problem with DVB-S?

> DVB-C is in general much better protected against troubles generated by
> changing environmental conditions, but in case of weather conditions
> which suddenly create ice on any surface, it is better to know the one
> in charge even there.

OK.

> Means, watch your dish. Maybe birds or a cat like to stay there
> sometimes or wind might move branches of a tree in the near of it.

There is no tree, but could be birds.

> This is card/frontend specific, but for the very few I have in critical
> reception conditions, SNR below 50% is a clear indicator that I won't
> have to blame any apps later. A thunderstorm comes up.

Measuring the strength and SNR is not so easy now. My SAT receiver
always says strength 70% and SNR 80%. My new Nova S Plus cards always
report strength 97% and SNR 99%. Only my TT 1500s reported reasonable
numbers like strength 63-80% and SNR 75-90%.

In the end, I think overall strength and SNR is not my problem. I always
get a lock. It's the glitches that happen every now and then.

> After that, on normal mpeg2 DVB-S all applications should still do
> fairly well, but if you go out for x264 HDTV, it is another and
> completely different additional story, especially for what I see on
> x86-64 quad CPUs.

I am not recording x264 at the moment, meaning I have no DVB-S2 card.

Thanks for the informations.

Thomas


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  reply	other threads:[~2008-08-20  4:52 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-08-18  5:13 [linux-dvb] A/V sync issues with DVB-S Thomas Börkel
2008-08-19  2:31 ` hermann pitton
2008-08-20  4:52   ` Thomas Börkel [this message]
2008-08-20 12:39     ` Antti Palosaari
2008-08-20 14:07       ` Steven Toth
2008-08-20 23:40         ` hermann pitton
2008-08-21  9:59         ` Simon Kenyon

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