[mythtv] Corrupt analog recordings

Torbjörn Jansson torbjorn.jansson at mbox200.swipnet.se
Mon Aug 14 14:11:40 UTC 2006

mythtv-dev-bounces at mythtv.org <> wrote:
> Torbjörn Jansson wrote:
>> For a few weeks now i've been having corrupt recordings from my
>> analog card. This only happends for some of the recordings and i
>> have not found any patern to it. 
>> A corrupt recording have perfect audio but the video looks like a
>> blocky mess, sometimes a more or less corrupted frame is visibel.
> I saw the same thing start a few weeks ago. The problem I had was that
> some change a few weeks ago has caused the analog video encoder to be
> much less efficient. I noticed that when recording from the
> analog card
> the CPU utilization went to 100%, were before it used to only hit
> 80%-85%.

Intresting, i'm prety sure i saw 100% cpu utilization too when one of the
bad recordings was being recorded.

My normal cpu utilization for analog recordins is also around 80-85% if i
remeber correctly.
Do you know what change it was that started this?

And do you also have the message "v4l2: unable to handle these sampling
parameters" in the backend log?

> To get it to work again I had to turn off the "Enable
> interlaced DCT encoding" option. (The only one of the four
> options left
> on now is the "Enable high quality encoding")
> I just tested different settings and looked at the CPU utilization to
> determine settings that would work for me. So the first thing
> I would do
> is check and see if your CPU utilization has gone up while
> doing analog
> recordings.

The problem for me is that i don't have a reliable way of reproducing this
so testing out different encoding settings is going to be problematic.

But i'll check the settings and see if i have some of those options on.
I haven't changed messed with the encoding options much, must be a year (or
two) or so maybe since i changed anything there.

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