[mythtv-users] Poor recording of races only

[Jim]

On 10/13/2014 8:49 PM, Yippee Three-eight wrote:
> I've finally gotten my Ceton InfiniTV 4 PCie working on Mythbuntu. 
> <YAY!>  Anyway, I've set up a bunch of shows to record, all of them 
> HD.  Many of those shows record just fine. However, I'm a racing fan, 
> and every race I've recorded so far has been of really poor quality 
> except one.
>
> All of those recordings show up with a yellow border.  I think that 
> means the recording is damaged from what I've read.  When I watch the 
> recording, every time a scene changes, the screen gets very blocky 
> (macroblocking?) and the audio cuts out, then it will return to a 
> beautiful recording for a moment until the camera changes, then it 
> repeats.  It gets worse and worse as the show goes.  I haven't let it 
> run, but I have noticed that the file size is very small.  For 
> example, a normal TV show recorded for 1 hour at 5.xx Gb.  A formula 1 
> race (3 hours) recorded at 0.5 Gb.
>
> I've also had some problems with BBC America.  Some recordings are 
> great.  Some show up as yellow like the races.  Of those, some just 
> hang the frontend.  Others come back with a message saying the file is 
> missing.
>
> The one race recording I recorded without problem was a NASCAR race 
> that was not scheduled to record, but I turned it on in Live TV.  It 
> looked great, so I went back to the program guide and tried recording 
> it.  It recorded fine.  As I said, these shows are all HD.
>
>  Initially, I was unable to record anything when I set up the box.  I 
> was getting buffer errors.  I found that my network was running at 
> 10Mb/s.  I fixed that so it's running at 1000MB/s, but I still have 
> some Cat5 (not 5e) cable in the walls.
>
> I looked at the channels that I've recorded on and here's what I got 
> for signal strength and S/N ratio:
> TNTHD - always good:  Signal Strength - 3.8 dBmV, Signal to Noise 
> Ratio - 32.6 dB
> WMAQHD - always good:  Signal Strength - 4.1 dBmV, Signal to Noise 
> Ratio - 33.4 dB
> WBBMHD - always good:  Signal Strength - 5.9 dBmV, Signal to Noise 
> Ratio - 34.6 dB
> BBCAHD - sometimes good recordings, other times not:  Signal Strength: 
> 2.3 dBmV, Signal to Noise Ratio:  34.1 dB
> NBCS1HD - always bad:  Signal Strength - 3.9 dBmV, Signal to Noise 
> Ratio - 34.8 dB
> FS1HD - always bad:  Signal Strength - 3.5 dBmV, Signal to Noise Ratio 
> - 32.1 dB
>
> Since it seems like a channel thing (higher channels have problems, 
> lower channels don't), I figured I'd look at improving my signal 
> strength.  I've had a Motorola 1-2 amplified splitter 
> (http://www.amazon.com/Motorola-Signal-Booster-BDA-S2-Amplifier/dp/B0017I1PVC/ref=pd_sim_e_5?ie=UTF8&refRID=0REJCWJTGHQ0WF945342) 
> on the line coming into my house for a while now.  It helped a lot as 
> before I couldn't tune.  I've got one of those lines going to my old 
> STB, and the other going to a 1-2 splitter. From the splitter, one 
> line goes to the cable modem, and the other line goes to my backend's 
> cable tuner card.  I've always read that splitters degrade signal, so 
> I tried disconnecting the STB and connecting one long line directly 
> from the Motorola amplifier to my cable card.  On all channels, SS 
> goes up by 2 - 3 and S/N goes up a bit too.  I've read that a perfect 
> signal strength would be 0 dBmV, but I'm wondering if that's wrong.
>
> Can anybody offer any suggestions on what I should look at to be able 
> to record these shows?
>
> Mike
>

Mike,

Please don't top post.

I don't think the races are being recorded in HD. Even bad quality HD 
produces large files. Can you double check things to make sure you are 
not recording from an SD channel or another source than you think you are?
I'm not saying you don't have an issue with splitters and poor quality 
signal I just would expect to still see file sizes roughly the same as 
any other HD recording.

-- 
Jim


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