Re: [mythtv-users] Video Quality

[Steve Briggs]

The URL,
http://www.mediachance.com/dvdlab/tutorial/bitrate.html
is fascinating!

My baseline is that I'm used to watching VHS tapes in EP mode.
(OK.. I'm showing my age -- I grew up watching fuzzy OTA from
an outdoor mast VHF/UHF antenna.)

I record analog SD as MPEG-4 at 432x480, 2 Mbps.  If I take that
chart and assume that MPEG-4 needs half the bitrate of MPEG-2 
(for the same quality) and that bitrate scales linearly with
frame size, I get the following bitrates
   For LP quality 2.7 Mbps / 2 * 432 / 352 = 1.7 Mbps
   For SP quality 2.9 Mbps / 2 * 432 / 352 = 1.8 Mbps
   For XP (?) quality 3.8 Mbps / 2 * 432 / 352 = 2.3 Mbps
All of this is assuming CBR.  I *assume* MPEG-4 is VBR, so
I'm probably in good shape (I *assume* when you provide at
bitrate, that's the average).  Of course, the VHS tapes 
are SIF at 352x240, I'm at least getting 432x480.  

OTOH, I do see artifacts (blockiness) in dark areas.
But, my criteria all along was to keep it under 1 GB/hr.
I record a *lot* of stuff.

Steve


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Re: [mythtv-users] Video Quality

[Brad Fuller]

Kerry Wilson wrote:
> What is the general consensus on video quality settings?  Is there a 
> bitrate where it becomes unnecessary? I have mine set at 720x480 6600 
> bitrate.  I decided that the 6 GB cache is plenty ( I can't imagine 
> rewinding beyond 20 or 30 minutes at the most ) so I might as well have 
> it at a real high bitrate.  Should I turn it up any further?  I have a 
> pvr-150, do higher settings put more stress on the CPU?
>   
This was posted recently:
http://www.mediachance.com/dvdlab/tutorial/bitrate.html

It seems very helpful
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Re: [mythtv-users] Video Quality

[Chris Ribe]

FWIW,  6600 Kb(B?)ps seems like a rediculously high bit(byte?)rate.  I'm no expert on the matter, however.On 1/27/06, Chris Ribe <
[EMAIL PROTECTED]> wrote: ( I can't imagine rewinding beyond 20 or 30 minutes at the most ) 



So your saying you don't have any kids? 





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Re: [mythtv-users] Video Quality

[Chris Ribe]

 ( I can't imagine rewinding beyond 20 or 30 minutes at the most ) 


So your saying you don't have any kids? 



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[mythtv-users] Video Quality

[Kerry Wilson]

What is the general consensus on video quality settings?  Is there a 
bitrate where it becomes unnecessary? I have mine set at 720x480 6600 
bitrate.  I decided that the 6 GB cache is plenty ( I can't imagine 
rewinding beyond 20 or 30 minutes at the most ) so I might as well have 
it at a real high bitrate.  Should I turn it up any further?  I have a 
pvr-150, do higher settings put more stress on the CPU?
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Re: [mythtv-users] Video (Quality/Size) Issues

[Mark L. Cukier]

Phil:
Thanks for the response.
I got the overscan issue fixed last night... i had to tweak the MythTV 
GUI Size and over/underscan setting after that... but now the GUI looks 
GREAT.

I had tried all that filtering, and I'm still not thrilled with the 
picture. I fiddled with the nVidia settings color adjustments, and this 
did help. Any other suggestions from anyone else out there? My 
picture is still washed out/grainy. However... see my next post for the 
big problem

Thanks again,
  Mark
Phill Edwards wrote:
(FYI, I'm using the 350 for capture and the 5200 for TV Out. I was
originally going to use the 350 for both, however the image quality as
horrible out of the 350...)
   

Lots of people seem to have problem with the 350 TV Out on this list,
so you're in good company :)
 

1) It seems that the TV-OUT on the 5200 doesn't quite fill my screen.
There are black borders all around the image. I'm pretty sure this isn't
an X problem per-se... because even my grub screen has the same issue.
This is pretty annoying-- any ideas/suggestions??
   

Could be an overscan issue. In your xorg.conf you could try this in
the Device section. Try a number of different settings to find the one
that looks best:
#   Option "TVOverScan" "Decimal value in range 0.0 to 1.0"
   Option "TVOverScan" "0.60"
 

2) The Image quality is just not where I want it to be. The lines seem a
little blurred, and the colors are a touch washed out... it's *close*,
but not quite there. Has anyone noticed this issue? Are there any fixes?
   

Try these in your channel settings- they work for me:
videofilter : adjust=18:237:1.0:35:220:1.0,denoise3d
contrast : 23200
brightness : 34000
colour : 32000
hue : 32768
(If you have lots of chanels you may want to update the channel table
directly in mysql).
In modprobe.conf I have these chroma_agc and combfilter options for my
BTTV card:
options bttv card=55,37 radio=0 tuner=0,28 chroma_agc=1 combfilter=2
YMMV with a 350.
And in Setup --> T VSettings --> Playback I'm using Deinterlace (even
tho I'm wathing it on a TV with the Bob 2x framerate algorithm. Try it
and see it it works for you.
 

I've tried to get the DVI on my 5200 to display on my Sony with no luck,
and I'm hesitant to drop the $150 for the more Recent nVidia cards (with
Component out) until I'm sure they'll make my video appear the way I
want it to.
   

I seem to remember something about component out not being supported.
You may want to check the archives for that.
Regards,
Phill
 


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Re: [mythtv-users] Video (Quality/Size) Issues

[Phill Edwards]

> (FYI, I'm using the 350 for capture and the 5200 for TV Out. I was
> originally going to use the 350 for both, however the image quality as
> horrible out of the 350...)

Lots of people seem to have problem with the 350 TV Out on this list,
so you're in good company :)
 
> 1) It seems that the TV-OUT on the 5200 doesn't quite fill my screen.
> There are black borders all around the image. I'm pretty sure this isn't
> an X problem per-se... because even my grub screen has the same issue.
> This is pretty annoying-- any ideas/suggestions??

Could be an overscan issue. In your xorg.conf you could try this in
the Device section. Try a number of different settings to find the one
that looks best:
#   Option "TVOverScan" "Decimal value in range 0.0 to 1.0"
Option "TVOverScan" "0.60"
 
> 2) The Image quality is just not where I want it to be. The lines seem a
> little blurred, and the colors are a touch washed out... it's *close*,
> but not quite there. Has anyone noticed this issue? Are there any fixes?

Try these in your channel settings- they work for me:

videofilter : adjust=18:237:1.0:35:220:1.0,denoise3d
contrast : 23200
brightness : 34000
colour : 32000
hue : 32768
(If you have lots of chanels you may want to update the channel table
directly in mysql).

In modprobe.conf I have these chroma_agc and combfilter options for my
BTTV card:
options bttv card=55,37 radio=0 tuner=0,28 chroma_agc=1 combfilter=2
YMMV with a 350.

And in Setup --> T VSettings --> Playback I'm using Deinterlace (even
tho I'm wathing it on a TV with the Bob 2x framerate algorithm. Try it
and see it it works for you.
 
> I've tried to get the DVI on my 5200 to display on my Sony with no luck,
> and I'm hesitant to drop the $150 for the more Recent nVidia cards (with
> Component out) until I'm sure they'll make my video appear the way I
> want it to.

I seem to remember something about component out not being supported.
You may want to check the archives for that.

Regards,
Phill
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[mythtv-users] Video (Quality/Size) Issues

[Mark L. Cukier]

Hello to All:
My Setup:
-Intel 2.4C HT
-PVR 350
- GeForce 5200
- 256MB RAM
- Sony 51" Widescreen HD, Rear Projection
- FC2, myth .17, originally setup with Jarod's Guide
I've struggled long and hard, but finally Myth is in my entertainment 
center! I'm having two main issues that are keeping me from cancelling 
my TiVo subscription:

(FYI, I'm using the 350 for capture and the 5200 for TV Out. I was 
originally going to use the 350 for both, however the image quality as 
horrible out of the 350...)

1) It seems that the TV-OUT on the 5200 doesn't quite fill my screen. 
There are black borders all around the image. I'm pretty sure this isn't 
an X problem per-se... because even my grub screen has the same issue. 
This is pretty annoying-- any ideas/suggestions??

2) The Image quality is just not where I want it to be. The lines seem a 
little blurred, and the colors are a touch washed out... it's *close*, 
but not quite there. Has anyone noticed this issue? Are there any fixes?

I've tried to get the DVI on my 5200 to display on my Sony with no luck, 
and I'm hesitant to drop the $150 for the more Recent nVidia cards (with 
Component out) until I'm sure they'll make my video appear the way I 
want it to.

Any and ALL suggestions for getting the quality I want are much appreciated!
Thanks in Advance,
   Mark

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