Quality of tuner/capture card

  • Thread starter Thread starter yaugin
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yaugin

How can you tell the real image quality of a tuner/capture card?
Beyond the simple resolution there are issues with color, scaling,
deinterlacing, and artifacts. I have an old Avermedia tuner card. It
works but I am not really satisfied with it, the image looks washed
out and grainy even compared to SDTV, unless I run it in a tiny
320x240 window (it just blows up the image pixel by pixel if
upscaled). So how do you know if you can actually get good visual
quality from the card? I don't want to buy a new card only to end up
with something that is still crappy compared to a real TV or HDTV. I
don't need something that is "perfect" but will at least pass for 720p
w/o issues.

I fear that the only real way to figure out is to buy the card and
return it if it sucks.
 
How can you tell the real image quality of a tuner/capture card?
Beyond the simple resolution there are issues with color, scaling,
deinterlacing, and artifacts. I have an old Avermedia tuner card. It
works but I am not really satisfied with it, the image looks washed
out and grainy even compared to SDTV, unless I run it in a tiny
320x240 window (it just blows up the image pixel by pixel if
upscaled). So how do you know if you can actually get good visual
quality from the card? I don't want to buy a new card only to end up
with something that is still crappy compared to a real TV or HDTV. I
don't need something that is "perfect" but will at least pass for 720p
w/o issues.

I fear that the only real way to figure out is to buy the card and
return it if it sucks.
Click to expand...

From my experience using a couple of Hauppauge cards and what I know
about the process (technically- not that much), the quality of the
capture is dependent on a few things:

The quality of the signal from your source.
The processing capabilities of your setup
The compression format
The speed of your computer's data transfer capability

As Grinder pointed out, having a hardware encoder right on the card
improves the processing capability because the capture card is doing all
the work of encoding the signal while you and your processor can do
other things.

I was having problems early on with ghosting and artifacting on my
capture cards, but no problems on my TVs. It turned out that my source
signal from the cable company was too strong. By simply splitting the
signal I was able to clear it up. It seems the capture tuners are much
more sensitive than my TV tuners. I find that the quality of my
recordings is highly dependent on the quality of the cable signal, and
it changes from night to night. Sometimes it is crystal clear and
another night it is terrible. I have my media PC on the floor and
sometimes the Restless Leg people in my house push it back towards the
wall and it crimps the wires and the pictures gets all snowy. You need
to spend time playing with the connections and signal.

Hauppauge uses an MPEG-2 encoder, which is an industry standard. If you
read about MPEG-2 you can get some idea about the loss issues with
encoding and decoding. You can check to see if there are better
encoders, or if any other brand of capture card uses something less than
MPEG-2. My Hauppauge cards record video at 800x600 native for analog TV.
If your card records at 320x240 native then you are stuck with the loss
inherent with blowing it up.

I set up an older P4 computer with EIDE hard drive and the older system
bus and clock as my media PC. I found that when playing the recordings
from that computer to my TV that the picture quality was low,
artifacting, pixelating, and with the occassional freeze. By transfering
the mpeg files to my new computer (i7, SATA drives, faster bus and
clock) the videos played much better and with no freezes.

Hope that helps.
 
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