Cap Card Noise

[Torrential]

Do capture cards add noise to the signal? If so, how much? I've heard DV boxes (like the ADVC-100) have no noise. Is this true?

[DereX888]

Its impossible to have analog-to-digital conversion without any kind of distortion invoked by the hardware as a "by-product" of the conversion process.
Hence there is no such thing as perfect cap card.
However ADVC is as close to perfection as it can be.

[lordsmurf]

ADVC close to perfection? Hardly. The NTSC colorspace conversions see to that. Every method has a flaw.

[Bjs]

If you want to cut down of this interference , just dont use the cards audio input .

Video to card = fine
Sound input via line-in only (record from line-in)

This seperates the signal , and dose provide a cleaner picture

I always tell users to use a vcr to split the signal in to two individual components , and never use the audio input on those cards .

It helps with fly and wintv cards quite well .

[DereX888]

ADVC close to perfection? Hardly. The NTSC colorspace conversions see to that. Every method has a flaw.

But thats what I said
I didnt want to go to any specific details, each cap card has its own good and bad sides, thats why I said in general that Its impossible to have analog-to-digital conversion without any kind of distortion.
I found ADVC to be the one with the lesser amount of bad sides when compared to same-level similar products out there.
By no means I meant that it is perfect!

[audiohominis]

Hi, folks. I'm a first-time poster, and this appears to be the appropriate thread for my problem.
I see what you guys mean about the unlikelihood of perfect analog-to-digital capturing. Nevertheless, the imperfection of my incoming picture has nothing to do with noise, waves, or any other kind of distortion peculiar to analog video signals. I'm convinced that the nature of quality loss is digital, since the image contains blocky artifacts similar to those yielded by loosey video compression formats (MPEG, DivX, etc).
What I'm trying to do here is to capture the output of a videogame console, (in my case the old SEGA Dreamcast) through my PC's composite video input. The source image is obviously perfect quality (we're talking interactive 3D content here) and I want it to stay that way when I capture it to lossless format for later editing. If it helps to know, Dreamcast's resolution is 640X480p.

Now, at the risk sounding silly, this newbie has the following questions:

• Does this look like my capture card limits the input quality to loosey real-time hardware encoding?
• Is it possible to increase the image quality at the cost of frame rate, or at least capture lossless still images?
• Do results vary depending on software (I use the very basic Windows Media Center)?

I went to Device Manager, but I couldn't figure out the model of my capture card/tuner; it's confusing. Please bear with me.
For any help, thanks a lot.

[edDV]

ADVC close to perfection? Hardly. The NTSC colorspace conversions see to that. Every method has a flaw.

But thats what I said
I didnt want to go to any specific details, each cap card has its own good and bad sides, thats why I said in general that Its impossible to have analog-to-digital conversion without any kind of distortion.
I found ADVC to be the one with the lesser amount of bad sides when compared to same-level similar products out there.
By no means I meant that it is perfect!

There is always some loss, the question becomes how much loss is tolerable and how much will you spend to optimize all forms of conversion loss.

Broadcasters aren't looking for perfection but they do spend > $1000 up for analog conversion for a reason. Below ~$1000 you are making tradeoffs and there are many variables depending on your source and destination formats. The optimization of such tradeoffs is called "engineering".

thats why I said in general that Its impossible to have analog-to-digital conversion without any kind of distortion.

For example, the Nyquest sampling theorem* says perfect analog to digital conversion requires an anti-alias filter of infinite quality. The rub here is such a filter requires infinite time delay so you will have to wait to infinity to view your perfect conversion.

http://en.wikipedia.org/wiki/Nyquist-Shannon_sampling_theorem
http://en.wikipedia.org/wiki/Anti-aliasing_filter

[audiohominis]

Hmm, I guess you guys can’t help me with this one, ha? Was this the right topic for me?

[harley2ride]

ADVC close to perfection? Hardly. The NTSC colorspace conversions see to that. Every method has a flaw.

But thats what I said
I didnt want to go to any specific details, each cap card has its own good and bad sides, thats why I said in general that Its impossible to have analog-to-digital conversion without any kind of distortion.
I found ADVC to be the one with the lesser amount of bad sides when compared to same-level similar products out there.
By no means I meant that it is perfect!

There is always some loss, the question becomes how much loss is tolerable and how much will you spend to optimize all forms of conversion loss.

Broadcasters aren't looking for perfection but they do spend > $1000 up for analog conversion for a reason. Below ~$1000 you are making tradeoffs and there are many variables depending on your source and destination formats. The optimization of such tradeoffs is called "engineering".

thats why I said in general that Its impossible to have analog-to-digital conversion without any kind of distortion.

For example, the Nyquest sampling theorem* says perfect analog to digital conversion requires an anti-alias filter of infinite quality. The rub here is such a filter requires infinite time delay so you will have to wait to infinity to view your perfect conversion.

http://en.wikipedia.org/wiki/Nyquist-Shannon_sampling_theorem
http://en.wikipedia.org/wiki/Anti-aliasing_filter

Just open up the case, and look at the names and serial numbers on the card. Then search google, and you should be able to find the exact make and model of your video card. I have done this numerous times.

[edDV]

Hmm, I guess you guys can’t help me with this one, ha? Was this the right topic for me?

Your post was off topic and could be considered a hijack. Start over with a fresh topic. Composite capture from a game console is limited to NTSC specs. You can't do better. The limits were placed at the game player end.