What are the relationships between analog and digital video interfaces?

Question

I have learned a lot about coaxial, composite (RCA), VGA (d-sub 15-pin analog), s-video (analog), DVI (digital, computer), component (RGB analog), and HDMI (digital and sometimes with HDCP encryption), but I'm missing how the big picture relates to my practical considerations of the various equipment choices and interfaces.

But when does each standard become helpful? Display size, resolution, response time? In other words, how do the acronymns: PAL, 720p (progressive), 1080i (interlaced), etc. translate to the video sources, and TVs or monitors that I am considering to purchase?

And how do they support both analog and digital in the same standard, while DVI requires variations (dvi-d, dvi-i, dvi-a)?

Do adapters care whether the signal is digital or analog, and if not, then are any losses with adapters?

And what is this talk about "upconverting" a signal? Is this specific to digital, or can it work for analog?

Lastly, can a capture card receive a digital signal without losses?

Answer 1

Lots of questions.

Here are some generic answers.
In principle, digital interfaces (DVI, HDMI) are better than analog (say component), although there are instances where component may still give you a better picture.

HD signals are only supported over component, DVI/HDMI, and VGA.

HD/Blu-ray players support 1080p playback only over HDMI. for copy protection reasons

Yes, there are cards that can receive digital inputs with no loses (DV signals over an i.Link/1394 i/f is one example).

Upconversion is a term used for the process of upscaling standard definition signal (eg from a DVD movie) to a higher resolution. In most cases, up -conversion is done digitally; however, the input and output signals can be analog.

Example: Analog input (say composite) -> digitizer -> scaler -> digital to analog converter -> analog out (say component)