On HDTV, which is better: S-Video in 1024x768 or DVI to HDMI in 720x480 ?

[the_importer]

If the S-Video will give me a better image resolution than the DVI to HDMI in 720x480 (I can't go any higher), then I'll just dump that cable and stick with S-Video.

A good example, if I were install a game and run it in Full Screen at 1024x768 with the S-Video, would the image resolution be better than with the DVI to HDMI at 720x480 (or 640x480) in full screen?

[dphirschler]

To my knowledge, S-video won't do 1024x768.


Darryl

[jagabo]

There's no such thing as s-video at at 1024x768. Anything that is sent from the computer via s-video is reduced to 720x480 or 640x480 and 60 fields per second -- before being sent over the s-video cable. And because s-video carries the color channels at half (or less) the bandwidth of the luma channels, colors will be 360x480 or 320x480 at best.

DVI or HDMI at 720x480 will give better picture quality. Although this would depend to some extent on how the graphics card performs the reduction from 1024x768 to 720x480 for s-video, whether or not your games are antialiasing, and your own personal preference.

Without antialiasing, the DVI/HDMI image will very very sharp but with jagged edges. The s-video image will be fuzzy but with smoother edges.

The display device will matter too. If its native resolution is not 720x480 or 640x480, whatever comes in will be scaled to the native resolution of the display. Exactly how good it looks will depend on how the device performs this scaling for HDMI and s-video inputs.

So there is no simple, general, answer to your question. You'll have to try both for any particular display.

[edDV]

S-Video is analog interlaced video at scanned 480 lines (576 for PAL). The video card sizes the desktop into a frame buffer. Typically ATI cards use 800x600 or 1024x768 as desktop sizes for conversion to S-Video.

The framebufffer is then downscaled and interlaced to 480 lines for output in S-video. Horizontal Y resolution is determined by the S-video path but probably falls under 6 MHz. Chroma resolution for NTSC (or PAL) is less than 1.5 MHz.

After various experiments, this was the best I was able to get over the S-Video output. In this case the S-Video was recaptured by a Canopus ADVC-100 and sharpening was applied to the capture file. A TV would look worse than this.

[the_importer]

So if I understood correctly, with S-Video connection, even if my desktop and game settings are at 1024x768, it's not really 1024x768, right?

So if S-Video is really 720x480, then it's the same resolution as my DVI to HDMI connection only a bit more degraded, correct?

[edDV]

So if I understood correctly, with S-Video connection, even if my desktop and game settings are at 1024x768, it's not really 1024x768, right?

So if S-Video is really 720x480, then it's the same resolution as my DVI to HDMI connection only a bit more degraded, correct?

Not 1024x768, more like 480x480 luminance and 100x480 chroma.