TV Out Quality

[GreatKent]

Hi All,
As I know many ATI Radeon VGA Cards come with a TV Out Connector, I wonder how good the quality is? Is it comparable to the Standalone DivX Player?

[SimonSez07]

with the default settings it DOES NOT compare to standalone players tv-out. to see the difference play a dvd full-screen with powerdvd and plug the tv-out into a tv. then play the same dvd on a standalone player or with a dvd card like realmagic h+ or creative dxr3 that has its own tv-out. you will see a world of difference.

one of the reasons for this is the resizing that the tv-out chip does before it encodes the image to ntsc. no matter what your desktop resolution is set to, the card will resize the image to about 544 x 408 or something like that and then add a black border around this to create a 640 x 480 picture to send to the ntsc encoder.

the reason for this is because most tv's will only display about 85% of the image in the visible area of the screen making the video seem zoomed-in and the borders seem cropped off. this is called overscan. the video card's tv-out tries to compensate for overscan and resizes/adds borders accordingly so your start menu and what not is displayed in the visible area of the tv.

this resizing degrades the quality of the image and you loose detail especially noticable when there is small text on the screen. so in my opinion the best way to achieve good quality output when watching a movie thru tv-out is to set the resolution to 640 x 480 60Hz and ENABLE OVERSCAN in the video cards settings. this will 'crop off' the outer edges of the screen when viewed on a tv, but that is not a problem when watching a movie because the outer edges would not be visible on a standalone player anyway.

so ... it is possible to approach standalone quality with the correct resolution refresh rate and overscan.

[UGAthecat]

actually, tv out from most video cards is not resized until you go to greater than 800x600 resolution. Most do underscanning so you can see your full desktop on the tv out, but they also have features that switch to 'normal' overscanning to remove the border when playing dvd. ATI calls this Theater Mode, Matrox and nVidia have similar features but I don't remember what they call it.
Anyway, on my AIW 8500DV, tv out at 640x480 or 800x600 in theater mode looks BETTER than my stand alone dvd player, and has more options to adjust the color, brightness, etc. when set to 1024x768 and not using theater mode there is some color banding and other problems on the tv out because the picture is resized, but these problems are ONLY present at 1024x768. at 1024x768 using theater mode, I think the tv out gets changed to 800x600 when you start to play a video so that resizing is not used.
I can't vouch for the quality of any other tv out because I haven't used them, but most non-ati cards use a tv out chip made by Chrontel, which normally works the same as the ATI tv out chip, 800x600 or less are sent without resizing, 1024x768 or greater are resized. Some older chrontel chips will resize at anything greater than 640x480.
Also note that underscanning (which creates the border when viewing your desktop) DOES NOT resize and put in extra black around the picture, it just modifies the refresh rate of the signal being sent to the tv so that more picture fits into less space.

[SimonSez07]

im afraid youre mistaken about the resizing. an ntsc video signal only has 483 lines of vertical resolution 480 of which can be used for displaying picture, the other three being reserved. the refresh rate of an ntsc signal is set to 59.94 hz (interlaced) to comply with ac power frequency. both of these can not be set to any other value, or a standard tv would not be able to understand and display the signal.

therefore any resolution that is higher than 480 horizontal lines MUST be resized, at least vertically, to comply with specs. this INCLUDES 800 x 600 and larger. a 640 x 480 image can be displayed without resizing, but will not be entirely visible due to the overscaning the television's CRT performs (on almost EVERY unit manufactured). therefore most tv-outs do indeed also resize a 640 x 480 image (a process called underscaning, denoting a reversal of the effect a television causes by overscaning). the black borders are NOT caused by a change in the refresh rate but simply by the underscaning of the video card (which includes resizing and adding black borders).

youre right about theater mode. it does indeed display the video without any underscanning and it does then take up the full tv screen (and then some), a great feature i use often. nvidia calls it 'full screen video mirroring' and theirs does still underscan unless you specify for it not to. i think matrox calls it DVDMax.

youre also right about all the options and color correction with an ati video card. it is better than many standalones. and yes overscaning is the 'normal' mode of all tvs i have ever seen.

i hope this helps

-simon

[GreatKent]

That sounds pretty good...

BTW. do you watch DivX movies on TV Set by using TV Out Connector?
As I think DivX will become the dominating Video Format in the future, so I like conveting DVDs to DivX format. However, similar to other computer users, I don't like watching movies on my computer's screen. Though there has been Standalone DivX Player on the market, but it's too expensive for me. In addition, it does not support the newest functions of DivX. Thus I am planning to play DivX movies in computer, and display it on TV Set through TV Out connector. Do you think the picture quality still comparable to the standalone player in this case?
Thanks a lot!

[Xayd]

Yeah, it'll be fine.

I wouldn't recommend a hardware DivX player/decoder. There just isn't a standard for DivX as of yet, new features will in all likelihood not be supported by any current hardware.

Take a lesson from Sigma and the nightmare that the X-Card was upon it's release ;).

[joveplayer]

JovePlayer for XCard can decode with software codec and display it through XCard when hardware decoder cannot, so you don't lose the quality. Check out www.8dim.com

[GreatKent]

According to Sigma Diesigns' Website: http://www.sigmadesigns.com/products/xcard_features_specifications.htm
XCard still does NOT support GMC, QPEL, 1/4 pixel and global motion compensation, so I think what XCard does for me is providing me with a remote control, and reducing my CPU load when playing DivX movies. Thus I would prefer the VGA Card's TV Out, especially the ATI Radeon series, because it has a quite powerful 3D Engine.
However, I would probably change my mind if XCard is much better in terms picture quality.
So, I wonder if the picture quality of ATI VGA Card's TV Out is comparable to that of XCard?
Thanks again...

[SimonSez07]

Originally posted by GreatKent
That sounds pretty good...

BTW. do you watch DivX movies on TV Set by using TV Out Connector?
As I think DivX will become the dominating Video Format in the future, so I like conveting DVDs to DivX format. However, similar to other computer users, I don't like watching movies on my computer's screen. Though there has been Standalone DivX Player on the market, but it's too expensive for me. In addition, it does not support the newest functions of DivX. Thus I am planning to play DivX movies in computer, and display it on TV Set through TV Out connector. Do you think the picture quality still comparable to the standalone player in this case?
Thanks a lot!

yes, i do usually watch divx using the tv out on my all-in-wonder 128 pro and am pretty satisfied with it (there is some noticable blotchyness / blockiness in the dark areas espically green and brown colored areas). this is visible on dvds and ripped movies. however my roomate's radeon 7000 has PERFECT tv-out.

i used to encode a lot of movies into divx 3, 4 and 5 but now i primarily encode into windows media 9. my home-theater pc i have hooked up to my tv (celeron 766) plays all three perfectly including dvds, xvid downloads, ogg and the like all through ati's tv-out. i have a dxr3 hardware decoder card but dont use it anymore because of how easy it is with powerdvd and tv-out.

-simon

[Xayd]

Depending on your TV and how discerning your eye is, I suppose?

I have a Samsung 27" Flat standard tube TV, not the best but not bad. It was one of the flat models that came out in the last year before HDTVs were available.

Anyways, with the old Rage 128 card I had, yes the Hollywood Plus image quality was infinitely better. The image from the Rage's S-Video out was "too hot", reds/browns were amplified and poorly blended, and the image was very blocky (speaking in terms of an uncompressed DVD).

I now have a Radeon 1 VIVO, and honestly can tell little if any difference between TV out and the Hollywood Plus assuming I keep the Radeon at 640x480 @ 60hz.

A good movie to watch for testing (the one that made me finally pick up a Hollywood Plus way back when ;)) is the first chapter of Goodfellas. You get a nice long scene of Ray Liota's face while he's standing behind a car with the brake lights on.

Try that scene on your Rage 128 and then the Hollywood Plus or XCard and you'll see a huge difference. Try the same with a Radeon or higher card and a Hollywood Plus or XCard and you'll see very little difference.

[theReal]

on my AIW 8500DV, tv out at 640x480 or 800x600 in theater mode looks BETTER than my stand alone dvd player I agree (maybe depends on the standalone player). A friend of mine has his PC (ATI Radeon VE) and a PS2 connected to a 100Hz PAL TV. Watching a DVD from the PC looks a lot better than watching it from the PS2. Although I'm not sure how the PS2 playback compares to a normal DVD player, I'm pretty sure the TV-out of the Radeon VE (which is a cheap card) is pretty good.

[rybread]

i run a radeon 9000 passive by saphire, divx quality is as good as my standalone dvd player and the dd5.1 is better running both through s/pdif, out to sony 42inch sony via s video as only moniter at 1024x768 w no black bars thanx to rage3d tweak util to turn on overscan. i personally love my radeon. quiet, $65 and highly recommended at avs forums, not nvidia. they use sep chip 4 2d processing while radeon intigrates it in gpu and have a lot of 2d experience.

[fisix]

a friend has an 80" rear projection tv. he had just bought a new computer with a leadtek nvidia card (probably a ti4200 or 4600) with a video in video out dongle that has svideo i/o. we hooked up the svideo out to his tv and it looked beautiful.. much better than previous nvidia cards i have seen.

we compared a dvd played on a computer with one played off of a stand alone player (both were svideo connections) and really couldn't tell the difference. very very nice.

the two things you should notice is that this was a 'rear projection tv' and that both connections were 'svideo'. i would bet that you would be able to see the difference between a computer svideo connection and a dvd component connection on a large crt... though, again, this was much better than the last nvidia card i tried.

the ati cards i've tried were only laptop version, but still looked pretty decent. i think that you will probably be ok buying one brand or the other using price as your guide, mainly because nvidia seems to have caught up to what ati has been doing right from the get go. (drivers are another matter entirely).

-fisix