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Church and H.O.W. Forums for HOW Sound and AV - Your Displayed Name Must Be Your Real Full Name To Post In The Church and HOW Forums => H.O.W. AV Archive => Topic started by: Jordan Manuel on February 03, 2010, 11:25:11 am

Title: Video converting problem!
Post by: Jordan Manuel on February 03, 2010, 11:25:11 am
The problem I'm having is sending a laptop signal (VGA at 1024x768) and being able to send it to a composite signal for recording.  Currently, an EXTRON VSC 500 is converting the high res signal to composite, unfortunately it looks awful.  I spoke to an Extron Engineer and he told me that there wasn't a true solution.  Any suggestions on getting this video conversion worked out? Thanks!
Title: Re: Video converting problem!
Post by: George Linkenhoker on February 03, 2010, 04:16:01 pm
Hi Jordan,

First off, you will need to change your alias to give your full real name per forum rules.

To answer your question, it would be helpful to know what you mean by "it looks awful". Is your image just not what you see on a computer screen or is there something like colors or lines that shouldn't be there?

If your issue is more that it doesn't look as great as it did on the computer screen then you may simply need to adjust your fonts, icon size, and so on, to compensate. Unfortunately, there is not a lot that can be done when down-scaling an image, pixels have to go somewhere in a much smaller space. So, for your example, you have a lot of information from a vga 1024 x 768 image that you are making fit in only a 560 x 384 or 480p resolution. The information that gives you that finer detail is not usable in the smaller space so things may appear pixelated or blocky.

I hope that helps.

-George L.
Title: Re: Video converting problem!
Post by: Arnold B. Krueger on February 04, 2010, 08:29:07 am
Jordan Manuel wrote on Wed, 03 February 2010 16:25

The problem I'm having is sending a laptop signal (VGA at 1024x768) and being able to send it to a composite signal for recording.  Currently, an EXTRON VSC 500 is converting the high res signal to composite, unfortunately it looks awful.  I spoke to an Extron Engineer and he told me that there wasn't a true solution.  Any suggestions on getting this video conversion worked out? Thanks!


Everybody who has fought this battle will tell you the same thing, which makes tremendous sense if you think about it.

When you convert 1024 to 768 video to 720 x 480 (DVD-V) or 640 x 480, or whatever even lower resolution you think your NTSC signal is, a tremendous amount of resolution is going to disappear.

No way can 720 x 480 (or worse) look as good as 1024 x 768 if your video is generated so it exploits 1024 x 768. The only way to make video look acceptable at lower resoltuions is to do your text and artwork with that lower resolution in mind.

If your final delivery resolution is standard TV, you will probably find that you will get the best results if you generate your text and graphics at that resolution. There's a lot of finageling with things like character generation that are modifed so that things look as good as possible at that low resoltuion. If you just take text generated at a higher resolution and downsample it, you probably won't get such good rsults as you would if you gnerated it at the final resolution.

At the very least, you need to use larger fonts than you would at 1024 x 768 if your final delivery resolution is regular SD TV.

Your Extron is a relatively high end product, but just because something costs more doesn't mean that its going to bypass the simple laws of optics.

If you want better compatibility between 1024 x 768 and TV, upgrade your TV system to HDTV.
Title: Re: Video converting problem!
Post by: William Sanders on March 11, 2010, 02:25:58 pm
Sorry, a little late on this topic but this may help someone else. We would use a Sony 1024 to convert the signal. Sony may have discontinued this unit. Analog Way makes several video switchers that scale. Ask your local A/V rental company. But if you have to use what you have then the best bet is lower the resolution on the laptop and use some of the image enhancing features of the Extron unit.
Title: Re: Video converting problem!
Post by: Brad Weber on April 08, 2010, 10:35:29 am
Just really reiterating the same thing but maybe look at it this way, 1024x768 is 786,432 pixels while 640x480 is 307,200 pixels, approximately 39% as many pixels as 1024x768.  So more than 60% of the pixels that make up the original image are inherently lost in the conversion.  How well the converter handles that may vary greatly but it still happens even with the best of them.

Adding to that, you may then be taking that 640x480 resolution recorded signal and viewing it on a higher resolution display, making the upscaling at the display from 640x480 to its native resolution also a part of what you see.

So think about having a 1024x768 signal, converting it to composite video and then watching that on a 1024x768 display.  That is almost like someone taking a picture, cutting it into 100 pieces and throwing away 60 of the pieces.  No matter how carefully they choose what pieces to keep, how much would the result look like the original?  Then ask someone who has never seen the picture to take the remaining 40 pieces and recreate the 60 missing pieces.  Just how close a reproduction of the original do you think you'll end up with?