Making dvd from avi of desktop capture - looks awfull

[jjbtnc]

Been making little video clips capturing the windows desktop and copying my actions, and giving them to a friend so he's got a record of how to do things like setting up his router, configuring his firewall etc.
It's worked pretty well, the captures are good quality, and it seems a lot more effective at instructing somebody than emailing or using a phone.

He stores them just as video files but i suggested it might be interesting/worthwhile/fun trying, to make a dvd of all the clips. We've both had ago using Nero and it looks dreadfull. Any text looks atrocious and some is unreadable, for example

in the avi video file i made the quality is this level comparable to this

http://www.geocities.com/jjbtnc/eaxmple.PNG

but in the finished dvd the quality is this level http://www.geocities.com/jjbtnc/eaxmple1.PNG

actually it is a bit worse these are just examples of the effect i am getting - see the way the text and numbers are breaking up, in this example you can still read 'internet' but on the dvd it's hard to make out.

The avi files that i made are a capture of the desktop which is 800x600 and i think it's the resolution conversion to 720x576 PAL DVD that is making it look crap.

I can't capture the desktop at 720x576 so is there anyway round this ?

Maybe converting my avi to a different resolution before making the dvd ?
Or maybe selecting a different resolution in Nero
Or just forget the whole idea ?

[guns1inger]

You have three problems facing

1. When resizing small text and fine details it is difficult to maintain clarity

2. Televisions are not designed for delivering this type of image, and generally do it poorly - ever tried hooking your PC up to your TV at 800 x 600 - it looks pretty average

3. The type of compression algorythms used are not friendly to text, edges and details.

You might get better results if you create a slide show instead. resize the key images in photoshop and provide voice overs for each slide.

The only other approach I can think of is to cap at an even higher res, but instead of resizing, zoom and crop instead.

[jjbtnc]

yeh - i've outputted a pc to a tv before and although it's ok for watching dvd and video files the desktop and text look pretty ropey - unfortunately my captures converted to dvd look even worse than a pc hooked up to a tv. Quite agree with the problems you identified but not much i can do.

Thanks for your help

[guns1inger]

If you had a DV camera with analogue input, and a PC with TV out, you could try a direct feed into the camera, just to see how it comes out. Transfer the DV back to the PC, filter it to sharpen up the details a little, then encode. Might work.

[jjbtnc]

I can actually capture different regions and then the desktop pans around in a follow the mouse sort of way. I set a region of 720x576 and it looks a lot better as a dvd. Before when it went, start button -> all programs (this is xp by the way) i couldn't really read the program names, some i could but i think i was being helped by the fact that i knew what 'should' be there.
Now i can read them fine and when it comes to a stage where i have firefox open i can read the url in the address box whereas i couldn't make it out before.
Only problem is it's more 'flickery' which is a bit annoying. Anybody know how to stop this ? I might try some different encoders to Nero.
Might try a few other things but i'm not going to waste too much time on it.

When you mention filters do you mean with vdub - any you would recomend any with possible settings to try ?
One thing i will be trying to do is to mess with the size abit more then add a border to deal with the tv cutting the edges off - overscan is it ?
I'm off to google and search forums but if anybody knows how to add borders or can point me to a good link then thanks - i've hardly ever used vdub before so it's a bit of a learning process.
One thing i am concerned about is if i want to add a border when i output the file from vdub is it going to be rencoded again with a loss in quality - a bit like if you have a jpeg photo, edit it and then save as a jpeg again. If this is the case is there anyway to prevent or reduce this.

Think i might have to start making some vdub video editing posts instead of continuing this.

Thanks for your help

[guns1inger]

avisynth is a simple way to add borders, although if you use tmpgenc to encode, you can do it there as well.

The flickering will be the interlacing. A slight vertical or gaussian blur will smooth that out. The trick will be finding the balance between the flickering and loosing too much detail. I would also look at using an unsharpen mask to add detail where possible (I know it sounds contradictory to the blur, but that's how it is).

A simple avisynth script to add borders for PAL footage

LoadPlugin("c:\video\avisynth 2.5\plugins\asharp.dll")
avisource("your file here")
crop(12,8,-12,-8)
asharp(2,2)
AddBorders(12,8,12,8)

Note, this crops off the edges and replaces them with borders. It does not resize.

Install the latest avisynth, download the asharp plugin from here http://www.avisynth.org/warpenterprises/, put the script into a text file with the extension .avs. You can load this into virtualdub to see the effect it has, or load it directly into you encoder and produce your mpeg2 file.

[Safesurfer]

Only problem is it's more 'flickery' which is a bit annoying. Anybody know how to stop this ?

This is due to the way TV works by scanning one field at a time, fine lines only show in one field and this leads to flickering. You could try applying a slight Vertical only Gaussian blur, or deinterlacing the AVI. You will lose some sharpness, but this should eliminate the flickering.

Edit: must type faster - Gunslinger beat me to it.

[jjbtnc]

Thanks guys you've given me quite a bit to work with - i'm actually enjoying learning about this. Been meaning to learn about vdub and avisynth for a while. The thing in my favour is that i'm working with small 2 minute clips so i don't have to wait for ages to see the results. I'd hate to have to wait hours for an encode with filters to find they didn't work.
Just one thing about the script you posted - there may be a chance that the size of video i capture may just need to have a border added so i guess i omit the crop line ?

[Cornucopia]

Couple of suggestions:

A word to remember is "Oversampling". Makes a big difference in smoothness.
Set your app to be displayed/capped to show in full screen mode. Then, make you screen caps using a much larger canvas, say 1024x768 or 1200x1024 ( >2x the final size is best, but you have to have a really great system to cap at that high a rez). Make it 16 or 24 bit.

Cap at at least 15fps. Better if it's 25/30fps (actually, for NTSC, 29.97 if you can convince the screengrab app to use non-integer rates, otherwise use 30 and change later).

Then, in Vdub/AVIsynth, you would:
1. Crop to "area of interest"--if full screen is area of interest, leave alone (Try to Keep 4:3 Aspect Ratio).
2. Pad border w/Black (or other color) by 5% (ActionSafe) or 10%(TitleSafe).
3. Apply Motionblur filter--best if you can do it only in the vertical direction, w/depth of only a couple of pixels.
4. Resize to 720x480 (NTSC) or 720x576(PAL)
5. For NTSC, interpret frame rate as 29.97, even if it's originally set to 30. You don't have to worry about sync. For PAL, leave as is at 25fps.
6. Encode to MPEG2 via frameserve (full D1 rez).

HTH,
Scott

[guns1inger]

What codec are you capturing to ? Some codecs, such as the techsmith codec, are much better for screen capturing than other (the MS DV codec, for example, is very soft). This might make a difference.

[jjbtnc]

Thanks for your posts - at the moment (on friends pc) the highest usable capture res is 800x600 unfortunately. Anything better and the pc has trouble coping. I may try again on my own pc which is a better spec. Codec wise so far i've been using camstudio (open source, similar to camtasia studio) lossless codec. I've done a few clips at various settings with and without compensation for overscan and then i'm going to repeat with the techsmith codec and try some other codecs and compare. I'm also going to check the results on a few teles.

thanks for carrying on offering advice, i think this is slowly moving away from dvd authouring so i may start a new post soon in a different forum section.

I also think it's time to move away from Nero and start looking at other dvd encoding and authouring apps.

[Safesurfer]

I haven't tried it yet, but there's also the new MSU Lossless Screen Capture Codec.

[jjbtnc]

Thanks guys - got some clips that look ok as dvd now, the gausian blur works pretty well. You also put me on the path of getting to use vdub more and starting with avisynth, and the adding of borders to compensate for overscan. It's something i've never realised before and only noticed when the 'start' button was missing from my desktop capture that was being dispalyed on the tv.
Tried the msu codec, it seemed to install ok and appears as a selectable codec in vdub and 1 of the 3 desktop capture programs i'm trying out. Unfortunately for some reason it doesn't appear in the list of codecs in the other 2 programs i'm trying - not sure why.
Just 2 things i wanted to check
i did want to try the vertical blur just for comparison. I see motion blur in vdub yet when i select it there are no configuration settings - is this correct ? Is there a plugin that can provide vertical bluring ?
Guns1inger mentioned "A slight vertical or gaussian blur will smooth that out. The trick will be finding the balance between the flickering and loosing too much detail. I would also look at using an unsharpen mask to add detail where possible (I know it sounds contradictory to the blur, but that's how it is) "
If i do try both does it matter in which order they are done ?
Thanks again

[jjbtnc]

Quite interested in getting to grips with avisynth, there's one thing i wanted to get clear in my head. When you make/generate an avi script to say add resize, add borders, and sharpen and run it in say virtual dub or tmpgenc, is it avisynth that is doing the resizing, adding borders, sharpening ? Or is it just telling virtualdub or tmpgenc what to do and they are doing the resizing, adding borders, sharpening ?

[guns1inger]

Avisynth does all the work. Whatever you load the script with is simply acting as a display device for the uncompressed output coming from avisynth. You can always add virtualdub or tempgenc filters on top of this if you need to.

[jjbtnc]

I've finally managed to get this working pretty well - a combo of capture desktop at 800x600 (on low spec pc at the moment and this is the highest i can get a reliable capture at) and then resizing where, after exhaustive comparison, i was surprised to find precise bilinear gave the best reults in my situation, a dash of gausian blur helps compensate for a slight flickering, and then a smidgen of using an unsharp mask just sort of brings a focus back to things. On a 17" portable i can read the text okish and on a bigger tv there's no problems at all.

I'm going to give my little clips as 800x600 avi files (haven't decided what codec i prefer yet) and then i've noted what settings/i have to do, so there's the option of coverting them in the future to a usable format to make a dvd.
Next thing i'm going to be looking at is using avisynth and frameserving more, and getting seperate mpeg2 encoding and dvd authoring apps instead of relying on Nero.

Anyway thanks to everybody who helped me, much appreciated

Now where are those old vhs vids...............................

[jjbtnc]

Just a bit of an update - really a different forum but i thought that if anybody was trying a similar thing and searched the forum they might end up here, so............

found a program called BB Flashback - i'm using the more limited express version that came free (full version of the express software - not crippled and no time limit) on pcanswers mag here in the uk (may be able to download from their website)
Performance is a lot better than the others i have tried - cam studio, camtasia, wink, - smoother, less resource hungry, doesn't seem to slow down the programs you're trying to capture so muuch, seems to be able to capture at higher frame rates. Works slightly differently than the others in that you don't specify a capture codec, you capture, then edit a bit, and then export as an avi where you select your codec. It seems to have all the codecs available whereas some of the other programs wouldn't have then all available. It's own proprietry capture codec seems to be lossless, well looks the same as the real pc desktop and exactly the same as the other camstudio, techsmith, codecs that are described as lossless. Has similar capture options to the others although camtasia seems to have a few more advanced features than the express version i'm using. But then flashback also has a few handy features that the others don't have.

p.s. i'm in no way affiliated with the makers of flahback

p.p.s i've gone through the new tool process so it may be added to the tools section soon.