jerky on tv - from screen recording

[latinmidi]

Hi and thanks in advance

I teach in a voluntary basis and make screen captures that when reproduced on the PC monitor are sharp and great.
When I encode them for MPG2, make a DVD and play on TTV... there's allways a kind of jerking, unstable image. Some of the people I help could benefit a lot from DVD because they don't have a home computer but most can get to a DVD player and TV. Any help would be greatly appreciated.

Recording lessons on computer apps and general know how.

Monitor resolution: 1280x1024 - 32 bit colour - 60 Hz refresh rate
Screen recording: Region - 720x576 x 25 fps
Export as avi and encode to MPG2 for DVD PAL interlaced - bottom first (also tried progressive)

Play with PC: NO problem with any tried player. Even with the compiled DVD in HD.

Play on TV:
Text: quite good, mostly sharp. Not much blur and readable.
Images: Good, fairly sharp

Problem:
Horizontaly Shaky, jerky...
Image is oversized on a 14" TV !!??

I've read and search every topic I could find on the forum. Very helpfull because I've managed to get better recordings and know a lot more about video but can not find a solution to my problem.

[gadgetguy]

Image is oversized on a 14" TV !!??

This is probably just overscan which is present on all standard TVs (and varies from TV to TV). You have to account for this in your capture/editing process.

Horizontaly Shaky, jerky...

My first thought was wrong field order (use top field first instead of bottom field first), but your source should be progressive so you should be able to encode it progressive and have it work fine. Of couse the TV is interlaced, but the DVD player should be able to handle that conversion. Have you tried it on different DVD/TV combinations to see if the problem is consistant? Another possibility might be the media you are recording on. Poor media obviously gives poor results, but even good media can give poor results on a given DVD player. What media are you using?

[latinmidi]

Thanks for such quick answer...

MEDIA: Ritek -R , DVDsale +R
Any other type of DVD with same compilation and same media, play fine.
It's only with <screen captured> source that the problem arises.

I've waisted about 25 DVDs with NO luck... Could it be the refresh rate of the PC???
Everything is really, quite good except for THAT "trembling, shaking, lines.

I will test a diferent stand alone player.
---------------------------------------------------

I'm thinking of another approach:

Has anybody tested recording video (with, text, graphics, etc.) from the TV out of the graphic card to an external stand alone DVD recorder...??

¿Do you think it would work better? ¿Would it be sharp and readable on screen?

I can get some sponsors to help with acquiring a recorder but, I really should know if its going to work. Else, I'm risking that they won't help the next time.

Most sincere THANKS to all and any answer

[guns1inger]

Without seeing it is hard to say exactly what the cause might be.

The fact that it works fine on a progressive display (your PC) and has issues on an interlaced display (your TV) would suggest that your detais are too fine, and what you are getting is shimmer due to the way interlaced displays work.

Alternatives you might try

1. Set your resolution to 800 x 600. This would also give you an idea of what recording with an external recorder might be like, as this is the resolution you would have to use.

2. Apply a slight vertical motion blur to your current material after resizing for DVD, then re-encode. While this might reduce clarity somewhat, it should reduce, if not eliminate, the flicker/shimmer effect.

[gadgetguy]

Ritek is not first class media, but you should be getting better than 0 acceptible in 25 burns. I've never heard of DVDsale media. -R media tends to be more generally compatible than +R but again, that's player specific and if you get the same results when tested in multiple players that's probably not the issue.

My limited experience of TV out from the graphic card is that it is fuzzy and text is hard to read on the TV, but that may be due to my old video card. Test the output to a TV and see if it's acceptible. If it is then there's no reason to believe that recording it with a DVD recorder will make it worse The drawback would be if you have to edit because the recorded video will already be in compressed format. You can still edit, but not without a quality hit (which may or not be noticable).

[latinmidi]

Captured at 800x600 -- Not Luck

Encoded a DIVx and played in TV : Same shimering, line shaking. Other DIVx are Ok.

Encoded a MPEG2 - Recorded as a File and let the DVD player do its job -- Same result

A friend encoded the capture file with Premier: Same result

Surely there must be a way!!!

or

Maybe I'm trying to do what I see on TV ...Too big for my feet??

Thanks again

[drewzor]

TV screens are not 1.1 square pixel and maybe the cause of the problem with your horizontal distortion. I would suggest capturing
768x576 which is the actual display size of 720x576 on pc @ 4:3.
When you encode 768x576 to dvd pal it will play back at the right aspect and not horizontaly distort the pixels.

Overscan is why the first thing that is said to people who are intrested in filming is "you can never capture too much in a frame but you can always capture too little" so use your work area in 704x528 and capture 768x576 and overscan will not be a problem.

Hope this helps you out.

[jagabo]

played in TV : Same shimering, line shaking. Other DIVx are Ok.

Encoded a MPEG2 - Recorded as a File and let the DVD player do its job -- Same result

I think you're problem is the sharpness of the picture and very thin horizontal lines or horizontal, high contrast edges. These will always shimmer and shake on an SD TV. If you can control the source use less contrast, fewer horizontal edges, antialiasing, sans serif fonts. If you can't control the source use an antiflicker filter or blur the image a bit to reduce the problem. A blend deinterlace filter will also help because it blurs along the vertical axis.

[latinmidi]

THANKS all again
I'll keep trying