What's wrong with the human FACE?

[mldragon]

I have converted a *.Mpeg MTV into divx5.02(solution:352*240)
But I found a problem.

When there was a sence that the actress face toward the camera(at stillness),there was a BLACK BAND laid between the face and the hair
But it didn't exist in the original mpeg file!And I didn't see at the
VirtualDub Output window either.

Then I use resize to change the divx5.02 solution to 640*480,it looks better,but the playback speed would slowdown.

Will someone help me to perfectly solve this problem ?

[Evil Andy]

Can you post a screenshot?

[mldragon]

I don't how to get a screenshot.:(
When I press the "printscreen" key(OR ALT+"printscreen" key) then paste it in the WINDOWS Print then save,it only get a BLACK screen.
Or I paste it in the photoshop,the image is covered with black nets.

BTW:I have installed ffdshow, and the problem is almost solved(only acceptable flaws).But when I use back the divx5.02 codec, it happens again.So I have to say it's the codec's playback problem.

However, thank you all the same.

[Evil Andy]

Open your AVI in VirtualDub and use the Mark In and Mark Out buttons to select a few frames where the problem occurs then go to File -> Save image sequence. This'll get you some screenshots in bitmap or tga format. Choose one as a good example of your problem and cut it down to under 200kB in photoshop (a high quality JPEG would be ideal). Then post it here.

[mldragon]

I did it as your instruction above.But as I have said beford, it can't make much sense.The picture quality is much much better than that when it was being played.

Maybe someone can tell me how to shot the picture when I play the divx avi file.

[Teegedeck]

Get yourself a simple screenshot utility. Like 'JPEG Clipper'. Get it at download.com, for example. Or get one of the zillions of other capture programs.

And try whether using ffdshow for DivX5 playback helps with your problem.

[mldragon]

HAHAHAHA!So funny:)

I have tried "JPEG clipper" and "Hypersnap-Dx5"(another screen shoter).Here is the result.
Maybe My PC has some problem, or you can help me to do some test.

When I shot a screen and save a jpg file.And then I open it with ACDSEE,I get a BLACK image.But when I play the divx MTV at the same time,the screenshot displays the movie!@~@

I think the divx5 file used some directx tech so it can't be shoted like normal program(said by "Hypersnap-Dx5" help page).

[mldragon]

Here, I got it:)

Use the "directx capture" funtion of hypersnapDX5 can get a shot.Oddly I only shot the image when I used divx5 codec.

It is the left face curve.The "black band"seens more cleanly at the chin between original mpeg and avi file.

What's wrong?I have posted my attachment but it doesn't work.I can see the attachment when I edit my post, but it links to a error page.
"Invalid attachment specified":confused:

[mldragon]

Divx

[mldragon]

ffdshow

[Evil Andy]

What resize function are you using eg. bilinear, neutral bicubic? How much bitrate are you giving it?

[Teegedeck]

Are you talking about the distortion at the edge of the face or what? I'm not sure whether this is what you were pointing at. That would result from strong compression.

[mldragon]

[That would result from strong compression.]
I think you are right.Thank you for that:)

My bitrate is 800kbps without any resize funtion seleted.Because the original mpeg quality is not worth so high bitrate.I use divx5.02 to compressed 4:37 mpeg into 30MB:p Except that problem, other thing is OK.

[Evil Andy]

When you say the mpeg quality isn't great do you mean it already has compression artifacts? If so then divx will be wasting a lot of bitrate on trying to encode them. You should try some noise reducing plugins in avisynth or vdub. Convolution3D seems to be a popular choice at the moment.

[mldragon]

Ok, i will try.Thankyou:)

[Navellint]

hi,
aren't the artifacts you are discussing called 'aliasing' ? It happens on sharp edges in mpeg-compression (and jpeg) due too a characteristic mpeg algorithm in case compression ratio is too high, so dvds with cheap transfer that are compressed to fit on a single layer dvd-5. When you compress a dvd to divx and forget to crop off a bit of black border on one side, you'll not only see that border in your encoded movie but also an extra black line alongside the border. I believe you can see that too in the third of your attached pictures (top border, between her hair and the logo).