How to set I-Frames manually

[Lukie]

Hi there.

Does someone know an encoder, that allows to set I-Frames manually? (not the I-frame interval) I want to enode a small Game-Video (~9min). It has mainly still backgrounds and some objects moving in front. So i want to set a Keyframe after avery scene change) for maximum Compression and Quality. DivX's auto keyframe setting is not optimal.

TIA

[DigitAl56K]

Actually if you use Slow or Slowest mode it is optimal, and even if you use Standard mode it is pretty darn close :)

What the codec considers to be a "scene change" is not nessecarily what we as humans percieve to be a scene change. In fact, forcing keyframes where humans percieve a scene change to take place is actually a very bad, non-optimal solution and you will probably lower your video quality if you do so.

However, you can do this by editing the DivX.log file after Multipass, 1st Pass.

[Lukie]

Cool. This is what i was looking for. Easy to use and precise. Thanks. :) :thanks:

In my case, I must set Keyframes manually. (BTW: The resolution of my vid is very small: 400x324px²)

There are many slow fades ('cross dissolve') between different scenes in my vid. Divx uses P-Frames for the fading. That's OK and good. But afer the fading the scene looks really ugly, because it is based on P-frames AND because resolution is very small. A second later *PLOP*, just in the middle of the scene, a keyframe is set by the 'maximum keyframe interval' function. The quality jump is really big from P to I.

So i want to set a Keyframe just after the fading is over.

[Soulhunter]

Originally posted by Lukie
There are many slow fades ('cross dissolve') between different scenes in my vid. Divx uses P-Frames for the fading. That's OK and good. But afer the fading the scene looks really ugly, because it is based on P-frames AND because resolution is very small. A second later *PLOP*, just in the middle of the scene, a keyframe is set by the 'maximum keyframe interval' function. The quality jump is really big from P to I.

So i want to set a Keyframe just after the fading is over.
That remembers me my "never ending" encode of Hulk... :rolleyes:

Bye

[SeeMoreDigital]

Originally posted by Lukie
... There are many slow fades ('cross dissolve') between different scenes in my vid..... So i want to set a Keyframe just after the fading is over. Jeez!

What bitrate and image pixel frame size are you using?

Cheers

[Lukie]

I captured a Computer-Game via S-VHS-out of my GeForce using a DV-Cam (with a LCDisplay). After a whole day of recording i watched the record using a TV. There was an extreme, ugly and moving moiré pattern. Reason: I used a S-VHS cable but output was set to composite. The pattern could not be seen on the small LCDisplay... I really could bite my a**.

So i had to 'postprocess' my vid using VirtualDub. I used denoising-filters, resized and denoised again and ended up with a resolution of tiny 400x324. You can see every mpeg-artefact if played in full screen mode.

I also want to publish my vid in the internet so the bitrate has to be as small as possible. I think 500kb/s should be OK. I also tried XviD but DivX looks better in my case.

[edit]
I have to set 50 KF only.

[edit]
Cool. It really enhanced vid quality. I only have to increase 'texture_quality' for the added KFs.

BUT: A problem occured. The scrolling credits are somehow affected by adding some KFs. The scrolling text leaves behind white traces (~dots). It only happened before while i enoded one-pass only. Why does it occur snd how can i fix it?
TIA

[edit]
Ahh. I found an answer in another Thread. Just split the vid and encode separately. :)