x264 - Optimized settings for Realtime Transparent Encoding

[zerowalker]

I am trying to find the sweet spot for a good size, and fast speed and achieving transparency.

Now all this (Size,Transparency,Speed), differs for everyone, so i will say my goal.



My goal in itself is to maintain a size that is about 100gb for Over 2 hours, preferably 3 hours.

Currently, i am using CRF 10, which is as you may know, dynamic, but it seems to be about where i want it, 50-70mbps i think.


Now for speed, i need it to be able to achieve a constant framerate of 30fps, without killing the system (4ghz quad core), currently that is done with,

Superfast Preset, CRF 10, weightp 1(Only using it as i read that without weightp, x264 fails with fadein/out).


Now, i think this can be optimized, as i have only put it together fast and it seems to be to my liking, i don't see any artifacts when i look (Of course i will see if i compare it to lossless, but you get the thing), and that is what i am aiming for.

EDIT:


Forgot the important thing.

The resolution that it's supposed to be able to handle, is at max 1920x1200 at 30fps.

[turbojet]

I spent a few hours comparing settings for visually lossless months ago and found trellis to be most important visually. Mainly 1080i to 1080p using tivtc and tried staying below 50 mbps. Settled on --preset faster --crf 14 which runs 25-30 fps and 20-35 mbps.

[zerowalker]

Ah great, will try to see if i can afford using Trellis.

[zerowalker]

Trellis seems to be quite the hit sadly.

I think weightp itself is also the performance taker.

Does someone knows if weightp is necessary, i mean is it needed for x264 to succeed on fades, or perhaps that's something old that has been cured?

As CRF 10 can usually give transparent picture, but i only need settings On that actually make difference, i don't much care for small differences, as B frames do or Reference frames.
I only want the necessary ones so to speak, and sadly, i don't know which are that.

Probably Cabac is one of those.

[cyberbeing]

Since your bitrate target is already so high, you could try just tossing more bits at fades with the --fade-compensate patch and see if that fits your needs any better.

[zerowalker]

I am limited to a certain x264 build, sadly can't patch it.

But do i have to worry about fades, i haven't checked if they "fail" or not, i just use it cause i think they can do, something about reference frames needing to be there.
I know for instance that Youtube's encodes with H264 fails with fades, however they are in a different category, but even then it's still H264, not sure if X264 has "solved" it, hence my wonder.

[Asmodian]

Personally, I wouldn't worry about fades in particular at the bitrates you are using. Youtube is at ~1/10th the bitrate. Just use the slowest preset you can.

btw superfast already sets weightp=1 so no need to set it again. Can you use veryfast? There is a lot of improvement with veryfast if your system can handle it.