"Very Slow" vs. "Very Fast"

[mduell]

There's only a small number of settings different between faster and veryfast; you could test them individually (or even all permutations) in a jiffy to satisfy your curiosity.

[Shibblet]

There's only a small number of settings different between faster and veryfast; you could test them individually (or even all permutations) in a jiffy to satisfy your curiosity.

LOL! Yep! I've been doing that. I took ~5, ~10, ~20 minute short films, and couple of full length "noisy" films (Like 300, and Saving Private Ryan) and encoded them with all the different encoder settings. And the picture from that article that shows "Very Fast" as an "outlier," always seems to be the case with all of my encodes. The file size is "close enough" to the "Very Slow" settings.

So, what I guess I keep trying to find out... Is "VerySlow - Faster" on a different scale than "VeryFast - UltraFast?"

[Lostless]

You have to remember that file size does not mean quality. The faster settings are designed to just throw enough bits to display the image good enough, and not further see how better to compress. It does its thing and moves on. It doesn’t try to save bitrate, just encoding time. It’s why it’s the fast setting.
But If you can’t see the difference, then great, but quality is lost in faster settings. I notice it in mainly in the sharpness of the overall image that’s very subtle. But in the days of you tube and social media with things compressed to all hell, the very fast actually looks very good.

[Shibblet]

You have to remember that file size does not mean quality.

Agreed.

The faster settings are designed to just throw enough bits to display the image good enough, and not further see how better to compress. It does its thing and moves on. It doesn’t try to save bitrate, just encoding time. It’s why it’s the fast setting.

Again, I agree. It's not that I don't understand how bitrate works... It's just that "Very Fast" doesn't seem to fit the curve. With H.264, as opposed to H.265, the slower the encode, the smaller the file. "Very Fast" throws this idea off... dramatically.

But If you can’t see the difference, then great, but quality is lost in faster settings. I notice it in mainly in the sharpness of the overall image that’s very subtle. But in the days of you tube and social media with things compressed to all hell, the very fast actually looks very good.

I truly cannot see the difference between "Very Fast" and "Very Slow" on 1080p content. At 720p, I can only notice differences in still frames, but not when I watch the video.

[mduell]

Comparing file sizes across the encoder presets is fudamentally invalid because you're not holding anything constant. The bitrate isn't and the actual image quality isn't.

[rollin_eng]

You seem fixated on this “curve”. There is no “curve” for size. The presets change the speed of the encode (thus their names). Size and quality will vary.

The presets are not labelled small, big, bigger etc.

[Shibblet]

Comparing file sizes across the encoder presets is fudamentally invalid because you're not holding anything constant. The bitrate isn't and the actual image quality isn't.

Interesting. So, what you are essentially saying is that a slower encode doesn't necessarily make a smaller file. I only see that to not be true with "Very Fast."

You seem fixated on this “curve”. There is no “curve” for size. The presets change the speed of the encode (thus their names). Size and quality will vary.

The presets are not labelled small, big, bigger etc.

I agree, I am very fixated on this "curve," since "Very Fast" is the only preset that doesn't really fit the concept of "Smaller File / Slower Encode."

Remember the "Speed / File Size / Quality - Pick Two" option? "Very Fast" doesn't apply.

Also, people keep saying the they can see a quality difference between "Very Slow" and "Very Fast" with the CQ slider set at 22-24. But I cannot. Therefore I am flummoxed.

[Lostless]

There is no curve. Very fast files may be similar or even slightly larger than slower settings. As I said before, the faster settings use as many bits as needed to get a decent picture and moves on. It won’t try to compress any further.
As far as picture quality, the difference is there, but very subtle and usually will just look a tad sharper because it retains higher frequency information (edges of things) and fast motion scenes retain more detail.

[rollin_eng]

Interesting. So, what you are essentially saying is that a slower encode doesn't necessarily make a smaller file.

This is correct.

Remember the "Speed / File Size / Quality - Pick Two" option? "Very Fast" doesn't apply.

It absolutely does. You have chosen speed, you have a smaller file and the quality has dropped.