x264, is q25 too low?

[silverwolf0]

I'm using xvid4psp to encode some mpgs into x264 mp4 files to decrease size. In most cases q21 will cut the size in half. I've tried q25 and that cuts the filesize even further in half, making it a quarter of the original size. This is a huge boon in space saved for me. However, I haven't thoroughly tested whether q25 is up to snuff as I've only used so far a blurry test video and I can't really make out the difference when the original is so bad. In your own personal opinion, do you think q25 is high quality enough? And I only change the quantizer values because one setting is enough to drive me nuts, so I'm sticking to one and don't want to waste time fiddling with the other myriad of options. Thanks in advance.

[guns1inger]

No disrespect meant, but only you can answer that question.

I can tell you that for me it is probably too low, and that for some videos even 21 is too low and 18 is better.

That said, many people think a movie crushed into a 700MB Xvid file is "DVD Quality".

Quality is in the eye of the beholder. You are the one who will be watching these videos in the future, and you don't want to be kicking yourself wishing you had done a better job.

[creamyhorror]

q25 generally sucks. But on a blurry source video, the visible difference will be smaller. As guns1inger said, you have to compare them with your own eyes.

At q20, you can make good-quality encodes of DVD movies at about 1.2-1.8GB (depending a lot on length).

If you're encoding from MPGs that were already encoded from a DVD or other source, your resulting files are going to look relatively crappy no matter what you do. You should get hold of the original source or simply keep the MPGs.

[Xpenguin17]

Using a lower quantizer for blurry videos might even make them look better as the distortion gives the illusion of detail, plus you save space.

The setting depends on your purpose and how jewish you wanna be when your videos are now missing a speck of noise that you consider quality.

So, if you really value the video, use q20 or q21 and it'll be high quality. If you could care less how it turns out, as long as its tolerable quality, use a minimum of q24. I've watched a couple videos at q24 with some friends a couple times and nobody could tell the difference unless they had the original to watch alongside and compare.

[silverwolf0]

I'm just looking for general acceptable watching quality. I'm not going to notice smaller details as much and just want a smaller filesize to save space. So is q24 a good size to quality ratio? Because doesn't it go up to q50-51? Jumping from q21 to q25 already shrunk it to 1/4 the size. I don't know how those higher numbers are gonna look are how big they are gonna be.

[Loader09]

first of all, i wouldnt recommend xvid4psp for anything, its encoding is bad and its very buggy, i use format factory for encoding and its very good, try that

[hech54]

first of all, i wouldnt recommend xvid4psp for anything, its encoding is bad and its very buggy, i use format factory for encoding and its very good, try that

Thanks Mom.

[neomaine]

first of all, i wouldnt recommend xvid4psp for anything, its encoding is bad and its very buggy, i use format factory for encoding and its very good, try that

Sounds like FormatFactory spam to me... If you want to go over the virtues of your preference, that's absolutely fine. But needlessly knocking Xvid4PSP isn't necessary. Everyone will have their favorites but you've bashed (here and in comments...) both Xvid4PSP and Super. What's next, Handbrake?

Well, I - as well as many other long time members here - would recommend Xvid4PSP. Its encoding presets work very well, is fully customizable and has been updated to match codec changes as necessary. Been using this for quite some time with no issues.

[Xpenguin17]

I'm just looking for general acceptable watching quality. I'm not going to notice smaller details as much and just want a smaller filesize to save space. So is q24 a good size to quality ratio? Because doesn't it go up to q50-51? Jumping from q21 to q25 already shrunk it to 1/4 the size. I don't know how those higher numbers are gonna look are how big they are gonna be.

As others pointed out, only you know what's watchable for you. Encode the same video using different quantizers and compare them. You can use an avisynth script to group the videos together where you can conveniently dissect them to your whim. Decide what's cool for you.

To me, q24 is the most ideal quality to size ratio, and q20 for the best quality-preserving setting. I would never go below q24, but you just might. Yes, they do go up to 51 but that's just a mathematical limit and is not there because it provides good quality. Try and use q51 and see what a stain of utter shit it'll result in.