How to meter the quality of .264 videos?

[spycam]

I want to encode the most optimal size/quality ratio videos for online streaming.
The sources are not brilliant quality and I end up getting test videos encoded with different settings that have different file sizes, but more or less similar visible quality.

Probably I'm having not the best equipment to have the best visual experience, so I can't decide which quality/size is the best option to go with.

Is there any way to "scan" the different takes of the same video, encoded with different settings, to determine which one is the best to use? The thing is that I don't want to use 5% better quality video that has 50% higher bitrate/file size.

[Baldrick]

Nope.

[redwudz]

I agree with Baldrick on that. But you could use MediaInfo, Tree View, and get some data for comparison. After a bit of practice reading the data, you may be able to make conclusions as to quality.

[jagabo]

You can use a video comparison program like MSU's Visual Quality Measurement Tool. But the results are of limited value since it's more a mathematical measurement rather than a human visual measurement.

[spycam]

What about measuring some noise ratio?

[jagabo]

What about measuring some noise ratio?

That's what MSU's tool does.

[Hoser Rob]

If there was such a tool that actually worked, believe me, every regular user here would know about it.

Not only that, it would be a feature of many encoders, and you wouldn't have to spend nearly as much time dicking around with which advanced settings to use.

Besides, quality is a bit subjective.

You're going to have to use your eyes. If your hardware as listed in your profile is current I can see why you'd want to avoid encoding too many times but you're still going to have to experiment and see what you find acceptable.

You could cut a small segment from a video (preferably with mixed video content) and try encoding that with different crf settings.

[_Al_]

For online streaming I'd denoise, deinterlace (if needed), resize and use H.264. Denoise can do miracles sometimes. Bandwidth will generate size and quality, that's the limit, so there is not much you can do. H.264 is best that you can get. Really compressed video you might slightly saturate, it looks always kind of better. You have to decide Profile , level, Baseline @3.0 , 1000kbps, no CABAC, SD resolution - for old computers like Pentium 4 or you crank it up to Main@3.1, 3000kbps, 720p-HD resolution. Default settings, do not look for miraculous settings.

It is all compromise for streaming rather than comparing quality. You start with bandwith and you get something .....Or you provide two streams for streaming because if you do not, somebody will always be disappointed ...

[spycam]

OK, thank you guys.

If your hardware as listed in your profile is current I can see why you'd want to avoid encoding too many times

LOL, the one in my profile is heavliy outdated, I just updated it to list my current setup

[WishMe]

compute the psnr, if you want to keep the video quality, you can remux the file, do not convert the video stream

[jagabo]

PSNR is a very poor proxy for visual quality. Suppose, for example, I made a new codec that compressed better than h.264, and in fact was perfectly lossless -- except that it shifted the frame one column to the left. Nobody would be able to tell the difference comparing the two videos on a TV that overscanned. But the PSNR results would be disastrous.