"Objective quality benchmarks are algorithms that compare the compressed video with the source and render a value that predicts how the compressed file would fare in subjective tests."
What open source tools would be recommended to perform an objective quality benchmark?
Announcement
Collapse
No announcement yet.
SVT-AV1 0.5 Released As Intel's Speedy AV1 Video Encoder
Collapse
X
-
Originally posted by jntesteves View Postthree dimensions:
output size × output quality (many automated metrics or perceptual) × encoding speed
To ease visualization you usually equalize one dimension, like trying to configure all encoders to produce same size, or same quality according to some automated metric, and then plot the other two dimensions.
This is not a focus of Phoronix.
For each encoder and bitrate, find the slowest speed setting that is faster than real-time. Now we are down to 2 dimensions; bitrate and quality, which can be measured and plotted.Last edited by andreano; 20 May 2019, 05:41 PM.
- Likes 1
Leave a comment:
-
If Intel keeps this up, they're going to be a software company.
Leave a comment:
-
Video encoder quality is hard to assess because there are three dimensions:
output size X output quality (many automated metrics or perceptual) X encoding speed
To ease visualization you usually equalize one dimension, like trying to configure all encoders to produce same size, or same quality according to some automated metric, and then plot the other two dimensions.
This is not a focus of Phoronix.
Edit: note that if one of these three dimensions is missing, a test is meaningless. It doesn't measure anything of practical use.Last edited by jntesteves; 20 May 2019, 10:27 AM.
Leave a comment:
-
Originally posted by HadrienG View PostFrom a quality point of view, SVT-AV1's output is comparable to that of x264 (source: https://forum.doom9.org/showthread.p...39#post1871939 ), and I doubt that it is as fast as the latter...
For those that don't know, here is the command line used for x264 in that test:
x264 --preset veryslow --tune ssim --crf 16 -o test.x264.crf16.264 orig.i420.y4m
For the uninitiated, the "very slow" preset is considered the "mastering" quality preset and crf 15 is generally considered visually lossless to the source; for this test they used "very slow" and crf 16 which means it would be nearly impossible for the average person to tell the difference between the source and the encoded version.
Further, the "very slow" preset, as the name implies is indeed very slow, encoding times are glacial.
If SVT-AV1 matched x264+veryslow+crf 16 with -q 20 -enc-mode 3 (as the command line says) then it doesn't get much better than that because with settings as aggressive as x264's SVT-AV1 would smoke it.
I would say that Intel's SVT family of encoders are the future, the only limitation I can see, if you want to call it that, is the high ram requirements, using ffmpeg patched to support SVT-HEVC, 4k encoding requires nearly 9gb of ram, on my R5 1600 with 8GB ram I can't do it, but on my 4790 based Xeon with 16 GB of ram it encodes just fine.
Here's some good info:
- Likes 1
Leave a comment:
-
From a quality point of view, SVT-AV1's output is comparable to that of x264 (source: https://forum.doom9.org/showthread.p...39#post1871939 ), and I doubt that it is as fast as the latter...
- Likes 1
Leave a comment:
-
Originally posted by tildearrow View PostIs it true that this encoder produces poor quality results?
Leave a comment:
-
Originally posted by tildearrow View PostIs it true that this encoder produces poor quality results?
- Likes 1
Leave a comment:
-
Originally posted by Namenlos View Post
Yes, of course. There is always a trade off between encoding speed and quality. The question is rather how good/bad it is in comparison with other video formats and encoders.
So while you are right, what would be the point if you couldn't mitigate some with faster code?
- Likes 1
Leave a comment:
Leave a comment: