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Without at least some semi-objective compassions on the "visual quality", your data is meaningless. Like, how can you tell crf23 of x264 is closer to your x265

Without at least some semi-objective compassions on the "visual quality", your data is meaningless. Like, how can you tell crf23 of x264 is closer to your x265-x265 version than, say, a crf24 x264 one? As a rule of thumb, x265 works better (compared to x264) at lower bitrate / worse quality. You won't be able to achieve "same quality, half size" at higher bitrate easily.

dylan604 6y ago
Sure, we could runs some PSNR or SSIM comparisons. However, I've been doing this for a hot minute, and h.265 is pretty damn good. Getting 4K video filesize for VR to run on a phone based headset was never going to happen without it. h.264 encodes just were never going to make it in the real world for the frame size and TRTs. Once we knew the target devices could handle h.265, it was a game changer. That was way back in 2015 when live action VR was almost a thing. From years of real world experience, h.265 produces much smaller files by being able to use a lower bitrate to achieve the same visual quality has previous h.264. Guess what. H.264 did the same thing to MPEG2. Not really sure why this is so unbelievable.
- fireattack 6y ago
  > Not really sure why this is so unbelievable No one is saying that. Everyone knows H265 is better than H264. Just saying your number is meaningless without either fixing the bitrate or the quality.
  - dylan604 6y ago
    Sure. Don't believe some random dude from the internet. But if you're not going to go through the hassle of running the tests on your own, your "meaningless" claims are meaningless. Have you spent time in your career as a compressionist? Have you encoded hundred of hours in various codecs looking at the best tweaks to get the highest visual quality for the smallest file sizes? The test files that I produced resulted in the h.264/crf23 with a bitrate of 970kbps while the h.264/crf28 result with a bitrate of 800kbps. The h.265 used less bitrate to achieve half the filesize. I have stacked the 2 videos and toggle between the two. There is no visible difference. I have done this experiment. It is up to you to do the same thing to see if you can replicate the results or not. That's science. But it is much easier to just post "no it doesn't" comments on the internet.
    - fireattack 6y ago
      Yes, I have spent hundreds of hours in comparing video encoder results, but that's beside the point. One don't need to have done that to be able to tell your experiment is flawed. All you have is literally one datapoint, 970kbps h264 has "no visible difference" compared with 800kbps h265, and I believe that. But maybe 800kbps h264 also doesn't have visible difference from it. Maybe there is just not much difference to notice from 500 to 1200kbps, for your specific video. Again, my point is your experiment has too few samples (literally 1 pair). Using that to conclude anything is the exact opposite of "scientific" method. I never say "h265 isn't better than h264" or "your result is wrong"; just your result doesn't prove the former. If you insist to use just one sample, you could at least use the same bitrate (2-pass if you want to have better rate control) and say "hey, the h265 one is visibly better!", and that would be more convincing.
      - boomboomsubban 6y ago
        >Again, my point is your experiment has too few samples (literally 1 pair). This experiment was to show that the gains the original post made wasn't solely due to the video being an unchanging desktop. There were enough samples done to show that claim seems to be false, though more data could change that. Basically, you're misunderstanding the theory tested, and while your complaints would make sense testing a different theory, they don't discount the experimental evidence for the tested theory.
        fireattack 6y ago
        > was to show that the gains the original post made wasn't solely due to the video being an unchanging desktop I assume your point is "while both reduced the size (from an unchanging desktop, which is easily compressible), H.265 reduces the size even further. So it (the choice of codec) is also a contributing factor." And I get it. My point is that even this wasn't proved by his experiment, because he failed to prove the two outputs have the same quality. And without having this, comparing file size is meaningless (because as stated by others, with lossy codec you can generate arbitrary file size by tweaking the parameters). Yes, he did say "there is no visible difference". However, most of people can't tell any difference bwtween 600kbps and 1000kbps, using the same codec, either. In other words, there is a huge range of bitrates where average eyes can't tell difference. So the "same quality" premise has to be very strict and objective. It's not I'm trying to be picky. A better approach, as I have said above, is to fix bitrate instead of quality. This way, you can find a certain point where people DO find the difference in quality, and then you can conclude more confidently that one is better than the other due to higher quality/filesize ratio.

dylan604 6y ago

Sure, we could runs some PSNR or SSIM comparisons. However, I've been doing this for a hot minute, and h.265 is pretty damn good. Getting 4K video filesize for VR to run on a phone based headset was never going to happen without it. h.264 encodes just were never going to make it in the real world for the frame size and TRTs. Once we knew the target devices could handle h.265, it was a game changer. That was way back in 2015 when live action VR was almost a thing. From years of real world experience, h.265 produces much smaller files by being able to use a lower bitrate to achieve the same visual quality has previous h.264. Guess what. H.264 did the same thing to MPEG2. Not really sure why this is so unbelievable.

fireattack 6y ago
> Not really sure why this is so unbelievable No one is saying that. Everyone knows H265 is better than H264. Just saying your number is meaningless without either fixing the bitrate or the quality.
- dylan604 6y ago
  Sure. Don't believe some random dude from the internet. But if you're not going to go through the hassle of running the tests on your own, your "meaningless" claims are meaningless. Have you spent time in your career as a compressionist? Have you encoded hundred of hours in various codecs looking at the best tweaks to get the highest visual quality for the smallest file sizes? The test files that I produced resulted in the h.264/crf23 with a bitrate of 970kbps while the h.264/crf28 result with a bitrate of 800kbps. The h.265 used less bitrate to achieve half the filesize. I have stacked the 2 videos and toggle between the two. There is no visible difference. I have done this experiment. It is up to you to do the same thing to see if you can replicate the results or not. That's science. But it is much easier to just post "no it doesn't" comments on the internet.
  - fireattack 6y ago
    Yes, I have spent hundreds of hours in comparing video encoder results, but that's beside the point. One don't need to have done that to be able to tell your experiment is flawed. All you have is literally one datapoint, 970kbps h264 has "no visible difference" compared with 800kbps h265, and I believe that. But maybe 800kbps h264 also doesn't have visible difference from it. Maybe there is just not much difference to notice from 500 to 1200kbps, for your specific video. Again, my point is your experiment has too few samples (literally 1 pair). Using that to conclude anything is the exact opposite of "scientific" method. I never say "h265 isn't better than h264" or "your result is wrong"; just your result doesn't prove the former. If you insist to use just one sample, you could at least use the same bitrate (2-pass if you want to have better rate control) and say "hey, the h265 one is visibly better!", and that would be more convincing.
    - boomboomsubban 6y ago
      >Again, my point is your experiment has too few samples (literally 1 pair). This experiment was to show that the gains the original post made wasn't solely due to the video being an unchanging desktop. There were enough samples done to show that claim seems to be false, though more data could change that. Basically, you're misunderstanding the theory tested, and while your complaints would make sense testing a different theory, they don't discount the experimental evidence for the tested theory.
      - fireattack 6y ago
        > was to show that the gains the original post made wasn't solely due to the video being an unchanging desktop I assume your point is "while both reduced the size (from an unchanging desktop, which is easily compressible), H.265 reduces the size even further. So it (the choice of codec) is also a contributing factor." And I get it. My point is that even this wasn't proved by his experiment, because he failed to prove the two outputs have the same quality. And without having this, comparing file size is meaningless (because as stated by others, with lossy codec you can generate arbitrary file size by tweaking the parameters). Yes, he did say "there is no visible difference". However, most of people can't tell any difference bwtween 600kbps and 1000kbps, using the same codec, either. In other words, there is a huge range of bitrates where average eyes can't tell difference. So the "same quality" premise has to be very strict and objective. It's not I'm trying to be picky. A better approach, as I have said above, is to fix bitrate instead of quality. This way, you can find a certain point where people DO find the difference in quality, and then you can conclude more confidently that one is better than the other due to higher quality/filesize ratio.