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30th March 2017, 14:12 | #1 | Link |
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HEVC killer sample (short movie)
Alright guys, here's one for your entertainment.
Despite our common belief that HEVC would be better (on average) than AVC whereas at the same quality the bitrate would be cut in half or at least 30-40%, there are samples, where H.265 is on par or even slightly inferior to H.264 (just a little bit, but still). At https://media.xiph.org/ there is a 12 minute lossless 4k movie "Tears of Steel" weighing 67 Gb (compressed) and about 180 uncompressed. https://media.xiph.org/tearsofsteel/...teel-4k.y4m.xz So I downloaded and resized the movie to 1920x800, then saved it to lossless AVC. Now it's 10.5 Gb and I uploaded it here: https://drive.google.com/uc?id=0B_Fl...xport=download Here comes the most interesting part. I've been playing with this movie for several days and I cannot get HEVC better than AVC on it, whatever settings I threw on it. I get it almost transparent at ~8900 kbit/s with HEVC and at the very same bitrate AVC looks the same or slightly better in scenes with high motion (please keep in mind that I assess the difference extremely scrupulously.. I don't advise to try finding it on a bad monitor or with frivolous attitude). The difference is absolutely minuscule between the codecs (virtually none). You can download and play with the movie for yourself. HEVC can't compress this movie better than AVC but is 4-5 times slower! Why so? I would understand if this was a very grainy source, but it's not. This is a very high-quality, naturally sharp source with a bit of film noise. I used only CRF for my tests. It would be interesting if others can also look into it and provide their opinion/conclusions. Especially it would be cool to get some feedback from the development team. Thanks Last edited by Leo 69; 30th March 2017 at 14:34. |
30th March 2017, 18:10 | #2 | Link | |
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30th March 2017, 19:27 | #3 | Link |
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To further add to it, when there enough bits any encoder can do good job. Try with 500 to 2000 ABR ranage and see if you opinion changes. Basically with low bitrates difference should be visible.
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30th March 2017, 19:45 | #4 | Link |
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x265_Project
Thanks for your reply! I agree with you on the absolute most part. My point, which I'm trying to get across is this: There is something specific about this movie, that renders HEVC practically useless, since it doesn't offer any advantages but only disadvantages (in comparison to AVC) -- slow encoding speed (4-5 times slower), film grain in most cases looks less than original one or simply disappears in one scene (this one is very high-frequency...not easy to spot!), overall feeling that H.264-produced picture is more close to the original. Compare the information I'm posting to that being posted at hydrogenaud.io, where audio-enthusiasts hold listening tests of different lossy codecs at various bitrates, certainly including those which suppose to bring transparency compared to the original WAV or FLAC. They seek for the artifacts to point them out in ABX test -- this gives some valuable food for thought to the developers, who continue to fine-tune and release new versions of the codecs. While what you're saying is basically true => "at this bit rate the encode is visually lossless to any normal person under normal circumstances", it contradicts with the general idea that we may find here: http://x265.org/hevc-h265/ "HEVC was developed with the goal of providing twice the compression efficiency of the previous standard, H.264 / AVC." Which is not the case here. Why? If I was a developer, I would at least be intrigued as to why certain movie cannot be compressed more efficiently than with the former codec generation. P.S. To most people with low-end or average audio equipment, so as to those who doesn't really care, 128 kbps MP3 is transparent. However, those, who strive for perfection, they point out the flaws of the lossy codec, proving that in the ABX test. Hopefully, I got my point across. Last edited by Leo 69; 30th March 2017 at 20:18. |
30th March 2017, 20:43 | #6 | Link |
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Here is another example of such a sample, it is a slicing of three videos of 60 frames at a frame rate of 30.
Https://media.xiph.org/video/derf/ crowd_run + park_joy + in_to_tree (2160p) ConvertToRGB () ResizeShader (1920,1080, "SSim") ConvertToYV12 (chromaresample = "spline64") raw_1080p30.y4m [534МБ] https://yadi.sk/d/O1bs1FTD3FPpgD SSIM metric on the quality close to lossless is always in favor of the x265, but the picture is visually blurry. To take into account this fact, I use MSU Blurring metric. First I measure the value of the original, taking it for 100%. After the value of the results of the encoding, and take a deviation from the original. ( SSIM(db) + MSU_Blurring(db*) ) / 2 * log(1-(encode_blur / source_blur))×(-10) if encode_blur < source_blur then (encode_blur / source_blur) - [be blurred image] if encode_blur > source_blur then (source_blur / encode_blur) - [be sharp image] if encode_blur = source_blur then 0.9999..9 SSIM http://s009.radikal.ru/i310/1609/10/5f75086b2ae9.png MSU Blurring http://s41.radikal.ru/i094/1609/4d/8b08d4ecb767.png SSIM + MSU Blurring http://s017.radikal.ru/i402/1609/a3/32e7964dfc77.png For example, if you select the bitrate of codecs, so that the value "SSIM + MSU Blurring" coincides, then the screenshots of the quality will also roughly coincide. |
30th March 2017, 23:29 | #7 | Link |
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Please keep in mind you only asses 1 specific HEVC implementation in form of the X265 Encoder and Psy R&D though there are quiet a lot more
You could and should also rate the result in Perceptual Scene stability "An improved deblocking fillter" Inloop filtering is always problematic and SAO is something really questionable hence metrics like it to much "HEVC was developed with the goal of providing twice the compression efficiency of the previous standard, H.264 / AVC." This is very theoretical for complex grainy sources Film Grain will never be really respectable without high bitrate overhead in motion the really first acceptable approach to it was Thomsons FGM/FGT, which though never really took off with it's database Modeling approach. https://hopa.memberclicks.net/assets...gt_hpa2006.PDF Though you should also understand that Film Grain as such will slowly anyways fade away in most content only very Hardcore Old Hollywood R&D folks still try to preserve it but it is already fading away grain as such is mostly artificially added already In case of Tears Of Steel it is extremely necessary to hide the artificial CGI results better, this is always the Perceptual Goal behind it in such content like it "Not let it look Artificial/Plastic" Though CGI becomes so extremely realistic that sooner or later this wont be necessary as well anymore
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all my compares are riddles so please try to decipher them yourselves :) It is about Time Join the Revolution NOW before it is to Late ! http://forum.doom9.org/showthread.php?t=168004 Last edited by CruNcher; 31st March 2017 at 00:15. |
30th March 2017, 23:37 | #8 | Link | |
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i also think that word "efficient" shouldn't be used if you have to encode with 5X more time to save 25-30% of file size. it's not efficient, when it needs a 5X better & more expensive cpu/device for both encoding & playing. Last edited by albt; 31st March 2017 at 00:05. |
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31st March 2017, 00:10 | #9 | Link | |
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PS - You're right... if anyone believes that 128 kbps MP3 is audibly lossless, they need better audio gear, or better ears. |
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31st March 2017, 00:33 | #10 | Link | |
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Decoding is often done by hardware decoders, and encoding is a one-time job per stream, making a longer encode only a small problem. You will not get any realistic size improvements without working harder for it.
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LAV Filters - open source ffmpeg based media splitter and decoders Last edited by nevcairiel; 31st March 2017 at 00:36. |
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31st March 2017, 00:39 | #11 | Link |
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Also the strength becomes really first visible if we talk about Spatial resolutions of above 1080p then HEVC becomes very interesting, all ready with it's much better internal banding handling results alone without even any 10 bit processing at all
This is one of the biggest visual hit you can see immediately no matter really which encoder you use when you have the right source @ hand It also showcases very well in the GPU (Asic) cores if they make efficient use of it. What really becomes interesting though is trying to avoid most of the complexity decoding side wise but still maintaining most of the visual benefits without moving into above 4 core land and here also WPP becomes beneficial
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all my compares are riddles so please try to decipher them yourselves :) It is about Time Join the Revolution NOW before it is to Late ! http://forum.doom9.org/showthread.php?t=168004 Last edited by CruNcher; 31st March 2017 at 01:05. |
31st March 2017, 02:45 | #12 | Link | |
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Next target 8K source.
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If you fail to plan; you plan to fail, would you not agree? Think about it. Last edited by HWK; 31st March 2017 at 02:50. |
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31st March 2017, 15:13 | #13 | Link |
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In my opinion, quality HEVC and AVC movies can't be compared.
By setting a specific bitrate of 6000kbps, it turns out that for HEVC the bitrate is 4700, AVC has 8500 and VP9 12000. My test: https://www.sendspace.com/filegroup/...RUa6g1XJ2REl2K For vp9 codec I used aq-mode four panoramic. I don't know what it means and whether it is recommended. Last edited by Jamaika; 31st March 2017 at 15:34. |
31st March 2017, 15:56 | #14 | Link | |
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Download the 1920x800 full version and try compressing it with HEVC and AVC with your favorite settings you're usually using to reach transparency. Then see if you get any reduction in bitrate with HEVC. https://drive.google.com/uc?id=0B_Fl...xport=download Last edited by Leo 69; 31st March 2017 at 16:35. |
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31st March 2017, 16:06 | #15 | Link | |
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It looks like many people don't understand the purpose of this thread. Also, overlooked the post by zub35. Let me reiterate. The movies me and zub35 posted have specifics, where HEVC does not have advantage over AVC at all. Not even 20% reduction in bitrate, while keeping visual transparency. However, the encoding process is 4-5 times slower. Why? Last edited by Leo 69; 31st March 2017 at 16:49. |
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31st March 2017, 16:16 | #16 | Link |
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Generally speaking. I don't know how to properly test animations. Apart from this fact. I don't know mean my "favorite settings". The veryslow preset isn't the same veryslow in x264. I can only state my setting and the opinion that x264 is no more than x265.
Code:
x265-10b.exe --y4m --input-csp i422 --input-depth 10 --output-depth 10 --preset medium --fps 29.970 --keyint 60 --info --no-open-gop --no-hrd --bitrate 6000 --colormatrix bt2020nc --range full --output "yuv422p10le_bt2020nc_rangepc.h265" - x264-10bit.exe --demuxer y4m --input-csp i422 --input-depth 10 --input-range pc --output-csp i422 --threads 4 --tune stillimage --preset veryslow --bitrate 6000 --fps 29.970 --keyint 60 --nal-hrd none --colormatrix bt2020nc --range pc --output "yuv422p10le(x264)_bt2020nc_rengepc.h264" - vpxenc.exe --bit-depth=10 --input-bit-depth=10 --i422 --codec=vp9 --best --threads=4 --cpu-used=0 --profile=3 --drop-frame=100 --end-usage=cbr --target-bitrate=6000 --kf-max-dist=60 --auto-alt-ref=1 --frame-boost=1 --aq-mode=4 --color-space=bt2020 --verbose --pass=1 --passes=1 --output=yuv422p10le_bt2020.webm - Last edited by Jamaika; 31st March 2017 at 16:18. |
31st March 2017, 17:28 | #18 | Link | |
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Oh okay, you have two issues going at same time. 1. bitrate reduction is not being achieved, even though HEVC standard says it will, while maintain quality. 2. Encode taking much longer for same source, but still no dice with regards to reduction. I need to better study your output and zub35, I guess this is what happens when you half awake pass midnight By any chance do you have setting which you used when encoding with x265, more so any specific setting used.
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If you fail to plan; you plan to fail, would you not agree? Think about it. Last edited by HWK; 31st March 2017 at 17:31. |
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31st March 2017, 18:11 | #19 | Link | |
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AVC x264.exe --preset placebo --tune film --crf 18 --ref 4 --no-mbtree --bframes 8 --deblock -4:-4 --subme 11 --psy-rd 1:0.05 --me umh --merange 32 ------------------------------------ x264 [info]: frame I:145 Avg QP:16.96 size:217384 x264 [info]: frame P:3799 Avg QP:19.15 size: 88343 x264 [info]: frame B:13676 Avg QP:21.54 size: 32445 x264 [info]: consecutive B-frames: 2.5% 3.3% 5.1% 15.4% 30.2% 27.8% 8.6% 2.0% 5.1% encoded 17620 frames, 5.16 fps, 8835.60 kb/s HEVC x265.exe --crf 19.5 --preset placebo --ctu 32 --limit-tu 3 --tu-inter-depth 3 --no-rect --no-amp --no-b-intra --qg-size 8 --qcomp 0.65 --cbqpoffs -3 --crqpoffs -3 --no-cutree --subme 4 --merange 57 --max-merge 3 --rc-lookahead 50 --no-strong-intra-smoothing --deblock -1:-1 --psy-rd 3.5 --psy-rdoq 8 --no-sao --no-rskip ------------------------------------ x265 [info]: frame I: 144, Avg QP:17.77 kb/s: 31575.81 x265 [info]: frame P: 3471, Avg QP:19.74 kb/s: 16834.43 x265 [info]: frame B: 14005, Avg QP:22.31 kb/s: 6578.72 x265 [info]: consecutive B-frames: 9.4% 7.5% 5.4% 22.0% 19.3% 15.0% 7.2% 5.6% 8.5% encoded 17620 frames,1.60 fps, 8803.30 kb/s http://screenshotcomparison.com/comparison/205248 HEVC smooths details here and there quite apparently -- especially where the flame bursts out of the nozzles. Therefore, in this case AVC is somehow BETTER and FASTER than HEVC at the same bitrate. Last edited by Leo 69; 1st April 2017 at 11:49. |
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