Netflix vmaf score psnr reddit. I used ffmpeg, at subsample 200.

Netflix vmaf score psnr reddit Under the VMAF Header: Mean is the average VMAF score of each frame. from vmaf. libvmaf can also calculate PSNR, SSIM, and MS-SSIM. 697386 SSIM Score: 0. The results for those two are wildly different than the VMAF results which made me throw out a big old "hmmmmmm". 8 times the original but get scores only ranged from 72. AV1 Intel GPU FPS + VMAF VMAF scores are provided and you can see its the same scores as Testing includes VMAF, SSIM (and PSNR) Results. " the relative QP vs. VIF is the basis of VMAF, alongside several other image quality metrics (DLM, MCPD and AN-SNR, all described in the VMAF link). mean PSNR). This kind of task is beyond the scope of VMAF and the predicted score really does not matter. No, it's not a valid comparison. We provide a few examples how you can construct the FFmpeg command line and use VMAF as a filter. Then I stitched them together to a lossless x264 video sequence via Kdenlive. VMAF’s Computational Complexity in Live Applications. However I read that to ensure right vmaf score, it is important that both source and encoded videos are in frame sync. Jun 6, 2016 · Because of this, it can be inaccurate to compare (or summarize) VMAF scores across different titles. yuv . yuv) = 100 happens. bad looking video with high vmaf score), you should report it at the link on the vmaf My understanding is that Netflix invented VMAF because they weren’t satisfied with the industry standards of PSNR, SSIM, etc. There are some corner cases, but if you find a significant divergence (i. And VMAF exist. Works well, the fastest, but it's not the best. I hope this data will be useful. It’s just not really transparent / visually lossless :) Nov 9, 2020 · In the context of this blog, after calculating VMAF scores of all frames of a sequence, we compute the 1 st, 5 th, 10 th, 25 th, and 50 th percentiles. Mar 12, 2024 · VMAF per frame latency: The time required to compute the three feature extractors to obtain a VMAF score for a single frame reflecting responsiveness. I used the 'Vmaf_v0. Input videos can be either . "slower" Based on quality metrics, AV1 output encoded with '-cpu-used 8' parameter using ffmpeg beats an output encoded with x265 at "veryslow" preset What's good r/DataHoarder (s), I'm deep in this media preservation project, trying to figure out how to conditionally re-encode videos based on their… Introduction • PSNR is widely criticized as a poor predictor of subjective ratings • Netflix switched from PSNR to VMAF about 14 months ago (still sites PSNR results) In the olden times you would analyse it with a PSNR analysis tool but now you would probably use VMAF as developed by Netflix. You should use VMAF. (Lower CRF = higher VMAF and PSNR) VMAF Score: 96. Gets a higher VMAF score than even veryslow preset and is just a tiny bit slower than medium. 265 10bit using a slow preset and a CRF of 16 which results in average VMAF-scores of 95-98%. txt (this psnr score looks ok, but all vmaf score of each frame is 0. I'll chuck ssimulacra2 in to join VMAF in my future testing, can never have too many data points. Some other components presented with VIF as part of the VMAF score don't seem to have the same problem. The command I am using is the following: . yuv model\vmaf_v0. It doesn't work because the noise pattern is too different, so VMAF actually drops when it shouldn't. vmaf-gui searches this folder for . An example is dropping the quality target (higher QP) in high motion scenes, while raising it (lower QP) in low motion scenes to maintain target output size, because people are more sensitive to the quality when the picture isn't moving so much; PSNR and SSIM don't account for this, and will score the better looking encode lower. for reference, scores in the low 90s are still considered I noticed some weird scaling with one of my test files. VMAF was developed by Netflix who clearly had a strong interest in not wasting any bandwidth transmitting large amounts of video. If I understand correctly, the code is actually calculating vmaf scores for the whole clip (thats how its doing the tuning). Nvidia's guide for NVENC in streaming makes reference to how high motion content can benefit from reducing the resolution. 6. sub. Oct 7, 2024 · To address banding artifacts, Netflix developed the CAMBI detector, which complements VMAF by assigning a score to regions affected by banding [14]. When 'Data usage per screen' is set to High, most videos have a VMAF value of about 85. I thought I’d enabled cheat codes when I… Apr 2, 2019 · If I take 10 10 second clips of game #1 at 1080p60, atleast 3 will will score below 80 while the rest will score 90+ at 1080p60. VMAF will be the only one which I display here as Graph in order to keep it simple. Vmaf とは簡単にいうと Netflix が開発したライブラリで、二つの動画を比較して片方を参照してもう片方がどの程度劣化したかをスコアとして表現するもの。疑問vmaf って要は動画のフレー… Perceptual video quality assessment based on multi-method fusion. It is just not well psycho-visually tuned in many ways versus better built modern metrics. The per-component PSNR would indicate that, but the VMAF and averaged PSNR values indicate differently. I do trust the Netflix kids VMAF algo, they know a thing or two and put hours-days-months into creating a subjective-objective model. yuv and output logs are available in a number of formats: . Encoding with the same settings and then finding the aggregate PSNR is what worked best so far since encodes from grainy sources generally have a lower PSNR score. The intuition here is that instead of weighing all frames equally and Jul 8, 2024 · For example, if we have a video sequence with two frames, the first with a PSNR score of 99 dB and the second with a PSNR score of 50 dB, the visual difference will be subjectively indistinguishable. Along with these three common scoring systems, there are others as well like SSIMULACRA 2 and Butteraugli. My HandBrake AV1 encodes of 1080p footage at 4-6Mb/s gets VMAF scores of >95. g. Your explanation makes sense, and maybe VMAF should be more general like PSNR or SSIM. 7167 instead. This score, known as the VMAF score, ranges from 0 to 100, with higher scores indicating better quality. 453462 0. PSNR The peak signal-to-noise ratio (PSNR) is a non-linear full-reference metric that compares the pixel values of the original reference image to the Under the VMAF Header: Mean is the average VMAF score of each frame. For example, comparing videos with slightly different resolutions caused by cropping black bars just shows up as low PSNR and VMAF scores, but might look perfectly fine. i'd love to use handbrake because batch encoding with ffmpeg has been a challenge Video Multimethod Assessment Fusion. That value is meant to indicate a quality of 85 out of 100, or a subjective rating of "good". 1% Low are the averages of the lowest 1% and 0. 8142). Sep 4, 2017 · This is confirmed by the 49. 997387 (25. Even at 250mbps the 3 would not score higher then 78. json, . sln as instructed and used yuv files provided on th cloud, I have encoutered some problem with vmafossexec in windows and hope I could get a solution. 1% is the average of the That's not true. Additionally, the vmaf tool provides a number of auxillary features such as PSNR, SSIM and MS-SSIM. The lower the resolution the lower the VMAF usually gets (at least that's what I read out of this data). I am thinking about doing a follow-up to this blog in some time and will certainly incorporate your suggestions. 4130 vs 46. Note that an existing quality metric can serve as a feature of a new quality metric. /model/vmaf_v0. I have attached a . 0+ can also calculate PSNR-HVS and CIEDE2000, but these aren't implemented in FFmpeg yet. 968904 May 28, 2020 · The link you provided is just to install the VMAF python library. You're comparing them based on having the same PSNR/SSIM/VMAF metric, while you've configured the software encoders not to optimize for those metrics. Personally I'd consider anything under 85 to be "dirty. Nov 28, 2018 · E:\Code\netflix_vmaf>x64\Debug\vmafossexec yuv420p 576 324 python\test\resource\yuv\src01_hrc00_576x324. 265 compression settings and was using vmaf through the command line to automate the process of grading my encoding settings, but I found vmaf typically difficult and time consuming to use. View community ranking In the Top 10% of largest communities on Reddit. 1 published; added a phone model libvmaf published; VMAF supported by FFmpeg Speed optimization; added a 4K model; added confidence interval First public showing at ICIP VMAF-enabled video optimization Arc is giving me more than 60% reduction in file-size with a average VMAF of 90+. TLDR (good for everything):-b 10 --lag-in-frames=35 --enable-fwd-kf=1 + on everything that is not rick and morty alike: A graph for each encoder parameter value, showing the variation of the VMAF/SSIM/PSNR throughout the video. I finally started digging into VMAF and testing out my own encodes. Also, it appears that the buffer size is different for aomenc, and aurora1 from the rest (2000 vs 3780). One of the most significant challenges with VMAF, particularly for live video or real-time applications, is its computational complexity. The command-line tool vmaf provides a complete algorithm implementation, such that one can easily deploy VMAF in a production environment. 1. This is why SSSIM et al. 75 bframes=16 threads=36 non-deterministic=true direct=auto ref=4 partitions=all. Testing a 1 minute clip I can't get a VMAF score of over about 74. VMAF is a `vmaf` is a command line tool which supports VMAF feature extraction and prediction. May 19, 2021 · It does not really mater how you are specifying source files in command line. In addition, graphs (saved as PNG files) are created where PSNR/SSIM/VMAF score is plotted against frame number. If a source had 1000 frames, then the 1% low is the average of the worst 30 frames, and 0. e. Testing encoding doesn't require no-refrence however, and ffmpeg has vmaf available already, and x264 can calculate psnr/ssim during encoding. 1% scores. To use VMAF with ffmpeg you need to install libvmaf first and then compile ffmpeg with libvmaf filter enabled. Mar 4, 2019 · I frequently use the VMAF quality metric to analyze encoding parameters and compare codecs. By default, source specified first in command line will become stream with index=0, source specified second -- stream with index=1. Metrics have commonly been computed at the encoding resolution. If your target audience is a phone you can probably get away with a lower score. Not sure why Brisque would be preferred. 472). I try to aim at a VMAF of >90 for 0. 1% is the average of the VMAF was developed by Netflix as improvement to PSNR/SIMM video quality metric. Sep 8, 2016 · I chose the point of the top line at factor=116 (dinnerscene q=40 and foodmarket2 q=158) and second line at factor=54 (dinnerscene q=90 and foodmarket2 q=144), which gives a combined bitrate of 454-457 kbps, and have a nearly identical VMAF score of 94. yuv distorted. *This is required because VMAF relies on a base 1080p comparison, so the final 720p footages gets scaled back to 1080p, bilinear. VMAF. also mostly encodes to get a target VMAF and not with a set QP. yuv python\test\resource\yuv\src01_hrc01_576x324. Jun 8, 2022 · Saved searches Use saved searches to filter your results more quickly Oct 7, 2019 · We tested two different VMAF versions under windows. 11 votes, 49 comments. Reply reply DrtyWzrd777 Jan 12, 2020 · By build the vmaf. VMAF doesn't guarantee a score of 100 between two identical videos. It predicts subjective video quality Netflix has released one model file (that they like) and people are free to develop their own model files --- which nobody does and kinda defeats the purpose of VMAF. 3/4 of the settings for libaom are not even taken into account, so they don't matter. It's strange i always got a score of zero. Also, The progress bar now resets when "Get VMAF score" is clicked. It depends, most movies are encoded with an average of 93-95 VMAF average score. xml file in the same folder after the encode has finished, which has frame-by-frame vmaf scores Oct 25, 2018 · An example VMAF-bitrate relationship for the default model and the phone model is shown above. json) is trained to predict the quality of videos displayed on a 1080p HDTV in a living-room-like environment. here is the vmaf json file: comp3. increase in high frequency MB content due to compounded transforms/quantization steps) will manifest as a net increase, unless someone "throws away" more data (ie. For the best practices of computing VMAF at the right resolution, refer to our tech blog. Compared source 1080p vs Encoded 1080p version to get SSIM and VMAF score. However, calculating the PSNR avg. arithmetic mean) of the per-frame scores mostly for its simplicity, as well as for consistency with other metrics (e. xml, . Can you please advise ho This post showcases how CUDA-accelerated VMAF (VMAF-CUDA) enables VMAF scores to be calculated on NVIDIA GPUs. In Netflix's AOM symposium presentation last October, Netflix was presenting VMAF as a more relevant tool for "new and future codecs". VMAF is a tool developed by Netflix to grade the quality of a compressed video file in comparison to the Original. But thank you for your input. The tool takes a pair of input videos as well as a trained VMAF model and writes an output log containing per-frame and pooled VMAF scores. It was made for lossy video, not lossless. Rav1e is really bad in terms of efficiency compared to SVT. 1 MB vs 129 MB. I was testing out some h. - Netflix/vmaf The only goal I have is for static transparency, I don't care what the VMAF score says about "visual transparency", it's simply not true. It would be interesting to know if Brisque would correlate with vmaf however. according to netflix engineers, a VMAF score of 98 or higher is considered visually indistinguishable from the original. It can be interpreted that the same distorted video would be perceived as having a higher quality when viewed on a phone screen than on a HD TV, and that the VMAF score differences between the 720p and 1080p videos are smaller using the phone model. Hi, all I am pretty new to using FFmpeg and use DVDFab to encode my films. pkl files to show on the form (Keep in mind that you must also supply the . i like to use FFMetrics to compare VMAF scores, so that i can (somewhat) scientifically tell how good/bad my encodes are. However, VMAF is only available through the commandline or as an extension to FFMPEG. In motion there's not a human in the world that'll see a difference on regular ~100ppi screens at realistic distances. it turns out that all the frames are analysed yet the aggregate SSIM and PSNR are not calculated and the vmaf score is very low. Use the script like this: Posted by u/Xen1311 - 2 votes and 8 comments 为了方便对比，我们也附上了上文提到的结果最理想的PSNR-HVS指标散点图。无疑VMAF的效果更好。 我们还将VMAF与该领域内目前公认最先进的具有可变帧延迟的视频质量模型（Video Quality Model with Variable Frame Delay，VQM-VFD）[13]进行了对比。 Video Quality Metrics-- command-line tool which encodes a video using specified x264/x265/AV1 CRF values (or x264/x265 presets) and creates a table showing the PSNR/SSIM/VMAF of each encode. My video processing flow(?) seem to be rather CPU bottlenecked and I want to offload the validation process (PSNR and VMAF) onto the GPU if possible. I'm willingly choosing to believe Netflix, Twitch and YouTube, since they all use VMAF as part of their inter-codec comparisons. Higher is better. PSNR is totally useless for comparing video quality. --tune=ssim uses SSIM, and it works quite well with live-action, and it is a bit slower(it is not really noticeable though). See the filter documentation for all available options. So I care about quality and I only encode the movies that I think, are masterpieces. I found some interesting outcomes which contradicted some of what the community had told me, and I wanted to ask you all a few questions about it. /vmafossexec yuv420p 1280 720 reference. 087603, using a subsampling of 2 yielded a VMAF of 96. 454/12. In my experience, VMAF scores tend to match my own subjective quality observations and the fact that Netflix uses it gives the metric great credibility. Don’t have the hardware to test NVENC or AMD, but both those are going to be $1000 until lower end cards are released on the new generation. 1 It may be more pronounced (tune=vmaf vs tune=psnr) for lower cpu=used. 6 points is generally considered to be the Just Noticeable Difference 2. Every single frame has different needs and even my method gets me a minimal of 80 VMAF score on certain frames. txt file which contains the JSON output of one of the tests that I conducted. Netflix still uses a combination of VMAF and PSNR to evaluate encode settings. Different goals. While the final VMAF measurement is an objective result, the VMAF model was built using Dec 7, 2023 · The software package offers a number of ways to interact with the VMAF implementation. My main reason is that I really love cinema and also optimization. Other metrics, such as VIF or SSIM, better correlate with the subjective scores. Get the Reddit app Scan this QR code to download the app now (Best PSNR to VMAF score result during all tests was 44. I use VMAF calculation de determine which crf I will use (on tv shows the gain are substantial) Anything averaging 93% or above indistinguishable from the remux I usually end up with files around 30% to 50% the original size and crf between 18 and 22 depending on the source Compressing audio can be a great place to reduce file size Good point too is to use x265 10bits, the quality gains for I also do thorough testing with VMAF, SSIMU2, PSNR, SSIM, eyes and even preset -1 (mainly used for debugging) can have differences on these results compared to preset 0. Essentially, --tune=psnr uses PSNR as the algo for determining how to distort the image. while ffmpeg is default which should also be PSNR. Originally, there was only one VMAF version, but Netflix has added both a 4K model and … There's PSNR, SSIM and Netflix's own VMAF which I finally settled on. Netflix highly relies on VMAF throughout its video pipeline. Video Multimethod Assessment Fusion (VMAF) is an objective full-reference video quality metric developed by Netflix in cooperation with the University of Southern California and the Laboratory for Image and Video Engineering (LIVE) at The University of Texas at Austin. 1920x1080 50 fps 500 frames VVC presets comparison: VMAF: PSNR: SSIM: BD-rates: What are BD-Rates? BD-Rate. , when using VMAF via FFmpeg). All the subjective data were collected in such a way that the distorted videos (with native resolutions of 1080p, 720p, 480p etc. UHD BluRay at 80-100 Mbps isn’t. The default VMAF model (model/vmaf_v0. model file as well or else vmaf will fail). FFmpeg is the leading multimedia framework, able to decode, encode, transcode, mux, demux, stream, filter and play pretty much anything that humans and machines have created. 3. VMAF is there to compare the perceptional quality. 6 VMAF points ~ 1 JND clip was 1 minute long and encodes are 5mbit Score based on worst 5% frames, not average for desktop/tv/laptop viewing only hey all. For more info, see So, considering that the VMAF score of the two videos is exactly the same, as shown in the images, and also their video bitrates are similar, both: 2,813 kb/s, and their resolutions are also the same, both: 1080p, but their total bitrates are different, one is 2,984 kb/s and the other is 2,985 kb/s, so can it be said that both videos have exactly the same quality? How do I compare the quality of a reencode? I have a lot of H264 videos I want to encode to H265 or even H266 in the coming months / years, but I… So that SHOULD bump up the score because there's 0 difference for 20%, same with VMAF. On one hand with PSNR, if 20% of the screen is pixel perfect then the pixels score would be infinite, dragging up the score by a lot But on the other that would also mean every non black bar pixel that had the same value would have the same effect VMAF is a codec-independent objective metric of comparable quality between source and output, using USC & Netflix's (and others) algorithm, which attempts to produce a model-based metric that is superior to other objective metrics such as PSNR/SSIM. y4m or . All of my test files were created exactly the same minus the CRF values and otherwise show normal scaling with CRF 16 being the exception. (Questions above table) The algorithm works by comparing a distorted video to a reference video and computing a score that represents the perceived quality of the distorted video. 4x speedup in throughput in the open-source tool FFmpeg and up to 37x lower Long story short, using an even subsampling number when calculating VMAF can result in VMAF scores that are inflated by a lot. x265's "faster" preset shows better quality than "veryfast" psnr- and ssim-wise, but not vmaf-wise, same as "veryslow" vs. I've tried FFmpeg and handbrake using - x264, x265, NVENC, with various CRF settings and 2 pass. That's visually lossless to me. 8 and 74. PSNR and SSIM measurement methodologies often yield similar results to VMAF. The beauty of VMAF lies in its ability to model human perception. with handbrake, i made two encodes, one with PSNR and another with no tune. That is for 4K/2K footage though. log with a frame of PSNR=99dB will increase the final average score, giving the false impression of the sequence PSNR is useful for detecting unintended changes and in seeing how good perceptually lossless but mathematically lossless encoders like prores perform. We observed up to a 4. Could you give some help on this? Thanks. Then I created video at the same length, from the high samples render. I heard from different people similar opinions and also that the HEVC Encoder tend to blur in general, thus seemingly worse in quality. For the corner case where the reference video and the video under test (distorted video) is the same, we expected VMAF values of 100 for each frame and PSNR values around 116dB(8Bit). The Bjontegaard rate difference, also known as BD-rate, allows the measurement of the bitrate reduction offered by a codec or codec feature, while maintaining the same quality as measured by objective metrics. Netflix says; Video Multi-method Assessment Fusion, or VMAF for short, is a video quality metric that combines human vision modeling with machine learning. About my choice of test files, I am 16 and have legal right to do this. You can use the n_subsample option to skip every x frames, which will speed up score calculation in exchange for reduced score accuracy. Could you do an official issue at the GitHub? With exact commands you used, full encoder logs, maybe a link to the uncompressed video if its available. And we can subtract this effect from the VMAF scores. vmaf is a command line tool which supports VMAF feature extraction and prediction. 1% lows and >95% on average. My question is, do VMAF scores pretty much take a hit automatically when going from a 1080p source to a lower resolution? I have no issues getting VMAF scores of 95+ when encoding 1080p movies from 1080p source, just curious about the 720p scenario. Jul 6, 2020 · Hi I have one source video and encoder version of that source. Netflix e. Now I need to find vmaf score. SVT-AV1 lacks many of the psycho-visual tricks that libx265 uses to increase perceived detail and reduce blur, and VMAF, while better than the other synthetic metrics, is still way too credulous of blurry encodes and over-penalizes anything it thinks is an artifact. Any thoughts? Anyone else find sub-90 VMAF scores good enough? As for the quality index, it obviously needs many hundreds of videos to prove whether the VMAF quality means anything. CPU encoding (5950x) takes a lot of time for me, not to mention a lot of watts. Still, an average VMAF of about 95 is definitely good enough for almost everyone. If you look, there is a vmaf_scores. It is important how video streams supplied to libvmaf filter. 828156) PSNR Score: 54. I used ffmpeg, at subsample 200. VMAF was designed by netflix to solve this problem. Even though the LCEVC encoder used has a PSNR tune, they used the VMAF_NEG tune instead. yuv, ref_tnlm_crf22. While it also takes significantly longer to calculate (I mean we still talk about way more than realtime performance but still) the results are pretty good. . higher average QP within a Nov 9, 2018 · Like most quality metrics, VMAF produces a single score per frame, and most tools that I’ve seen average the scores for the individual frames into a single overall score. 2 It took me 1h15 vs 1h58 to encode, file size is 99. You can find samples of the Encodes on the AV1 Subreddit's Discord Server. That's nearly lossless when comparing frames side-by-sidw. I don't remember the specs of the source, though, I think it was a 1080p@30fps video. See full list on streaminglearningcenter. Features are individual inputs that (VMAF) models may use to fuse into a final quality metric score. This is for a 95 seconds file! Jul 17, 2020 · I've noticed that when using libvmfaf with FFmpeg,some frames have a VMAF score of 0. Dec 7, 2020 · How does VMAF NEG mode work? To make the long story short: we can detect the magnitude of the VMAF gain coming from image enhancement, and subtract this effect from the measurement. Nor is it true that other codecs do better (x264 doesn't even support HDR, x265 smooths out just as much and has artifacting). You can compare manually the 2 videos side-by-side with the video-compare tool . After hearing about VMAF I wanted to see the score between the original file and the file encoded with DVDfab. Also it will utilize any CPU power you have. That said, *at that bitrate* H. And they've been using VMAF to evaluate AV1 for over 2 years now. PSNR and SSIM is useless in that case, but VMAF actually is pretty good in getting the perceptional quality right (it was meant for that). You can blur the shit out of a video and the PSNR will be fine. Or you can run a more detailed analysis with FFMestrics . Total throughput: How quickly the VMAF score for a video sequence can be computed. PSNR tune was also used for x264. 34 (logarithmic VMAF=12. This graph shows the variation of the VMAF score throughout the video: An example of the per-frame SSIM graph and per-frame PSNR graph can be found in the example_graphs folder. VMAF image feature extractors are ported to CUDA, enabling it to consume images that are decoded using the NVIDIA Video Codec SDK. I have checked the frames of the two videos, didn't find any significant difference. Recently, I discovered that using -r instead of -vf fps= gave me much better PSNR, SSIM, and VMAF scores. total bits per piece (so long as frame size/frame rate are normalized) will reveal how much entropy was retained by the encoder for a given MB. Games VMAF score isn't a percentage, it's a score between 0 and 100. VMAF alone is a nice and comprehensive metric, but if you compile the library and make a build of ffmpeg with it, you can also include PSNR and SSIM next to VMAF, side by side in your log files. Here's an example There you can set a target VMAF which adjusts QP to any scene so that it will provide a target VMAF (so perceptional quality) while minimizing the file size. for some reason, when i try to re-create the same encode in handbrake (latest nightly) and ffmpeg (also latest), the ffmpeg variant scores a good bit above the handbrake variant. "Bad" is intrinsically subjective, so your question depends on me understanding what "bad" is for you. In order to maximize throughput I do software encoding + hardware encoding in parallel, and then validate the results with PSNR, VMAF and a manual inspection. Features can also be enabled individually without fusing (e. I am mainly encoding in H. Each point on the scatter graph represents a separate test file, with the coordinates set by the DMOS score on the horizontal axis, and the VMAF/PSNRHVS score on the vertical axis. So this obviously will skew the VMAF results in favor of LCEVC. There are some notes in the script to show how I arrived at such settings. CRF 18 had a better VMAF score than CRF 16 (94. CRF=34 often gets in the range of 93, which researchers have suggested is a good setting for high quality VOD. Information about how I got VMAF/SSIM/PSNR is in the notes. I exported 8bit PNG lossless images of every render the high quality renders made using Sheepit! Render Farm. Fragment 1 can be CRF 32 = 96 VMAF and fragment 2 can be CRF 56 = 96 VMAF and really the next one can be CRF 8 = 96 VMAF. So I've found VMAF scores often very misleading when comparing the two encoders Aug 28, 2018 · But for some videos, I got a vmaf score of zero. Do not use a preset above 8 for normal encoding, everything above is realtime encoding and gives weird results. 3 dB PSNR score, which would be visually indistinguishable from the original score of 59 dB. Comparing noise levels to the original is the first thing I tried. 275s) Best For that reason, metric subjective metrics did not prove to be useful as I found that images with higher PSNR and SSIM did better in those applications than those with higher LPIPS and lower PSNR/SSIM. Then I used FFmetrics to calculate the Vmaf score. The hardware used for this measurement was a 56C/112T Dual Intel Xeon 8480 compute node and a single NVIDIA L4 GPU. Since you already have a faster way of measuring whether a video is lossless, why not use that instead? VMAF itself is not what I would call a bad metric. 6118 vs 94. All of my VMAF scores were up in the mid 90s, and they were all within 6 points of VMAF, so we can infer that The advanced parameters encode score higher in PSNR, SSIM but a little lower with VMAF metrics using FFMetrics 1. Jun 7, 2022 · Keep in mind that even in a case where you would compare a video to itself, VMAF would not guarantee a perfect 100 score, however, you should get a score close enough, like 99 for instance. Personally, I consider a VMAF score over 95 to be “good enough” for my use cases. 0) here is the ffmpeg log: You can use VMAF scores to evaluate this objectively. Test Clip is from an Hentai ( ͡° ͜ʖ ͡°) in 1080p Resolution and has a length of 30s. Hardware encod Jun 19, 2018 · I have compiled today VMAF from source and run the PSNR, SSIM, MS-SSIM and VMAF measurements against two yuv files. Obviously Netflix thinks VMAF is accurate enough to evaluate AV1 against AVC/HEVC A: By default, the VMAF output reports the aggregate score as the average (i. txt If yo Tested my A380 yesterday, quality had a similar VMAF score to SVT software but was 275 fps vs 89 fps for my 12700k rig. Option -an (remove audio track) was always present. 3941), with PSNR being worse as well (47. With the correct PSNR/SSIM/VMAF tuning, you'd get even smaller bitrates out of the software encoders for the same PSNR/SSIM/VMAF output. Well, the SSIM, PSNR and VMAF Results don't really represent the quality for the individual viewer. Jul 5, 2018 · I still prefer using Netflix’s VMAF metric, particularly for assessing the quality of files in an encoding ladder. A lot. I started using a tool called FFMetrics that also shows PSNR and SSIM. The encodes ranged from 1/3 the size of the original to 2. You feed it the original file and the 'distorted' one and it calculates a quality metric between the two, 100 being perfect, 0 being horrible. That’s because VMAF scores range from 0 to 100, providing a more meaningful spread, and because VMAF is designed to rate files from resolutions ranging from 240p to 1080p and has been used to rate videos as large as 4K. Dec 13, 2018 · Traditionally, PSNR has been the metric of choice given its simplicity, and it reasonably matches subjective opinion scores. core. Unfortunately a good PSNR score doesn’t necessarily mean a nice looking video. Having a graph helps me figure that out BEFORE I spend a bunch of time doing a full battery of tests. In other words, when Netflix delivers uhd at 15 Mbps, they’re making compromises. VMAF/SSIM Comparison Methodology 720p: Compared source 1080p vs Encoded upscaled 1080p* version to get SSIM and VMAF score. csv, . 052375 to 95. 25:0. Video Multimethod Assessment Fusion (VMAF) is an objective full-reference video quality metric developed by Netflix in cooperation with the University of Southern California, the IPI/LS2N lab Nantes Université, and the Laboratory for Image and Video Engineering (LIVE) at The University of Texas at Austin. They have millions and billions of $ on the line for achieving the best quality they can for the lowest bitrate they can get it. 0. It won't necessarily matter if your audience is a phone, twitch doesn't release statistics, but they do transcode for you now whether your a partner or not. 6 subme=8 rc-lookahead=60 psy-rd=0. Jun 18, 2019 · Neflix explained in interview with Jan Ozer that six points of VMAF equals the JND. com Sep 4, 2017 · VMAF stands for Video Multimethod Assessment Fusion, but all you really need to know is that it’s the video quality metric co-invented by Netflix to replace the Peak Signal to Noise Ratio Jun 7, 2016 · In the article, Netflix compared VMAF to PSNRHVS, the highest performing traditional algorithm. Of course, a metric alone shouldn't be used, so VMAF by itself shouldn't be trusted, but VMAF + avmetrics PSNR HVS + ssimulacra2 should provide a very wide net to more properly evaluate subjective quality. Most lower rungs saw a very significant boost in PSNR score, but more importantly multiple VMAF improvements above the 6-point threshold. By definition, the 5 th percentile gives us a VMAF score of the worst 5% frames while the 50 th percentile is the median. Although it also has some flaws. Since VMAF uses SVM to predict the quality, it is not easy to diagnose in the feature space why VMAF(ref. Their models are, at the least, controversial at this point. The vmaf models are tuned/trained so that a high vmaf score (mostly) implies that the video should look good to the human eye. This release allows the user to supply their own model files in the model folder. For example, when a video stream generated from an SD source achieves a VMAF score of 99 (out of 100), it by no means has the same perceptual quality as a video encoded from an HD source with the same score of 99. ) get rescaled to 1080 resolution and shown on the 1080p display with a viewing distance of three times the screen Aomenc parameters benchmarked. I wouldn't expect FP rounding errors at this scale, especially for double precision, but it's certainly possible. 1% Low and 0. I have a lot of TV show DVDs I need to process and pop on the plex box. Since VMAF scores align better with humans, VMAF is typically considered better than SSIM or PSNR for scoring video compression. For one of the rav1e-encoded sample files that has a ground truth VMAF of 93. v2. Fiddled around with some options and testetd with Netflix VMAF. 317 and 94. 264 (AVC) encoder from AMD lags behind substantially in terms of image integrity, image stability and compression artefacts compared to Turing/Ampere NVENC and x264. I arrived at this with medium preset: aq-mode=3 aq-strength=0. It absolutely butchers animation, so don't use it for any kind of animation. generational encoding distortion (ie. You must be doing something wrong. But, it's a relatively complex assortment of software, whereas SSIM and PSNR are very simple algorithms and are even built into x264 and x265 if you enable them with flags (and they were configured at compile time). But I seem to have lower standards than a lot of people on this sub. feature_extractor import VmafexecFeatureExtractorMixin, FeatureExtractor class FloatMotionFeatureExtractor(VmafexecFeatureExtractorMixin, FeatureExtractor): TYPE = "float_motion_feature" This script does two-pass encoding and aims for a target VMAF, starting at higher CRF values (lower quality) to see if we can get an acceptable VMAF score quickly, moving to the next lower CRF and trying again if needed. First VMAF running in prod @ Netflix Started collaboration with UT Austin VMAF went live on Github; first VMAF techblog published VMAF 0. That too when I am adding in a keyframe every second. 390919 I'm using NMKoder on a couple of the older tests to see the scores but if I understand, these numbers above are good, correct? I also took the time to calculate the VMAF, PSNR, and SSIM scores for each of my 13 compressed files. [2] Here's an example of graph type [1]. That looks like garbage. I made this choice because, from my perspective, video quality dips below 94 become noticeably poor and don't hold much interest for me. pkl. json' model) Vmaf is only available as a command line application and you have to learn how to use ffmpeg to enable vmaf to do its thing. VMAF does not have a great correlation in the lower score region Dark scenes present different challenges, and none of their screenshots are really indicative of these types of scenes. No tune flag was applied to SVT-AV1, so in this case the default would be used, and that is PSNR. The grayscale map in (f) above demonstrates the magnitude of the image sharpening performed in tune=vmaf. VMAF was developed by Netflix as improvement to PSNR/SIMM video quality metric. There's also a ffmpeg VMAF plugin that is also free compared to the other $1000 alternatives. Using FFmpeg+libvmaf is very powerful, as you can create complex filters to calculate VMAF directly on videos of different encoding formats and resolutions. My own version of that proves it. I averaged these scores in the below table. 286454 and took 12. Filesize(byte) PSNR(Y) SSIM(Y) VMAF AURORA 10064824 38. I tested with M5. pkl --psnr --ssim --ms-ssim --thread 0 Start calculating VMAF score An observer might notice that my graphs only show VMAF scores above 94 even though my data includes scores below that threshold. 3x-4x more time while roughly 2x more watts for comparable file sizes and negligible VMAF difference compared to qsv encoding. You can see the VMAF value of a video by checking the video's technical information. Though Netflix notes that there are other averaging techniques available, the article states that “simple arithmetic mean (AM) is the best way of averaging, in that it so i've been messing around with AV1 encodes with handbrake and having a hell of a time lately. Here are the VMAF values and bitrates for The Adventures of Tintin (avc at 480p): Your VMAF MS_SSIM and PSNR scores will all be lower if you rescale from your native resolution from 1080p to 720p and your viewer scales it back up to 1080p. rknbv kgkameh aawc zhk caaypoe dqfja soeuo qla pvwgwb gfwb