Codecs: Best MPEG2 Encoder for metrics objectives tests
~ Movie Metric Benchmark Challenge ~
You think that your MPEG2 coder is the best : prove that ... !!? A - Introduction The purpose of this challenge is to determine which is the best codec for the metrics and only for the metrics : this test will not speak about subjective visual quality. If you want subjective visual comparison download sample and compare yourself ... B - Rules Rule 1 : Source You must use this source for the test : Harry Potter II trailer, 720*576 MPEG2 MP@ML 4.5 Mbps HPII Part1 winrar, HPII Part2 winrar, HPII Part3 winrar, HPII Part4 winrar & HPII Part5 winrar Rule 2 : Pre-process and encoding You must use DGindex with 32-bit SSE/MMX iDCT algorithm for .d2v project and DGDecode.dll for MPEG2 decoding in avisynth scipt. You must use MPEG2 with DVD standard MPEG2 MP@ML Pal DAR 4/3 PAR 128:117 profil (edit ... lol). You must use this avisynth script for make encoding: Code:
source=Mpeg2Source("D:\Mes dossiers\B.A\Harry Potter\azerty.d2v",idct=2) Rule 3 : Bitrate You must use these bitrate/size for encoding: The first round use is very low bitrate for MPEG2 : maximum bitrate is 1800 Kbps for mini-DVD profil encoding. Mini-DVD: Maximun 1800 Kbps for Video Elementary Stream or 28125 Ko for m2v file. Rule 4 : Metric Tests SSIM (YV12): IMO the best metric. it uses some HVS properties but not all ... PDF description for VSSIM Overall PSNR (YV12): Very good metric test, particullary for Rate Control Quality test ... MSE = Sum t = 1 -> NFrame Sum x = 1 -> width Sum y = 1 -> height (F'(x,y,t)-F(x,y,t))² / (NFrame*width*height) Overall PSNR = 10 * Log ( 255² / MSE) Average PSNR (YV12):The worse metric test but Frame PSNR graph is very good to compare RC strategy ... MSE = Sum x = 1 -> width Sum y = 1 -> height (F'(x,y,t)-F(x,y,t))² / (width*height) Average PSNR = Sum t = 1 -> NFrame 10 * Log ( 255² / MSE) / Nframe SSIM vs PSNR "For a given reference video and a given compressed video, it is meant to compute a quality metric, based on perceived visual distortion. Unlike the well-known PSNR measure, it's not purely mathematical, and should correlate much better with human vision." "A higher MSE (and so lower PSNR) should mean that the compressed clip is a worse image but MSE and PSNR are flawed in this respect as numerous tests have shown. However with SSIM, according to tests carried out on the VQEG dataset, a higher Q (SSIM value) has a much better relation to the visual quality of the compressed clip. Despite this, bear in mind the SSIM metric still isn't perfect." Here last AviSynth plugin for VSSIM in YV12 Average PSNR vs Overall PSNR It's easy to increase artificially Average PSNR with Rate Control tweak. In certain case CBR (0% for variability) will be better than real VBR (100% for variability or constant quant). It's generaly not possible with Overall PSNR. Overall PSNR is very good to test Rate Control quality. If difference between Average PSNR and Overall PSNR is very high, "local quality difference" (difference between Pframe or Bframe for exemple) or "scene quality difference" (difference between low motion and high motion for exemple) will be too high and Rate Control for this codec not very good. Here last AviSynth plugin for Overall PSNR in YV12 Open your avs metric script with VirtualDub. Select file > preview input for run the test. Select file > close video file for obtain final result in log metric files. You must use these AviSynth type script for metric test: Code:
# --> Video Opening <-- Code:
# --> Video Opening <-- C - Results At this time here the best result ... but done better if you can ... :devil: Code:
|-----------------|---------|---------|---------|---------| MPEG2 MP@ML : TMPGEnc encoding by Sagittaire File: MPEG2 1800 Kbps MPEG2 MP@ML : QEnc encoding by Sagittaire File: MPEG2 1800 Kbps MPEG2 MP@ML : Mencoder encoding by Sagittaire File: MPEG2 1800 Kbps MPEG2 MP@ML : FFDShow encoding by Sagittaire File: Not available MPEG2 MP@ML : HC015 encoding by hank315 File: Not available D - Conclusion At this time for this trailer The best is Mencoder encoding by Sagittaire IF YOU DON'T AGREE WITH THAT, TRY TO MAKE BETTER WITH YOUR FAVORITE ENCODER ... !!! Annexe - Update 15.08.05 : upadate with TMPGEnc KDVD "6 hours" profil 14.08.05 : Sagittaire with QEnc, Mencoder and FFDShow 14.08.05 : hank315 with HC015 |
Re: [Challenge] Best MPEG2 Encoder for metrics objectives te
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BTW there are too much things you don't tell in the condition of your own test. Even if "MPEG2 with DVD standard MPEG2 MP@ML Pal DAR 4/3 PAR 12:11 profil" should fix things like matrix, GOP and DC prec, it does not tell anything about open GOP or not, auto I-frame insertion (scene detect), min bitrate... But your post is nice for people that didn't know how to use metrics plugins. Thanks. |
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- open/closed GOP are compliant with DVD MP@ML PAL standard: you can use the best for you - custum matrix are compliant too : you use the best for you - GOP PAL compliant : you must use GOP max 15 frames with 2 bframes no adaptatives - DC prec is compliant too : 8, 9 or 10 ... use your best DC |
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Standard PAL DVD 720x576 playback is @ 13.5mhz using PAR 128:117 |
12:11 or 128:117 don't change anything for my eyes and certainely for your eyes ... lol
mencoder, ffdshow, WM9Encoder ... use 12:11 PAR for PAL DAR 4:3. But it's perhabs not exactly the good value ... I don't know and it's not important for this test. Use 128:127 if you want ... |
1) Update with libavcodec core class codec (Qenc, Mencoder, FFDShow)
2) Many user think that CCE or Canopus Pro coder are the best (I don't think ... IMO Libavcodec is the best for MPEG2) prove that with this trailer ... |
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It's full of spikes, underruns, overrruns, etc. That's why we dumped it here, until further notice. You should take a look here: http://www.kvcd.net/forum/viewtopic.php?t=16073 for some insights about visual quality ;) We don't need to proove anything with any trailer :cool: -kwag |
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Any change in target aspect ratio, different from the source, will scale the image incorrectly causing jagged edges and other artifacts, gibbs, moire patterns, etc., and that WILL produce visual degraded picture on some scenes. -kwag |
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But as long as all encoder are treated the same way, this problem introduced by a wrong PAR is not important if you do not consider the visual quality. |
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-kwag |
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"12:11 (=1.0909) vs 128:117 (=1.0940) can will scale the image incorrectly causing jagged edges and other artifacts, gibbs, moire patterns, etc" ... you are sure ... !!! Perhabs with DAR error but not with PAR error. I use PAR only in resizing process with lanczos4resize (1% approximation here) and not in encoding process (I choose standardised DAR value in encoder ... 4/3 PAL or 16/9 PAL ...) Anyway it's not important in my test (dgindex decode MPEG2 without PAR or DAR but in square 1:1 formatp pixel) and you must use my avs script for encoding ... Quote:
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1) With good source and adaptative avs script I can make encoding in HDTV 720p (1280*720*60) or 1080i with high quality and low bitrate: Batman begin trailer 1280*720*60 MPEG2 MP@HL 4000 Kbps 1,1,1,2,2 image sequence TMPGEnc CQ 65 with Sagittaire matrix 2) screenshots don't prove anything (I, P or B bframe) ... with screenshots I can prove that shrink is the best MPEG2 coder in the world ... lol |
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IMHO no contest can determine the best encoder. It can just determine which is the worst (generally all people agree on the bad quality of worst encoder - but there is not two identical advices about the best one). |
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I can read. Do you ?
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Karl try to explain you that no libavcodec based encoder respect the MPEG2 MP@ML defined standard and that is why lot of encoders can't read their results. :arrow: You are comparing things that respect the rules of your contest and other that don't. It's like allowing drug usage in a 100m contest. |
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Yes, ALL are based on avcodec, and so is Mencoder, which is simply a front end to avcodec :!: Quote:
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-kwag |
I thought Hank's HC Encoder was not based on the libavcodec but instead written from scratch by Hank in the programming language called Fortran?
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1) better intra / inter repartition for my eyes (only for my eyes here ... lol) 2) better global / HF repartition for my eyes (only for my eyes here ... lol) Quote:
1) Codec A and Codec B must have the same frame type frame for same frame 2) Codec A and Codec B must have the same quant for same frame 3) Codec A and Codec B must have the same RC strategie Quote:
Nero Burning Room is the most used (IMO the best) CD/DVD burner in the world but perhabs not the most compatible for standalone players (Libavcodec work with my old DVD player but not Nero Burning ... lol) |
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Just compare I to I, B to B, and P to P from each encoder on a same segment of footage ;) Quote:
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Every encoder will be different, so each will have different constraints applied during conversion. In the end, the visual quality is what counts. And again, in the I to I, B to B, and P to P, you can compare encoder X (I frame) for the same frames on encoder Y by looking at the I, B and P specially after a scene change, where there is less compression. That is, compare the first header of an MPEG GOP, which should be IBBP. Then you can compare those four frames to another encoder. Just make sure the frames you are comparing on both encoders are truly splitted on a scene detect. -kwag |
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