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23rd July 2008, 22:04 | #21 | Link | |
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Quote:
Just to add on this script. I always add a subtitle so that I know what I'm comparing. For example: Code:
source1 = DirectShowSource("C:\Personal\Videos\Van Helsing DXVA-HD-FAST.mp4",fps=23.9759856527702,audio=false) source2 = DirectShowSource("C:\Personal\Videos\Van Helsing SA-HD-DVD.mp4",fps=23.9759856527702,audio=false) StackVertical(source1.subtitle("DXVA-HD-FAST"),source2.subtitle("SA-HD-DVD")) |
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23rd July 2008, 23:46 | #22 | Link |
Bruce Wayne
Join Date: Dec 2007
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Is it just me or does anyone else notice MPC uses TV (16-235) color levels for playing avs files instead of PC (0-255) colors? This results in the quality of the images being lower than they actually are.
However, MPC uses PC (0-255) for all media files, so why not for avs files? Last edited by Avenger007; 24th July 2008 at 00:15. |
24th July 2008, 01:25 | #23 | Link |
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If MPC uses a renderer other than Haali's or the Overlay Mixer, if the decoder is outputting non-RGB video, the color levels will be limited.
Either use one of those renderers, or force ffdshow to output RGB32/RGB24 video only, with high quality YV12 -> RGB conversion enabled, and the RGB Conversion set to Full Range. |
24th July 2008, 01:43 | #24 | Link | |
Bruce Wayne
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BTW, both Haali's and the Overlay Mixer also cause media files to use TV levels, so I'm using VMR9 (renderless). Also, all media files and avs files use PC levels in Windows Media Player. Can you or anyone else confirm my observations? |
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24th July 2008, 02:36 | #25 | Link |
Mr. Sandman
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it's all ok here.
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MPEG-4 ASP Custom Matrices: EQM V1(old), EQM AutoGK Sharpmatrix (aka EQM V2), EQM V3HR (updated 01/10/2004), EQM V3LR, EQM V3ULR (updated 04/02/2005), EQM V3UHR (updated 17/12/2004) and EQM V3EHR (updated 05/10/2004) Info about my ASP matrices. MPEG-4 AVC Custom Matrices: EQM AVC-HR Info about my AVC matrices My x264 builds. Mooo!!! |
24th July 2008, 02:44 | #26 | Link | |
Mr. Sandman
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Quote:
as this is a public forum, everyone can reply with a valid answer. what the original poster asked in the first post does not exist but since he was looking for some other thing instead (his request was just badly worded) he got some valid replies from others. now, if you're finished with insults/flames, since now we all know what the original poster wants, we can help him.
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MPEG-4 ASP Custom Matrices: EQM V1(old), EQM AutoGK Sharpmatrix (aka EQM V2), EQM V3HR (updated 01/10/2004), EQM V3LR, EQM V3ULR (updated 04/02/2005), EQM V3UHR (updated 17/12/2004) and EQM V3EHR (updated 05/10/2004) Info about my ASP matrices. MPEG-4 AVC Custom Matrices: EQM AVC-HR Info about my AVC matrices My x264 builds. Mooo!!! |
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24th July 2008, 03:08 | #28 | Link |
Bruce Wayne
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Thanks for the response.
I created a thread with the problem here: http://forum.doom9.org/showthread.php?t=139623 WRT the topic, I use MPC to compare frames by removing the status and menu bars using ctrl+1, ctrl+2, ctrl+5 and ctrl+0 so the image fills the entire window. |
27th July 2008, 12:21 | #29 | Link |
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Hi everybody. I dont think the original question in ill-posed, at the outset only eyes can compare quality, but I'd say that one of the ideas is to identify better and better metrics that approximate that comparison; otherwise most of the developments described in this forum would be pointless...
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28th July 2008, 02:12 | #31 | Link | |
Mr. Sandman
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Quote:
metrics like PSNR, SSIM, VQF, etc measure the difference from the source. there is some relation with quality but a higher value does not always mean higher quality since the human eye has a very complex perception that cant be just described as a mathematical function.
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MPEG-4 ASP Custom Matrices: EQM V1(old), EQM AutoGK Sharpmatrix (aka EQM V2), EQM V3HR (updated 01/10/2004), EQM V3LR, EQM V3ULR (updated 04/02/2005), EQM V3UHR (updated 17/12/2004) and EQM V3EHR (updated 05/10/2004) Info about my ASP matrices. MPEG-4 AVC Custom Matrices: EQM AVC-HR Info about my AVC matrices My x264 builds. Mooo!!! Last edited by Sharktooth; 5th August 2008 at 17:10. |
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29th July 2008, 00:39 | #32 | Link |
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Code:
clip1 = DirectShowSource("C:\Foo.xxx", audio=false) clip2 = DirectShowSource("C:\Bar.yyy", audio=false) StackHorizontal(clip1.crop(0,0,-320,0),clip2.crop(320,0,0,0)) |
29th July 2008, 01:10 | #33 | Link |
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My attempt of a simplistic tool to compare encodes:
http://www.mediafire.com/?bhkl0qhknne Put it in your VirtualDub folder and make sure Avisynth is installed
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5th August 2008, 09:11 | #34 | Link |
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This seemed quite good, around 94% seemed good with my eyes.
http://www.ece.uwaterloo.ca/~z70wang/research/ssim/ and again in MatLab http://www.mathworks.com/access/help.../ref/psnr.html |
5th August 2008, 17:09 | #35 | Link |
Mr. Sandman
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Location: Haddonfield, IL
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read my previous post. metrics do not mean quality.
infact psychovisual enhancements usually lower the metrics but rise the perceived quality by much. you cant automatically compare quality with a program or using metrics... you still need your eyes.
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MPEG-4 ASP Custom Matrices: EQM V1(old), EQM AutoGK Sharpmatrix (aka EQM V2), EQM V3HR (updated 01/10/2004), EQM V3LR, EQM V3ULR (updated 04/02/2005), EQM V3UHR (updated 17/12/2004) and EQM V3EHR (updated 05/10/2004) Info about my ASP matrices. MPEG-4 AVC Custom Matrices: EQM AVC-HR Info about my AVC matrices My x264 builds. Mooo!!! Last edited by Sharktooth; 5th August 2008 at 17:26. |
5th August 2008, 18:12 | #36 | Link |
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I usually use my eyes to compare for the reasons Sharktooth gave
I've noticed a trend when taking a series of frameshots for comparison from the same frames (between 2 different encoding settings from same source, same bitrate), when converting the .bmp => .png (or even a direct .png capture), the "higher quality encoded" frame is almost always larger in size (Disc space). Of course the .bmp screenshot between the 2 encodes is the same size. I'm guessing that the "higher quality" frame has more detail retention and information in that frame, and this is an objective metric. I'm not sure what goes into the .png compression algorithm - it might be similar to the PSNR, SSIM measurements? |
5th August 2008, 18:14 | #37 | Link |
Mr. Sandman
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no, but it can be a false measure since compression algos prefer certain data sequences instead of others...
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MPEG-4 ASP Custom Matrices: EQM V1(old), EQM AutoGK Sharpmatrix (aka EQM V2), EQM V3HR (updated 01/10/2004), EQM V3LR, EQM V3ULR (updated 04/02/2005), EQM V3UHR (updated 17/12/2004) and EQM V3EHR (updated 05/10/2004) Info about my ASP matrices. MPEG-4 AVC Custom Matrices: EQM AVC-HR Info about my AVC matrices My x264 builds. Mooo!!! |
10th August 2008, 00:06 | #38 | Link |
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I agree that your eye are the best tool, It pointless in compairing 2 lossey picture files as you wouldn't be measuring the loss from codec. I think PNG is lossless, it uses compression like zip which is why png's are bigger than jpg's. bmp is certinally lossless as it's pure uncompressed data.
I found that you can do PNSR (Compare), SSIM & VqmCalc in Avisynth. SSIM is supposed to be much closer to human perception that PNSR. |
10th August 2008, 14:07 | #39 | Link | |
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Quote:
Last edited by ggf31416; 10th August 2008 at 16:21. |
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12th August 2008, 02:41 | #40 | Link |
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Considering the "performance" of common TFT LCD screen, I don't think it is a good idea to stack the video horizontally or vertically. Even the same video looks different on different position of the screen. The distorted color, brightness, contrast, etc. have a great effect on the perceived quality.
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