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19th June 2015, 22:54 | #1 | Link |
Soul Architect
Join Date: Apr 2014
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When Are Debancing and Dithering Needed?
I'm still confused about the whole Debanding/Dithering thing.
I wrote a software that contains a Media Encoder that allows upscaling SD content into HD with just a few clicks; GREATLY simplifying the process, especially if you need to convert 50 videos. Here's a sample video before and after. Now my question is: would this video benefit from any debanding and/or dithering? What difference do they make? When are those needed?
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FrameRateConverter | AvisynthShader | AvsFilterNet | Natural Grounding Player with Yin Media Encoder, 432hz Player, Powerliminals Player and Audio Video Muxer Last edited by MysteryX; 24th June 2015 at 05:59. |
19th June 2015, 23:08 | #2 | Link |
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Location: Germany
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Recent example I did on a wallpaper (possibly nsfw)...
original: http://i.imgur.com/gQVFk5W.jpg fixed: http://i.imgur.com/UwRFR8K.jpg script: Code:
ImageSource("source.png", 0, 0) ConvertToYV12 GradFun3(smode=2, thr=0.35*2, thrc=0.35*2, radius=16, radiusc=16) |
19th June 2015, 23:31 | #3 | Link |
Soul Architect
Join Date: Apr 2014
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Yes I know what debanding is, but I honestly don't notice any of it in most videos.
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FrameRateConverter | AvisynthShader | AvsFilterNet | Natural Grounding Player with Yin Media Encoder, 432hz Player, Powerliminals Player and Audio Video Muxer Last edited by MysteryX; 24th June 2015 at 06:00. |
20th June 2015, 06:46 | #5 | Link |
/人 ◕ ‿‿ ◕ 人\
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Debanding is the process of removing banding. Usually it's performed by reconstructing gradients to a higher bitdepth.
Imagine having a gradient that goes from 0 to 10 in 20 pixels - you need a >8 bit colorspace to store it. Dithering is the process of lowering bitdepth. Just dithering makes on sense - you can't lower 8 bits to 8 bits. After debanding you have 16-bit image - so you have to lower bitdepth at some point. Most debanding filters (if not all) have built-in dithering. Some have an option to output 16-bit image, so you can process it further (read about dither tools) and dither it down to 8/10 only at the end. Will your video benefit from debanding? Probably just a bit. But you'll need way higher bitrate to encode all noise it adds. Or 10 bits. |
20th June 2015, 08:56 | #6 | Link |
ангел смерти
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You left enough grain in these videos that there's no appreciable banding -- banding noticeably occurs when a video is too clean, not when it's dirty. Of course you won't get any use out of debanding.
There's a much bigger problem though: The after video exhibits severe judder, so something about your 25->60 frame rate conversion is incorrect. It's producing very jerky video that appears to skip frames several times a second or double up frames too many times, I'm not sure. |
20th June 2015, 18:31 | #7 | Link | |
Soul Architect
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Quote:
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23rd June 2015, 07:48 | #9 | Link | |
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Quote:
I'm not really seeing the judder either. Maybe my eyes are getting crap with age, all I see is ocassional crap camera-work I did see one slight jerk in the beginning but that was about it. Couldn't tell after that if it was frame repeats / or shitty camera man when watching in real-time. |
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