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  1. Hi,

    I have videos that I would like to convert to Divx to play them on a protable media player.

    These videos are Music videos recorded from TV (analog cable ) with my standalone DVD Recorder in 1 hour mode.

    The source is then 720*576 interlaced 25 fps
    The target is 384*288 25 fps Divx 6 (800 kbps => compression speed set to "average" to have a quite decent fps).

    So, what denoise filter would you recommend me (avisynth or virtualdub) ? MSU Denoiser,... ????

    For some videos, they have black bars in top and bottom so I cut them to have more bitrate for the video. But sometimes on the cutted encoded video, I can see noise on the bottom of the video (like a jpeg compression around a sharp edge). How can I avoid it ???? Is there another filter for that ?? This noise is not on the original source.

    Thanks.
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  2. Member GMaq's Avatar
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    Hi,
    The MSU DeNoiser is OK, if you want ultimate absolute blow your mind noise reduction, check out www.neatvideo.com and try their demo, I've had some VHS restorations sitting for years that free plug-ins and filters couldn't help much, the NeatVideo plug in for VirtualDub did the trick!!!
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  3. Always Watching guns1inger's Avatar
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    NeatVideo is also one of the slowest plugins yet written - it even gives Magic Bullet a run for it's money in the "I'm slower than you" stakes. And for all that, you still lose a lot of detail to it.

    One of the prices to pay for over compression is artifacts, especially along high contrast edges. No denoising filter will help because the artifacts appear during encoding, after all the filters have been applied. Live with it, or use a higher bitrate.
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  4. Member GMaq's Avatar
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    guns1inger,
    Without a doubt Neat Video is slow, however since the frame size is fairly small the speed will be improved somewhat, and since the OP is doing music videos it will not tie the computer up as long as doing full length features would. Since I don't know how noisy these caps are NeatVideo is probably overkill, but the demo is a useful tool to evaluate other de-noisers.
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  5. Member Soopafresh's Avatar
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    VirtualDub Plugins in general are slow, but oh so convenient. Here's a huge list - check out the ones by Stolyarevskiy Sergey - he's a noise reduction specialist. His website has an English pack of his best filters as well. http://www.thedeemon.com/VirtualDubFilters/

    Avisynth plugins are fantastic. Many rival the $2000 + commercial noise reduction packages out there. But, it is a bit more work getting everything up and running. Worth it, in my opinion. The best ones are FFt3dfilter, DegrainMedian, and MVdegrain2 - all made by another Russian programmer, Fizick. (Those Russians must have pretty bad TV reception)
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  6. Thanks,
    I tried MSU Denoiser, slow but quite good, need to tweak.
    I will download the demo of NeatVideo to test.
    Avisynth filters listed not working

    And about this kind of noise (2-3 pixels height) ? not present in my source:





    It's only present on the bottom of the encoded videos.
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  7. Member grannyGeek's Avatar
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    with many of the aviSynth filters, you must specify a parameter for Interlaced = true or = false.
    Some of them have the default set to Interlaced = false, so they won't work properly on interlaced material until you change the default parameter.
    You'll have to check the documentation for the particular filter you are using.
    See if that helps to get them working


    I second the vote for FFT3d, it's doing a really good job on my current project.
    If you use the setting to denoise all 4 planes (Y,U,V,Luma) with a single parameter setting, it is quite fast, but if you have different parameters for each, it is deadly sloooowwwww.
    I don't care how slow, I'm happiest with this one so far of all I have tried.

    I'm surprised no one mentions Convolution3d. Cleans pretty good, and very very fast. It might soften your video more than you like, though.


    PS - ADDED
    The noise on the bottom is hard to see in your attached image, but I think it is ordinary head-switching noise, you don't see in on TV viewing because it falls into the "overscan" region, and is only seen when you view on a PC monitor.
    UNLESS-- if you do NOT see it when you preview your capture on pc monitor, then it might be something else and I would have no idea.
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  8. The noise on the bottom of the encoded video is not on the original, it appears on the encoded video after I crop the black bars.
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  9. The noise at the bottom of the frame might be DCT ringing. Use frame sizes that are multiples of 16 to reduce the problem. Using a higher bitrate will help too. It could also be overshoot from a sharpening filter.
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    I know this post is old as I'm sure the technology has changed a bit from 5 years ago. Has this changed? Is it possible to eliminate noise in video without blocky artifacts from forming during encoding? Or rather, is there a special script that can be composed in Avisynth that can prevent this?

    I know Deblock() can do it. Adding CUP(6) for example during postprocessing can help.
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  11. Originally Posted by unclescoob View Post
    I know this post is old as I'm sure the technology has changed a bit from 5 years ago. Has this changed? Is it possible to eliminate noise in video without blocky artifacts from forming during encoding? Or rather, is there a special script that can be composed in Avisynth that can prevent this?

    I know Deblock() can do it. Adding CUP(6) for example during postprocessing can help.



    You should continue in your own thread instead of hijacking others, because there is relevant information you have omitted


    Yes technology has improved, but I gather from your other posts that you're making a DVD. This limits your options. That compression technology is old. Blocky artifacts are quite normal for that. Using a higher bitrate can help, but I gather you're more interested in a specific scenario, like macroblocking in dark scenes, not general macroblocking

    If the macroblocking occurs only during encoding, then it's not in the source. Then deblock or cpu=6 wouldn't help you in that specific case, because from what you've said it's a function of encoding. Unless you're using a very poor denoiser that generates block artifacts even before compression.

    Some encoders are better than others. You can use adaptive quantization to allocate more bitrate to dark areas. x264 (AVC encoder) excels at this, but I gather you are making a DVD, hence stuck with MPEG2 video. HCEnc does have AQ but it isn't as good.

    You can add specialized fine noise in gradients and dark areas by dithering e.g. gradfun2dbmod, this "convinces" the encoder to allocate more bitrate to those areas that it usually drops, because it "sees" those areas as noise and lower quantizers are allocated. But to human eyes, a fine dither is barely noticeable. But you need higher bitrates or better compression for this to work effectively, often it's not possible with DVD MPEG2 compression
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  12. Macroblocks from over compression aren't noise, they are a form of posterization, and often result from a lack of noise. You need to differentiate between the things you want to fix and then find the right filters to fix those things. There is no magic "fix what's wrong with this video" filter.
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    Macroblocks from over compression aren't noise,
    Well, technically "macroblock noise" is an "artifact". Both of those quoted phrases/words are correct and proper technical jargon. It's just not video noise. It's encoding noise.

    they are a form of posterization,
    Posterization is color palette compression. Macroblocks are only visible on boundary edges, shown due to insufficient bit rates. I can see how these might be related, but I don't think either is a subset of the other.

    and often result from a lack of noise.
    Don't you mean "lack of bitrate"?

    There is no magic "fix what's wrong with this video" filter
    Aside from paying a pro to do all the work for you. That's the "easy button".
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    That makes sense...adding noise (fine dither). So to what format can I compress my current VOB (MPEG2) video in order to achieve this with the highest quality?
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    Thank you LordSmurf, for clarifying what I stated. Now about paying a pro to do it for me...hold on a sec! This is a forum where the regulars here (I know alot of people are gonna be pissed, but here goes)...swear by....

    .....the high and all-"powerful" Avisynth! The great Avisynth that can work all things, knows all things and work it all! In fact, someone in my other thread told me that once I get to know Avisynth, I'll "wonder how I lived so long without it!" Although that statement was actually parroted from the animemusicvideos.org guy(I believe).

    So Avisynth kicks Virtualdub's ass, does everything that no other video program can do, can do this, do that (hell, it can even raise the dead!) yet if I want to eliminate these simple artifacts...I have to either "compromise" or take it to a pro?

    W-OWWWW!!!! Avisynth, you rock!
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  16. You've got to be more specific here . Details are important . Or post a sample video and what processing you're using.

    Is this for DVD-video? How are you watching it ? You only have 1 option for DVD-video, that's MPEG2

    Are you referring to macroblocking that occurs in gradients, dark scenes? or some other problems ?

    Are you using sufficient bitrates ? because in general, denoising will lower your overall bitrate requirements . The "macroblocking" you see in dark gradients will be from high quantizers (not enough bitrate allocated to those regions) . Your comments that the blocking occurs after denoising suggests this is the case.
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    LordSmurf, if I increase the bitrate in my encoding (to a limitless number, perhaps) and lowe the quantization to say, 1 or 2...will that help eliminate the macroblocks caused by encoding a video that I have applied a denoise filter to? for instance, I think Spotremover is an awesome filter and I don't see any blocks in solid/dark backgrounds in the "after" screen on Virtualdub. However when I burn the footage on DVD and play it on TV..that's when I see it. I figured I'd process it with HCEnc (with the high bitrates and low quant) THEN burn it on DVD.

    What do you think?
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    Poison, yes I'm referring to macroblocking that I see in dark and/or flat areas. Not on edges or anything like that. The macroblocking that I'm referring to specifically appears AFTER I apply denoise filters. The low bitrate statement that Smurf said made sense, as when you denoise, you're removing a part of the video, perse (even if it is noise, it's still a part of the video). So during encoding, the encoder detects low bitrates and raises the quantization to make up for lost detais...hence the macroblocks. Does this make sense?
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  19. Originally Posted by unclescoob View Post
    Poison, yes I'm referring to macroblocking that I see in dark and/or flat areas. Not on edges or anything like that. The macroblocking that I'm referring to specifically appears AFTER I apply denoise filters. The low bitrate statement that Smurf said made sense, as when you denoise, you're removing a part of the video, perse (even if it is noise, it's still a part of the video). So during encoding, the encoder detects low bitrates and raises the quantization to make up for lost detais...hence the macroblocks. Does this make sense?

    That last part isn't true. Low complexity video (denoised, very smooth) requires lower bitrates to maintain a certain level of "quality". The encoder doesn't "see" or detect bitrate; it sees the decompressed image. Similarly when you look at the output pane in vdub, you're looking at decompressed image with filters applied. You're seeing what is being fed into the encoder.

    Flat and dark areas are deemed not as important to most encoders, so higher quantizers are assigned. Raising quantizers means lower quality, lower bitrates. Since the bitrates are lowered in those regions, you get macroblocking (when the bitrate isn't sufficient, you get macroblocking). It doesn' t "make up for lost details". In order to "convince" that encoder that those areas are important, you need to add noise to those areas, thus lower quantizers are assigned. That is essentially what dithering filters do. They are applied preferentially to problematic areas, not a general type of noise. So the problem in your case is both a lack of noise, and bitrate allocation

    Note you can't use a limitless number for bitrates. DVD-video is fixed capacity and has limitations on max video bitrate. If you're goal is DVD-video, you don't have an option to use better compression formats . Better compression formats like AVC have inloop deblocking and (good encoders like x264) can have adaptive quantization (preferentially distribute bitrate to flat and dark areas). They are much more efficient (better quality, smaller filesizes). You can't play AVC video with a regular DVD player
    Last edited by poisondeathray; 4th Mar 2011 at 14:08.
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    AVC...isn't that MPEG-4? So a blu-ray will play AVC for me?

    Also, can I convert MPEG-4 to AVC without losing or degrading quality?
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  21. Originally Posted by unclescoob View Post
    AVC...isn't that MPEG-4? So a blu-ray will play AVC for me?

    Also, can I convert MPEG-4 to AVC without losing or degrading quality?

    AVC (or h.264) is mpeg4 part 10

    be careful when you say "MPEG-4", because it encompasses about 20 different things, including AVC, xvid/divx, AAC etc...

    http://en.wikipedia.org/wiki/MPEG-4


    Yes, Blu-ray can play certain AVC profiles (subsets of AVC are compatible)

    You can convert to lossless AVC without losing quality, but blu-ray doens't support the lossless subset

    With blu-ray you have more bitrate headroom as well
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    Since my other issue has been solved yet this "blocking" demon has always been the "vulture on my shoulder that just won't go away", I'm going to continue my thread here. Tell the guys to scoot on over here.

    Yeah, I know MPEG-4 consists of many parts compatible with different decoders and whatnot. So if I convert my finished product (after applying filters, sharp, etc.) to AVC (but not lossless) can I burn this on a DVD or Bluray Disc in order to play on a BluRay player?
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  23. Originally Posted by unclescoob View Post
    So if I convert my finished product (after applying filters, sharp, etc.) to AVC (but not lossless) can I burn this on a DVD or Bluray Disc in order to play on a BluRay player?
    blu-ray requires special encoding and authoring (there are limitations and restrictions to what AVC encoding you can use)

    If you have a blu-ray player, the some can play from DVD5/9 media if it's prepared correctly, some require firmware updates to do so . BD media is usually more successful

    SD blu-ray is only 50i/60i , so if you have 24p material it has to have pulldown . 24pN native is only supported in HD for blu-ray

    You can consider other methods like getting a media box (e.g. WDTV, asus oplay , popcorn hour, etc...) - they have fewer restrictions and play many more profiles and formats. Unless there is a reason why you want to stick with optical media ?
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    Ok...I feel like I'm getting a bit ahead of myself and this is going to further confuse me. For the time being, I'm going to work on getting my masterpiece on DVD and making it look GOOD. I'm going to read up on dithering filters. Sounds very interesting.
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    Smurf, any advice?
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  26. Video Restorer lordsmurf's Avatar
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    Increase bitrate.

    It's hard to give advice without knowing more about the source and full workflow.
    I'm guessing with the limited info given so far.

    There's also a chance that you can't do anything, if the source is damaged.
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  27. Fix the black level on your TV.
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    The source is an official DVD of a cartoon series. The source itself does not have these artifacts, just after I apply denoising filters. I'm going to post a sample clip early next week to show what I'm talking about.

    For DVD standard, what's the highest I should increase the bitrate to? I plan on doing a CQ encoding with about 2.
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    Jagabo - funny.
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  30. Originally Posted by unclescoob View Post
    Jagabo - funny.
    I was serious. Most people who complain about too much macroblock noise in dark areas have the black level turned too high.
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