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Poll: What is worse? Mosquito noise, or blockiness?

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  1. Guest
    What is worse? Mosquito noise, or blockiness?

    Personally I think blockiness is the worst thing. With Mosquito noise it can look like it's just noise that was in the picture itself, and on TV it's barely, if at all, noticable... Blockiness however, would look like bad compression...

    So personnaly when compressing with CCE I put the "Flat part priority" on 0 and when compressing with TMPGEnc allways use the "Soften block noise"

    How about you people?

    Mpegobsession
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  2. Member adam's Avatar
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    If you experiment with the priority setting you will get the best of both worlds. Everyone complains about CCE's mosquito noise. If you use it correctly you won't get any, and it will not increase blockiness. 0 is way to aggressive, you should be much closer to 25 for general movies. If there is little movement (chick flick) go with 30 or 35. If its a very high action movie maybe go as low as 9.

    With an adequate avg bitrate, ~2mbits, there is no reason why you should be getting mosquito noise or blockiness in any of your scenes.
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  3. Guest
    I set t to 0 so I won't have ANY blocking, because though it adds a lot of Mosquitos, it's not too noticable on TV. What I think is too bad is that you can't set different values for different regions of the film, that would have been best....

    I wish TMPGEnc would have such fine control over Block/Mosquito ratio, becuae it's great for MPEG-1 movies, thought it's block filter isn't the world's best.
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  4. Originally Posted by mpegobsession
    What is worse? Mosquito noise, or blockiness?
    So personnaly when compressing with CCE I put the "Flat part priority" on 0 and when compressing with TMPGEnc allways use the "Soften block noise"

    How about you people?
    Mpegobsession

    I almost always use Soften Block Noise in TMPGEnc. For CVDs and good source I put 15. If the source is blocky then I put 55. For normal VCDs, maybe the same result can be achieved wih lower values ?
    Best wishes,
    UP
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    It's easy to get rid of blocks, but mosquitos are everywhere.I'm using DVD with 6000 kBits/s.
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  6. Originally Posted by Dragonsf
    It's easy to get rid of blocks, but mosquitos are everywhere.I'm using DVD with 6000 kBits/s.

    Well, not exactly everywhere. Close to the edges of high contrast I would say.
    Best wishes,
    UP
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  7. Member adam's Avatar
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    Originally Posted by mpegobsession
    What I think is too bad is that you can't set different values for different regions of the film, that would have been best....
    This is EXACTLY what this setting does and this is exactly what you are negating by using a setting of 0. The image quality priority affects how CCE allocates bitrate to scenes according to their complexity. By setting it at 0 you tell CCE to allocate full bitrate to high and moderately high motion scenes, and all others be damned. By raising this # you give CCE some flexibility and it will be able to adjust its allocation more intelligently, allocating full bitrate where it is absolutely needed, and shaving just enough off the top of other scenes to make the low motion ones smooth and free of mosquito noise. With a logical setting, CCE neither takes too much away from low motion scenes nor has too little to allocate to high motion scenes.

    If you were to physically change the image priority of individual scenes than you would simply be encoding in manual VBR, which CCE also supports in the advanced settings.

    Assuming your bitrate and resolution are reasonable, there is no reason why you should be getting ANY blocks or ANY mosquito noise. I have used CCE for years and I have experimented extensively with the priority setting. I never get either of these artifacts and I don't have to resort to any extreme settings to achieve this. If you simply use logical settings than you will get a very high quality encode free of either of these types of artifacts.

    Yes if your priority is set too high for you particular source then you will get macroblocks during fast movement, if your setting is too low you will get mosquito noise fairly consistently on sharp contrasts. So rather than just pick the lesser of two evils, the logical thing to do is pick a value in between these two extremes so that you avoid both problems. Use something like 23 as a median. The more movement in the source, lower it. The less movement, raise it. Eventually you will find some good rule of thumb settings to use for your various types of sources.

    Just looking at your settings I think it is evident that there must be a better way. You say you use 0 to prevent any macroblocks...well what if you use 1, do you now see macroblocks? I doubt it. Well how about 2? I still doubt it. You have now decreased mosquito noise slightly yet have not adversely affected anything else about the picture. So keep raising this number until you start to notice macroblocks. Use 1 # less than this and you have found, what you consider to be, the best compromise between the two. Even if mosquito noise is still present, which it probably won't be, you have at least decreased its effect without adding any more macroblockage.

    Essentially what I am saying is that if you are starting with a value of 0, then you have lots of wiggle room...use it. If you can decrease one problem without adding to the other than it is a win/win situation.
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  8. Guest
    Well, to distribute bitrate as best as posible, I set the "Bias" in advanced settings to "0", which is like using CQ, but you can also select the avarage bitrate.

    Thing is, if you encode at the speed of 8fps, tring to adjust would be a big pain... If you encode from VHS, then 0 (or let's say, very low value) will dismiss macroblocs as best as possible... And if you have some mosquitos then it just mingles in the back ground... I'm sure that if I'd use 1 or 2 it could reduse noise, but I just rather play safe...
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  9. Member adam's Avatar
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    Well you don't have to encode everything numerous times, I meant just run a few sample tests to get an idea of what settings work with what kinds of sources. You could always just try the settings I already listed above, they generally work very well for their respective source types. Even a setting of 10 is still probably very extreme for most types of sources. At this setting you would be virtually guaranteed that you would not get any macroblocks at all, assuming your bitrate is decent, and this will substantially cut down on the mosquito noise. 0 just seems incredibly unreasonable to me.

    I can understand your prioritizing macroblock removal over mosquito noise, but you have to realize how incredibly inefficient a method of encoding this is. The goal of encoding is to try to get a relatively even level of quality. With your method the encoder is going to allocate more bitrate than necessary to achieve good results in high priority scenes and the rest of the scenes are going to get whatever bitrate is left over, which is generally not going to be enough. Personally I can only see this method being viable with a very low average, in which case you are going to get macroblocks even in lower motion video.

    If these settings work for you and you like the quality than that's all that matters, but there is no reason why you can't have the best of both worlds. I'm just curious, have you tried using a setting of say, 17? Ignoring specific types of artifacts, if you just sit back and subjectively view it I think you will find the quality far better.

    When it comes to macroblocks versus mosquito noise, of course I find the blocks more intrusive. However, when you look at the occurrence of these two types of artifacts and their relation to the image quality priority setting in CCE, I think mosquito noise is MUCH worse and overall much more detrimental to your quality. Even with a high priority setting, your only going to get macroblocks during very high motion scenes, which even in an action flick are probably going to make up the minority of the movie. With a low priority setting you get mosquito noise consistently throughout almost the entire movie. Again, I see no reason why you should have to have either of these types of artifacts.
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  10. Member Super Warrior's Avatar
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    Originally Posted by mpegobsession
    What is worse? Mosquito noise, or blockiness?
    None.They are both equally annoying and both should be stopped if possible.
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  11. Guest
    Adam,
    I'm now very confused... Doesn't this setting mean that when there aren't enough bits to encode with, CCE preffers the creation of mosquito noise over blockiness, and actually not matter when there are enough bits? Because what you say, actually make it sound to me like what the "Dithered quantization" option is...

    And now I find this on a CCE help PDF file, and I'm even more confused, because it seems like 0 makes less mosquito and more blocks rather then the other way around:

    Quantization characteristics
    This parameter changes the balance of characteristics at quantization. The range is 0 to 64. As the value becomes closer to 0, a higher bit amount is allocated to complicated images areas. As the value becomes closer to 64, a higher bit amount is allocated to flat image areas. When the value is close to 0, the mosquito noise at the edges (noise causing hazy part along the edges, looking like flying mosquitoes) is less outstanding, but the contouring noise (noise which looks like contour line patterns, which appear in flat and wide areas, such as a dark background) is more outstanding. The opposite occurs when the value is closer to 64.

    As the value becomes smaller, the mosquito noise is less outstanding,
    but the contouring noise is more outstanding. The optimal setting depends on the footage, but roughly speaking, 16 to 40 is recommended. If the bitrate is relatively high, greater value may cause better result.
    Now I just know that 0 makes the picture look better, as I don't know what it REALLY does... I'm REALLY confused...
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  12. Member adam's Avatar
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    Man, I totally forgot about this thread.

    mpegobsession, no this setting does not prioritize mosquito noise vs macroblocks per se. Like I said, and the manual says, this setting adjusts how CCE prioritizes flat scenes versus complex scenes. Every encoder is going to allocate more bitrate to complex scenes, and it will get this extra bitrate by taking it away from the flat scenes. The problems occur when you take too much or too little away from the flat scenes, and this causes the mosquito noise and blocks to appear. If you take too much, your flat scenes suffer, and according to the CCE manual you get blocks. If you take too little then you don't have enough for your complex scenes, and according to the CCE manual this is when mosquito noise appears.

    I have read that little paragraph in the manual so many times, but somehow I just substituted my own experiences instead of actually reading the words. Like you, I seem to get more mosquito noise the lower the number I use. My guess is that this is just because I never use the high end of the spectrum, where presumably the mosquito noise would be REAL bad. With such a low setting you are probably introducing both mosquito noise and blocks, rather than prioritizing one over the other. All I can say is experiment, 0 is really a completely illogical setting to use, no offense of course.

    Regardless of my misinterpretation of the manual, I still think my suggested settings are appropriate, and they do fall within CCE's suggested settings. At least give them a try, I really think you will get substantially better results because like I said, if you use this setting correctly than you shouldn't get mosquito noise or blocks. Try encoding a very flat movie. Something like a drama which is mostly dialogue. Use 24 on this setting and compare it to the same encode at 0. I guarantee you will be suprised at how much worse the one at 0 looks.
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