San_Marino | 22 points
I often see a movie posted here that claims it is 1080p quality and the file size is usually ~2 gb. However, I also see frequent posts with the same movie that says it is 1080p quality and a file size ~10 gb, but sometimes even ~30 gb. The larger file usually looks a bit better, but I was wondering what is the difference between these posts? Thanks for the help.
[-] Frodo_Bomb | 18 points
If two movie files are different sizes, then they are not the same quality. Period.
If a movie is 1080p, that only means that the resolution of the movie is, at most, 1,920 pixels wide by 1,080 pixels tall, but this isn't the only factor that affects what quality a movie is. The difference in file size is due to the amount of compression that's done to the movie after it's ripped from its source, which is generally a Blu-Ray disc because they are the highest-quality format commercially available to consumers.
Sometimes compression involves crunching down the ranges of color and contrast, replacing similar colors with a single color to reduce the number of unique colors needed to display the picture on the screen (Image Compression). Sometimes it involves a more complicated process that analyzes how much the video in a scene changes over time and decides not to update parts of the screen to the next frame if the change is insignificant (Motion Compensation), like this. You can read more about compression here
The untouched movies on Blu-Ray discs can range anywhere from 20-70GB each, but many prefer to compress them down to a smaller, more portable size, at the cost of video fidelity. Occasionally the audio is compressed as well, but it doesn't take up nearly as much space as video, so it may be left alone, depending on the compression preferences of the person encoding the movie.
Something important to consider is that one of the biggest contributors to the size of a movie file is the resolution of the video, so compressing a 1080p movie down to 720p might actually reduce the size while preserving the quality, whereas keeping the movie at 1080p but crunching down the quality to save space would have a greater impact on the quality. Resolution isn't everything, a 6GB movie at 720p would look substantially better than a 6GB movie at 1080p.
30GB - Usually an uncompressed copy from a Bluray disk copied oe "remuxed" into a common PC video file live mkv or mp4.
The coded used, if it's the most recent copy, settings used all make an impact. the same Encoding coded can be a lot smaller while being the same quality or better if the person making it uses the right settings and gives there computer serveral times as long to encode (a nice quad core i5/3ghz can spend a day or more with the best output settings... and that's just on a single x264 movie;
x265 or HEVC takes a lot longer but can create better quality encodes at under 25% x264 size at 480p, or 50% at 1080. (those are old poc benchmarks for live software encoding systems, and HEVC isn't a completed format so it may yet have non-backwards compatible features to enhance it before it's finalized, after that it should just be mostly optimization - that's why it lacks large mainstream support or many hardware based decode assists.
Additionally many smaller encodings are re encoded from a larger encode, the process has drastic costs in quality for size compared to the same type of encoding made from the highest quality source then just taking a good quality 1080p encode and converting it to 720 (which is difficult to differentiate other than color accuracy on screens under 52"...unless you have a plasma screen or OLED with good quality display circuitry).
sub-par quality is most easily noticed in freeze frames and ofter dark scenes. Color banding is one of the biggest problems, blut artifacts (often patterns of sorts creating small patters of distortins, sometimes squares, sometimes other paters in an image that are visable but hard to describe), blurring, even a stepping effect on borders akin to lower resolution 3d renderings. Often they're hard to see during motion (although color banding stands out to me strongly).
Good encoding is a difficult and often timely process.
uncompressed
poor word choice.
50% at 1080.
x265 is good, but it's not even close to that good.
[-] [deleted] | 1 points
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[-] Nuero_Filter | 2 points
This the 5th or 6th time you have said this "Also amazon rips are sometimes better than blurays and sometimes dvd and hdtv are too." What the hell is wrong with you??
[-] [deleted] | 0 points
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[-] Nuero_Filter | 1 points
LOL, well the way out kept repeating the exact same sentence over and over I expected you to be a bot or something, ha sorry bro didn;t mean to offend.
[-] kaching335 | 9 points
1080p is the resolution, not the quality.
Bigger size = higher quality, but they're the same resolution.
It's got to do with the amount of data that is being calculated per second, the bitrate. A 769mb file has a bitrate of about 2000 kb/s, which when broken down even more has a bitrate of about 80 kb per frame of video A 1.7gb file has a bitrate of about 5000 kb/s, which figures out to about 200 kb per frame. yes, there is obviously a considerable difference in quality, considering the larger file can fit more than double the amount of data (and therefore different coloured pixels) into the same amount of time. yes, you can also take a low quality video and stretch it to a higher resolution (which is exactly what the Xbox and PS4 do) but that doesn't mean the file will be of any higher quality, quite the contrary actually.
dont waste your bandwidth and hard drive space downloading any movie over 4 gigs, 2-3 gig movies in x265 1080p 5.1 channel audio or better is the best way to start a collection, look for movies from these encoders, joybell, tigole, mzabi, Qman, Byteshare, MRN, PSA, MeGusta, lordvako, NAHOM, rmteam (is ok quality, they remind me of yify but in x265), i have over 2200 movies, and most of them are in the 1-3 gig range and look and sound great
[-] Frodo_Bomb | 5 points
Huh personally I'd say not to waste bandwidth or hard drive space downloading any movie under 4 gigs, because the quality is so low you're better off just streaming it from putlocker or some equivalent site, especially if you're going with 1080p movies crushed down to that size. A 720p movie would look way better at that point if you're truly just trying to get quality as small a size as possible
[-] GamerBears | 2 points
I use to get JYK releases, they did 1080p at DTS 768kbps. They inspired me to try to encode my Blu-rays at the same settings, but I always end up having to increase the bit rate on the videos on some movies. Most of my movies have been under 3GB range but my biggest one was Titanic at 5GB and still looks like shit.
I have a question and better to ask here .
What s the difference between x264 & H264? Which one s better?
[-] gaycocksinmyass | 2 points
Both x264 (also called H264, but colloquially, it's x264) and x265 (other name is H265 or HEVC) are codecs. They're different methods of encoding video files. x264 is an old codec while x265 is a newer codec. Usually, x265 files have the same quality as x264 files but with higher quality. For example, if you're dealing with a 30 gig video source, a x265 will probably give you a file that's about 2-4 gigs in size (depends on the settings you use but this is what I usually get when I do it); while x264 will probably give you a file that's about 8-10 gigs in size. YIFY does x264 encodes, but his source files are much smaller, which is why the quality isn't very high and the file size is relatively small. Sure, there is of course a loss in quality because of loss in bitrate, but I'm willing to trade that higher margin for saving disk space.
tl;dr they're different methods of making video files smaller without (easily noticeable) loss in quality.
[-] ruralcricket | 1 points
I don't know for sure but I suspect that it is the # of bits per color per pixel. The more bits, the larger the range of colors and contrast levels you can have.
The way they are encoded is what makes for the file size difference. Take something like a YIFI upload, about 2 gb for a "1080p" movie but if you look at the bit rate it will be extremely low. So those uploads might be fine for a small screen like an iPad or non retina laptop but if you play that same file on a HD monitor or a 4K tv it will look and sound awful. Other uploaders like SPARKS or a UTR upload will be a larger file size because they are encoding with a higher bit rate which will make for better overall quality. So those two things aren't really the same 1080p file. Hope that clears it up. To summarize, the size is determined by how you encode, the higher the bitrate the higher the quality.
[-] jackbw0890 | 1 points
Being of same resolution doesn't necessarily mean they're of "same quality". You said yourself the larger file looks 'a bit' better. Those 10/30GB movies you've come across have higher bit rate than 2GB ones and thus hold more info. Picture quality will undeniably be better on larger files, with lesser compression artifacts in uniform sections of colors. This is especially noticeable if you use large HDTVs. If you're watching on smaller screens (laptop/smartphone), you're not as likely to notice any quality difference and are better off getting smaller files.
There are plenty of good explanation in the web with examples and technical details if you want to know in-depth so fire up that google search if you're interested.
[-] Blue-Thunder | 1 points
These are all good explanations.
[-] street0721 | 1 points
480p at 500 bitrate is still good enough.. otherwise uploaders wont upload it.. =p
[-] DontKnowHowToEnglish | 27 points | May 20 2017 06:09:51
Resolution doesn't equal to quality,
Here is a good short video with the basics.
The higher the bitrate, the bigger the file. I usually download movies with 8-10mbps (~10 gb), they look way, waaay better than the ~2gb ones. I just download things that I want to watch, and I don't want to watch them in a shitty quality, but it depends on the person and their setup.
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[-] Toysoldier34 | 5 points | May 20 2017 09:48:01
That video is a great example, and to make it more specific to OP's question, that video is 1080p at all times.
So as you watch it at no point does it stop being 1080p video just like a 1GB movie and a 30GB movie are both 1080p. Though as clearly demonstrated there are more video quality factors than just resolution. Bitrate is far more important.
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[-] TheGoodSheep | 1 points | May 20 2017 08:05:36
This is weird. I was confused, why YouTube showed me a German title for an English video. Then I clicked on it and it showed me the English title. Is that a new YouTube feature I hopefully can turn off somewhere?
E: Turning the language to English works, but what a poor feature by YT once again.
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[-] San_Marino | 1 points | May 25 2017 01:14:55
Good video, thanks for the explanation.
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