VideoHelp Forum
+ Reply to Thread
Results 1 to 10 of 10
Thread
  1. Member
    Join Date: Feb 2006
    Location: United States
    Search Comp PM
    If finding the bit rate is bit rate x movie length (in seconds) are the same for all except .264 then what makes all those different encoding different form one another.

    Why do people use different kinds of encoding for does avi have that mpg can't do or how is (if) encoding in .264 is the most current whats so great about it besides the ability to keep the file small.

    And I just found out instead of spending about 60 bucks on the wonder share ultimate for there feature that calculates the file size I can find a video calculator for that to do it for me then use the handbreak video converter that every forum is talking about. So can someone point me to a good video calculator (online or download) to help me find out the estimated file size instead of guessing on it.
    Quote Quote  
  2. Member
    Join Date: Feb 2006
    Location: United States
    Search Comp PM
    Just finally discovered that almost all files are encoded with either xvid or divx (if there are more please post and one is't better than the other is all on what the user wants) but this bring to question which file types belong to which encoding. And brings my question as before up again what is the the difference between all those major (and minor) fie types (cause I now know its not bit value if one formula fits them all) like avi mpg wmv and the one that I see a lot that (kinda) just came up ... mkv

    What I have above is wrong about xvid and divx do not encode the rest of the file types
    Help me please I am totally confused.

    Just found this
    http://projects.lowtech.org/openmovies/codec.html
    Which talks about there being a container and codecs I think i understand but would like some help on finding which file types are containers and which are codecs and which are both.
    Last edited by AndreL; 25th Aug 2012 at 20:52.
    Quote Quote  
  3. Member FulciLives's Avatar
    Join Date: May 2003
    Location: Pittsburgh, PA in the USA
    Search Comp PM
    XMedia Recode is one program that has a bitrate calculator built-in so I'll often load a source into there, select what I want (usually MKV and H.264) and select my audio file(s) and then use the calc to see the bitrate I need to use.

    Then I'll do it in HandBrake using the bitrate calculated by XMedia Recode LOL

    Sort of an ass backwards way of doing it but I trust HandBrake more so really I'm just using XMedia Recode to calculate the bitrate for me.

    I think MeGui has a bitrate calculator built-in but I've tried to use that program a few times and it makes my head hurt. Worst interface and design ever.

    However try not to get overly obsessed with file size. Often times it's best to use a Constant Quality CRF type of encode to ensure quality (although you never know ahead of time what the file size will be).
    "The eyes are the first thing that you have to destroy ... because they have seen too many bad things" - Lucio Fulci
    EXPLORE THE FILMS OF LUCIO FULCI - THE MAESTRO OF GORE
    Quote Quote  
  4. Member yoda313's Avatar
    Join Date: Jun 2004
    Location: The Animus
    Search Comp PM
    Originally Posted by andrel_
    Why do people use different kinds of encoding for does avi have that mpg can't do or how is (if) encoding in .264 is the most current whats so great about it besides the ability to keep the file small.
    Check the links that t_jet posted for starters.

    Second of all those are containers not codecs - h264 is a codec the others aren't. Technically there isn't anything that is mpg that is a codec. Its either mpeg 1 (vcd) or mpeg2 (dvd - and svcd but that is a really really niche section that is virtually worthless in todays world at least in my opinion).

    The main things to consider on your codec choices are playback requirements, storage requirements, and features needed.

    Basically if you only ever play videos on a computer it really doesn't matter at all. As long as you have enough storage space any codec at any bitrate will do what you need to - as long as it can support hd resolutions if you do hd video than you can use virtually any codec for your needs.

    The tricky parts begin when you have to meet requirements for either a hardware player, storage space (ie smaller file sizes) or features like subtitles, multiple audio tracks and menus.

    If you just need a video to play without anything extra anything will work. You start needing to do selectable subtitles and mpg1 is out the window (I don't think strictly speaking mpeg2 can do it in a .mpg container but not sure on that). The more complex your needs the narrower your choices start to become (sort of - more on that later).

    Basically if you want to make a dvd it MUST be mpeg2 video and you author that into a video_ts folder with a dvd authoring program. If you do avchd you have to meet its requirements for hardware players to play it. Even though bluray kind of has less restrictions to an extent you still have to conform to certain specs for bluray players to read the discs you make.

    If you do hardware players like a ipod/ipad or android tablet or other type of portable video device you have to meet its strict requirements. That includes max bitrate, container type, codec and resolution.

    If however you are going to use a settop media player like a wdtv media player than you can pretty much have virtually any file type and throw it at and it will play. Of course nothing is perfect and won't play ABSOLUTELY everything you throw at it but it will be much more forgiving that lots of other playback equipment you run into (and the wdtv isn't the only game in town but its a well respected player).

    So basically its not just what can give you the smallest file size at a good quality level but it depends on what you will be using to playback the file. Form follows function and vice versa. Without meeting a certain minimum requirement your video will not play. Thats why you have to pick and choose your formats carefully.

    However like I said if you plan to only playback on a computer and have plenty of storage space then you can use just about any codec and container you please. Though there are some "common practices" you could follow to make things easier on you. Like using h264 in an mp4 or mkv container for hd video (with aac, ac3 or dts audio - ac3 being the sweet spot for audio quality and file size savings, dts would be the top of the line -generally speaking all in the eye or ear of the beholder - but dts takes up a lot more space and dtsma on blurays takes up quite a bit more).

    So all in all it is all about your intended destination and playback environment. There is no real "correct" answer it is what best fits your needs. However some do have right answers if there is a strict playback requirement that a lot hardware players can have.

    Edit - also avi is an "old" container that doesn't have the flexibility or capability of mp4 or mkv. Also mpg is more suited for dvd destinations than other needs - though can contain hd but not a "common" practice.

    Edit -
    Which talks about there being a container and codecs I think i understand but would like some help on finding which file types are containers and which are codecs and which are both.
    Check out our glossary here - well Baldricks glossary but its a community effort for updating and editing -

    http://www.videohelp.com/glossary

    Basically the most common types are:

    h264 - codec
    mpeg1 - codec
    mpeg2 - codec
    divx - codec
    xvid - codec
    wmv - codec (windows media video)

    .mp4 - container
    .mpg - container
    .avi - container
    .mkv - container
    .wmv - contianer - (windows media video is in this container but I believe other video can be put in a .wmv file almost 100% certain on that).

    There are of course others like .ogm and stuff like that but those are a bit rarer.
    Last edited by yoda313; 25th Aug 2012 at 22:07.
    Donatello - The Shredder? Michelangelo - Maybe all that hardware is for making coleslaw?
    Quote Quote  
  5. Member
    Join Date: Feb 2006
    Location: United States
    Search Comp PM
    What is Constant Quality CRF type is that like VBR (variable bit rate).

    My over all plan is to reduce the file size with out making the movie worse visually. I think the main think I want to keep is the container type and codec type the same an just reduce the resolution (which key point in reduce the file size). How can I do that with out making the move noticeably bad where you can't see the difference in the movie that was large in size and had a resolution of 1080 and the new converted move that was just maid to reduce file size.

    And how can you tell your resolution is 1080 or 720 wha do you look at as far as the movie detail, is there a formula to help you figure it out
    I've seen files that are about 1.2 no more than 1.5 GB in size that look great. How can I get that.

    Also what about a program thats easy to read on the media details I have MediaInfo 0.7.51 is there one that is better.

    Thnks every one for your post
    Quote Quote  
  6. Member FulciLives's Avatar
    Join Date: May 2003
    Location: Pittsburgh, PA in the USA
    Search Comp PM
    Constant Quality or CRF is a type of encode where you pick a number which is like a QUALITY setting and the encoder tries to keep that level of quality throughout the encoding process. The bitrate will go up and down of course but it will always retain a certain level of quality based on the CRF number. The bitrate is varible because it will adjust itself due to the complexity of the image but always with an idea of maintaining the CRF quality level you pick.

    With H.264 (which is probably the codec you want to use) the CRF most commonly used is between 19 and 21 but I prefer to go lower myself, like 18 or sometimes even 16 (the lower the number the better the quality but that will also increase the file size).

    The best thing to do is pick a source you know well and encode it many times over at different CRF numbers. Then compare them and see how high the number can get (less quality but smaller file size) until you can start to spot and be bothered by the compression artifacts. Once you figure out your "tolerance level" for the CRF you know to use that in the future but of course it's going to be slightly different for different movies. The more complex the film the lower you may need to go with the CRF whereas the easier the movie the higher you can go.

    Darker movies with a lot of dark scenes need more bitrate. Brighter movies don't need as much bitrate. Complex action in a movie needs a lot of bitrate. So an action movie would need more than say a drama because there's not a lot of action in a drama. These are just some things that affect the encoding and bitrate needed to make something look good.

    There's no magic CRF or bitrate value that looks good for all movies. Well you can argue that if you go very low with the CRF that it will ALWAYS look good. For instance if you always use CRF 16 then it will almost always look VERY good but you will get some HUGE filesizes if you do that.

    So file size and quality is always a trade off and sometimes you can't tell until you encode it and watch it. I've encoded movies sometimes as much as 3 or 4 times until I get it just right (although I've gotten better at picking the CRF so I often hit it the first or second time). I think there was only ever one movie that I did 4 times. Mostly because that movie proved to be super easy to compress so I kept lowering the CRF to see how low I could get it while still having a file size that I was A-OK with (I think I got it down to 12 which is just absurd but even then the file size was smaller than other movies at CRF 18 so just shows how different movies can be very different).

    H.264 with SD (Standard Definition) video can look good around 1.4GB (which is the size of two CD's ... a number that some people shoot for as a "good size" to target). But it really depends. With SD video, if we are talking a full movie, I usually shoot for around 2GB or I see artifacts (with most movies) but I'm not very tolerant of compression artifacts.

    Basically it's trial and error so start encoding at various CRF values or bitrates (always try to do a 2 pass if using a VBR bitrate method) and see how it looks to your eyes. After a while you'll get a feel for what method and bitrate to use for your preferences and the style of the movie. But it takes time.
    "The eyes are the first thing that you have to destroy ... because they have seen too many bad things" - Lucio Fulci
    EXPLORE THE FILMS OF LUCIO FULCI - THE MAESTRO OF GORE
    Quote Quote  
  7. Member
    Join Date: Jun 2003
    Location: United Kingdom
    Search Comp PM
    Originally Posted by AndreL View Post
    What is Constant Quality CRF type is that like VBR (variable bit rate).

    My over all plan is to reduce the file size with out making the movie worse visually. I think the main think I want to keep is the container type and codec type the same an just reduce the resolution (which key point in reduce the file size). How can I do that with out making the move noticeably bad where you can't see the difference in the movie that was large in size and had a resolution of 1080 and the new converted move that was just maid to reduce file size.

    And how can you tell your resolution is 1080 or 720 wha do you look at as far as the movie detail, is there a formula to help you figure it out
    I've seen files that are about 1.2 no more than 1.5 GB in size that look great. How can I get that.

    Also what about a program thats easy to read on the media details I have MediaInfo 0.7.51 is there one that is better.

    Thnks every one for your post
    MediaInfo is as about as simple and as good as it gets. It'll tell you all you need to know about your video file - codec, resolution etc.
    Filesize = bitrate*playing time - reducing the resolution in itself does not reduce the filesize, though a smaller resolution would enable you to use a lower bitrate to get comparable quality, so indirectly reducing the filesize. A 90 minute movie encoded at 1920*1080, 2000kbps would be the same filesize as a 90 minute movie encoded at 1280*720 2000kbps.
    Quote Quote  
  8. Member
    Join Date: Feb 2006
    Location: United States
    Search Comp PM
    So CRF and bit rate are the same cause I'm looking at this program AVS and here is the adv settings I don't see a CRF.
    http://i49.tinypic.com/2i0z04k.png

    How that program Microsoft Expression Encoder 4 Pro
    I've read the it allows you to view a sample before you encode the movie and it tells you the estimated file size.
    Quote Quote  
  9. Member FulciLives's Avatar
    Join Date: May 2003
    Location: Pittsburgh, PA in the USA
    Search Comp PM
    I guess it depends on the device you intend to use for viewing your video files but these days most people are using H.264 aka x264 aka AVC and there are many tools for making such files but the most popular is HandBrake

    The first program shows MPEG-1 and nobody should be using that these days and I've never heard of that Microsoft program.
    "The eyes are the first thing that you have to destroy ... because they have seen too many bad things" - Lucio Fulci
    EXPLORE THE FILMS OF LUCIO FULCI - THE MAESTRO OF GORE
    Quote Quote  



Similar Threads