VideoHelp Forum
+ Reply to Thread
Results 1 to 9 of 9
Thread
  1. Member
    Join Date
    May 2012
    Location
    Portland, OR
    Search PM
    I've got a collection of HD backups but the programs I use leave most of them ranging around 6 to 10 gigs each. I've heard of some programs and settings that can get it down to 4 gigs roughly without a loss of quality. Is this possible and what program do you suggest? Thanks in advance for whoever takes the time to help this video n00b.
    Quote Quote  
  2. Member yoda313's Avatar
    Join Date
    Jun 2004
    Location
    The Animus
    Search Comp PM
    Originally Posted by appr3ntic3
    4 gigs roughly without a loss of quality. Is this possible
    Without a loss of quality? Technically that is not possible. There will always be some quality loss in a conversion of this nature.

    What you are really asking for is "decent" quality at a lower file size. That is certainly attainable.

    However what you want to do is go back to your original sources and do the conversion properly the first time with the bitrate set to hit your target the first time.

    Converting an already converted file is not usually a good idea. To the average joe/jane a conversion from a conversion will probably look ok but you should start over from the source to give it the best chance at looking good.

    You should use ripbot264 or avchdcoder.

    Also what is your playback device? Does it have a fat32 harddrive restriction? Is that why you want to reencode to a smaller file size? Or do you need to fit to single layer discs?

    If its to fit to single layer discs consider investing in a dual layer dvd burner if you don't have one. They should be less than 30.00 usd new at places like tigerdirect.com and newegg.com.

    If this is to play back on a media player or game console you may want to look into alternatives. You could buy a used wdtv media player for under a 100.00 on a site like ebay. They can read a multitude of codecs and file types from ntfs drives with no file size restrictions.

    Edit - and you should list the programs you use. There is a high degree of probability that they have bitrate settings that you don't know about. That way you can target your file size the first time to hit what you want. They most likely either have a bitrate calculator built in or a slider option to hit a certain file size. Often its called cq or constant quality to achieve a fixed file size.
    Donatello - The Shredder? Michelangelo - Maybe all that hardware is for making coleslaw?
    Quote Quote  
  3. Member
    Join Date
    Jul 2001
    Location
    United States
    Search Comp PM
    Originally Posted by yoda313 View Post
    ... Often its called cq or constant quality to achieve a fixed file size.
    Say what?

    CQ mode is to achieve a constant quality for a given video. It will choose a bitrate necessary to maintian a given level of quality. With the encoder choosing the bitrate ... the file size will be unknown. The video will vary in bitrate, and therefore size, in relation to what CQ level is desired.

    If you want a given filesize, then you use a fixed bitrate (or narrow min-max), or something like 2-pass encoding to maximize available space for a given bitrate.
    Have a good one,

    neomaine

    NEW! VideoHelp.com F@H team 166011!
    http://fah-web.stanford.edu/cgi-bin/main.py?qtype=teampage&teamnum=166011

    Folding@Home FAQ and download: http://folding.stanford.edu/
    Quote Quote  
  4. Member hech54's Avatar
    Join Date
    Jul 2001
    Location
    Yank in Europe
    Search PM
    Originally Posted by appr3ntic3 View Post
    I've got a collection of HD backups but the programs I use leave most of them ranging around 6 to 10 gigs each. I've heard of some programs and settings that can get it down to 4 gigs roughly without a loss of quality. Is this possible
    No.
    Quote Quote  
  5. Member
    Join Date
    May 2012
    Location
    Portland, OR
    Search PM
    My setup is a WD TV with a USB hard drive attached. It's formatted as NTFS I'm just running low on space and wondered if there was a way to 'cut the fat' now I know this won't work with my watchmen with all the scenes or my lord of the rings extended editions. But some of my 1h30m movies are 8gb. Since they're backups and I still have the blu-rays stored away in my basement I'll try the programs you mentioned Yoda.
    Quote Quote  
  6. Member
    Join Date
    Jul 2001
    Location
    United States
    Search Comp PM
    Originally Posted by appr3ntic3 View Post
    My setup is a WD TV with a USB hard drive attached. It's formatted as NTFS I'm just running low on space and wondered if there was a way to 'cut the fat' now I know this won't work with my watchmen with all the scenes or my lord of the rings extended editions. But some of my 1h30m movies are 8gb. Since they're backups and I still have the blu-rays stored away in my basement I'll try the programs you mentioned Yoda.
    I'd get a new/another hard drive and leave the movies as-is. At 8-10gb, you could fit another 100 movies on a 1TB drive. They're once again running under US$100. Or even go with a 2TB for US$120 or so for 200+ movies.

    For those prices I don't reencode anything. Sure I get 1/2 the movies on a drive, but they're at 100% quality. For the movies that you've mentioned quality is far more important to me.

    (Good movie choice BTW. )
    Have a good one,

    neomaine

    NEW! VideoHelp.com F@H team 166011!
    http://fah-web.stanford.edu/cgi-bin/main.py?qtype=teampage&teamnum=166011

    Folding@Home FAQ and download: http://folding.stanford.edu/
    Quote Quote  
  7. Member yoda313's Avatar
    Join Date
    Jun 2004
    Location
    The Animus
    Search Comp PM
    Originally Posted by neomaine View Post
    Originally Posted by yoda313 View Post
    ... Often its called cq or constant quality to achieve a fixed file size.
    Say what?

    CQ mode is to achieve a constant quality for a given video. It will choose a bitrate necessary to maintian a given level of quality. With the encoder choosing the bitrate ... the file size will be unknown. The video will vary in bitrate, and therefore size, in relation to what CQ level is desired.

    If you want a given filesize, then you use a fixed bitrate (or narrow min-max), or something like 2-pass encoding to maximize available space for a given bitrate.
    Oops.....

    My apologies for getting that one a 100% backwards....

    --------------

    Since we know more about the posters setup I too agree with neomaine - get another harddrive. Save up a little and buy an extra one. No reencoding needed. Then you can just keep doing what you're doing. You won't have to waste time and effort to get a smaller file size.

    But yes if you WERE to reencode you definitely should start over with the original sources - much cleaner that way
    Donatello - The Shredder? Michelangelo - Maybe all that hardware is for making coleslaw?
    Quote Quote  
  8. CQ mode is to achieve a constant quality for a given video.
    careful with that,.. most people nowadays will connect cq to 'constant quantizer' not 'constant quality' and no quality and quantizer are not the same,...
    Quote Quote  
  9. The OP never mentioned what program was used to produce the backups. Since they apparently vary in size I would guess crf encoding was used. Anyway, a couple observations:

    1) 4 GB is utterly inadequate and you'll be sorry you wasted your time, especially if not encoding from the originals. 4 GB can be acceptable for animation, or at a stretch, video with very little grain, noise and movement. (Assuming commercial Blu-Ray movies here.) What's acceptable depends on the display and how discerning you are.

    To give a couple examples, WALL-E encoded at a crf of 20 with BDRB comes in just under 5 GB, Saving Private Ryan at nearly 20 GB. And of course the latter has a helluva lot of grain and noise to encode, the former none. (There's a runtime difference as well, but you get the idea). Most other movies will fall somewhere in between as to how compressible they are.

    2) Ideally, as neomaine suggests, you'd solve your dilemma solely with more hard drive space. For new backups, no compression or use crf encoding at perhaps 18-20, and more hard drive space as well. (With crf encoding, the lower the better, and personally I wouldn't go over a value of 20).

    You'll find that with more experience you will become more discerning. Most Blu-Rays compressed down to ~ 4 GB will show blatant artifacts like posterization in dark areas. Try one at crf 20 and again at 4 GB and compare.
    Last edited by fritzi93; 20th May 2012 at 09:40.
    Pull! Bang! Darn!
    Quote Quote  



Similar Threads

Visit our sponsor! Try DVDFab and backup Blu-rays!