understanding mkv and iso file formats
#1
I am not sure if this is the appropriate forum for this question, but I am getting very confused on different file formats and how they are used. So far I have been just ripping my DVD collection to .ISO files.....they seem to be average around 4 gigs in size. Eventually I will upgrade to getting Blurays once I get a HDTV, so I am trying to learn the ropes ahead of time on how to get Blurays onto the HTPC hard drive. It seems to me that a lot of people rip the Blurays into an MKV file format, using a program like MakeMKV....and then shrink it down using Handbrake. I was trying to learn the ropes of these programs last night, so I tried experimenting with making a regular DVD into an MKV, and then shrinking it down. The first thing I didn't understand about the MKV folder is....why was it so much larger than my .ISO rips? My MKV folder ended up being just over 7 gigs, where my ISOs that I make using DVD Cloner 8 are always around 4 gigs. I then went into Handbrake and tried shrinking it to see what kind of space savings I could get. I chose the "High Profile" preset, and I believe I left all other settings alone. When I started the encoding, the estimated time to completion shot up to over 10 hours! And this was just for a DVD! Now granted, I only have a single core, 1.5 gig machine.....is this the main culprit, or was it due to the settings I chose? I am just extremely confused on this whole process....despite the fact I read all of these Wiki tutorials and articles, and I search for answers on the forums, I just don't seem to get it.....it seems to get all very technical, with multiple ways and programs to do any given task. I would appreciate very much for some guidance on my questions. Thanks!
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#2
ISO is just an "image" of a disc. It can be a bit for bit reproduction of the original or it can be an altered copy to reduce size etc. If you are getting them all around 4gb odds are you are compressing them when making the ISO, this is fine if that is all you plan to do to the files.

If you plan to further compress or change the ISO you should start with a bit for bit reproduction and not shrink it when ripping.

MKV is just a container format, it can hold video in any number of formats audio etc, it has no menu structure though which is something an ISO image of a disc can retain.

It's entirely possible when encoding video for the resulting file to be larger than the source if you choose a bitrate or settings that are higher than the original source. If you take a 720x480 resolution 6mbit/sec dvd source and encode it to x264 and tell the enncoder to give you a 1920x1080 18mbit resulting file, you will end up with a very large resulting file, much bigger than the original.

what MakeMKV does is take the original source and essentially "repackage" the original video and audio in a new container. No menus or anything but it maintains the original quality. If the original was a DVD you'll end up with a 4-8 gb standard def file, if it was a blu ray you end up with a 12-40 gb HD file. if you want to re-encode them you can but the settings you use will need to vary based on source, that's something that you really would want to read up on and there are countless articles and posts and blogs and wiki's about how to do that.
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#3
Only thing I would like to add is that I prefer iso files because then you have all the special features and no loss of quality. It is exactly the same as having the whole dvd only it is stored on the hard drive instead of a disk. I can understand though the need to make it take up less space.
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#4
It is strange then if I am making ISOs out of my DVDs that I am rarely getting the file sizes over 4 gigs. I am using DVD Cloner 8, and I choose the "Save to ISO" option when ripping to the hard drive. I would hope the program is not compressing the video at all!
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#5
bgaviator Wrote:It is strange then if I am making ISOs out of my DVDs that I am rarely getting the file sizes over 4 gigs. I am using DVD Cloner 8, and I choose the "Save to ISO" option when ripping to the hard drive. I would hope the program is not compressing the video at all!

If the resulting file sizes are just over 4 gb then it sounds like it's making the copy of the disc that is ready to be burned to a single layer DVD at 4.37 gb maximum capacity, you should check the settings and see if there is a target size or something like that, I don't have the software but a quick google search makes it seem like the software can do 1:1 copies without any recompression, I'd double check that. Almost all commercial DVD's are larger than 4.37 gb and on a dual layer disc, most clock in at 7-9 gb.
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#6
patm95 Wrote:Only thing I would like to add is that I prefer iso files because then you have all the special features and no loss of quality. It is exactly the same as having the whole dvd only it is stored on the hard drive instead of a disk. I can understand though the need to make it take up less space.

If storage space is no issue then this is a good solution IF it's your preference.

At first I was ripping DVD's full ISO then I realized that 99% of the time when using xbmc I'm just interested in the movie, and the DVD menu was just a tedious delay. Now I press play and the movie starts, I still have my subtitles and audio streams etc and if I want to i can rip the extras that I really enjoy and place them separately but that is pretty rare. If there is some movie I really want to watch the extras from I'll just grab it off the shelf.

Another thing to watch out for is a lot of older DVD's will often have a widescreen and fullscreen version on the same side, if space is not an issue that's no big deal but it starts to add up to a lot of wasted space on those fullscreen versions of the movie being there in the iso, 2-3gb or more of wasted space per title like that. Mostly for me I liked the uniform behaviour of converting the movies to mkv, I click play and In a second I'm watching the movie, No advertisements no piracy warnings, no menu delays and animations that while cool 13 years ago when I bought the dvd and the tech was still young are just a waste of time now.

But again it's a preference thing. I prefer ripping my movies to mkv over ISO, I think it's a cleaner aesthetic choice when it comes to how the library "works".

I know that blu ray rips in iso format are nice when you have a system that plays back the full menu support, but even then I just see it as most often time spent navigating a menu when I could already be watching the movie after the first click.
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#7
You're right, I may have to go back and see if I am not using the correct settings in DVD Cloner 8.
Also, was it normal for me to experience Handbrake showing a 10 hour encode time for a 7 gig DVD?

ibixat Wrote:If the resulting file sizes are just over 4 gb then it sounds like it's making the copy of the disc that is ready to be burned to a single layer DVD at 4.37 gb maximum capacity, you should check the settings and see if there is a target size or something like that, I don't have the software but a quick google search makes it seem like the software can do 1:1 copies without any recompression, I'd double check that. Almost all commercial DVD's are larger than 4.37 gb and on a dual layer disc, most clock in at 7-9 gb.
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#8
bgaviator Wrote:You're right, I may have to go back and see if I am not using the correct settings in DVD Cloner 8.
Also, was it normal for me to experience Handbrake showing a 10 hour encode time for a 7 gig DVD?

Handbrake encode is going to vary greatly depending on the settings, the source and the cpu. A single core 1.5 ghz machine is probably going to take a long time encoding files no matter what. The PC I use is a 3.2ghz quad core amd phenom II, re-encoding a blu ray can take a few hours, a dvd usually 30-80 minutes depending on the settings.

With the procesor you have I'd suggest either 1:1 DVD ISO's of the dvd's or using makemkv to make a 1:1 copy of the streams in an MKV container. Any re-encoding is going to take a long long time.
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#9
Well I did finally find out that I was in fact using the option to put a DVD on a smaller size disc....I think DVD Cloner calls this DVD-9 to DVD-5.....I started using the 1:1 copy option and it got my file size to just over 7 gigs instead of the 4 gigs I had been getting. I tried playing with MakeMKV last night just to see how it worked.....#1. To me it seems that MakeMKV takes longer to rip the DVD than DVD Cloner 8 does. Is turning it into a MKV format a more lengthy process than ISO in general? #2....and maybe this was just my eyes playing tricks on me.....but it seemed like the resolution wasn't as sharp on the MKV file as opposed to the ISO.....aren't they both supposed to be untouched video?
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#10
the videos should be identical if you are doing a 1:1 iso and comparing the video to a mkv made using makemkv, Makemkv should be able to run as fast as any other dvd ripping software, I'd compare the same disc using both programs, comparing different discs won't get you legitimate comparable results, you have to rip the same disc to truly compare speeds. All things considered makemkv should be faster if all you are ripping is the movie itself, if you are ripping each title it may take longer as some video elements may be used more than once, for example I have some older dvd's with french and english credits/openings and they have both versions on the dvd, it uses branching to keep the main movie on there just once and the credits in 2 formats, when using makemkv you can end up ripping the disc effectively twice if you choose both sets of titles.

This is not all that common but it can happen.

Are you using xbmc for playback, it's possible that deinterlacing may be playing a part, if the dvd iso is being deinterlaced and the mkv is not on playback that can cause some visual oddities, or vice versa.
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#11
yes I am using XBMC for playback....I have the deinterlace setting to auto.
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