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  1. Member
    Join Date: Jul 2006
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    What i would quickly like to ask here, is if there are any noticeable differences between an x264 mkv blu-ray rip of 4-6GB and an uncompressed blu-ray format?
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  2. I'm a MEGA Super Moderator Baldrick's Avatar
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    Yes, it's noticeable for me. But then some doesn't even notice any difference between sd and hd, so it depends who is watching.
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  3. Member
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    This is like the PCM vs MP3 argument, some people notice more than others.
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  4. I'm a MEGA Super Moderator Baldrick's Avatar
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    And a blu-ray is never uncompressed (an uncompressed 1080p movie would be GIGANTIC). The 4-6gb are just much more compressed.
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  5. Member dwisniski's Avatar
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    It depends on how the rip is encoded, but if done properly the difference is almost indiscerenable. Some will argue with that statement, but the .h264 codec is that good with compressing files.
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  6. Member edDV's Avatar
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    Not that good.

    Near Uncompressed is something like 3200 Mb/s

    BluRay (MPeg, VC-1 or H.264) is ~35 Mb/s max. or near 100x.

    h.264 4-6Mb/s is... well ... over compressed.
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  7. Mod Neophyte Super Moderator redwudz's Avatar
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    I backup my BDs to 8GB MKVs, two pass encoding. The quality is quite good, better than commercial DVDs. I can tell the difference from the BD when I project them on a twelve foot screen, but they are still very good quality. On a 22" monitor, hard to tell much difference. Considering they are compressed to about 1/3 their original size, I'm very impressed with the quality of H.264.

    Reducing the size down to 4GB, the quality does drop off a fair amount. Probably 10 - 12GB would be the optimum for compact size vs quality.
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  8. Video Restorer lordsmurf's Avatar
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    There is a difference in quality, seen easier as displays get larger.
    Last edited by lordsmurf; 14th Feb 2010 at 03:48.
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  9. Originally Posted by lordsmurf View Post
    There is a difference in quality, seen easier as displays get larger.
    Or as you get closer. A 12 foot screen from 12 feet away is about the same as a 2 foot screen from 2 feet away.
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  10. Member
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    I'm only asking cause i;m trying to decide if it's worthing backing up blu-rays to 1:1 dumps which can easily fill up a drive unless burned, or encode them and compress them to 4-6GB mkv files.

    My Screen is 50 inch Plasma and I'm sitting in 2-3 meters distance when viewing, and this is why compression is a concern for me...
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  11. Member
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    Also depends on the content , and the quality of transfer to blu-ray from master. Some retail blu-ray titles have been low-passed or upscaled to 1080p, and barely have 720p actual resolved detail. In these latter cases downscaling to 720p and using 4-6GB will be hardly noticeable. On other titles there will be a huge difference with the proper setup
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  12. Member Abas-Avara's Avatar
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    I've never seen a true Bluray movie, only BR-rips

    sorry if I go off topic
    What would be better h264/AVC 15MBS or MPEG2 15MBS?
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  13. Member
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    Originally Posted by Abas-Avara View Post
    What would be better h264/AVC 15MBS or MPEG2 15MBS?
    It depends on the encoder and settings used. Some h.264/AVC encoders generate worse than high quality MPEG2 encoders. Some are more than 2x better (i.e. MPEG2 would need over 2x the filesize for equivalent quality)
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  14. Member Abas-Avara's Avatar
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    Originally Posted by poisondeathray View Post
    Originally Posted by Abas-Avara View Post
    What would be better h264/AVC 15MBS or MPEG2 15MBS?
    It depends on the encoder and settings used. Some h.264/AVC encoders generate worse than high quality MPEG2 encoders. Some are more than 2x better (i.e. MPEG2 would need over 2x the filesize for equivalent quality)
    I use Sony Vegas internal export settings.
    You have Mainconcept MPEG2 and Mainconcept AVC/AAC
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  15. Member
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    Originally Posted by Abas-Avara View Post
    I use Sony Vegas internal export settings.
    You have Mainconcept MPEG2 and Mainconcept AVC/AAC
    The licensed versions of Vegas' Mainconcept AVC and Sony AVC implementation are limited versions of their full featured encoders. They only offer a limited subset of their own higher end encoders. This results in low quality for AVC, almost the same as MPEG2 (worse in some ways, better in others). Anyways, this is getting off topic. Start another thread if want to discuss Vegas encoders
    Last edited by poisondeathray; 14th Feb 2010 at 10:48.
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  16. Member
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    Originally Posted by poisondeathray View Post
    Also depends on the content , and the quality of transfer to blu-ray from master. Some retail blu-ray titles have been low-passed or upscaled to 1080p, and barely have 720p actual resolved detail. In these latter cases downscaling to 720p and using 4-6GB will be hardly noticeable. On other titles there will be a huge difference with the proper setup
    Is it possible to know beforehand where the end result is coming from?

    Especially concerned about TV Shows. IS it possible that sources is an actual 1080p?

    BTW ho much disc space do Blu-rays use? Do they get close to 25GB or 50GB?
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  17. Member
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    Originally Posted by therock003 View Post

    Is it possible to know beforehand where the end result is coming from?
    No. You have to check it manually. There may even be differences from different versions of the blu-ray (eg. director's theatrical cut, limited editions, etc...)

    A crude way of checking is to resize to 720p then resize back to 1080p and check in avisynth. If there is a big difference, you know that source has over 720 lines of actual resolution. If there is very little difference, that source was likely low passed , filtered , upscaled , or a bad transfer.

    It matters, because 1920x1080 requires more bitrate than 1280x720 for a certain level of quality. If the source you have is only 1280x720 of actual resolution & detail, but upscaled or filtered, then it makes no sense to encode to 1920x1080 at a high bitrate

    Note the content matters too. If you have an action movie, or a movie with lots of grain for example, it will take a lot more bitrate than a slow moving drama with minimal grain to encode for a certain level of quality. So don't get fixated on a certain size like 4-6GB or a certain bitrate

    You can do these tests yourself, and that's really the only way to be sure with a particular source, and particular hardware setup

    Especially concerned about TV Shows. IS it possible that sources is an actual 1080p?
    Broadcast TV shows rarely have 1080 lines of true resolved resolution. When broadcasted interlaced , they are 1080i and each field at maximum has 1920x540 lines (540 lines). It's actually a bit more complicated and there calculations and Kell Factor (google it if you want more info). When broadcasting telecined content, the transmission bitrates are too low to have true 1080 lines of actual detail. The point is, the actual resolved detail is lower in either case. It is possible retail blu-ray versions of a series were transferred with 1080 lines of actual detail, but it's usually not the case from what I've seen

    BTW ho much disc space do Blu-rays use? Do they get close to 25GB or 50GB?
    Yes, the capacity is 25 or 50 GB, but remember much of that is often taken up by audio tracks, and other features.
    Last edited by poisondeathray; 14th Feb 2010 at 13:55.
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