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  1. problem: I have a iso image of a DVD wich has 7GB, and I want to leave ac3 audio untouched, but encode the mpeg2 video to a just enough small file size to prevent any quality loss, artifacts, reduction of pixels, resolution

    questions:
    what is the most advanced codec for this purpose? is it x264? if so, what is the best tool for encoding dvd's to x264? what is the best guide to teach me how to do this, but not necesarily an easy guide, it can be any guide that gives the most professional results no matter how much time it takes, while making sure that audio is perfectly synchronized; how do I determinate what is the sufficient video bitrate in order to not loose any quality, but still have the smallest file that it can have in order to maintain full quality, within reason.
    Last edited by codemaster; 8th Feb 2011 at 16:59.
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  2. Always Watching guns1inger's Avatar
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    What are you going to play this on ?
    How small do you want the final output ?
    Read my blog here.
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  3. Member edDV's Avatar
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    Just burn the Iso to a DVDR dual layer. Done.

    Any recode will cut quality.
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  4. guns1inger: to play it only on PC (with mpc-hc or vlc), I don't care if it doesn't work on standalone dvd players, or on macs, I only want to use the most advanced, most powerful tools that we have at present, to encode this huge mpeg2 video to a video file that has a file size just enough to avoid ANY loss in picture quality (of the original dvd), but not larger, that is why I also need a method to find out what bitrate it should have, but it has to be based on the actual content of the frames I believe, to find the right ballance between quality and file size

    edDV: the goal is to watch it with .srt subtitle on PC, and not occupy so much hdd space, just enough so that the source dvd quality is maintained as much as possible, hence the question about the most advanced codec
    Last edited by codemaster; 8th Feb 2011 at 17:27.
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  5. Member edDV's Avatar
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    Is the content 576i/25 interlace or 576p/25 film or other?

    If interlace, h.264 doesn't re-compress as well. If progressive, figure 0.7x bit rate for low recode loss, 0.5x for adequate quality.

    If you have access to the D1 or DigiBeta masters, you could encode to about half MPeg2 bit rate at same quality.

    Keep in mind 10 bit uncompressed D1 (SMPTE 259M) is 270 Mb/s (including audio).

    Digibeta is 3x compressed at about 90 Mb/s. Gives you some appreciation of how compressed a DVD is and why it makes a poor copy source.
    Last edited by edDV; 8th Feb 2011 at 17:39.
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  6. Always Watching guns1inger's Avatar
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    Use Handbrake or XmediaRecode and do a quality based encode. XmediaRecode will allow you to put AC3 in an MP4 container, or you can sue MKV if you prefer. Doing a quality based encode means the file be the size it needs to be, based on the quality level you select - i.e. you have no control over the file size. Start with a Constant Quantizer encode with a value of 21 and do a test encode. Then test again at 20 and 18 and see what suits your needs.
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  7. Member hech54's Avatar
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    Originally Posted by codemaster View Post
    to encode this huge mpeg2 video to a video file that has a file size just enough to avoid ANY loss in picture quality
    #1) 7GB is not huge. That is a normal DVD.
    #2) There WILL BE QUALITY LOSS.
    #3) Read #2 again.
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  8. Member AlanHK's Avatar
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    Originally Posted by codemaster View Post
    problem: I have a iso image of a DVD wich has 7GB, and I want to leave ac3 audio untouched, but encode the mpeg2 video to a just enough small file size to prevent any quality loss, artifacts, reduction of pixels, resolution
    What is your purpose?
    If you need to save space, how big do you want to make it?
    If you don't need to save space, you can just play the ISO directly as if it were a disc, in eg VLC.

    Or you can use DVDshrink-- you don't have to "shrink" the main video, but there are usually several audio tracks in various languages you could omit (though you might want to keep the commentary track), also subtitles (though these are pretty small), and DVD extras, many of which aren't worth watching once, let alone archiving. Just trimming the stuff you don't want may save you a few GB.
    Last edited by AlanHK; 9th Feb 2011 at 03:07.
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  9. 1) Daemon Tools to mount ISO image.
    2) DgIndex to build an index file and export AC3 audio.
    3) AviSynth to open index file -- Mpeg2Source("filename.d2v").
    4) x264 CLI to encode as h.264.
    5) MMG to mux audio (from step 2) and video (from step 4) to MKV.

    As others have noted, you will lose quality any time you recompress a video. I use x264 in CRF mode at 18 where the loss is very small. This typically gives a MKV file that is about 1/3 the size of the DVD VOBs.
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