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  1. hello
    can someone tell me the difference between mpg.1 and mpg.2?did you ever tryed to encode a mpg.1 with value of mpg.2(till 2500 rates)?i mean if i sit on my couch(5meters away from tv) you almost can't see a difference between a high encoded mpg.1(xvcd) to a mpg.2 svcd.so what is mpg.2 able to do what mpg.2 can't(only picture).i mean you can see really diffrences only from 5000rates on,and this is almost dvd.

    so we can say mpg-filesize=quality(doesn't matter mpg1 or mpg2 as far player support it)

    maybe you belong to people they hear a diffrence between a mp3 coverted cd to an'original:-)

    greetings

    crossflight

    people who see my xvcd ask me if it is a dvd.
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  2. Member adam's Avatar
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    Your post is pretty hard to make out but you are largely correct. At the same bitrate and resolution mpeg1 and mpeg2 should look roughly the same. Mpeg2 does have some real benefits over mpeg1 but if you don't take advantage of them then you won't notice a difference.

    Things which mpeg2 supports that mpeg1 doesnt...

    1)Interlacing. If you have an interlaced source than you can achieve substantially better quality by encoding in mpeg2 as opposed to mpeg1.

    2) Non-linear quantization. This is more of a mathmatical benefit and not really something you will see with your eyes, but still it does help.

    3) Higher DC precision, 8-10 whereas mpeg1 only supports 8. This will only be beneficial at high bitrates such as over 4MB's and lower than this a higher DC will actually lower quality.

    4) Overlayed subtitles so you can have multiple subtitle streams which can be turned on and off, even on a SVCD.

    5) Multichannel audio. You can have up to 7.1 channels of audio, though few players/recievers will play it. More practicly you can have 4 mono or 2 stereo tracks in a SVCD. So this allows for true multilanguage disks in stereo which VCD cannot have.

    6) Native support for VBR and higher bitrates in a standardized cd format. (Maybe VBR mpeg1 >1150kbits is supported in DVD standard, I don't know. )You can encode mpeg1 in VBR and at high bitrates but there is no cd based format that actually supports this, so hardware playback is not guaranteed. Even though an XVCD might actually be more compatible overall than a compliant SVCD, at least you can be certain which players will support SVCD, whereas it will be a toss up as to which players support XVCD.

    I'm sure there are some more benefits but these are the major ones. Like I said, you will only see a difference between mpeg1 and mpeg2 if you actually take advantage of these benefits.

    A Ferrarri doesn't perform any better than a Geo Metro if you are only going 20mph.
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    Originally Posted by adam
    A Ferrarri doesn't perform any better than a Geo Metro if you are only going 20mph.
    great finisher to a detailed explanation.

    crossflight, try encoding two test cdrws with 3 minute clips.
    set both to 720x480 resolution
    set both at 4800 "cbr" not vbr(encoder of your choice, just use the same for both)
    notice the answer for yourself

    everything else that adam stated is why we use mpeg2 instead of mpeg1. after about 2700(45 mph in geo terms) mpeg1 is on a fast and staedy decline in performance.

    also, we don't notice this because we set our bitrates manually, mpeg2 has a greater compression then mpeg1(although in terms of straight compression-divx is the super souped Lamborghini that pulls up and stills your woman from the front seat of your ferrarri )
    Where I walk, I walk alone. Where I fight, I fight alone.
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  4. Originally Posted by jkl
    (although in terms of straight compression-divx is the super souped Lamborghini that pulls up and stills your woman from the front seat of your ferrarri )
    yea...but also consider the big increase in CPU (and overall system usage) when playing divx as compared to VCD or even SVCD

    not all comps can handle that much...
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  5. hello
    ADAM; now it is more clear as before.the audio stream make the big diffrence between mpg1 and mpg2(till 3000 bitrate).the picture diffrence you will see only at a high bitrate(near at 5000).

    ADAM and JKL;if i would encode with bitrate near at 5000,i would burn a dvd.i this case with mpg2 anyway.dont you think?

    sorry POOPYHEAD,but what has divx(avi) to do with mpg?

    ok,to be honest,i don't know why a divx(avi-format) is also called mpg 4.

    thank u 4 repling me.
    greetings

    crossflight
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  6. Member adam's Avatar
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    At a high enough bitrate the other benefits in video quality of mpeg2 become moot, since you can't see any flaws in either case, mpeg1 or mpeg2.

    But regardless of what bitrate or settings you use mpeg2 supports interlacing and mpeg1 doesn't. With an interlaced source mpeg2 should yield superior results at any bitrate, this is the main benefit of mpeg2 over mpeg1.
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  7. Member
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    Originally Posted by crossflight
    ADAM and JKL;if i would encode with bitrate near at 5000,i would burn a dvd.i this case with mpg2 anyway.dont you think?


    its the "format" of the entire disc that makes it a dvd svcd vcd.
    even though not compliant-a dvd with a video bitrate of 1400kbs is still a dvd,although not great quality. and a svcd of a video bitrate of 9000kbs would still be a svcd(alright xsvcd) although i don't know where you would play it.
    Where I walk, I walk alone. Where I fight, I fight alone.
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  8. The Old One SatStorm's Avatar
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    In a way, when a standalone reads mpeg 1, is like reading a "null" mpeg 2.

    @Adam: About DVD @ 352 X 288/240 > 1150kb/s VBR: I have the same question! I tested mpeg 1 on DVD discs in generall with no probs @ any resolution/bitrate! But maybe the DVD standalones I tested that was flexible in -x- matters.... If you ever discover the truth for this, please post it and add it in the infos for mpeg 1 on DVD!
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