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  1. Member beammeup's Avatar
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    Hi,

    I have been capturing HDV ( 1440 x 1080 x 25fr interlaced ) with the latest Vegas HD Movie studio.
    I then encode to PAL DVD widescreen specs.
    My problem is that the bitrate calculator i have been using for years for AVI to MPG2, is no longer accurate
    for these larger and more complex HDV files it seems and I end up waiting 2 - 3 hours just to find out my
    MPG2 file is a few hundred mpg too big for DVD.

    Example ... i just encoded a 68 min HDV at 7900kbs + 192 audio and ended up with a 4.5g mpg2, however
    my current bitrate calcultor said i should be OK with approx 8500kbs

    I can't find a suitable calculator for HDV to DVD

    Any tips ?
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  2. I'm a MEGA Super Moderator Baldrick's Avatar
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    Have you checked the average bitrate in the encoded mpg with for example Bitrate viewer?

    What does fitcd or https://www.videohelp.com/calc calculate with same settings? They include the dvd/mpg overhead data also.
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  3. Member beammeup's Avatar
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    Thanks for the info. https://www.videohelp.com/calc doesn't predict an accurate size mpg2 DVD file in regards to HDV to DVD widescreen specs, as I've tried this previously. I will however do some analysis on my DVD mpg2 files to see if Movie studio isn't bumping up the bitrate without my knowledge.

    cheers
    Scott
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  4. I'm a MEGA Super Moderator Baldrick's Avatar
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    The source or if it's widescreeen doesn't matter. But compare with FITCD, it's even more accurate.
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  5. The source of the video makes no difference to the bitrate calculations. Only the properties of the output video matter. If your getting files that aren't the right size your encoder is screwing up. Or the calculator is wrong.
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  6. Member AlanHK's Avatar
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    Originally Posted by beammeup View Post
    I end up waiting 2 - 3 hours just to find out my
    MPG2 file is a few hundred mpg too big for DVD.

    If it's just a few percent too big you can compress the MPEG very quickly using Rejig.

    I encode using HCEnc; it seems very accurate in hitting the size selected.
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  7. Member Cornucopia's Avatar
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    Simple math:
    7900+192=8092 kbps
    68 min * 60 sec/min = 4080 sec
    8092 * 4080 = 33,015,360 kb
    33015360 / 1024 kb/Mb / 1024 Mb/Gb / 8 bits/Byte = 3.94 GB

    This says that "IF" your encoder is encoding at an average bitrate that you set it at (7900v+192a), it will fit. No 2 ways about it. Can't be "wrong calculator".

    The problem is with your encoder. It either isn't set to that correct bitrate, or it's set to some VBR/CQ setting that is letting it vary enough that the average is NO LONGER what your target average is supposed to be, or you have a crappy encoder.

    What are you using, Vegas HD Movie Studio? What are the settings?

    Scott
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