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Tip: online DVD/SVCD/VCD bitrate calculator....

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  • Tip: online DVD/SVCD/VCD bitrate calculator....

    IF you don't have any other MPEG bitrate calculator for DVD/SVCD/VCD you can use the online one at GuyGraphics;



    Dr. Mordrid
    Dr. Mordrid
    ----------------------------
    An elephant is a mouse built to government specifications.

    I carry a gun because I can't throw a rock 1,250 fps

  • #2
    Interesting! I tried it out over a couple of recent projects and it was roughly right. However, it doesn't take into account the subject matter. With MPEG-2, the data recorded in the intermediate frames is very dependent on the differential movements within the frame, compared with the key frame, so that, if there were a lot of movement (e.g., panning racing cars from the side of the track), it may give a too-high bitrate figure. Conversely, if the camera is tripod mounted and looking at a talking head with a plain, static, background, you may be able to squeeze a lot more in at the indicated bitrate. My last project was for a roughly 44 minute SVCD and I made an inspired guess at the bitrate and the mpeg-2 file, from TMPGEnc VBR, came out at exactly 700 Mb. I swore an awful cussword, but went ahead anyway and Movie Factory told me I needed 632 Mb, so I burnt it and it worked! This calculator told me to use 1835 kbit/s average and I actually used 1900. The subject matter possibly had slightly less than average movement.
    Brian (the devil incarnate)

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    • #3
      Well....taking into account subject matter and the effects of motion compensation *would* make it a bit more accurate, but I think they did a bang-up job in providing this to their customers.

      Dr. Mordrid
      Dr. Mordrid
      ----------------------------
      An elephant is a mouse built to government specifications.

      I carry a gun because I can't throw a rock 1,250 fps

      Comment


      • #4
        Yes, I agree. Notwithstanding, it is well to state that the results should not be taken as gospel truth and it may be wise to lower them a tad if you know you have a lot of movement (or camera shake ).
        Brian (the devil incarnate)

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        • #5
          Since it takes so long to render I just use "worst-case" estimates

          8000 Kbps for 1hr
          7000 for 1 hr 15 min
          6000 for 1.5 hr
          5000 for 1hr 45 min
          4000 for 2 hr

          This always leaves a bit of head room for the bug in DVD Movie Factory where it can't set chapter points in files >4GB.

          I ideally one of the encoder parameters would be "total project length" and this would calculate an average bit rate and be a parameter for the VBR encoding.

          --wally.

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          • #6
            Wally

            This sounds reasonable. The above on-line applet "calculates":

            9346 Kbps for 1hr
            7922 for 1 hr 15 min
            6564 for 1.5 hr
            5594 for 1hr 45 min
            4867 for 2 hr
            and goes haywire for 2 h 15 min !!!

            I agree that a little headroom is desirable, not just for the valid reason you stated, but because of unexpected increases in file size (which can and do happen).
            Brian (the devil incarnate)

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