Content-type: text/html Manpage of avicalc

avicalc

Section: Misc. Reference Manual Pages (August 06, 2003)
Updated:
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ABOUT

avicalc is a small script to calculate some values which are very important for encoding videos: bitrate and resolution.

SYNOPSIS


avicalc [-Hh] [-c] [-m mode]
[-s size -d duration]
[-b bitrate [-f fps] [-a aspectration] [-r resolution]]

OPTIONS

-h: display usage
-H: display full help
-m: mode (bitrate|bpp|lr)

        bitrate - calculates the needed
          br for a wanted endsize of
          an avi of a given length/duration

        bpp - calculates the bits per
          pixel-rate for a given resolution,
          bitrate and frames per second.

        bpb - calculates bits per block (16x16)
          for a given resolution, bitrate
          and frames per second.

        lr - display a lot of resolutions
          and the responding bpp's. enable
          colormode to see what would look
          ok.

        lb - display a lot of resolutions and
          the responding bpps/bpb for a list of
          bitrates

-s: wanted size (x|xKB|xMB)
-d: duration (in seconds)
-b: bitrate (in kbit/s)
-a: aspect ratio (16/9|4/3|1.33)
-r: resolution (widthxheight)
-f: fps (25 is default)
-i: increment (for -m lb)
-c: color mode

BPPS

red: : < 0.10 : don't do it. please. i beg you!
yellow: : < 0.15 : It will look bad.
cyan: : < 0.20 : You will notice blocks, but it will look ok.
green: : < 0.25 : It will look really good.
white: : < 0.25 : It won't really improve visually. magenta : > 0.30 : Don't do that either - try a bigger resolution instead.

EXAMPLES

calculate br for 5 minutes of the movie that will result in a 10mb - file:

    $> avicalc -m bitrate -s 10mb -d 300  -> 279kbit/s

calculate the bpp for this movie:

    $> avicalc -c -m bpp -r 512x244 -c -b 279 ->  0.8 bpp

last output should be displayed red for showing it wont look good for sure. so, display some more resolutions to getting near the final resolution:

    $> avicalc -c -m lr -b 279 -a 16/9

now choose one of the cyan or (better) green marked resolutions for encoding the avi.

LINKS

the main-source for this script:

    http://www.mplayerhq.hu/DOCS/tech/encoding-tips.txt

AUTHOR

mathias gumz <gumz at cs.uni-magdeburg.de>

BUGS

not yet known

This document was created by man2html, using the manual pages.
Time: 10:37:17 GMT, August 06, 2003