Steven M. Schultz:
you can use this checklist when preparing a video bit budget:
Total Size of a DVD disk = 4700000000
subtract 5% as a reserve (DVD .ifo,.bup, UDF info,)
subtract audio. With 192Kb/s this works out to 1440000 bytes/minute.
subtract the still menus, guidline is 100000 bytes/menu
As an example, assuming a 90 minute video with 192Kb/s audio and 3 menus:
4700000000 - 427000000 - 129600000 - 300000 = 4143100000 ^^^^^^^^^ If I haven't made a mistake in the arithmetic that works out to:
4143100000 bytes / 90 min = 767240 bytes/sec or 6137920 bits/sec
you'd use "-b 6140" to the encoder. Maybe a little more but that is a good starting point. The default of 7500 will be too high.
If you've motion menus, transitions, and so on then they take up space that needs to be taken into account when figuring the bit budget.
Sorry for the delayed quote and nit-picking but where does that "427000000" come from?
Isn't 5% reserve from a 4700000000 byte DVD _235000000_ bytes?
BTW, is it OK to assume in these kind of calculations that 1 kb/s always equals 1000 b/s in the data _rates_? And 1 kb equals 1024 b otherwise?? Or do different encoders use different multipliers?
Thanks for the nice guideline.
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