presets don't seem to do what they promise...

yes that's what i noticed too.
unfortunately, the difference is a bit bigger than the amount that dvdsp's disc size meter is out...

i currently have 4 or 5 projects of this size to finish all with similar durations and problems. yesterday i tried building some of them and ended up with builds that were too big for the medium (5GB or over)

my biggest problem is predictability in compressor;
in the inspector panel, only the slider for the average bitrate seems to affect the prediction of how many minutes will fit on a disc while the slider for maximum bitrate has to be used in the blind as compressor's preview is utterly useless. it bares no resemblance to what i see on the television after burning....

generally, it would be nice if a preset that advertizes to fit 120 minutes on a dvd5 disc, would _actually be able to fit 120 minutes on a disc and not waste 6+ hours in rendering only to find out that it is 500+MB too big...
(and this is rendering on a quad processor machine...)
</rant>

robert,
i have to say i'm very unimpressed with both one pass and dual pass processing by compressor - both in terms of quality and speed. on a quad g5 i only see 25-30% cpu usage...
basically, anything over 1.5 h starts to look like vhs, even with slow dual pass processing

chris,
it seems a lot of people here are using either bitvice or megapeg.x as software alternatives to compressor.
yesterday i came across compression master.

am wondering if someone did a comparison of these packages under different circumstances.
other than that, i guess i'll be doing tests with demos these days 🙂

thanks

for now, it doesn't seem to work on a quad g5 - http://www.innobits.se/f/index.php?topic=1045.0 - which is a bummer as that is my main machine.... 😟
i guess we'll have to wait for version 1.7 to materialize...

it __should fit but it did not - and i only found out after i had rendered the project and mastered the dvd (as noted here, the disk size meter in dvdsp is off), forcing me to re-do about 3 hours of work.
as i will need to master 3 to 5 discs of this size per day in the coming months, it seems compressor will simply not do.
am currently running tests with bitvice and megapeg.x to see how they hold up.
so far, i'm partial to megapeg's approach of emphasizing max bitrate and quantization floor as those two are a lot more important for what you eventually see on the monitor than the "average bitrate"

thanks for all the suggestions so far

roger,
good to see you here online too 🙂

That may be true, but "max bitrate" and "quantization
floor" cannot give you any control over the final
file size. Only the "average bitrate" can do this.

while it is frustrating when you end up with an m2v that's too big for the disc it was supposed to fit onto, my clients tend to make a bigger fuss out of blockiness and other compression artifacts

and probably the ultimate encoding is a good balance between all 3 parameters - so far however encoders seem to fall into two categories, both emphasizing a different subset of these or a different combination of these.
which works for you may then also depend on your way of looking at the problem...

Divide the file size (in bits) by the duration (in
seconds), to get the average bitrate that your
encoder generated, as opposed to what you told it to
do;-)

that's what failed for me with compressor - resulting in 5+GB discs for 1h50m of material, using the 120 minute per disc preset....
btw audio was ac3 at 192

This is why you can trust BitVice not to generate bigger files than you ask for.

still looking forward to that version 1.7 of bitvice later this week to finally see how it will do on a quad g5 🙂

since the topic seems to drift to more general encoding problems, i'll mark this one as "answered" even though the answer seems to be varying between "do the math yourself" or "use other encoders"....
at least it's clear i wasn't the only one having this problem with compressor..... thanks all for the replies!