Size prediction?

Acaila · 6th January 2002, 10:19

Maybe I'm understanding DivX4's workings incorrectly, but I'm hoping some people here can help.

DivX4 2-pass mode creates a logfile in the 1st pass which gets used by the 2nd pass to encode the movie. The only setting you can change on 2-pass second pass is the used bitrate. So shouldn't it be possible to create a program that can calculate the exact size of the final movie at any given bitrate based on the info in the 1st pass logfile?
I know DmirtyR's log editor does something like that, but not quite.
It sure would make fitting a movie on certain numbers of CD's a lot easier.

Acaila · 8th January 2002, 14:43

Doesn't anybody know the answer or is the question is too stupid? Either way I'd like to know.

ciler · 8th January 2002, 19:21

Hello,
I'm afraid that nobody knows the answer...
As far as I know it, even the guys from DivX Network are unable to give another answer than "compress and you'll see the size".
Another problem is that for a given bitrate, even videos with the same resolution don't give the same final size (it's close, more or less 10 Mo, but it's not the same thing...)!

For me the problem is in the fact that the codec don't estimate correctly is compression capacity.

6th January 2002, 10:19	#1 \| Link
Acaila Retired Join Date: Jan 2002 Location: Netherlands Posts: 1,529	Size prediction? Maybe I'm understanding DivX4's workings incorrectly, but I'm hoping some people here can help. DivX4 2-pass mode creates a logfile in the 1st pass which gets used by the 2nd pass to encode the movie. The only setting you can change on 2-pass second pass is the used bitrate. So shouldn't it be possible to create a program that can calculate the exact size of the final movie at any given bitrate based on the info in the 1st pass logfile? I know DmirtyR's log editor does something like that, but not quite. It sure would make fitting a movie on certain numbers of CD's a lot easier.

8th January 2002, 19:21	#3 \| Link
ciler Registered User Join Date: Oct 2001 Location: France Posts: 39	RE : predict size Hello, I'm afraid that nobody knows the answer... As far as I know it, even the guys from DivX Network are unable to give another answer than "compress and you'll see the size". Another problem is that for a given bitrate, even videos with the same resolution don't give the same final size (it's close, more or less 10 Mo, but it's not the same thing...)! For me the problem is in the fact that the codec don't estimate correctly is compression capacity. __________________ Black Rose of the Artist Clan

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8th January 2002, 14:43	#2 \| Link
Acaila Retired Join Date: Jan 2002 Location: Netherlands Posts: 1,529	Doesn't anybody know the answer or is the question is too stupid? Either way I'd like to know.