Re-doing the second pass of DivX4 with a different bitrate?

[Mithrandir]

Hi, I've been fooling around with DivX4 2-pass lately, and I usually end up getting files a lot smaller than my optimal size, so I want to fiddle around with them until I get the right size.

However, doing a full 2-passes again takes a lot of time, so I'm wondering... can I re-do the second pass with a different bitrate with the same log file as the first pass? Will this mess anything up?

Thanks!

[guitar_george_skank]

I haven't really had much experience with encoding in divX but here's my thoughts...

The first pass is to allocate the bitrate effectively, i.e. higher bitrate for high motion scenes etc. Changing the actual bitrate for the second pass will mean that the first pass is no longer valid as a higher or lower bitrate will need allocating differently.

Of course if someone knows otherwise...

GGS.

[Mithrandir]

see, the way I understand it is that the first pass just figures out which frames need more, and allocates a percentage of the total bitrate to each frame, not a specific amount?

I dunno.

[hoola_loop]

i jsut read the topic again. im not sure seeing you want to use a different bitrate i would think you woudl have to do the whole thing over again. the 2pass first pass analize info would be useless(i would think) because you want to change the bitrate. i most likely am wrong though

maybe cut out a 3 minute clip and test on that. i would like to hear if you figure this out. cause it is irritating to wind up with a 360mb file when you calculated it for a 640mb file.

But....i also think that you wind up with a smaller file because the bitrate is maxed out for the movie. **dark scenes and such**
in my tests on some movies it dont matter if you set your bitrate to 850 or up to 1400 the file will remain the same give or take 30 or so mb. on really really dark movies bitrate calculations involving divx are way off.

[Mithrandir]

But....i also think that you wind up with a smaller file because the bitrate is maxed out for the movie. **dark scenes and such**
in my tests on some movies it dont matter if you set your bitrate to 850 or up to 1400 the file will remain the same give or take 30 or so mb. on really really dark movies bitrate calculations involving divx are way off.

yeah, no kidding; I did a DVD Rip of Dark City last night, and was aiming for 2.05gb (3cd), and it ended up at 1.2gb... whoa.

[Mithrandir]

Well, it appears that you can! I just re-did the second pass at a higher bitrate, and the file works perfectly at the new bitrate!

hooray!

[hoola_loop]

hey KUDOS!!! that will save tons of time. :P :P