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View Full Version : One Pass "Q" Mode : big oversize!!!


TuRiSOft
24th May 2004, 19:47
- Added a One Pass VBR mode for those who are using CCE SP. It performs sampling pass(es) during PREPARE phase that predicts an appropriate Q rating based upon the space available. That Q is then used for a one pass encode. Total time for an encode is reduced dramatically while quality is maintained at a known level. This is the first iteration of this set of routines and its still being tested, so some level of sizing error is expected. Please provide feedback in the DOOM9 rebuilder forum. Note added: It seems to be oversizing consistently. I will do some mods and post a fix soon.

I just did a Title of my own (only testing).
It was "Lo chiamavano Trinità..." and its original size is 7,80 Gb.
The structure is real simple :
VTS1 contains the Main muxed with two audio streams (It 5.1 AC3 and IT 1.0 AC3 and i kept only the 5.1 one)-6.81Gb-;
VTs2 -28.1Mb-,3 -414Mb- ,4 -404Mb-,5 -136Mb-,6 -2,69Mb-are Extras with only one Audio stream (IT).
DVD-RB selected VTS1,3,4,5 for re-encoding.
I tried it with Half D1 and Half bitrate cheked and as a result I got about 700Mb oversize (but a real speed up , only three hours to do all things).
Then I tried it with Half D1 and Half bitrate uncheked and as a result i got 781 Mb oversize.
I noticed that DVD-RB calculated a Q factor of 28 in the first case and 26 in the second case for VTS1 , but for vts3,4,5 in the first case it used Q=1 , in the second respectively q=18 for V3 , q=1 for V4 and q=1 for V5.
I think DVD-RB does the check on a "too-small piece" of video.
I got no rooms to post Rebuilder.ecl , Analysis.ecl and Rebuilder.inf of the second try (the first ones I put in Trash).
I'm keeping them as backup.
If they can be useful please let me know and I'll send you them.
bye!!!

juan0r
24th May 2004, 22:11
In this (http://forum.doom9.org/showthread.php?s=&threadid=76663) thread the problem is currently being discussed.

jdobbs
25th May 2004, 01:05
It's a known bug... it may take a couple of versions before I get this reasonably accurate.

TuRiSOft
25th May 2004, 09:15
Have you ever been here --> http://forum.doom9.org/showthread.php?s=&threadid=68527 ?