Question/Request: Manual Q-value settings for CCE OPV

[nashcity]

I use CCE OPV for most of my movie backups, partially because of speed, but mostly because I've compared the results with CCE multipass on multiple DVDs, on multiple TVs, and I really do believe CCE OPV looks better. Of course, the main drawback is unpredictable sizing, but most of the time I end up with sizes in the 4.24 - 4.37 g range. Occasionally, the DVD ends up very much undersized, in the 4.11-4.19 g range. I usually try to change the Q_sample_percentage when this occurs, but most of the time it makes no difference.

For example, I'm currently trying to backup The Chronicles of Narnia. It states that the TargetSize is 1,795,559 sectors. A Q-value of 12 yields a predicted size of 1,788,268 sectors. Pretty good right? Usually this ends up with very good sizing, but the final sizing ended up being 4.20 g. I tried to mess with the Q_sample_percentage, but with the predicted size being so close it makes no difference. I would love for some way to select a Q-Value of 11, but that's impossible right? I know that would yield a size closer to 4.38 g, in my experience so far Q+/-1 usually add/subtracts about 100-150 mb to the final size.

So my request would be: How about a manual Q-Value setting for CCE OPV? Maybe an additional option when the User selects OPV to either use the standard sizing algorithm, or use a manual Q-value.

Love the program, many thanks.

[jptheripper]

is the q in opv editable with rb-opt? i think it is

[robot1]

is the q in opv editable with rb-opt? i think it is
Yes, it is.

[nashcity]

Thanks for suggesting Rb-opt, I tried it and yes I see how I can use custom Q-values.

What I found interesting was that Rb-opt divides the movies into seperate vob-ids, so if you use their opv prediction, you could get varying q-values for different parts of the movie. DVDRB seems to use a constant q-value for the entire movie. I guess what I'm wondering is, which is better? Am I correct in assuming DVDRB goes with a sort of "average q-value" over the entire movie, while rb-opt uses a potentially different q-value for different parts of the movie?

[jdobbs]

I did a lot of testing on DVD-RB with Q values when it was first implemented. My experience is that, while using different Qs for each segment can make the sizing more accurate (which I would guess is why it is done that way in RBOpt) -- I don't personally like the change in quality that can happen at each segment point... it is too inconsistent. I'd personally recommend a single Q for an entire VTS.

[nashcity]

I think I agree with you jdobbs, that is my concern as I use this rbopt method. So, using my original post example with Chronicles of Narnia, I could just manually use a Q-Value of 11 for all segments in rbopt, correct? That should allow me to do what I intended to do I'm thinking. Is there anything I'm missing?

On a side note, does rbopt allow you to look at menu segments? I didn't see any when recently used it for CofN.

[nashcity]

Sorry, just another question, is there a good way of "installing" rbopt, or do you simply run the .exe file after DVDRB finishes the prepare stage? I notice DVDRB had an addons folder in the start menu, just wondering if there was anyway to open rbopt from withing DVDRB.

Thanks.

[jdobbs]

No, sorry. The plan has always been to, at some point, improve the Segment Editor so it would include most of the functions in RBOpt... I've just never gotten around to doing it.

You could also open the REBUILDER.ECL file in notepad and if, for example, the selected Q was 12 and you wanted to change it to 11 you could do a global replace of

opv_q_factor=12

with

opv_q_factor=11

[nashcity]

Thanks for the suggestion, I'll try that.