minimum bitrate??

[nad]

Is it necessary to change the minimum global bitrate during the CCE configuration?

I ask because I always set it to 0 before the first pass and before the multi-pass just as the DOOM9 guide suggests..

And when I increase the global minimum bitrate from 0 during the VBR Advanced configuration, (to remove gray areas).... It doesn't seem to have much-very little-of an effect as long as the average bitrate is higher. It doesn't increase or descrease the size of the output file at all.

So I am wondering if I should leave this at 0 and only increase the average??? Does increasing it have any negative playback effects? Does keeping it at 0 produce bad results or better results?

Here is my settings:

1st pass: minimum-0, maximimum-8500
VBR 3pass: minimum-2000, average-4500, maxiumum-8500

Does this look OK?... or is it conflicting? I went ahead and put it at 2000.. Should I have left it at 0 since the first pass was done at 0, or does the first pass matter at all?

BTW, I found maximum of 8500 to work well with Scenarist... I can never get 9800 to mux without the underflow error due to max bitrate too high... Also 4500 average is the max I can go to keep the movie on one disc.

[jdobbs]

I really don't understand the point of increasing the minimum bitrate from 0 to 2000. All that does is force the encoder to use more bits than necessary for low demand video portions.

When you set the average bitrate it is going to fix the output filesize (give or take a little) and create the balancing point for allocating bits. When you raise the minimum bitrate it steals bandwidth from complex scenes and uses it for scenes that may not really need it.

If you set the minimum to 0, the encoder will still allocate 2000 on the low end if and when it is needed -- in some instances it may never go below. But by setting the minimum to 0 you've given it the opportunity to allocate bits more efficiently.

According to CCE documentation, the "DVD Compliant" box is supposed to prevent instantaneous bitrate spikes abover 9.8Mbs within GOP units. Did you have that set?

[nad]

Thanks, I will keep it at 0 from now.. Very helpful information and good reason.. I was a little unsure about minimum bitrate.

Yes, I always set DVD Compliant... but Scenarist always gives errors when maximum is set to 9800..

I am not the only one. Seems that many others who use 9800 get this problem with Scenarist too..

Other programs like SpruceUp work fine. Scenarist is very picky.

[jdobbs]

Yeah, I find that to be true on the GOP configuration also. I can set the GOP to 15 frames and SpruceUp with take it every time -- not so with Scenarist.

[nad]

Multiple PGCs is the problem.. I wish I could just use SpruceUp.

Most of my movies have multiple PGCs and usually there is at least one of those extra PGCs required for the DVD to play back correctly without illegal navigation.

Like, for example, Ocean's Eleven.. I am having problems. PGC1 is the main move which uses VOB IDs 3 and 4... and PGC2 is the warner logo and PG-13 rating screen using VOB IDs 1 and 2. Now, when you play the DVD from the beginning, it starts PGC2 before it even gets to the menu (it is supposed to do that). And then when you select "Play Move" from the menu, it starts from the beginning of PGC1. I am a little confused on exactly what to do.

First, I assume I first use smart ripper to extract PGC2 (m2v and AC3)

To begin with, In the Scenarist VOB set, VOB ID1 will be PGC1 and VOB2 will be PGC2.. That is just the way it creates it.. Of course PGC2 plays before PGC1. Will that be a problem that VOB ID 2 has to play before VOB ID 1? Or would that be fine as long as the cell sectors are set properly and in order?

Also I was wondering... Are there any cases in which it is absolutely necessary to re-encode the extra PGCs that are required? They are very small and I assume that it is not necessary if they barely take up space? Or should I always be able to use the original m2v file? Because it seems that the time stamps are weird when the are not re-encoded.. because the first scene in PGC2 has a time of 1:01:00:00 in Scenarist?? That can't be right.

[jdobbs]

When you want to dump the Warner Logo that precedes the menu, you can just modify the command in the First Play PGC of the Video_TS.IFO file using IFOEdit. In Oceans Eleven I set it to go straight to the menu. You can do that kind of thing (or something similar) most of the time to make it work. The pain comes when they mix the movie with things you want to keep as multiple PGCs in the same VTS. Luckily that doesn't happen very often.

[nad]

I guess you have worked with Ocean's 11.

So, I am able to just keep VOB IDs 3 and 4 which are the main movie of Ocean's Eleven? And then modify the VIdEO_TS.IFO file as you said? What about PGC 3-7 of Ocean's Eleven? They contain teasers, trailers, or other logos? Can these be stripped out too?

What about with other movies with multiple PGCs that play AFTER the main movie? Can I usually strip out these PGCs also? And not worry about the FirstPlay since they play after the main movie PGC?

[jdobbs]

If you don't care about them you can dump them. But if you want to keep them you can do a couple of things. First you could just use Scenarist (as you are aware). If you create them as separate M2V files and drag them into SpruceUp (for example) they will be written as independent VTS's. You can then take those and rename them as if they were part of the same VTS. For example, assuming you have 3 .VOB files in VTS_01... you could then:

Rename VTS_02_1.VOB to VTS_01_4.VOB
Rename VTS_03_1.VOB to VTS_01_5.VOB etc...

You still have to update the sectors/cell pointers. I'm looking at a way to make IFOUpdate do that work for you if you create your file this way.

[nad]

I really appreciate your help... IFOUpdate is very helpful too.


Next time I work with a movie that has Warner Logo, PGC2, play before the menu and PGC1, I will try to edit the VIDEO_TS like you said.



As for PGCs after the main movie... I usually never care about them.. or they are pointless, but your SpruceUp method makes sense. I assume that renaming would also work for PGC2 which plays before PGC1 if I am using SpruceUp and want to keep Warner Logos?


Also, does IFOUpdate update all sectors/pointers for every cell of just for cells that are chapters?

[jdobbs]

IFOUpdate updates based upon the configuration of the newly authored IFO.

It cycles through each PGC of the newly authored IFO and for each it makes changes to the original IFO. It:

1. Does error checks and makes sure it will fit.
2. Corrects the chapter and cell count to match newly authored.
3. Corrects the BCD time to match the newly authored.
4. Fixes the pointers at offset E4 - EA to match output.
5. Copys a complete block of information including:
a. PGC Program Map
b. Cell Playback Table
c. Cell Position in VOB Table

The reason I did it that way was to make it unnecessary to build the new IFO with the exact VOB and Cell information of the original. All you have to do is make sure the chapter count and times match so jumping to chapters from the original menu works.

A new version I'm working will also have an option to just copy cell information -- but that implies you have authored the new set with VOB/Cell parameters that match the original.

[JJF007]

The Problem with Scenarist and a max. Bitrate set to 9800 is, that Scenarist can have only 9800 completly for all streams, that means movie, audio and subtitle.

So if you have one stream with 384kbs you can set only a maximum Bitrate in CCE to 9400!

I don't know if other DVD Authoring Tools handle this the same way, but i thin they do it, because Scenarist is a Pro Authoring Tool!

[nad]

Thanks I understand now...

But does Scenarist need all video and audio assets to add up to 9800?? Or just each track.. Like if I had m2v/ac3 file for PGC1 (main movie) and m2v/ac3 file for each additional PGC that I am keeping, does it look for 9800 total for each track/PGC or for all PGCs combined?

[jdobbs]

Each track. The maximum bitrate is not an additive attribute. It just sets a limit on how fast the data can be transferred (peak).