Imoprovement possible by segment bitrate distribution ?

[apfraats]

Ok, let's stay with the segment bitrate distribution.

Is it possible to make an extra setting in DVD-RB-PRO that does the following:

1) First determine average bitrate for whole movie and for the segments.

2) Make a variable to increase by x% the bitrate on segment's above the total avarage, so they get more bitrate, and steal this bitare equally from segments =< average dvd bitrate (after compression).

In this way, the segments with action scnenes get's higher bitrate allocation and it is stealed from the segments with lower than avaerage bitrate for the DVD. As most movies have just a few parts with high action, these segments could be 'tuned up' in bitrate and the other segments could be tuned down.

This why even with BIAS=0 the encoders (like HC and CCE) can't ceep up the original quality when there are sudden peaks scenes (these get blocking as a result).

So the DVD is ok, besides a 2 or 3 scenes with high bitrate.

If you could steal some bitrate of the lower demanding scenes and add this to the few higher bitrate scenes it would greatly improve final result especially at lower averages.

You can decide to leave this setting at 0%, but also set it to 20%, meaning you'll get:

|--------2000-------|-------3000------|------2000------|

will be adjusted to

|-------1850--------|-------3300------|------1850------|


If you could also could set the point at witch bitrate adding occures it would be ideal !!!!

So you would get two variables in DVD-RB:

Treshold bitrate level: Being the level where segments with average above get's x% extra, that's stealed equally from segments below or equal to this treshold level.

%-of bitrate levelling: The percentage of increased average bitrate for segments with original averages above treshold.

There are some contraints here of course, but these can be build in.

Of course DVD-RB-PRO should be able to SHOW:

- ORIGINAL AVERAGE BITRATE PER SEGMENT and total average DVD-BITRATE.

- ADJUSTED AVERAGE BITRATE PER SEGMENT after applying THRESHOLD and percentage.

So if you have 2 segements that clearly have bitrate above average, you could give them more bitrate allocation stealing it from all other segments by setting the correct TRESHOLD and PERCENTAGE INCREASE.

A good example is LORD OF THE RINGS , which are generally slow low action, but have a few high action high motion scenes.

You can spend extra bitrate to these scenes and DVD-RB would automatically adjust the other segments to provide this bitrate.....

Of course these are 'advanced' settings, because wrong settings messes up a lot.

It's just a concept I thought about because I always see just a few parts in a movie blocking, while 95% is ok, using heavy compression (like 55-65%).

Could also the minimum bitrate of 500 be removed, or be removed by option ????

[manono]

Hey there-

Maybe it's time for you to start encoding your movies manually. Then you can tweak away to your heart's content. If you do it manually, you can adjust the bitrate down to the GOP level (in CCE anyway). Of course, giving more bits to high-action scenes is limited by the max bitrate you're allowing. From your posts it sounds to me like you spend a lot of time experimenting, and you might be better served by doing the encoding outside of DVD-RB.

I think you're asking a lot of jdobbs to make DVD-RB as tweakable as if you were encoding manually. One of DVD-RB's main advantages is its ease of use, allowing relative beginners to make quite good backups. This is one of the problems that len0x had in developing AutoGK. There were lots of experienced users that kept asking for more and more features, even if stuck away in the Hidden Options so the rookies couldn't mess things up by fooling with things they didn't understand. You kind of have to draw the line somewhere or there would be no end to the requests.

Just my opinion. It's worth about what you paid for it. And I'm a fine one to talk anyway, as I'm pushing for the ability to IVTC.

You can adjust the minimum bitrate already, in the ini file. For CCE you can. Boulder says it's not possible if you use HC. I wouldn't know.

[random asshat]

You might like a small proggy called RB-Opt for tweaking some of the encoder
settings in the Rebuilder.ecl file.

I still open the .ECL in my favorite text editor, "find & replace"
with some manual tweaking of parameters gives me the finished
output I am happy with.

[apfraats]

@manomo:

I'm happy with DVD-RB as it is, but still everytime a lot of compression is needed, the high demanding high movement scenes get's blocky. It's not about maximum bitrate, that's enough as it is set to original max bitrate of the segment, so if the original stream is not messing up, the compressed stream wouldn't be either (if the original NOT contains lot's of artifacts and blocking, which is even seen more than occasionally on frames in original DVD compilations).

But still the first thing that is obvious is the blocking.....

More static scenes are provided (more?) than enough bitrate.

I just want some 'automatic' option for moving bitrate distribution more towards high demanding scnes, a kind of affinety towards high demanding scenes.

As almost >90% of the movie is ok, you gonna think of alernatives, such as leaving out a bit of bitrate in the 90% area of the movie and spend this extra bitrate *9 to the remaining 10%.

I never see the lower bitrate parts suffering...

Always the higher bitrate parts , especially with peaks suffer.

Of course DVD-RB-PRO must be easy to handle.

But is a windows conmputer easy to handle ????

Yep, as long as you do not gonna do things you don't know about.

A windows-xp environment alone is pretty complex, and DVD-RB-PRO is running within it.....

So if you wish to make things foolproof in the way you state, you should have a simple hardware device in which you put the original DVD and the backup DVD and press the one and only button "COPY" :)

Just like a paper-copier....

But DVD-RB-PRO is alraedy behond that with it's advanced settings, take for example selecting a custom matrix or using AVISYNTH functions.....

There is a lot to mess up already.

But if you implement a button called 'RESTORE DEFAULTS' in DVD-RB-PRO , this won't be a problem. This button should set all things to standard again, such as it is when you install and first start DVD-RB-PRO.

Don't see the problem here.

Now I have to 'tweak' using RB-OPT, which is time consuming and the main problem is: It's a stand alone developped tool.......

The function of RB-OPT is indeed what I need, and a bit more simple procedural automation around it. Like increasing bitrate on >average segments and decreasing on lower =< average bitrate. Even choosing lineair or proportional increasement can be usefull.

I agree it's not the primary goal.

But as I watch my movies backupped by DVD-RB-PRO I have generally the problems with average to high compression (around 60%) , in respect to blocking in SHORT HIGH ACTION HIGH DEMANDING scenes, these are in 99% of the cases just a very few % of the total movie....

As the primairy goal is quality backups, and it can be improved, it would be nice to be possible but I didn't build it and I don't know how much work is involved in this kind of functionality..... That's up to JDDOBS.

Indeed I experimented a lot, and concluded uptill now that the 'blocking' problem can't be solved using another encoder, although every decoder has it's own properties., or any other tricks, besides using RB-OPT.

@random asshat

Thanks a lot, it's indeed a tool to use for this.....
It's however not automated, so you have to make changes manually.

Not so bad for trying to see if things could be improved this way.

[jdobbs]

At some point you'll be able to tweak bitrates by segment. Not yet. You can set the minimum bitrate in the REBUILDER.INI file with:

[Options]
MIN_BITRATE=NNN

Where NNN is the value you want to set in Kbs. The reason it is set to 500 by default (it used to be 100, I think) is because of problems that the early versions of CCE 2.70 had with the HBO white noise screen. I'm not sure if its still a problem -- so be careful.

Restoring defaults will be possible with the Template Load/Save feature in the next version.

The current method of dynamic allocation already distributes bitrate based upon demand -- so high action scenes will already get more of the allocated bandwidth (based upon the original encoding distribution). That's why the applied average bitrate isn't the same across all segments now.