Aggressive Layer Break removal question

[rpboy]

In regards to this change in the 1.05.2 build of DVD-Rebuilder Pro:

- Reduced the aggressiveness of the layer break
removal, as some Sony Players appear to be very
strict in how they handle streams marked with the
"seamless" flag. If you wish to override this
setting, add "AGGRESSIVE_LAYER_BREAK_REMOVAL=1" to
the "[Options]" area of the REBUILDER.INI file.
I just burned my first DVD with this new version with the layer break removal set at the new less aggressive method. But neither of my DVD players seem to be able to play the DVD reliably.

So I wanted to set the layer break removal back to the more aggressive method. If I change the INI file as it says above, can I just rebuild the DVD I did last night? Or do I need to go through processing and encoding again?

[jdobbs]

Yes. You can just REBUILD.

But I don't think there would be a relationship to "not playing reliably" -- if there was a difference as all it would only be a very slight pause (more like a "tick") at the layer break (exactly as you would have seen on the original as it changed layers). Removing that "tick" is all that layer break removal accomplishes...

[rpboy]

Yes. You can just REBUILD.

But I don't think there would be a relationship to "not playing reliably" -- if there was a difference as all it would only be a very slight pause (more like a "tick") at the layer break (exactly as you would have seen on the original as it changed layers). Removing that "tick" is all that layer break removal accomplishes...
For me, its some titles just won't play. On one DVD player, it just hangs. On the other, it says "Invalid title."

Also, the startup time from inserting the disc to the player recognizing the disc is a lot longer, and after pressing the menu buttons, there is a long pause before a title will start playing.

None of which happened on other DVDs I've done with previous versions of DVD-Rebuilder.

[jdobbs]

Nothing has changed in that regard... try another title.

[rpboy]

I went ahead and added the AGGRESSIVE_LAYER_BREAK_REMOVAL=1 to the INI file and rebuilt it. I burned it to DVD and now it works fine on both DVD players.

Glad I didn't have to encode it again. :)

[apfraats]

Not that I have to agree with JDOBBS at any time, any place (he's getting sick seeing my name only :) , but I have to agree on this one with him. Layer Break issues will be noticed as a puase or skip for just one moment (m ost of the time a little pause)

I stick to JDOBBS and I think some other factors are of importance here.

Media used, quality of burning, etcetera.

As a player WON'T scan for the layer break in advance, it can't be saying TITLE NOT FOUND or NOT PLAYABLE when inserting it.

It will NOT search for the layer break in advance.

[blutach]

If you are worried, check for, and get rid of, the LB in PgcEdit (http://www.videohelp.com/~r0lZ/pgcedit/index.html). Open the DVD in PgcEdit, double click on the movie PGC and scroll down to the cell with the LB in the middle of the title. Untick it. OK. Save and burn.

Total time taken = about 20 seconds. No need for rebuild at all since the LB is in the IFOs :)

Regards

[ron spencer]

or if that is too difficult don't forget DVDShrink and pass it through...it always gets rid of layer break.

[jdobbs]

Remember not to call me, though, if you have a Sony player... I compared the output of the layer breaks removed by Shrink -- and it seems to use the exact same methodology as DVD-RB in aggressive mode.

[laserfan]

So if anyone wants layer break removal to operate in the same manner as DVD Shrink, which is the way RB worked in prior versions, they need to change the INI for AGGRESSIVE_LAYER_BREAK_REMOVAL=1? Correct?

Wondering what exactly the new "less aggressive" method is i.e. how it changes the flags--can someone explain?

[jdobbs]

Generally what is done in removing "Layer Break" is resetting the seamless playback flag in the cell playback information table at the point where the layer changed. Most methods used by DVD copying software (if you search here on DOOM9) simply reset the flag. But... there are some rules as to what can be considered seamless that can be violated when you do that.

Often when there is an SCR discontinuity and the the SCR is restarted at zero (and possibly even when it isn't) you will find that the audio of the last cell of the first layer is padded. When this happens you shouldn't reset the flag, as the stream is not truly seamless. Most DVD copy programs appear to just reset it anyway -- and virtually all players will just play right through it. Some players, though, are a little more finicky and choke when this happens and "glitch" during playback... When you select "aggressive" mode... it will change it anyway. Non-aggressive follows the rules and leaves the seamless flag off under these circumstances.

[laserfan]

:thanks:

Great answer! I've never seen this explained quite so well before!

And for working on this particular Sunday--best wishes for the new year to you jdobbs!!!

[mrslacker]

Open the DVD in PgcEdit, double click on the movie PGC and scroll down to the cell with the LB in the middle of the title. Untick it. OK. Save and burn.
It has been quite a while since I have used this aspect of pgcedit or even posted here, but I recall that the layer break tick box was functionally a status tick. I remember needing to specifically change (unset) bit 3, "Seamless playback joint", in pgcedit's cell type flags editor for the removal to stick. ...Just checked, it still seems that way in 0.6.2.

@jdobbs

So does DVD-RB check for an actual seamless joint by looking for audio padding? Or does it just never change cell type 2 (STC disc.) to 10 (STC disc. + seamless)? Just wondering.

Also, to provide some feedback, my Sony DVP-NC665P hasn't had a problem with removed layer breaks so far. However, it was especially picky about PTM values, and would freeze on versions prior to 0.56. I'm still quite glad you were able to track down that one!

[blutach]

Neither has my SONY although my NAD is highly finicky about audio buffer runout.

mpucoder has posted a forumula about this - see http://forum.doom9.org/showthread.php?p=582515#post582515

Regards

[mrslacker]

Ahhh! That's the thread. I remembered posting about this in a thread with mpucoder.

It was frustrating to successfully demux before josoto's PGCdemux for the reasons mpucoder cited regarding reading across VOBID boundaries for the complete audio data.

[JFerguson]

Has something changed recently with Layer Break removal (i.e., under the standard setting)?

I've been seeing a lot of layer breaks during playback of my DVD-RB backups lately...

Wait... I haven't been running some of my output through Shrink lately -- that's probably it. I'll try that aggressive flag if it does the same thing...

[magic144]

just to add another 2 cents

I DO have a SONY player which VERY occasionally choked on layer breaks that had been forcibly removed by shrink or RB (agressive mode)

the sure-fire solution I found was, IF the LB was left in the output of RB (used in the default non-agressive mode) and I still wanted to remove it:
use the excellent pgcdemux to demux the audio, video, subtitles
use the excellent muxman to reassemble/rebuild the DVD

(subtitle colour palette will also have to be copied back from the original)

alternatively, of course, you could pgcdemux, muxman the original source files BEFORE using RB (but you won't get help from jdobbs if you preprocess anything and there's a problem!)

[HKT3020_1]

If you are worried, check for, and get rid of, the LB in PgcEdit (http://www.videohelp.com/~r0lZ/pgcedit/index.html). Open the DVD in PgcEdit, double click on the movie PGC and scroll down to the cell with the LB in the middle of the title. Untick it. OK. Save and burn.

Total time taken = about 20 seconds. No need for rebuild at all since the LB is in the IFOs :)

Regards

@Jdobbs

How do you feel about the layer break removal method suggested by blutach? Will this cause problems on dvd playback, mainly Sony models?

[jdobbs]

It gets complicated when the video/audio just isn't meant to be a seamless joint.