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fordman

Show MUX rate in layer break selection windows

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I understand that it is necessary to have a LB flag (or is it STC discontinuity flag) between cells that have different MUX rates. PGCEdit shows the mux rate when making a layer break selection.

 

Is there any easy way, i.e., through IFOEdit or something to examine the mux rates without going through a mock burn process with PGCEdit? Are there any other utilities that allow one to examine the mux rate?

 

I would suggest that at a minimum, IMGBurn should include this info in the LB selection window, so one does not end up removing a LB flag where there is a mux rate change to another cell which has the same mux rate before and after it.

 

fordman

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Does anyone really know for sure that the mux rate is important?!

 

It strikes me that programs have been setting layer breaks without any regard for mux rate for ages and it's never really been an issue!

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Does anyone really know for sure that the mux rate is important?!

 

It strikes me that programs have been setting layer breaks without any regard for mux rate for ages and it's never really been an issue!

 

They are independent. It's like claiming that a stop light take aways energy from your car since it always seem to slow down at one. He's making a broad association that's not causal. I layer break merely tells the drive head where to look for the next block. It has nothing to to with Mux rates. A point in the video where it changes may be a point to put one but there are even better point to use and ImgBurn is already pretty good at finding such locations.

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Yes we know what the layerbreak is in physical terms, however for DVD Video there are lots of other things to consider. You can only really say either way if you've actually read the DVD Video specs - and unless you work for an authoring company that's paid for them, I doubt you have!

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Does anyone really know for sure that the mux rate is important?!

 

No, I think I was going from what I read in the PGCEdit screen or in a related discussion group. Now that I think more about it, I think the only instance where the MUX rate may change is when there is a change from one VOB ID to another VOB ID, e.g. from VOB 1, cell 26 to VOB 2, cell 1. So that would indicate that it has to do with the STC discontinuity, which for some (most) DVDs also coincides with a non-seamless flag.

 

I have to admit that I'm not even sure why the an author would use one mux rate for part of the movie and then finish with a different mux rate, but it somehow seems sensible that some kind of interruption may be necessary to give the player a chance to adjust to the change.

 

No, I don't have access to the DVD-VIDEO specs, so I cannot be certain that this is in fact needed. However, I am certain that every pressed DVD-VIDEO that I've looked at with PGCEdit that had mixed mux rates in fact does have a non-seamless and STC discontinuity flag where that occurs. Perhaps only the STC discontinuity flag is needed, but it also provides a convenient place for a non-seamless flag?

 

I have seen some pressed DVDs that have a change in VOB ID that happened to have the same mux rate for each VOB ID. However, it seems the STC/non-seamless flags are there also at the transition.

 

It strikes me that programs have been setting layer breaks without any regard for mux rate for ages and it's never really been an issue!

 

As stated above, all pressed DVD-VIDEO discs that I've come across did have STC/non-seamless flags at the transition between mux rates, so how can you be certain that they were authored without regard to the mux rate?

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The bit about DVD Video specs was aimed more at DoIt than you fordman.

 

I already kinda guessed you were just going by what you'd read in the Doom9 forum - I too have read that thread.

 

I'm not one of these people who likes to do things based on hunches. If someone can say to me - "if something is such and such, you must do this and that" - then I'll do it. If not, I wait until they can :)

 

I don't recall hearing that layer breaks have been causing any problems for people over these past few years so (being honest) I'm really not all that worried about changing the current method used or the info displayed to the user.

 

As stated above, all pressed DVD-VIDEO discs that I've come across did have STC/non-seamless flags at the transition between mux rates, so how can you be certain that they were authored without regard to the mux rate?

 

I was mainly talking about all the discs people have done themselves and burnt using all the various tools available - not original discs.

 

Until its recent inclusion in PgcEdit, I hadn't ever really seen 'mux rate' mentioned anywhere - and especially not in software that just burns your VIDEO_TS folder.

 

I was actually given a heads up about dvd video specs and layer breaks some time ago. Out of the 5 or so points made regarding what makes a good layer break and how/where to position it, mux rate was not one of them.

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Tests have shown the mux rate is not that important - we initially thought it was, but clearly, it isn't as superbit DVDs use high mux rate.

 

But, do test for seamless layer break - don't go burning 10 DLs in a row and wonder why they ALL don't work. Do one and then see.

 

From my guide on the PgcEdit site:

 

Seamless layer break and the mux rate

 

After much research (see here and especially mpucoder?s comments at post 69), PgcEdit has implemented an experimental feature. Use this at your own risk and read carefully the caution after Seamless Layer Break down the bottom.

 

Selecting this option removes the ?layer break flag? and marks the cell to be seamlessly played back (without pause).

 

Essentially, it is lower risk to use this option if the cell is muxed at a ?low mux rate? (purple highlight). If it is not, the player may not have sufficient time to refocus the laser on layer 1 and you may have made a coaster.

 

Regards

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Now that I think more about it, I think the only instance where the MUX rate may change is when there is a change from one VOB ID to another VOB ID, e.g. from VOB 1, cell 26 to VOB 2, cell 1. So that would indicate that it has to do with the STC discontinuity, which for some (most) DVDs also coincides with a non-seamless flag.

 

Many DVDs have a layer break without an STC discontinuity or non-seamless flag. See Criterion and SuperBit titles. All of the new James Bond Ultimate Edition DVDs I've checked have a layer break within the same VOB ID. So do SuperBit DVDs. Blade and L.A. Confidential have seamless layer breaks with one VOB ID. LAC has the STC discontinuity flag set in error. I've never heard of anyone having problems with these DVDs, so the rule seems irrelevant.

 

I have to admit that I'm not even sure why the an author would use one mux rate for part of the movie and then finish with a different mux rate, but it somehow seems sensible that some kind of interruption may be necessary to give the player a chance to adjust to the change.
When this was discussed on Doom9, someone eventually pointed out that not all DVDs have a different mux rate at the LB. If the VOB ID changes, they might, but SuperBit DVDs have a single VOB ID with a high mux rate throughout.

 

every pressed DVD-VIDEO that I've looked at with PGCEdit that had mixed mux rates in fact does have a non-seamless and STC discontinuity flag where that occurs. Perhaps only the STC discontinuity flag is needed,

 

Try checking Blade, L.A. Confidential, any SuperBit DVD, and many Criterions (Naked, Fear & Loathing). The STC discontinuity flag is may be correct, but the non-seamless flag is unnecessary with most players. Lots of DVDs break the rules and I haven't heard about widespread problems with the titles I mentioned.

 

I have seen some pressed DVDs that have a change in VOB ID that happened to have the same mux rate for each VOB ID. However, it seems the STC/non-seamless flags are there also at the transition.
You should set the STC flag for a VOB ID change, according to Spec. However, L.A. Confidential has the flag set even though a VOB ID change doesn't occur. It also has a seamless layer break. So, the rule seems largely irrelevant.

 

As stated above, all pressed DVD-VIDEO discs that I've come across did have STC/non-seamless flags at the transition between mux rates, so how can you be certain that they were authored without regard to the mux rate?

 

Only the STC flag is needed, not the non-seamless flag. It is customary, but Superbit, Criterion, Blade, and L.A. Confidential show that it is not required. EDIT. Many DVDs have seamless layer break. That's a separate issue from the STC flag.

Edited by calweycn

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