Progressive/Interlaced flag setting issue needs to be addressed

[Blackout]

hi all,

i have re-encoded 10 dvds in the last few weeks. They were all hollywood movies, 16x9, PAL. I checked with each dvd to see if the actual movie was progressive (i loaded the vob's into DVD2AVI and looked for combing artifacts) and they were all PROGRESSIVE. This is what i would expect for a million dollar, 35 mm shot film.

But guess what. 8/10 of the movies had their flag incorrectly set as "Interlaced".

This is a big problem. Because if you leave DVD Rebuilders settings as default, then CCE will encode in the wrong mode, and the picture quality suffers.

It would be great if DVD Rebuilder actually displayed what the flag is set to, so that it can be more of a standalone program. Currently im loading Bitrate Viewer, DVD2AVI, etc every session to get thru this annoying issue. Any chance j?

Blackout.

[Paced]

Alot of PAL DVDs (approximately 95% of the ones I run through DVD-RB) have their flags set as interlaced, even though in reality, they are progressive (when viewed through DVD2AVI, for example). Additionally, DVD-RB just basically duplicates/replicates whatever is fed into it - including the original flags; therefore, I personally don't see any reason as to why DVD-RB is required to change the original 'format' of the DVD. Also, in my experience, even though CCE sets the interlaced flag, video quality should/does not suffer as a result. By all means, please correct me if I'm wrong ;)

[Blackout]

Hi Paced,

its well documented that CCE is better at progressive than Interlaced. Less macroblocks. Block Scanning Order is different (eg ZigZag)...etc. It is more efficient...progressive takes less space...etc...it makes a difference to the quality. Its not hard to see yourself...perhaps they make the flag wrong so that copies of the dvds dont look as good when theyre processed wrong...perhaps its a compatibility issue with more DVD players...perhaps its just that the mastering houses dont know what theyre doing....either way it makes a difference to the quality of DVD Rebuilder results.

Blackout

[wmansir]

There is really no way for DVD-RB to automatically fix this because the discs are authored incorrectly. You may know about the "Disable Interlaced" option under the AVS advanced settings to adress this problem, so the real issue is some way of indicating that the problem is present.

I don't think you can get the interlaced/progressive state from the IFO files, so perhaps something could be put in the status panel during the prepare phase when the VOBs are scanned. Maybe a %Film/%Interlaced value for each VTS?

[KeyserSoze]

"Disable Interlaced" option under the AVS advance setting is the way to go.
The problem is that its not permanent .If only there was an option to have it as Default.

I used to have this problem too... not only the quality is worst but CCE renders MUCH faster in progressive mode

From my 400 PAL DVDs, only 5 of them are true interlaced and they are of course Japanese Manga titles

[Blackout]

Youre right wmansir, there is no way for DVD-RB to automatically fix this...unless theres some magical code to detect whether footage is actually progressive or not without having to physically look at it with a human eye. I dont really expect that. But to at least be able to highlight and show the status of the flag for us to be able to select the "Disable Interlaced" option would be great. Next to the video title sets list where it already lists the size and ratio of each VTS would be ideal really...at least it would make DVD-RB a bit more standalone....

[TheSeeker]

Or better yet... Not sure how difficult it would be for jdobbs to add code to the prepare phase or something that will detect interlaced or progressive sources and automatically set the disable interlace option on the vts's that require it. That would be ideal. Of course you could manually override this for situations where rebuilder incorrectly detects interlaced/progressive. But I always seem to forget to do the whole disable interlace thing, and I have to say that no matter what movie Im running through Rebuilder it seems that the interlaced=true thing is always there in the Convert line, in the avs script.

[Fr4nz]

Originally posted by TheSeeker
[B]Or better yet... Not sure how difficult it would be for jdobbs to add code to the prepare phase or something that will detect interlaced or progressive sources and automatically set the disable interlace option on the vts's that require it.

DVD-RB does the check! Try more dvds...sooner or later you'll find a dvd which is truely progressive and dvd-rb will encode it as progressive.

As Paced stated before, lot of dvds are progressive but the flag is set (improperly) as interlaced...so DVD-RB is not wrong, it'll just follow the indications of the original dvd.

Anyway in this case it is just sufficient to disable the interlace mode (look at the DVD-RB options).

[TheSeeker]

I realize it looks at the original dvds flags. But what I meant is to check the actual video stream itself. There MUST be some other way to detect interlaced/progressive other than the flags. Oh and i HAVE done many many dvds and i know about the option to disable interlace. Just throwing out ideas to make Rebuilder a little more intuitive. I dont know if it is even possible to make a more accurate detection scheme, but I thought it would be cool not to have to worry about setting disable interlace, because like i said, I always seem to forget to do that.

[Blackout]

Fr4nz youre missing the point...DVD-RB does read the flags, but 80% of the time the FLAGS ON THE DVD ARE WRONG. We have to manually override them. We are just asking for a visual indication of the flags to help do the "Disable Interlaced" override that DVD-RB provides...

Blackout

[idbirch2]

I used to use DoItFast4U before switching to DVD-RB so have been involved in a few discussions about this before. I have 2 questions:

1) Why do DVD Autohors set the flag incorrectly and if its wrong why aren't there problems when playing them back in DVD players?

2) Is Blackout correct in saying the quality of the encode will be better and faster if CCE is told to encode in Progressive mode? I encode PAL DVD only so also have about a 98% progressive:interlaced ratio of DVDs. If this is true do I just need to check "Disable Interlaced" for every encode to get faster, better quality backups?

Cheers.

[TheSeeker]

Well I dont know about cce being better and faster in progressive mode, its just that when the flags are set incorrectly to interlaced than your dvd player that has progressive scan capabilities wont be using progressive scan on the dvd so playback will be a little worse.

[Wilbert]

DVD-RB does read the flags, but 80% of the time the FLAGS ON THE DVD ARE WRONG. We have to manually override them.
I'm not saying that you are wrong, I simply don't know. But it can be they are progressive streams encoded as interlaced. For YUY2 there's no difference, but for YV12 there is a subtle difference (wrt chroma) between 'progressive encoded as interlaced' and 'progressive'.

[f@chance]

Much has to do with the source. For example I just backed ip Voyager season 4 PAL and it is all Interlaced because I guess it was for TV than using DVD2AVI, I looked at Spiderman 2 and I could not find any Interlaced artifacts but DVD2AVI displayed a solid Interlaced in the Preview mode. Does that Indicate that it is progressive and the authors just set the flag wrong.

Is DVD2AVI the only tool that can easily indicate if VOBs are progressive or interlaced?