Mixed Aspect Ratio DVD

farss wrote on 4/16/2004, 5:23 AM

It's a little late in the night and I should be able to nut this out myself but maybe someone else has some clearer thoughts on this.

I'm trying to put 16:9 and 4:3 PAL footage on the one DVD. Now I figure this should work.out OK, at least on a 16:9 tele. The player should send the correct flags to the TV and it'll swithc AR as appropriate. The menus can be all 16:9 and apart from a glitch while the TV switches AR all should be well.

However what happens with a 4:3 tele?
If the DVD player is setup correctly so it knows it only has a 4:3 tele connected then it'll letterbox the 16:9 menus and video and leave the 4:3 footage as it should be.

If this will work then all is simple. If not I suspect I need to make 2 DVDs, one for 16:9 with the 4:3 letterboxed into the 16:9 frame and a 4:3 AR DVD where the opposite happens.

Hope what I'm saying makes sense and thanks to anyone whose had any experience with this, I'm also a tad worried as I seem to recall a mention of a issue in Vegas with 16:9 and PAL.

Comments

farss wrote on 4/16/2004, 6:30 AM

Hm,
this thing just got messy, the DV tape has the two clips on it, first one 16:9 and second 4:3. During capture VidCap saw the change in the DV flag and correctly displayed the preview. However when I drop the second clip on the TL into a PAL 4:3 project it's letterboxed. I edited out the first few frames just in case they contained 16:9 flags and rendered to a new 4:3 AVI but it's still letterboxed. Tried again selecting 'Maintain Aspect Ratio, do not letterbox" with same result.

Now I can resize the video with track pan/crop BUT I suspect I'm going to take a resolution hit and this clip is from an ancient VHS by the look of it so I certainly don't want that to happen.

Any help now really appreciated.

PAW wrote on 4/16/2004, 7:14 AM

Hello Fars,

I am no expert but I thought the DVD spec did not allow the mixing of different aspects ratios for footage

I think you can have 4:3 menus with 16:9 footage but not both 16:9 and 4:3 footage on a single DVD - Ifoedit may let you change this, maybe

The only issue I have seen with PAL 16:9 is on the external monitor preview where is has not displayed correctly on recompressed frames, the final out is fine though.

Paul

Ps. I have seen 16:9 menus go completely screwed on a 4:3 tv, ii guess this is why commercial dvd's typically have 4:3 menus even if they are widescreen

PAW wrote on 4/16/2004, 7:16 AM

Just reading the post again DVD players add the black bars if sending widescreen to a 4:3 TV, this is usually controlled in the setup of the player itself

Paul

ScottW wrote on 4/16/2004, 7:38 AM

The trick with mixed aspect ratios is that you need to group movies into VTS's according to their aspect - iirc, the VTS is what signals the aspect ratio, hence the restriction.

DVDA puts each movie in its own VTS, so you won't have a problem with having multiple aspect ratio movies on the same DVD. Other authoring apps do things differently, and if they put all the movies in the same VTS, then you will have a problem.

It's recommended that menus be in 4:3, the reason being is that buttons are in fixed positions on the screen. If you create a 16:9 menu and then view it on a 4:3 display, all of the buttons will still be in their 16:9 positions. I'd have to check the DVDA menu structure to be sure, but one option here is to start out with a 4:3 menu, and then if you have a standard/wide screen selection, the menus branching off of widescreen can all be 16:9. If you're up for some hand editing of the IFO file, you can query a register in the player to see what the aspect ratio is set at, and then branch to an appropriate menu/movie. The problem you might have is if DVDA groups all of the menus into the same VTS menu domain - if that's the case, you won't be able to do mixed aspect menus. if sub menus are placed into different VTS's the same way that individual movies are, then you'll be ok - the more I think about this though, I'll bet the menus are grouped into the same VTS-M, so you'd be better off sticking to 4:3 menus.

I think what you are recalling about the 16:9/PAL issue was a discussion on the DVDA forum where someone was having a problem - I wasn't able to reproduce the problem they described, and when I looked at the IFO structure created by DVDA, everything appeared to be as it should have been.

--Scott

farss wrote on 4/16/2004, 2:46 PM

Thanks guys,
sun is back up so I'm going to have a stab at it. Seems from what Scott is saying set DVDA to 4:3 so the menus are 4:3 but encode the 16:9 as 16:9 and all should be OK.