Change an ifo from 4:3 to widescreen (help)

[asphaltgym]

I've got two streams from smartripper (ac3 and m2v) that were pulled from a dvd I loaned to someone (12 monkeys) so now I no longer have the original vobs. The challenge now is simple: how can I author a dvdr that simply contains the movie - it should fit with plenty of room to spare.

I used dvd-jr to create a one button menu, brought in the m2v and it finds the ac3 - then I author to a hard drive folder and all the vobs and ifos are created. Problem is the video plays faster than the audio - you can see it 'jumping' ahead every 2nd or so.

Figuring that maybe the mutiplexer in dvd-jr isn't so great I tried to multiplex using streamweaver before dvd-jr and then imported the result. I noticed inside streamweaver that the audio stream was slightly shorter than the video stream. Streamweaver did a fine job anyway (a+v in sync) but split the .vobs into several files and then left off the last 1/3 of the film!

Next I tried spruceup. This went much better - the m2v and ac3 came in fine and when I authored to hard drive it worked and they were in sync.

I noticed that the film played back in 4:3 mode when it obviously is supposed to be widescreen since everything looks squished horizontally. If I take off powerDVDs 'keep aspect ratio' and stretch the window to what widescreen is supposed to be it looks great - I don't think this is possible in a set-top player.

Then I used IFOEdit (awesome tool) to examine the films .ifo files and saw in the tables that it was set to 4:3. Now I'm pretty sure this is a limitation of spruceup. Since I have no other authoring tools besides the audio infererior dvdit pe, i'm looking for a way to just flip this setting to 16:9.

please help!

asphalt gym

[mpucoder]

Use IfoEdit on the ifo file for the movie. Display VTSI_MAT, find offset 200 (where it displays the aspect ratio). Double click on it to edit, and add 3072 to the value. I know this isn't elegant (yet). You should also find the copy of this byte in video_ts.ifo and change it as well. You'll find it in VMG_VTS_ATRT, the field called VTSTT_VOBS for the appropriate vts. Don't forget to save the bup, or copy the ifo to bup.

edit: I just realized that aspect ratio information also appears in the video stream itself, and this won't do it. You will need to locate and change that data in the sequence header, which will be in the first video pack. Unfortunately VobEdit doesn't handle this yet, so you'll need to find it and modify it with a hex editor. For help see the layout of the sequence header at MPUCoder DVD info (new server) (http://mpucoder.kewlhair.com/DVD/mpeghdrs.html#seq)

[asphaltgym]

thanks mpucoder- the ifo edit was all i needed (and your number was right on the money)!
the video stream itself was already at 16:9, i guess the ifo just tells the dumb dvd player how to show it. I should have mentioned that the .m2v file plays in 16:9

It's amazing how I blew a whole dvr just because of 1 bit!

As gratitude I'll gladly send you a free 12 Monkeys DVD in 4:3 format :) !

[dtmf]

What code would you use to denote '4x3 letterboxed'?

[mpucoder]

Make sure bit 1 of the word is set to indicate that the movie is already letterboxed. To see all the bit positions and their meanings look at http://mpucoder.kewlhair.com/DVD/ifo.html#vidatt

[The_Flash]

I just edited the two sections in my .ifo that mpucoder suggested. My video is encoded 16:9 as well. The disc plays fine on Sony players and on a few others. However on my friend's Aiwa and an Apex 500W the picture is still full screen and distorted. Are there other settings that need to be changed to make this compatible with all players? Any help or suggestions are appreciated. Thanks.

[mpucoder]

Your friend has his DVD player set for use with a widescreen TV. Switch it for use with 4:3 televisions and it should look alright.

[The_Flash]

That was actually the first thing I checked for, and it is set to 4:3. What's puzzling is that on the Aiwa the aspect ratio is fine, but the picture is displayed in full screen mode. On the Apex 500W the picture is displayed full screen and is distorted. The same disc displays flawlessly (16:9 and letterboxed) in a Sony S330 and an Apex AD-800. All players are set to display 4:3 mode.

[aviators99]

It's not clear to me from this thread or others what I need to do. I have a DMR-E30, and have recorded several things in anamorphic format. However, the flag doesn't seem to be set, since when I bring them over to other people's houses with 4x3 sets, their DVD player doesn't letterbox them. Can I simply set the flag in the IFO, or will I need to set something in the stream as well?

In a related question: for some reason, the first DVD I recorded in this anamorphic format somehow got the flag set (?!) I have no idea why, but I can't reproduce it.

[mpucoder]

In order for the DVD player to display an anamorphic as letterboxed on a 4:3 monitor several things must be true.
1) The video stream must have 16:9 as the aspect ratio (note: if the source is other than 16:9, such as 2.35:1, you will need to resize and add black on the top and bottom to convert to 16:9)
2) the video attributes for the title set must be 16:9 (bits 2&3 of the first video attribute byte set)
3) the "automatic letterbox" flag (bit 0 of the first video attribute byte) must be 0.
4) "letterboxed" attribute (bit 1 of the second video attribute byte) should NOT be set.
5) The player must be set for 4:3 output, otherwise a widescreen capable monitor is assumed.

[aviators99]

Thanks for the tips. Assuming the AR of the material is indeed 16x9, can the rest of the stuff be done simply by using IFOedit?

[mpucoder]

Yes, the video attributes can be set correctly using IfoEdit.