Aspect ratio keeps switching during playback

[Daffyd39]

Hi,
It's been a long time since I consulted with my "video elders" but I have need of your collective wisdom as I have a problem I've never encountered before and can't find a solution in the forums here.

I have a video_ts file that I am keen to burn but whenever I check the playback using either the files from the folder or the iso file I created with ImgBurn, during playback the aspect ratio keeps flipping from 4:3 (full screen) to 16:9 (letterbox)and then back again at random throughout the whole disc. Gspot says that the sample vob file is in 4:3.

Is there any way to repair the files to ensure that they stay in the 4:3 ratio before I burn it to disc? (btw, I have Vobblanker and ReStream if needed but don't have a clue how to use them).
many thanks.
D

[guns1inger]

Different VOBs have different aspect ratios, or the same title keeps changing aspect ratios ?

I have seen a commercial DVD where a single title switched aspect ratios for different chapters.

[Daffyd39]

It seems to be within the same vob.
I just tried to re-author using DVDShrink as I discovered that the 4th and last title was listed as an extra (!) and although it seems a bit cleaner it still re-sizes within all the titles at random. I also opened the files with Vobblanker and they all are listed as 4:3.
I should also add that so far I've only used 3 software players to view the files: Nero Showtime (where I tried to lock the aspect ratio but it didn't work), MediaPlayer Classic and VLC. I'm out of ideas. Should I burn the new iso and just try it in my Oppo player or is there another software fix I could try?
many thanks,
D.

[guns1inger]

IFO2WSAR will update the IFO files to reflect 16:9 titles. However this does not change the headers of the video files. Restream can re-write the headers, however it only works on elementary video streams, so you would have to demux, change the headers, then remux.

Has this come from a commercial disc, or a self-authored one ?

[Daffyd39]

This is a non-commercial, self-authored disc that has been passed on to me. It was recorded on tape in 1979 in NTSC, so I assume that the proper aspect ratio is 4:3. I think I understand what you're suggesting, but unless there is a guide somewhere, I'll have to do some more research on de- and re muxing.

[Daffyd39]

Another question, wouldn't changing the headers via ReStream or using IfoAR2WS to make the vob's 16:9 just distort what was originally a 4:3 picture?

[Alex_ander]

Restream can re-write the headers, however it only works on elementary video streams, so you would have to demux, change the headers, then remux.

DVDPatcher works with VOBs in an authored DVD (no remuxing). And yes, AR information should match in VOBs and ifo's to prevent that issue (IfoAR2WS is also needed).

[Daffyd39]

I have both apps now. What's the sequence? Do I use DVDPatcher first? I opened it and looked and it seems fairly straightforward but I'm not sure about the settings. What bitrate should I use and what horizontal settings? The defaults seem to be 3.5 mb and 352 respectively....I also still am wondering about the question re making the headers 16:9 if it was origonally in 4:3....
thnx.
D

[guns1inger]

Yes, if the original AR is 4:3 then you don't want to change it to 16:9. Sorry, but the original AR wasn't made clear in the first post so I wrongly assumed 16:9 was the target.

Do patch with DVD Patcher first. Make sure it sets everything to 4:3. You can then use PGCEdit to manually check, and if necessary change, the IFOs to 4:3.

[Daffyd39]

Thanks Gunsl1inger, much appreciated and will do tomorrow.
In regards to DVDPatcher (ref my question above) should I stick to the default settings in DVDPatcher (+ the 4:3 settings) for the bitrate and horizontal settings?
cheers,
D

[Alex_ander]

It usually reads the settings from the file and shows for confirmation what input set of parameters to what output set will change. If you see something you know is incorrect (e.g. pixel numbers differ from actual) you can also change this. It is also recommended to check 'patch whole file' option. DVDPatcher doesn't make backups but it is safe since you can edit everything back if you write down the original settings somewhere.
As mentioned, for ifo's you can't use IfoAR2WS in 16:9=>4:3 direction, you'll need either PGCEdit or DVDRemake (if you have it). The latter is not free but much easier to use and can do everything for both VOBs and ifo's in 2 clicks. The first (left) click is selecting a VTS in DVD tree. The second (right) click is on Video/display mode line =>check 4:3 instead of 16:9 and press OK. Then export DVD.

[Daffyd39]

Thanks for the info Alex_ander, but please bear with me, I'm still a little confused. How do I know what bitrate and pixel numbers are correct for the file?

Also if I use DVDPatcher (assuming I use the defaults it's already displaying) , do I need to use IfoAR2WS as well?

I've already made another copy of the file (it's only 3.19gb) so I'll use the suggestions on the copy and keep the original elsewhere for safety.
D.

[Alex_ander]

You can calculate average bitrate from file size / video length, but that parameter in MPEG header is not critical. If you made DVD yourself you usually know pixel numbers, and unless somebody altered the headers intentionally, you can believe what GSpot shows.

IfoAR2WS could help if you wanted to go 4:3=>16:9 but you can't use it for correcting ifo's in the other direction as in your case (you say 4:3 is the correct AR for your video).
Also test: maybe your video contains letterboxed fragments along with fullscreen 4:3, then what you see as switching AR in a player can be normal for such composite video.