identify field order and frame type of VOB file with DGINdex

[RogerTango]

Sure, there are several ways and means to identify the properties of a VOB, but over the course of 20+ years working with the dreaded VOB, I have relied on DGIndex to yield the most accurate & consistent trustworthy results.

Why do we need to know these things about a VOB? Cant we just encode?

It's not that easy... We need to know a few basic things about a VOB to assure it is encoded properly. For a progressive type, I only apply some denoising. For an interlaced type, I need to apply deinterlacing and denoising. In addition, the interlaced media often needs to be identified as Top Field First (TFF) or Bottom Field First (BFF), most deinterlace filters require this parameter to be passed in order to function as expected.

I hope it helps someone out!

https://www.youtube.com/watch?v=aek-WY26DP0

[_Al_]

Unce upon a time I created "DVD to hardisk.BAT" still available for download here: DVD to hardisk.zip.
You drop one of those VOBs on BAT and it launches menu to select audio track. Menu allows playback of a title with particular audio track via ffplay (right click gets you into whatever part of video during playback) , just to be sure what audio track is selected. Then it uses DGindex for indexing, It uses mediainfo to find out interlace vs. progressive and if interlaced , QTGMC is used using avisynth script and the h264 is created using x264 , audio is created using ffmpeg and neroaacencoder to aac, then it is muxed to mp4 using mp4box. All automatic after that audio track selection. It also handles SAR flag accordingly, for that mp4, as you described in that video, it does not resizes (iirc), but also, it could be switched to always resize to 1:1 , no SAR flag in mp4, while designing that avs script within BAT.

Obviously it is used for homemade videos or propagation videos that were made with camcorders, so not for DVD's from 24p footage. But it seams you work with these DVD's. If not, you can adjust making of that avisynth script within BAT, to get 24p out of 60i. Or you can look for inspiration in that code.

[_Al_]

I dug out some data, that I actually made same thing to actually resize those mpg's to square pixel if wanted, it was uploaded while ago as mpeg to mp4.zip
you can easily change those command lines located at the bottom of script to use handbrake cli etc.

[hello_hello]

Sure, there are several ways and means to identify the properties of a VOB, but over the course of 20+ years working with the dreaded VOB, I have relied on DGIndex to yield the most accurate & consistent trustworthy results.

Why do we need to know these things about a VOB? Cant we just encode?

It's not that easy... We need to know a few basic things about a VOB to assure it is encoded properly. For a progressive type, I only apply some denoising. For an interlaced type, I need to apply deinterlacing and denoising. In addition, the interlaced media often needs to be identified as Top Field First (TFF) or Bottom Field First (BFF), most deinterlace filters require this parameter to be passed in order to function as expected.

I hope it helps someone out!

https://www.youtube.com/watch?v=aek-WY26DP0

The only way to know for certain what sort of video it is, is to look at it.
DVDs are often encoded as interlaced even when the content is progressive. Here's an example:
https://forum.videohelp.com/threads/403901-Questions-about-digital-video-in-standard-d...on#post2638861
You'll only reduce the quality de-interlacing progressive video.

Even though you described it as interlaced, it was pretty obvious one of your examples was telecined, not interlaced. DGIndex has no way of knowing which it is, assuming it's encoded that way rather than having repeat field flags, but ideally you shouldn't de-interlace them as such either.

I don't know if you're using Avisynth for DVD encoding, but most Avisynth de-interlacers have an auto-parity option and it's generally the default. They'll simply obtain the field order from Avisynth, and although it has no way of knowing the correct field order itself, DGIndex/DGDecode reports the field order to Avisynth when it's decoding, so of the many things to fuss over when it comes to DVD encoding, field order generally isn't one of them.

[RogerTango]

True that field order generally isn't a concern, but some deinterlacers want the value passed.

For example, NVENCc's CUDA_YADIF filter, you must tell it TFF or BFF. It's in the help...

[ProWo]

Load your vob in clever Ffmpeg-GUI.
it will give you the info you need.

[clashradio]

Are DGIndex and clever Ffmpeg-GUI more advanced programs than MediaInfo?