recognition of interlaced frames

[influenza]

I have a question about the latest doitfast4u version. I have multiple movies lately (PAL) which doitfast4u recognised as deinterlaced. However both dvd2avi and bitrate viewer tell me the source is interlaced.

So can I trust doitfast4u and encode is if it was deinterlaced?

[Eyes`Only]

DoItFast4U saw it as progressive? Can you send me the logfile and d2v please?

I'm not sure my program detects PAL type 100%. If you run it thru dvd2avi does it see it as interlaced from start to finish?

[influenza]

DVD2Avi sees is as interlaced (every vob).

How do you want me to send it?

[Eyes`Only]

send it here (doitfast4u@cox.net) please.

[influenza]

What logfile do you exactly mean?

[Eyes`Only]

Hmm.. it seems as if PAL interlaced and PAL progressive use the same .d2v filestructure?

Well, from what I understand, you should be able to use that .avs, you'll just have to encode it interlaced.

If you have your heart set on deinterlacing it though, uncheck the autodetect option, and check the FieldDeinterlace() option. Then all .avs for that VTS will have FieldDeinterlace() added to them, which will deinterlace your movie.

[influenza]

older versions of doitfast4u did recognise the frametype correctly for pal movies.

I can easily change it ofcourse, but it's so easy to have it autodetected.:sly:

But anyway the program is great.

[Eyes`Only]

Thanks, glad you like my efforts to make this world a better place.

I don't think older versions could have recognized it correctly, because I haven't changed anything in the code since 1.0.8 probably.

Just FYI:

After getting your post, I worked on this issue.
I have Matrix R2. I demuxed VTS02 PGC1, which is the main movie (progressive) and also VTS01 PGC1 which is an extra (interlaced). After running dvd2avi on both, I analyze the data and they look the exact same!

So.. this got me thinking.. how do I analyze this correctly? So I scoured the forums. It seems all PALs should only have 2's in the .d2v. This in no way helps us, because diagnosis cannot be performed via the .d2v if both PAL interlaced and PAL progressive look the same.

So, next step. I looked at parsing the mpeg header from the .m2v. Surprisingly enough, those headers say 'interlaced' on both my tests. I asked around and found out that almost every PAL video has that interlaced flag set in the headers. So that idea is out too. Just to confirm, when you run DVD2AVI manually on your PAL main movie .m2vs, do they say 'interlaced'?

I'm now looking at going further into the .m2v and comparing field values. For now, I've replaced the code to say "PAL video diagnosed. Keeping original structure". I'll keep it this way until I solve this problem.

Luckily, I didn't remove the ability to manually select FieldDeinterlace (I almost removed all the Forcefilm/Decomb/FieldDeinterlace stuff from the GUI, thinking we had autodetection down to a science)! So you can still deinterlace your extras if you want, but it will have to be manually until I can get a handle on this issue. Sorry!

[influenza]

I'm 100% sure thta in older version I got an avs with a deinterlace line in it. But now I'm thinking that this maybe was not correct after all (that this line was always there even if it was progressive).

To answer your question: dvd2avi says is interlaced (and so does bitrate viewer).

A lot of PAL dvds seem to be interlaced (even the main movie). I checked a couple of the dvds I have and a lot are interlaced (probably because they are copied from a NTSC source or so). For the main movie I don't think you'll notice a quality loss if encoded without deinterlacing. But for the extras it's terrible ofcourse.

I must say that I always use the vob file and not the m2v to analyse (but I don't think that makes a difference?). Bitrate viewer seems to analyse it correctly. It also sees if it's progressive, because if I understand you correctly it looks like PAL is always interlaced if you solely look at the headers?

For me it's not a really big problem, I'll just check first and then manually turn on deinterlace. I can only imagine that other people who are not aware of this will be disappointed by the queality of encoding of especially the extras.

But anyway thanks for all the effort!

[Eyes`Only]

Yeah older versions did the opposite... they incorrectly assumed all PAL was interlaced and added the lines to .avs, even if they were progressive! hehe

Well I'm determined to give this a damn good shot, I'm talking with mpucoder and hoping he'll have an idea, since he wrote the dvd bible that all of us coders use for information on how dvds are made!

Just fyi: I talked with D2S (author of DVD2SVCD) back when I started this project. He's the one that helped me with some starting ideas on how to determine IVTC for NTSC video.

As such, I thought DVD2SVCD could diagnose PAL correctly, but I just got a PM back from the author saying, "Unfortunately dvd2svcd can't autodetect interlaced/progressive automatically, that's why I have made a preview option in dvd2svcd, that way the user can determine this manually before starting the conversion."

So hopefully if I can solve this issue, I can help DVD2SVCD to become a better program too!