Bill_st
13th July 2002, 22:04
I am trying to encode a S-VCD from this DVD: Conan The Barbarian (Region 2).
The problem I have found (and it's the first time I find this) is that even if the movie itself and the DVD are progressive, some scenes come up as "falsely interlaced" because the bottom field and the top field don't match. Comparing top & bottom fields side by side in Virtualdub, it seems that on some scenes, each frame in the DVD is made with the bottom field and top field of two consecutive frames from the real progressive frames, and therefore the jaggies are much more noticeable than the jaggies of true interlaced frames, since the time shift between odd and even lines is double. On others the fields match and there are no jaggies at all. It doesn't change from correct order to incorrect order every few seconds, it takes quite a few minutes to happen.
Since this error only happens when a progressive player (like software players) or a encoding tool intend to reconstruct the progressive frames, the movie plays just fine on my conventional standalone with interlaced output (I guess that's all that matters to some DVD-authors :p ).
Searching the forums I've come up with some posts about other PAL movies with seemingly the same problem (I think Pulp Fiction (R2) was one?), but the solutions that others gave were using deinterlace>selectevery(PAL) in DVD2SVCD, which in turn adds these lines to the avisynth script:
SeparateFields()
SelectEvery(2,0)
This obviously cuts vertical resolution by half, which is OK for VCD encodes (they have half the DVD resolution anyway), but it is a waste of frame information for a SVCD encode.
My question is, what the **** happened to this DVD? Is this error in more PAL DVDs? I have encoded a few region 2 DVDs so far (35) and never seen this before (except for those cheesy PAL versions of anime, but that is a whole different issue). But of course, what can I do to encode the movie with full vertical res and correct frames? I have no experience with this kind of stuff at all, any ideas will be welcomed.
The problem I have found (and it's the first time I find this) is that even if the movie itself and the DVD are progressive, some scenes come up as "falsely interlaced" because the bottom field and the top field don't match. Comparing top & bottom fields side by side in Virtualdub, it seems that on some scenes, each frame in the DVD is made with the bottom field and top field of two consecutive frames from the real progressive frames, and therefore the jaggies are much more noticeable than the jaggies of true interlaced frames, since the time shift between odd and even lines is double. On others the fields match and there are no jaggies at all. It doesn't change from correct order to incorrect order every few seconds, it takes quite a few minutes to happen.
Since this error only happens when a progressive player (like software players) or a encoding tool intend to reconstruct the progressive frames, the movie plays just fine on my conventional standalone with interlaced output (I guess that's all that matters to some DVD-authors :p ).
Searching the forums I've come up with some posts about other PAL movies with seemingly the same problem (I think Pulp Fiction (R2) was one?), but the solutions that others gave were using deinterlace>selectevery(PAL) in DVD2SVCD, which in turn adds these lines to the avisynth script:
SeparateFields()
SelectEvery(2,0)
This obviously cuts vertical resolution by half, which is OK for VCD encodes (they have half the DVD resolution anyway), but it is a waste of frame information for a SVCD encode.
My question is, what the **** happened to this DVD? Is this error in more PAL DVDs? I have encoded a few region 2 DVDs so far (35) and never seen this before (except for those cheesy PAL versions of anime, but that is a whole different issue). But of course, what can I do to encode the movie with full vertical res and correct frames? I have no experience with this kind of stuff at all, any ideas will be welcomed.