Progressive footage

A

andre

Well-known member
Progressive DV images are recorded and transported as interlaced fields. So APP behaves exactly the same way as with interlaced pictures. Field order may be not important but frame recognition IMHO is needed. If not, it can happen that consecutive field pairs comming from two different frames are being processed as a frame, and if there is motion, all processed frames will show "mouseteeth". So, my question is: does APP with progressive footage, recognise the fields which belong to the same frame?
 
Andre,

If you choose or a project template that has field order set to None, or customize a template to None, then the footage will be treated as progressive footage. That means all titles, transitions, effects, etc. will be done on a frame, not field basis. It works.

Josh
 
Agree Joshua, but I wanted to know which fields in a progressive video sequence are being taken together, and if all fields from the progressive footage are being used. Some NLE's just use one field and apply field doubling when set to progressive, resulting in reduced vertical resolution. I wanted to know how APP processes progressive footage...
 
The footage is stored as an interlaced stream, so the apps will use both fields in proper order (lower field first). The system doesn't know the footage is progressive unless you tell it specifically, or if it has automatic detection (like Vegas does) and if that's the case, it'll detect the proper field order and group them together appropriately.
 
Barry_Green said:
The footage is stored as an interlaced stream, so the apps will use both fields in proper order (lower field firstThe system doesn't know the footage is progressive unless you tell it specifically, or if it has automatic detection (like Vegas does) and if that's the case, it'll detect the proper field order and group them together appropriately.
Click to expand...


Agree Barry, but my question also relates to systems which don't have frame cadence detection (like Vegas). Do we need to set the field order? What, if the source material needs upper field first?
 
i don't think that's talking about DV. dv is lower field first...pal or ntsc.

since you're not just talking about dv what other footage are you talking about?
 
novelt said:
i don't think that's talking about DV. dv is lower field first...pal or ntsc.

since you're not just talking about dv what other footage are you talking about?
Click to expand...
The link is only to illustrate that upper/lower, top/bottom, even/uneven, though often used, are not unambiguous, even for DV. Only Field order A/B or Field 1/2 first are the correct expressions for all interlaced systems.
Even when DV would always be "lover field first", what makes you think that the lower field in a progressive (interlaced) DV stream is not the last field of frame n, and the upper field the first field of frame n+1 ? In this case the wrong fields would be combined as new frames..

Other video material is analog captured footage and processed as MJPEG. Field order choice in APP is there for something...
 
didn't answer my question...

however funny...in the mpeg encoder it says "lower field first/DV"...hmmmm.
 
andre, the engineers behind 24p have taken this into account; when it's recorded, its fields are properly flagged and what you're worried about won't happen if the software removing the pulldown knows what it's doing.
 
Thanks David. I am not specifically thinking on 24p and pulldown, but just 30p (or 25p) where no pulldown is involved. Is the frame flagging also present then?
 
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