Interlaced to progressive conversions

[Alan Christensen]

One of the side activities that I do is to put together college recruiting DVD's for high school athletes to send to college coaches. These are typically composed of the athlete's best plays from the year. I assemble the clips, highlight the player at the beginning of each play, and use slow motion when appropriate. I typically receive game videotapes or game DVD's from which to extract the plays based upon timecode.

The source material that I get comes in a lot of different formats. I use Adobe Premiere to do the capture and editing.

Although I am completely clear with respect to the meaning of interlaced vs progressive video, I am not 100% clear with how Adobe Premiere converts material when the export settings are different than the source material. For example, if the source is interlaced video, then what will Premiere do if I export to 30p? Will it de-interlace the video (i.e., interpolate the missing lines from every other field), or simply combine the two fields into a single frame (thereby having a double image on each frame where motion had occurred)?

If I get progressive video, then what happens if I export as 60i? Does it simply take the odd lines of the first progressive frame to populate the first field, then use the even lines from the first frame to create the second field? I am assuming that this is what happens but would just like to have someone confirm it.

Sometimes I get interlaced source video that has already been converted from interlaced to progressive at some point. If I am in an NTSC project (interlaced), than does Premiere essentially pull the fields back apart when it does any processing, like slo motion? Or is there a need to tell Premiere to do this by setting "interlace consecutive frames" in the fields menu? Would I get any different result if I used this setting vs not using it? If not, then when would you use this setting?

One of the issues that I have with figuring this stuff out by myself through experimentation is that Premiere always de-interlaces the preview monitor. Is there a way to turn off de-interlacing of the monitor, so that you can see the all the contents of a single frame and not just the odd lines? Or a way to step through fields rather than frames?

[Bart Walczak]

Interlaced to progressive => deinterlaced

Progressive to interlaced => if frame blending enabled, you get field A from frame A and field B from crossfaded frame A and frame B, if disabled, fields A and B come from frame A.

Interlaced to progressive to interlaced - like progressive to interlaced, the footage does not have the fields anymore.

preview interlaced - go to view panel menu and select "display both fields" (or something like that). However, it would be better if you had some kind of monitoring hardware like BlackMagic/Aja/Matrox.