exporting from premiere: progressive or interlaced ?

[codemaster]

I've edited an MPEG2 video in Premiere Pro CS3, but in the same window where I choose to export using DebugMode Frameserver plugin, there is a place called "Keyframe and Rendering", where the Fields option is set to "Lower Field First", but how do I know wich option is correct here: "(No Fields) Progressive Scan", "Upper Field First" or "Lower Field First" ?

[poisondeathray]

You have to determine what the original video was.

use the same as whatever your asset and project settings were

if it's interlaced, it's either top or lower field first . If pick the wrong one, it will be jerky (like forward-back-forward-back) , then you know it's the wrong one

if it was progressive, choose progressive

[codemaster]

You have to determine what the original video was.

use the same as whatever your asset and project settings were

if it's interlaced, it's either top or lower field first . If pick the wrong one, it will be jerky (like forward-back-forward-back) , then you know it's the wrong one

if it was progressive, choose progressive

after analysis with MeGUI, I know that the source mpeg2 is interlaced with upper field first, but in the project settings, fields is set to lower field first and it is greyed out, I can't change it to upper to correspond with the source. Are there any problems if source is upper ff, project is lower ff, and I export with upper ff ? What if I have progressive and interlaced sources mixed in the timeline, or a mixture of sources with different field dominance ?

[poisondeathray]

If you mix TFF, BFF , sections will become jerky , but mixing progressive and interlaced can be ok in an interlaced timeline. Ideally you should use the same format or convert everything to the same format

you're using an older version of premiere, but you can set custom "desktop" settings (instead of a DV-PAL setting in the editing mode) which unlock everything for the settings. You may have to set it for the sequence settings or project settings. It's a bit different than the newer versions. DV is ALWAYS lower field first, that's why it's greyed out

[codemaster]

if my source is MPEG2 upper field first, does it matter if I create a custom premiere project, with editing mode set to "desktop" and field set to "upper field first", so that I can export to signpost avi, also with upper field first, using DebugMode ? Or it doesn't matter what field dominance the premiere project has, nor the exported avi ? Is it wrong not to preserve source field dominance, or does Premiere detects mistakes related to field dominance, in case the user is not familiar with interlacing?

[poisondeathray]

if my source is MPEG2 upper field first, does it matter if I create a custom premiere project, with editing mode set to "desktop" and field set to "upper field first", so that I can export to signpost avi, also with upper field first, using DebugMode ? Or it doesn't matter what field dominance the premiere project has, nor the exported avi ? Is it wrong not to preserve source field dominance, or does Premiere detects mistakes related to field dominance, in case the user is not familiar with interlacing?

assuming megui's analyzer is correct (it's been wrong before), just set it top field first , and whatever you encode to , keep everything top field first

It matters. If you get the wrong field order, it will play jerky. Premiere will not automatically fix anything

If this is a movie (hollywood), it's probably not interlaced. It's probably telecined

[rallymax]

I think it's mute because you're exporting to the frameserver I think that makes it progressive. In the Premiere Compiler (the frameserver plugin) it can only ask for Progressive frames (BGRA444) so any deinterlacing has already been dealt with. If the FrameServer plugin were a complete editing mode then it's possible that you could get direct from source interlaced frames but it is my understnading that it is an importer and exporter only (ie it doesn't have the "editing mode" smarts too).
The field order that is used is set when you make a new sequence. The upper/lower/progressive is set in the General Tab.
I might note that the reading of the frame order in Premiere CS4 is mostly broken. I have some footage from my iPhone 3G and an Australian Canon Camcorder (thus 25fps) that are both supposed to be 720p30 and 1440p25 and they are actually both pulled down interlaced ie 720i60 and 1440i50. If you open them in a progressive sequence they are in the wrong field order (probably coz SD is lower and HD is upper first (or vice versa I forget) and the legacy (SD) would be around the wrong way). Thus Premiere decodes them around the wrong way. The only work around is to make a Desktop sequence and edit in a custom mode (ie it'll be BGRA444 all the way though) and thus in the sequence settings force the field order to trick the Premiere importer to flip it so that it's the right way around.

[poisondeathray]

i think it's mute. because you're exporting to the frameserver I think that makes it progressive. I the Premiere Compiler (the frameserver plugin) it can only ask for Progressive frames (BGRA444) so any deinterlacing has already been dealt with.

Are you sure? If that's the case, I wouldn't use that frameserver. Even if you wanted progressive output, premiere's deinterlacing quality is horrendous

I was under the impression it frameserved the same thing as the sequence settings (I don't use it for premiere, and it doesn't work for CS5, and was unstable for CS4)

[codemaster]

rallymax, if DebugMode asks for progressive frames, then the signpost avi should't contain progressive frames ? 'Cause AutoGK had this to say about my signpost AVI:

...
[04.01.2011 07:49:15] Analyzing source.
[04.01.2011 07:49:53] Source has percentage of interlacing in motion areas: 83,30
[04.01.2011 07:49:53] Source is considered to be interlaced.
...

these lines are from autogk's log file

[rallymax]

I'm 99% sure. I'll check the Adobe SDK tomorrow for you.
If you look at this old post
https://forum.videohelp.com/threads/309449-Adobe-Premiere-MainConcept-s-H-264-vs-x264-o...=1#post1952594
you'll see what Adobe Premiere can give a compiler (aka exporter)
By default all exporters must support 8bit per channel RGB in rec601. In the SDK this is called "BGRA_4444_8u".
Note that it and all other editing modes are full frame. There is no way to get an interlaced frame from the source UNLESS *somebody* makes an "Importer", a "Player" and an "Compiler". These 3 together make an editing mode and where possible that format is copied instead of converted to RGB and then back to format X. But this ONLY happens if every step in between (eg transitions and filters) have that FourCC code format supported. (99.999999% of them don't).
Simple cuts will work without re-transcode if the "Player" is capable of dealing with the clipping of footage and smashing them together to make single stream.
Bottom line - I see absolutely no where in the workflow where you use transitions or filters where you can get interlaced output.

[rallymax]

as for the signpost (which I assume is the frame buffer between Premiere and whatever client is absorbing it) showing as interlaced that would make sense if
A: The sequence is interlaced
B: The Frame Buffer is populated by the Premiere Render engine a field at a time.
C: The Compiler can generate INTERLACED OUTPUT.

In the "Compiler" (aka Exporter) I'm 99.99999% sure you ask for FRAMES not FIELDS (regardless of Progressive or Interlaced Sequence or Output mode). Note that timestamp X:XX:XX:XX which in the SDK is a floating point number ie xxxxx.xx will fill the frame buffer with the (Sequence's lower/upper) FIELD of that FRAME and then the other FIELD with the next FIELD in the Sequence. For Progressive Sequences it would be the entire FRAME at that timestamp.
I assume that the Lower/Upper setting of the export gui is so that you can choose output FIELD order if you're making Interlaced. There is no guarantee that the Compiler is using that radio button. It's hard coded into the GUI and is optionally used by the implementor of the plugin.


If the exporter is making Interlaced (and it seems from your comment that it does) it will then take the frame and encode the first FIELD then the SECOND field. If your SEQUENCE is in the same INTERLACED FIELD ORDER it should look ok. If it's around the wrong way you'll get the jerkies (Fix this by reversing your Sequence order or changing to a progressive editing mode). The DE-INTERLACED button is turning on Adobe's BAD de-interlacing engine so that if you're not capable of handling Interlaced FRAMES in your Progressive Exporter it'll do it for you.

[rallymax]

...snip...
after analysis with MeGUI, I know that the source mpeg2 is interlaced with upper field first, but in the project settings, fields is set to lower field first and it is greyed out...snip...

[Attachment 4957 - Click to enlarge]

It's greyout out because you can only change that when you create a Sequence.
Change your preview to high quality and scrub your footage. If it shows no interlaced problems with the lower field order then the source must be getting decoded to FRAMES because FourCC:M2V isn't the native editing mode. It just happens that the Importer is getting the FIELD decode right. ( I have 2 cameras that it's around the wrong way so you're lucky).
If it is decoing wrong the only way to fix it is the make a new Sequence with it set the UPPER and hope that Premiere doesn't screw it all up in the decode.

[rallymax]

found this table on what each output size has for lower or upper field first...
DV - PAL - 576i - LFF
DV - NTSC - 480i - LFF

DVD - PAL - 576i - UFF
DVD - NTSC - 480i - LFF

HD - 50fps - 1080i - UFF

DV100 - 50i - 1080i UFF
DV100 - 60i - 1080i UFF

UFF=Upper Field First - LFF=Lower Field First