Re: FCP6 TemporalImageAPI - returning an image different from main input
Re: FCP6 TemporalImageAPI - returning an image different from main input
- Subject: Re: FCP6 TemporalImageAPI - returning an image different from main input
- From: Pierre Jasmin <email@hidden>
- Date: Wed, 02 May 2007 23:26:10 -0700
- Organization: RE:Vision Effects
// did not go through as I was exceeding 12 bytes
Here's a random question for all of you - AE/Premiere are doing a lot
of resampling when they hand you full-size frames that were generated
from fields, right? (Or are they just line-doubling the fields?)
if the source is interlaced, Adobe Pr and Ae or Combustion deinterlace
using field blending
- to help speed up process if your source is footage it will tag lower
or upper as an hint so you can skip scanlines (Premiere always set that
on every frame height fields, AE only when the source is footage)
- in Premiere the timeline advances by 0.5 increments when your project
is in fields, in AE you have to set the comp to 59.94 to see both fields
- in AE in RAM previews at 29.97... the other field is skipped
if the source is not interlaced then it will pass you a progressive
frame (fields happen only at the end via subsampling)
if the output is 59.94 fields per second it renders 59.94 frames per
second and reinterlaces
if the output is 29.97 no fields and the source material is interlaced
it will skip a field when rendering
This to say it's ok to skip pixels when you scrub the timeline...
for the sanity check test
maybe render in AE a number counter movie with fields that advances (+1)
one per field and color each field differently (eg red for lower and
green for upper)
- apply a blur: it should never turn yellow etc... (just to explain
it's not necessarily a time only thing)
- apply a blur on a progressive source in an interlaced output project
or a progressive output project and you should not get a blur that is
twice as high in one case vs the other
make sure you use 29.97002997 when moving data to AE and from AE to
FCP... (as OMF, Premiere, FCP... all are on the 29.97002997002997 NTSC
period and not 29.97 - in fact the Premiere - AE link in prev cycle is
sort of broken in fields because of that - you don't see it because by
default AE shows you only one field but that difference will make you
fall on the other side of the .5 on the second field, so in effect if
you render a 29.97 movie in AE, import in Premiere and render that movie
NTSC with the default fields based setting and import without changing
the interp in AE, then look at it in 59.94, one field is gone (field 1
and 2 are the same).
A long term solution could be to simply defer upscaling fields to full
height frames until some tool requests a full frame, so then you could
stay upsampled until the output. what you don't want to do in life is
at each step scale and resample down, only scale once if needed, only
resample down once at the end if needed. The same thing could be said
about color space, you don't want to do YUV to RGB to YUV at each filter
when you have many consecutive ones. You maybe want to do once YUV to
RGB if the filter only works in RGB and then at the end convert back to
YUV if the output codec is YUV...
Pierre
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