Hi,
this thread is for all of you who are struggling
with poor quality when using footage from the inflationary used low budget
consumer cams like gopros or dji stuff or other Cams (A7 a.s.o.a.s.f) with
progressive codecs in an interlaced project. (There are many threads about this
and similar issues but none of them have a real solution I think)
Also I want to draw the attention to
another issue which you get when you use footage from gopro or other progressive cams bottom
up in an interlaced project.
Both issues happen with every MC Version I
know so far.
I start this thread to summarize everything
I found or investigated to these topics and to get more information from you
who have the same issues.
Issues in short:
Issue A)
When changing the frame/field motion from
progressive footage (25p or 50p) to 50i (for delivery) inside of avid you get
jagged and flickering lines/edges and a blurry image.
Issue B)
When you get footage from a progressive
cam (gopro/osmoaction…) recorded upside down, avid applies a frameflex with 180°
Z-Rotation while linking. So the image is orientated right after that. But the
result is an image with wrong field order (bff).
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About Issue A) :
I found a lot of threads where some users
suggested to encode the progressive files to 50i before ingesting. Other users
suggested to edit/finalize in 50p. Export in 50p and then afterwards convert
the file to 50i. Also some users did not see any issues. I guess they have the
same issues but simply do not realize them. Some use premiere (with
antiflickering), some use after effects, some use resolve. No one has a workflow
inside of MediaComposer. By the way I
use FFMPEG.
HELLO AVID are you aware of that?
When I watch TV I see these jaggy and
flickering lines everywhere. On the other hand there is also many content which
looks gorgeous. So there are workflows which work and some don’t.
Correct me when I am wrong: When it comes
to DJI Equipment (Drones and Osmo) there is no workaround. You have to
reinterlace the footage before you get it into Avid Media Composer. If not, the
results are very disgusting and frustrating. I heard, the small chip in these
devices creates too sharp images but this could not be the whole story.
For reinterlacing we take ffmpeg and the reinterlace
filter. It takes odd lines from frame 1 and even lines from frame 2 and so on.
The result is slightly blurry (maybe I can figure out a better algorithm in the
future). But the motion is smooth and you don’t have the aliasing artefacts I
mentioned before.
When It comes to gopro footage the
aliasing is not quite as annoying as it is with DJI. But it is still there. It
gets worse when you activate the hypersmooth stabilize in the gopro 7 or
higher. So you guess it: We should reinterlace it outside of Avid.
But here is another problem: While the
osmo or drone footage are only a few clips per shooting day, we get so much Gopro
footage we can’t (do not have the time) convert it before ingesting. (48h of
footage per day (from 8 Gopro Cams) 20 shooting days a week).
We AMA link the 50p files into a bin and transcode
the clips to XDCAM EX35 1080i50. -> jagged lines. If the image is used in
the final edit and if it is too jaggy we take the clip, from original footage,
reeinterlace the clip with ffmpeg and then reedit it into the timeline. Not a very
handy workflow.
And for those people who think shooting in
25p or ingesting in 25p is the holy grail: I do not think so. When you use the
Gopros as bodymount cams you get seasick when you not have the motion
smoothness you get from 50p or 50i. Reinterlaceing with Motion Adaptor and rendersettings
->”use frameblending in motion adaptors” leads to ugly artifacts. And the
jagged lines are also there. We made some tests. And on the other hand if you
do not activate the frame blending setting you get 25p motion. Which is also
not what we need.
Does
anyone has a quick solution for a huge amount of footage? Maybe Marianna or
Pat?
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About Issue B)
We are dealing with the same Gopro clips
from Issue A.
Some of theme where shot upside down. Avid
MC is so kind to add a frameflex with 180° Z-Rotation while linking so you
could see the image in the right way. But now it gets complicated:
We shoot in a multicam environment. So we
group all the footage. Since Multigroup Mode could not render on the fly we see
every Image which was shot upside down, you guess it, upside down. Our Editors
hate it.
So we thought it would be a good idea to burn
in and apply the source transformation while the initial transcode of the
footage from 1080p50 to 1080i50. A really good and handy idea I thought. Every
footage was orientated in the right way in the group, everything seemed to be
fine.
But, no, not so with Avid Media Composer. After
the transformation is applied and transcoding has been done the field order is
wrong. I guess the order of the transcode process is
first interlace then
Z-rotate. It should be the other way
around.
So when we make the final adjustments, we
have to “Commit Multicam Edits” “re-Z-Rotate” the image and then apply a good
oldfashioned Flip-Flop effect on every clip which is bottom-up
Avid? Really?
What is your supposed way to do this.
Requirements:
1. Getting
to edit fast in a shared storage environment
2. Edit
every image in groups with the right orientation
3. Avoid
field order issues
4. Preserve
the 50p or I motion
5. Deliver
in 1080i50
**********************************
When I watch TV I can see which content has
been created with Avid Mediacomposer because of these quality issues.
@Avid: I would like to get the best quality out of my footage. Please provide me the tool for that. Do you think 1080i50 is no longer
used or do you think everyone shoots in the framerate and field motion he
delivers? Not in my world.
Since there are a lot older posts and Avid
never dealt with it I guess there will be no fix for those issues in the
future. So I investigate further in using ffmpeg. I hope I am wrong.
My goal is to program a script which takes
any footage. Converts it to clean and crisp 1080i50 directly in a codec we like
(DNxHD120 so far, but I would like to get XDCAMEX or HD working also to safe storage
space). And output directly in Avid Media Files - MXF OP Atom. Since FFMPEG is quite
fast and you safe the time for consolidating, this could be a good solution. And
if I can read out the rotation flags from the original files (I guess I will) I
can auto rotate the image while converting. Both issues will be gone.
But I would prefer If Avid finds a way to
get these things working inside of Media Composer.
***********************************
Am I missing something? Is anyone with same issues here? Maybe we can
work together on a solution?
Sorry for the very long post but this kept
me busy for a very long time now. I hope we will get a solution together.
Regards