Dissolves of HD footage in Premiere producing interlaced lines

[Jon Barrie]

Are you using CS3 or CS4?

JB 🙂

Jon Barrie
aJBprods
http://www.jonbarrie.net

[Nicholas Shera]

I’m using CS4.

I should add that the problem does not manifest when I output a 720p file from within the 1080i timeline. It only occurs when I have placed 1080i clips into a 720p timeline and output from there.

[Jon Barrie]

Do a test.

Select one of the 1080i clips and duplicated it. (Edit>Duplicate).

Ask the original clip to interpret as Progressive from the Project panel.

Then try another test with the duplicated 1080i clip that is natively interpreted. Add it to the timeline and right click to set the field options to reduce flicker.

Export each to compare.

– JB

Jon Barrie
aJBprods
http://www.jonbarrie.net

[Nicholas Shera]

Thanks so much for your advice. I don’t know why I didn’t think of doing any of that earlier.

The results:

Interpreting the 1080i clips as Progressive from the Project panel is not sufficient to get rid of the problem. It actually worsens the problem by making the artefacts visible for the entire clip, not just during the dissolves. However, applying Flicker Removal to the clips (in addition to interpreting them as progressive) solves the problem.

Keeping the 1080i clips native, and then reducing flicker, also does not solve the problem. However choosing “Always Deinterlace” solves it.

Given that the second option involves only one step, it is the easiest solution to my problem.

[Anne Innes]

I’ve noticed a similar problem with field artefacts with 1080i clip speed changes in cs3. Deinterlace doesnt seem to fix it.
Does anyone know if the problem has been resolved cs4 ?
or a suitable workaround ?

Also for motion on stills – get the same problem with interlace lines on the output. Deinterlace has no effect.

Workaround tips greatly appreciated.

AI

[Nicholas Shera]

I just did a test in CS4 where I slowed down a 1080i clip (in a 1080i timeline) and rendered out an MPEG-2 file using the appropriate HDTV 1080i preset (in my case, 1080i 25p as the that was the frame rate of the source footage).

My results are:

By not changing any of the field settings, I see interlacing.
By selecting “Always deinterlace”, the interlacing goes away.

So I don’t know if your problem is a CS3 issue or whether you’ve chosen wrong settings along the way.

[Anne Innes]

No I didnt do anything wierd.

From the Adobe site forum – it’s apparently a glitch that came into being with CS3. It has to do with the way PP interprets the footage and handles effects in the backengine.
When CS4 was due for release the issue had not yet been solved (to great outrage according to PP users on the Adobe site) – I was hoping a later patch may have resolved the bug (nothing mentioned on the Adobe site). Or curious to see if anyone else had found a workaround.

You can not see it on your monitor in PP – you only see it when you go out to a full grade environment (or alt can check with a frame still output in photoshop).

The dissolves have horizontal streaks/field lines – even with “de-interlace” on,
Similarly for changes in speed on a clip.

My objective is to have a progressive output from the 1080i footage.
For the grade I was asked to generate a tga sequence of the scene.

It’s like the de-interlace gets turned off under those effects, as the preceding and following outputs are fine.

[Nicholas Shera]

Well like I said, I can overcame the problem in CS4 by selecting “Always Deinterlace”. And like I said, that was for a fully rendered MPEG-2 file (which can be burned to Blu-ray).