Apparently I did this wrong from the start and need to know how to fix it for now (and next time).
720p project with lots of AMA'd SD interlaced footage, edited already.
When the project is switched to 720x480 30i, to deinterlace, there are bad interlacing artifacts when exporting tests, with and without a mixdown. (Yes the timeline was refreshed and the source is registering correctly as interlaced). Same problems in QT export (DNXHD) with deinterlacing checked.
The mixdown doesn't deinterlace.
When TImewarp is put on the clip (setting is both fields, interlaced to progressive), I get stepping and a somewhat soft clip.With hundreds of clips in a two hour project, 3/4 of them interlaced, I'm also wondering if it's practical to apply an effect like that.
What's the best way to approach this? I have searched this extensively online and am still lost as to a solution for fixing this in a long, already edited, AMA'd project.
The project is going to DVD, so my next step is to see if the interlacing shows up on a burned DVD. But I will have to output digital files as well.
This project is almost done. So close.
Under the source setting for the AMA linked source clips. How dioes it show the interlacing? It may show as progressive.
My workflow is normally to AMA link clips in an interlaced project first. Ensure the source settings are correctly identifying as such.
Use field stepping to confirm sources are interlaced and correct field order.
Then switch to HD and P if needed (has to be P for 720)
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Thank you Pat. I'm checking this, please stay tuned.
So far in the field motion column, most have shown as interlaced, although I found one that says progressive, yet observation of the source file shows interlace lines, so I'll have to determine what's going on there.
I did try AMAing a test file in a new 30i project, then opening the bin in my main project set at 720p, then refreshing the sequence. It did not solve the interlace lines. (example attached of a still frame). They almost seem more like artifacts than interlace lines. But there are others that are clearly interlace lines and I am testing those as well.
I've created this wonderful project IN the program, but cannot get it OUT of the program! Like the bug that crawls into the jar but can't get back up the sides to get out. It's so absurd at this point it's laughable. Oh the joys of learning Avid. Good times. But at some point I have to actually materialize this project and deliver a master.
You can change the metadata of the one clip which thinks it is P to I just by right clicking on the Progressive in the Field Motion column and selecting Interlace. But that will not help if the clip in question is TRULY progressive. But why would it show interlace artifacts? Maybe it got "baked in" at some point and is not really fixable at this point. You may need to follow the bread crumbs back to the true source.
I have just finished a HD show using tons of old SD which had been captured from tape over the years with various capture cards using various codecs and not always the best practices. I basically had to arm wrestle each and every clip to get the best result as there was no real "best setup".
I also did NOT use Avid's upconversion. I do not feel it is near best quality. I normally would use Alchemist. But with the truly random nature of each and every clips problems, the best option for me was to use Adobe Media Encoder to sort out the issues and upconvert to the HD format I needed. Horribly time consuming but I got something I can live with.
Good luck,
Jef
_____________________________________________
Jef Huey
Senior Editor
Testing now and will follow the "crumbs" back. This post gave me a bit of panic as I already have one file that's "baked in" and that will be another thread - but hopefully this is happening in Avid and not the other source files.
Please stay tuned... do not adjust your set..lol... I have to run out but will continue testing as soon as I get back.
I'm sort of shocked how ridiculously difficult and convoluted some things are in Avid. Although most of this on my part is just learning curve. If it's not handled properly at the outset, well... here we are.
Thanks folks =)
It's mixed. I went through and for the most part, it showed properly as interlaced or progressive. There were a few that were incorrect - I corrected them.
I AMA'd a few test clips in a 30 i project and then opened the bin in the 720p project. I am not sure if it was that, or if I changed the field motion in the bin (pretty sure I changed that one to interlaced) - at any rate, the example posted earler was corrected.
However there is one clip that won't change - am still working on all of these and testing them. So just to be clear, if the clip is interlaced, it should show interlaced in the bin, not be changed to progressive, correct?
The key here is to ensure in an interlaced SD project the content shows no interlacing artefacts when you field step. Not frame step. Field step.
With each field movement in the image should progress along slowly and each filed should be free of interlacing tearing.
If the movement progresses for every 2 field steps you have progressive content. If you see any interlace artefacts in any field you have baked in issues that you won;t resolve.
So the key is to ensure the sources are good and correctly identified. MC should then de-interlace as required. But SD up to 720 you are going to see stepping as you are scaling the image.
Pat Horridge: The key here is to ensure in an interlaced SD project the content shows no interlacing artefacts when you field step. Not frame step. Field step. With each field movement in the image should progress along slowly and each filed should be free of interlacing tearing. If the movement progresses for every 2 field steps you have progressive content. If you see any interlace artefacts in any field you have baked in issues that you won;t resolve. So the key is to ensure the sources are good and correctly identified. MC should then de-interlace as required. But SD up to 720 you are going to see stepping as you are scaling the image.
Exactly what Pat said with four additions.
1. Remember: Avid only shows you 1 field when in pause. That is why Pat is underlining the Field Step. This is a button you need to map to your keyboard somewhere. When you use it , you will see a small "2" in the upper right of the record or source monitor telling you you are looking at field 2 at that point. A must have for interlace work.
2. Always evaluate quality with the Video Quality selection on at least full Green. Not Yellow / Green. This is the small box to the lower left of the timeline area. When in Yellow / Green Avid is doing a lot of tricks to make the video easier to play in real time. All reduce the quality and are not showing you what you really have.
3. The Field Swap effect. This is a life saver in interlace shows with messed up footage. I am not sure what version it showed up, but it is in 8.9.3. This will let you correct clips where the field order is reversed.
4. This is the bad news. Deinterlacing is almost always a destructive process. Read up on it. https://en.wikipedia.org/wiki/Deinterlacing.
Avid shows an option for Adaptive Deinterlace. I have not found a techical explanation of exactly what they are doing. But know that there is no real magic bullet.
I am not sure how MC handles SD interlace into 720p. There are two methods I can think of. But I have never had to do this so I don't know for sure. But the fact that 720p is either 50 or 60 full raster progressive frames and you are coming from either 50 or 60 interlace (half raster) fields makes for a very hard ask.
Ok guys thank you so much. I'm going to go through all this and make some decisions today how to move forward with this project.
One initial question: how do mixdowns affect the deinterlacing issue?
Garbage in - garbage out. A mixdown makes media with the codec that you select in the raster size and P or I 'ness of the of the current sequence.
Only real thing to know there - DNx HR does not respect interlace. DNx HD does (make sure to choose right codec variant).
Fun, ain't it?
LOL good times!
Still troubleshooting. I have this ONE clip (haven't gotten to the others as a result).
It WON"T deinterlace.
However, it's not in the clip. You know how I know? Because one time it DID deinterlace. Problem was, it was in the middle of about 20 tests, and out of habit I refreshed the sequence, and it hasn't put out a proper clip since.
I've checked the source settings, the settings that were in a (now removed) effect on the clip, relinked the source file after bringing it in from a 30i project, exported from the source clip loaded in the source monitor, tried making the ama sequence relink to the subclip (unsuccessfully), changed the project format, exported from the separate 30i project as well. Every. Single. Time. It artifacts.
Except that once.
It seems to be only on clips that have motion effects added to them. The adjacent clips from the same source are okay. Re-editing does not solve it.
Can you send me the clip?
Thanks Jef, I guess I could although the currently linked file is 7 hours long and 37 gig in size.
Except it's not curently linked because the project is mostly offline right now. I replaced the source files in the Finder with newly transcoded h264 mp4 files, for better quality since the motion jpegs seemed to be not great. Avid doesn't want to connect to the new files. I did check 'ignore extension', but it says the new files don't match the format. I tried linking by other criteria but most of the options were grayed out. So I'll hit this again tomorrow.
Does it just not allow you to replace the AMA source files with new files? Serously? The duration has not changed.
If the relink ever works, perhaps it will solve the interlacing issue, who knows.
My patience is growng very thin for the wasted time on this project. I am trying to love Avid because everyone else does, but it's making it very hard to do.
If you are trying to relink the AMA linked files in a bin you'll struggle. Relinking works ok on a sequence (of clips)
You AMA link the new clips into a new bin. With that bin open and the clips selected you can AMA link the sequence using the option link to slected open bins.
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