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HDV Sequence to SD Sequence to MPEG 2 nightmares
Sorry for the long subject… it’s getting to be a long project as well.
We’re working on a DVD with sequences of high res photography in motion over music. Sounds nice, right? All of the sequences are being done in HDV, since that’s what we have the equipment to master to tape when everything is said and done (for Blu-ray or HD-DVD version down the road).
We’ve gone through several rounds of revisions now, and it seems that some key problems have been poping up more and more.1) Trouble downconverting the HDV sequences to anamorphic SD via nesting
2) Jerky motions in keyframing on clips even with simple two-point contant-speed motion settings
Here’s as much info as I think someone will be willing to read…
1) I recently started this job, and the company I work for typically outputs to uncompressed QT then reimports that to convert to MPEG 2 using compressor. Many of the moves rotate, and outputting like this seemed to be distorting the images’ aspect ratio during rotations (round things became ovals, etc.)
For this reason we decided to do it the way I have always gone about outputing differently than I edit… nesting the sequence in a sequence with the desired output settings.
Up until the last round of revisions this worked like gangbusters… I nested, it scaled; I made changes to the original, it updated… On the last round, several of the sequences decided they would no longer be constrained to anamorphic 720 x480. The sequences returned to their original size, and I just saw the center portion of the nested sequence. What’s more, deleting and re-adding the sequence produced the same results.I wonder if anyone can shed light on why FCPs behavior changed with respect to scaling the nested sequence vs centering it, and leaving me to do the scaling (which I don’t want to do manually for fear of inprecision). Not all of my sequences did this, just 3 of 11. The only thing I could think of that had changed was a File Error I had that day, so I had to do a Save As, and make a duplicate of the file.
2) The pictures we’re using are really high-res (in the thousands), and I expected, and have been dealing with, pulsing scan-line issue stuff (as best as you can with images that big with small detail I suppose). The image problems I’m curious about are jerky motions on clips with very smooth motion paths (2 points, no ease). Changing center points to speed up or slow down the motion seem to work, but I still want to know why it’s happening in the first place, and if there’s a rule of thumb with high res pictures, specifically in HDV.
I know that was probably way too much information, but this is my first project dealing with HDV, and I don’t even have HDV footage, just big ol’ pictures.
Thanks in advance for any light anyone can shed on this stuff.
Zak
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2 Replies
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[Zak Mussig] “On the last round, several of the sequences decided they would no longer be constrained to anamorphic 720 x480. The sequences returned to their original size, and I just saw the center portion of the nested sequence. What’s more, deleting and re-adding the sequence produced the same results.
I wonder if anyone can shed light on why FCPs behavior changed with respect to scaling the nested sequence vs centering it, and leaving me to do the scaling (which I don’t want to do manually for fear of inprecision). Not all of my sequences did this, just 3 of 11.”
I don’t know what could have caused this. It’s supposed to do what you want it to. Try trashing your preferences.
If you’re worried about inpreceision, just examine what the Motion settings are for the clips that did automatically scale. You can copy and paste those attributes. I think 1080 to 480 is “Distort -12.5%” and “Scale 50%”. Don’t take my word for it though, I’m just going on memory.
Sean
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Thanks for the help Sean. I finally figured it out after about 25 minutes or so, and spent the rest of the day trying to find a workaround for the other problem… no such luck so far.
I’ve been using FCP for 5 years or so, and I never knew you could open nested sequences in the viewer and apply motion settings, filters, etc. Kinda embarrased about that now, but I guess you learn something new every day, huh?
Thanks again,
Zak
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