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Downscaling 1080 60i AVCHD video within a 1080×1920 frame
Hello!
I am shooting a show in a room where there isn’t adequate space to get as wide a shot as I need for the size of studio that the show is being shot in.
To fix this, I created a virtual studio that gave the illusion of more space, since the subject is relatively static near the center of the frame.
So I used PS 5.1 (64) to create the studio and props, AE 5.5 to create the animations, and exported the necessary animations from AE in 1080p AVI. In windows media player, the studio and animations play seamlessly.
Then I import that AVI into Premiere 5.5, (project preset for AVCHD 1080 60i), and composite the studio in the background of the ultra keyed green screen footage from the in-home studio. The in-home footage looks and exports excellently in the H.264 – HDTV 1080p 29.97 high quality format.
So here’s the problem:
When I manually scale down the in-home footage to superimpose into the 1080 virtual studio, the quality is always downgraded noticeably.
Furthermore, when I export the AVI virtual studio footage out of premiere, with the settings specified above (H.264…), the quality is very noticeably deteriorated.
So currently I feel stuck with poor quality footage, which is unacceptable. I imagine there must be a way to retain video quality when scaling down, at least proportionally to the new number of pixels which contain it. And the AVI virtual studio should not be losing any quality.
Please note that the final product must remain 1080×1920.
Any and all suggests would be appreciated, thank you!
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4 Replies
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Why not do the whole thing in AE? I think the scaling might be better, and it will save an export generation.
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Firstly, thank you for the reply. Secondly, I cannot export a reasonably sized file from AE, the 1080p 29.97 weighs in at 7.9 MBs/frame. That being said, the quality of video that AE exports is very good, as you estimated. Any idea how I could adjust the file size significantly (around 40KB-60KB per frame would be appropriate)?
Also, H.264 HDTV 1080p 29.97 seems to be the highest quality codec available from Premiere CS5.5 (the FLV won’t upload properly, and I can’t use the H.264 Bluray). Am I mistaken that this is the highest export quality?
Thank you!
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8 MB/s h.264 is not particularly high for full HD. It’s actually quite low, and I imagine the video would be noticeably worse than the original. For Blu-Ray quality, I’d aim at 15-20 MB/s.
If this is for web viewing, you might consider doing 960×540 (half size).
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Thank you again for the reply.
I’m afraid you’ve misunderstood, the video is 7.9 MB per frame, not second. So it’s almost 240 MB/s :). I have to take the quality down to a quarter resolution to get a reasonably sized file, but the quality is horrific at that point.
And still, so far as I can tell, if I want 1080p output, this is the only option that AE provides.
Likewise, any idea on whether there is a distinctively better quality codec from Premiere CS5.5 (my last post briefly details that question more).
Also, 720p output “could” be deemed usable, however all my attempts at that so far show that 1080p comes out better (not surprising). And AE still exports 720p as an enormous file (something like 5MB/frame).
Thank you!
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