I have a project I'm producing where the source clips are generated from Quicktime doing a screen recording. The dimensions are 2880 x 1800, 60fps.

The source dimensions are a little unusual, but Quicktime saves as mp4 and offers no option to change the recording dimensions. This is not ideal to be re-rendering mp4 but I have no option.

When I render to 1080p, it seems the scaling is causing some mild blurring. I've used Maximum Render Quality and Render at Maximum Depth but still get blurring. Bitrate is fixed at 8mbs, but I have also tried up to 16mbs with the same result.

I've also tried doing 50% renders at 1440x900 with the same options but again, the there is slight blurring. My thoughts were that with double the data available at 50%, there would be little to no blurring.

Does anyone have any ideas about what I can do here?

Edit 2 days later with more steps I've tried:

  1. Created a new sequence at the clip native resolution of 2880x1800. I rendered out using h264, mp4, Max Render Quality and Maxium Depth enabled, 16mbs. Still showed blurring.

  2. Created a sequence at half the native resolution, 1440x900 using the same previous settings. I then scaled the clip to the frame. Still showed blurring after rendering.

  3. I installed Apple's Pro Res codecs and tried both 1 & 2 scenarios again. I got blurring with each codec except for the very highest bitrate one, and only at native resolution of 2880x1800. A 10 second clip was about 500mb, so that made it an infeasible attempt.

I then found that Apple has a 30 day trial of Final Cut Pro so I installed that. I took me a little bit of experimentation but I was able to do a test render at full resolution that came out perfectly.

I then recut the entire project in Final Cut and was able to export it.

FCP is ok, but it was a huge cpu hog during the editing process where Premiere seems to perform a lot better overall.

I'd still like to figure out this problem with Premiere if possible.

  • 1
    Since you tagged Premiere.. I imagine you're dropping these clips into a premiere timeline and then attempting to export. Are you scaling the clip to a 1080 timeline or cropping it or just using it at the dimentions above and scaling it in the export? – integris Jun 10 '15 at 12:47
  • @integris Just added some more info from after the original post. – Geuis Jun 10 '15 at 22:18
  • Well you have source material in h264 which is a compressed format, you are scaling the size and then compressing it again. Each of these operations will increase apparent "blur". You will get the least apparent blur by exporting uncompressed at full resolution.. even so you can't add information, Only a bunch of file size. You might try exporting a clip as uncompressed prores, then reexporting it as an h264 again, possibly the the recompressing wouldn't fight with the artifacts as bad. avsforum.com/photopost/data/2363756/5/55/… – integris Jun 11 '15 at 1:54

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