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trouble finding right h.264 formula for particular website upload

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Robin Rosenthal
trouble finding right h.264 formula for particular website upload
on May 27, 2010 at 5:17:55 pm

Hi. I'm new to Compressor but learning fast.

I have a 3-minute teaser that I need to upload to a "crowdfunding" website called kickstarter.com. The site recommends using an h.264 codec, with acceptable file types MOV, MPEG, AVT, MP4, 3GP, WMV, FLV, video file size limit 200 MB. They also suggest starting with a bit rate of 1500 and adjusting from there.

My 3-minute sequence is HDV edited natively (1080i60). FCP7.0.2, on a Mac 2x2.66 Quad–Core Intel Xeon. OSX 10.5.8. Using Compressor 3.5.2. Sequence has moving people, moving camera...nothing is locked down, ever.

So I began my adventure with a droplet for HD going to Vimeo. Settings as follows:
Video Settings: compression type h.264, frame rate current, key frames every 30, frame reordering checked, compressor quality high, encoding best quality multipass, date rate restrict to 5000kbits, optimized for download.
Audio: AAC, stereo, 44.1, render quality normal, target bit rate 128 (no problems here, audio comes out great)
Frame Controls: On, resize filter better, output fields progressive, deinterlace Better, with adaptive details checked, anti-alias all the way to the left, details level all the way to the left, rate conversion fast, duration 100% of source
Geometry: Crop to Custom (all zeros), 1280x1070, pixel aspect default for size

So, the only tweaks I did were upping the date rate to 7000, and adding a gamma correction of 1.2. My sequence took less than 20 minutes to compress and looked pretty good for the purpose at hand on my end. File size 161 mb. Uploaded to youtube (minus the gamma correction, which I hadn't discovered yet), where it also looks pretty good (for youtube, especially at 720p) here's that link in case it helps you help me:






But when I upload the same file to kickstarter it looks crummy. Whatever happens on their end is degrading the file considerably. I can't show you that version cause I haven't launched my page yet. But I'd say it just looks "lossy"--not steppy in the motion, but more just noisy and having trouble settling on which pixels, especially in flesh tones on smaller size faces.

I've tried several more uploads with files created with different adjustments. I made one to their size (560x420), with data rate on automatic, some brightness and contrast tweaks (again before discovering gamma) and put the letterbox in myself using padding (learned a lot!). Looked really crisp and fantastic on my end but still crummy after upload.

Tried putting in more key frames (15). Looked odd so didn't upload. Tried one with date rate 8000 and all resizing and retiming controls set to their maximum best (guessing the retiming probably was moot since frame rate was set to current). This increased my encode time up to many hours, with same file size (183 mb). Looked not noticably better on my end, and same if not worse after upload.

I'm beginning to wonder if I should be doing something counter-intuitive like decreasing data rate, or trying 1-pass constant bit rate.

The people at the website are looking into it, but no answers yet. All the other videos I've seen on the site look quite good.

With apologies for the novel length of this post, but I wanted to put out all the info I could in hopes of getting help.

many thanks,
Robin


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