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Compressor anamorphic export HELP!
I’m having trouble exporting footage from Compressor shot in 24p Advanced on a DVX in Squeeze mode. In the screenshots below, I have exported two different movs each with everything identical, h264, 6k bitrate, key every 120 frames, etc. except for the frame size and pixel aspect ratio (PAR).
This one I encoded with a custom pixel frame size of 854×480 with a PAR of 1.00 or square. Notice the artifacting and in the blacks especially, but this is the frame that matches what I see in the Canvas in FCP the best.
Next, this one is encoded in 720×480 with a PAR of 0.8438(or anamorphic) and has little or no artifacting in the blacks, but this frame looks horizontally stretched a little bit compared to my canvas in FCP. Note: quicktime compensates for the 720×480 frame and stretches it to 854×480 to display correctly on a LCD right?
Basically I need help on what I’m doing wrong here, I want the cleanest image possible, so if that means a slightly stretched frame, then thats ok, but I’d like not to. Should I be exporting to 720×405 with a 1.00 PAR instead?
Also, my setup is a Macbook Pro March 2009 with FCS 3 with all the latest updates. Any compression tips, advice would be much appreciated!
Thanks in advance! 🙂
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3 Replies
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The first export is the correct one.
Everything for the web or to be played in a computer must be done with square pixels.
But why in the earth have you set K-frames every 120 frames?
That makes no sense.
Your picture with a data rate of 6 Mbps could have a K-frames every 6 frames or so.
K-frames is what holds the quality in H264, MPEG-2, etc.
Think that normal DVDs MPEG-2 set a K-frame every 12/15 frames.
So put the K-frames in Auto and export again.
rafael -
Apple’s site says, “…have one key frame every 5 seconds (multiply the frames per second by 5)” so I took 24fps and multiplied by 5 with gives me 120. Is this wrong?
Read it here at section (c.)
https://www.apple.com/quicktime/tutorials/h264.html
Also, should I keep the PAR set at square no matter what even though quicktime will compensate for this? And if I do, what resolution should I set it at? 720×405 or 854×480?
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And just below they write:
“For H.264, we recommend leaving the key frame interval up to the compressor; so you should choose “Automatic” for the best quality result”.[Micah Smith] “Also, should I keep the PAR set at square no matter what even though quicktime will compensate for this? And if I do, what resolution should I set it at? 720×405 or 854×480?”
QT is compensating in this case, but many times doesn’t.
If you want your clip display well everywhere, don’t take risks and use Square pixels.
Any of both sizes are OK
864×486 would be better than 854xx480.
Rafael
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