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Why does my exported movie stutter in QT player?
A recent project has a long sequence of still images that move across the screen from left to right. The animation was created in after effects and imported into a HDV timeline. It plays perfectly out of Final Cut or when down converted to a SD DVD.
My client want to put it on a CD, but when converted to H.264 or Flash the long pan of images seems to stutter on playback. The camera footage portion of the video seems to play fine, or if it is skipping it is not noticeable due to the content.
Also I can take the full res HDV export and bring it back into FCP and it plays smoothly, but if I play the exact same file using the Quictime Player it stutters.
Why does it work in the NTSC world and not in the computer world?
Thanks,
Walker
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17 Replies
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Dave,
Thanks for the response. I should have mentioned that the animation was frame rendered and the video is 720P so there is no interlacing.
This looks more like dropped frames when played in quicktime or flash vs.perfectly smooth in Final Cut or as a DVD. Do you have any other thoughts?
Thanks,
Walker
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I noticed this when encoding an h264 the other day with some very fast cuts on stills. The only thing I can think of is that it’s the way the h264 GOPs are encoded. I don’t understand all the ins and outs of it, but their GOPs allow for reordering. According to apple: “Frame reordering is the concept of allowing frames to be decompressed in a different order than their display order” which means to me that the compression is having a hard time keeping up with the fast moving stills (in your case, animation). As a test, if you make a Sorenson 3 movie instead, does it keep up then? Also, if you export the movie as a self contained, then do the encode, that happens then?
Jeremy
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Thanks Jeremy,
I originally exported a self-contained HDV Quicktime and have used that as the source for my compressed versions. I tried a Sorenson 3 version and got the same results. I’m wondering if this is a function of how computer monitors receive data from the computer in packets and or the refresh rate. Because it is a long slow pan of images, any jerk or stutter is very noticeable.
However I can use the exact same monitor in FCP Digital Cinema Desktop mode and the file plays perfectly. Maybe FCP buffers the file and regulates the frame rate where the quicktime player does not.
Walker
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Look at your compression settings…
Most of the time when you compress to something that is web based, the setting will want to compress at a lower frame rate, say 15 or 10 fps. If this is the case, just set it back up to 30 or 29.97 for DF.
_______________________________
Wayne Carey
Schazam Productions
http://www.schazamproductions.com
https://blogs.creativecow.net/waynecarey -
Thanks for the suggestion Wayne. The movies are at 30 frames. The jerkyness is not constant, it is very random.
I tried playing the finished dvd (which plays smoothly on a dvd player and monitor) on my laptop and it does the same random stutter in this long pan. This has to be something to do with how computers play back video. Maybe all the other things the computer is doing diverts resources for a split second, and video sent to the screen is delayed.
I’d love to hear any other ideas.
Walker
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Any chance you can throw that section up on a website somewhere so we can look at it?
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Jeremy,
You can download the first 30 seconds in h.264 format from the COW folder using the link or the iDisk instructions below. The file is called LD h.264 test.
Thanks,
Walker
https://homepage.mac.com/redhotmedia/FileSharing1.html
or on a mac > Mac Finder > Go Menu > iDisk > Other User’s Public Folder > redhotmedia > connect > COW folder > drag and drop files.
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Cool, I’ll take a look and thanks for posting this. It will make it much easier.
Jeremy
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Honestly, that looks great to me. For a web movie it’s nice and clean and I don’t see much stutter at all. It looks like progressive video to me. I appreciate your eye to detail, but I think you might be staring at this too much! What kind of computer are you watching from? Just curious.
Jeremy
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Jeremy,
I really appreciate you taking the time to look at it. Perhaps we are expecting too much from a compressed movie.
I’ve watched this on my G5 and my MacBook Pro. The client has been looking at various mpeg and flash versions on a variety of pc machines.
Thanks for helping us with your opinion.
Walker
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