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03-17-2009, 09:40 AM #1
YouTube - Bad Frame Rate with slo-mo?
I did a short video for Snowbird and due to a serious lack of footage I resorted to using a boatload of slo-mo rendering . The end result is an OK little video (apart from all the slo-mo and cross dissolves ). It plays fine locally on my machine but when re-compressed for the web the motion in the slo-mo scenes becomes very choppy. I'm seeing this to a small extent on MobileRider http://www.snowbird.com/video/mobilrider but it's much worse on YouTube http://www.youtube.com/watch?v=VuqKhSTenBs
TH? I think I saw some similar choppiness in the YouTube version of your latest "Twin Peaks" vid but you don't use that much slo-mo so I can't be sure. Seems maybe like part of the YouTube compression might be to lower the frame rate... Is this yet another reason to use Vimeo? FYI the HQ version is even choppier.
Note sure that it matters but my uploaded a 640x480 MOV with H264 compression at medium quality. File size was 71MB for the 3:09.
Edit: Here's the YouTube embed.
"I'm a man of the past, living in the present and walking in the future..."
03-17-2009, 10:17 AM #2
03-17-2009, 11:40 AM #3
Just to be clear, I'm not talking about compression artifacts or loss of resolution. I'm talking about choppy video playback. The sort of thing you see when the data rate is too high for a computer to render so it starts dropping frames. I think I might try a test with an mpeg original and see if that helps..."I'm a man of the past, living in the present and walking in the future..."
03-17-2009, 12:29 PM #4
what did you initially shoot in? 60i most likely?
All your slo mo should be at 50% for a 30fps output that matches everything else. (60i plays at 30fps for all intents and purposes) I assume youtube expects 30fps files or at least handles those the best.STRAVA: Enabling dorks everywhere to get trails shut down........ all for the sake of a race on the internet.
03-17-2009, 12:47 PM #5
Sorry. I have no idea how you slowed your video down, but assume you basically de-interlaced your "normal" 60i vid and then doubled the frames to get 60p, which when played at 30p gives the impression of slowed motion.
When that video was then automatically converted to .flv by youtube it basically did that process again (since it still thought it was interlaced) and thus you get the judder.
03-17-2009, 12:49 PM #6STRAVA: Enabling dorks everywhere to get trails shut down........ all for the sake of a race on the internet.
03-17-2009, 12:56 PM #7
I'm exceeding my payscale but here's my best guess:
"Slowing down" standard (read non-overcranked) video by 1/2 can be done two ways - deinterlacing 60I video (ending with 30p) and doubling the frames - thus playing 60p video at 30p, or playing 60i vid at 15 fps, which simply displays the fields longer.
Keep in mind there is no true motion in video, just a series of pictures that fool your brain into seeing motion.
Since the .flv conversion is bitmap based (I think) it emphasizes the stopped motion of the slowed video
03-17-2009, 02:22 PM #8
My export for upload to YouTube is 640x480 VGA deinterlaced @ 30fps which is what YouTube specifies.
Tipp your thoughts on the compression sound plausible but then why would the HQ version (with less compression) be choppier than the low-res version? Are you guys also seeing the choppiness I'm describing? And the increase with HQ?
Last edited by 4-TEEF; 03-17-2009 at 04:09 PM."I'm a man of the past, living in the present and walking in the future..."
03-17-2009, 04:06 PM #9
Not here, but I let it buffer 1/2 way before watching...
03-17-2009, 05:42 PM #10
Sounds like you probably already know this but anything beyond half speed means FC has to interpolate/create frames through blending and a bunch of other messy stuff.
I'll be honest, the first few shots in that vid look fine to me. But I think I see what you're talking about at 1:40. And it looks like you tried to slow down something more or less than exactly 50%STRAVA: Enabling dorks everywhere to get trails shut down........ all for the sake of a race on the internet.
03-18-2009, 10:22 AM #11
The "frame dropping" I'm talking about is super obvious to me on the YouTube HQ version but this other version @ http://www.snowbird.com/video/mobilrider looks fine.
Thanks for the input."I'm a man of the past, living in the present and walking in the future..."
03-18-2009, 11:36 AM #12
I don't know man......keep shit off you tube?
More to satisfy my curiosity about how FC does it, try and do another render with nothing other than 50% stretching and see if that improves it.
03-19-2009, 08:39 PM #13
Looks pretty good despite some chop. The slow mo is actually nice.Nothing is more dangerous to the adventurous spirit within a man than a secure future. The very basic core of a man’s living spirit is his passion for adventure.
03-20-2009, 03:28 PM #14
I know Vimeo converts all footage to 24p, but I have no idea what Youtube does.
4-TEEF, yeah, my Twin Peaks vid sucks balls on Youtube but is smooth on my computer. It seems to me that Youtube went to shit soon after they allowed "HD" uploads. At first the site worked well, then it slowed down.
Anyway, I prefer Vimeo.
Sorry to ramble and not add shit to the conversation.
03-20-2009, 04:10 PM #15
I know YouTube isn't the place for quality but goddamn it's a good place for P.R. and branding which is the purpose of what I'm doing anyways."I'm a man of the past, living in the present and walking in the future..."