YouTube - Bad Frame Rate with slo-mo?

[4-TEEF]

Hey gang.

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.

Thoughts?

Edit: Here's the YouTube embed.

[Tippster]

http://blogs.chron.com/makingmovies/...e_and_the.html

[4-TEEF]

http://blogs.chron.com/makingmovies/...e_and_the.html

Thanks for the link. There's not much relating to my specific slo-mo problem but it's handy to have the dimensions and estimated frame rate.

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...

[kidwoo]

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.

[Tippster]

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.

[kidwoo]

Sorry. I have no idea how you slowed your video down, but assume you basically de-interlaced your "normal" vid and then doubled the frames. When that video was then converted to .flv by youtube it basically did that process again (since it still thought it was interlaced) and thus you get the judder.

If that's the case, why would youtube try to deinterlace what were already progressive frames? I don't know you tube at all but most editing applications don't touch progressive frames in a deinterlacing command.

[Tippster]

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

[4-TEEF]

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.

Hahaha. This is straight up ghetto SD on a Mini-DV cam here guys. 720x480, 30fps, interlaced NTSC is the original capture. Slo-mo is just slowed down in Final Cut with all the "extra" frames blended/generated/rendered by the software. Final Cut's slo-mo is actually very smooth but it does soften the footage some.

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?

[Tippster]

Not here, but I let it buffer 1/2 way before watching...

[kidwoo]

Hahaha. This is straight up ghetto SD on a Mini-DV cam here guys. 720x480, 30fps, interlaced NTSC is the original capture. Slo-mo is just slowed down in Final Cut with all the "extra" frames blended/generated/rendered by the software. Final Cut's slo-mo is actually very smooth but it does soften the footage some.

All right fancy pants did you at any time slow down to any number other than 50%?


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%

[4-TEEF]

All right fancy pants did you at any time slow down to any number other than 50%?

Of course. I think the slowest was around 40% and the fastest was around 60%. FCP actually changes the % input to a number by adding/subtracting decimal percentages from your input so that it can evenly divide that input into the FPS. Looking at the files it seems like the software isn't creating just the frames in between the original frames but ALL the frames therefore smoothing out the footage.

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.

Yep I totally understand and in this case the quality is acceptable for the final product. This stuff will rarely ever make it to a TV set let alone a projection screen. 99.9999999% will be viewed online.

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%

I don't think that you and Tipp are seeing the same thing as me. Are you guys both on PCs? the only computer I have to view on is a MacPro that should have no problem playing this but for some reason is having problems.

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.

[kidwoo]

Of course. I think the slowest was around 40% and the fastest was around 60%. FCP actually changes the % input to a number by adding/subtracting decimal percentages from your input so that it can evenly divide that input into the FPS. Looking at the files it seems like the software isn't creating just the frames in between the original frames but ALL the frames therefore smoothing out the footage.

I'm not sure how (or if) this is too different from what after effects (and newer versions of premiere pro) do. I do know that with 60i footage, rates other than 50% do look better than starting with progressive frames, and that uncompressed AVIs usually look much better than compressed renders. But once compressed, the fine details of frame blending start to show up in force and it's much more apparent.

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.

[pmcgrath]

Looks pretty good despite some chop. The slow mo is actually nice.

[Trackhead]

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.

[4-TEEF]

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.

I thought it might be some kind of bug with the Flash wrapper + encoding + Mac OS because it seemed like Tipp and Kidwoo weren't seeing the same chop and I assumed they were on PC's. You're on a Mac right?

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.