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POV video and frame rates

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Eric HansenPOV video and frame rates
by on Oct 14, 2009 at 8:15:04 pm

I wasnt sure what forum to post this question in. But since i'm trying to upconvert using Magic Bullet Instant HD Advanced in AE, i thought this would be the one.

I'm working with footage shot by various POV cameras. the main ones being the VIO POV.1 and GoPro. neither of these cameras are HD, so i'm using Instant HD Advanced to upconvert them to 1920x1080. both of these cameras use AVI as the container format.

i'm getting a strange issue dealing with frame rates. using the footage from the GoPro as an example: if i open a file in Quicktime player, i get the following information:

Format: Apple OpenDML JPEG, 512x384
FPS: 26.74

Final Cut thinks the file is 27fps. Compressor thinks the file is 30.00fps and so does After Effects. when i step through the video frame by frame in Quicktime, everything is fine. but if i open the file in After Effects or FCP and step through, there is a frame doubling every 5 or 6 frames. even if i interpret the footage as 26.74 and set the AE comp for 26.74, there is still a frame doubling. i have tried to interprete at 24, 25, 29.97 and 30.00 and theres still a frame doubling. these files are progressive btw.

i have also tried to open the file in Cinema Tools to change the frame rate metadata to something like 25, and it still doubles frames.

i'm conjecturing that the cameras are not shooting a true SMTPE frame rate or timecode. that it's constantly wobbling. my goal is to eventually have these videos at 1920x1080 at 25fps. i thought about maybe outputting DPX files to get a true frame by frame. i tried to output TIFF files from Quicktime Pro, but since it asks for a target FPS, it wont work without doubling a frame somewhere.

any suggestions?

thanks

e


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Dave LaRondeRe: POV video and frame rates
by on Oct 14, 2009 at 8:27:51 pm

[Eric Hansen] "...i'm conjecturing that the cameras are not shooting a true SMTPE frame rate or timecode..."

That's an excellent conjecture. To salvagewhat you have -- and I do indeed mean salvage, NOT resurrect -- I recommend that you conform your footage in AE to 25fps (go File>Interpret>Main) and see what happens.

Then get yourself a camera that actually shoots at 25fps, okay? Life's too short to fart around with bad gear.

Dave LaRonde
Sr. Promotion Producer
KCRG-TV (ABC) Cedar Rapids, IA


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Eric HansenRe: POV video and frame rates
by on Oct 14, 2009 at 8:49:03 pm

thanks for the suggestion Dave.

interpreting the footage for 25fps was one of the first things i did when i noticed this problem. but it still doubles frames when stepping through. it happens no matter what the Comp fps settings are.

i couldnt agree with you more about the camera. my personal favorite is the Iconix HD cameras (of course they use a bulky SDI breakout box and require a separate recorder, besides being expensive). i also really want to try Sony's new AVCHD POV camera. but the reality for this project is that i am working with action sports athletes that are sponsored by these particular POV camera companies.

thanks

e


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Dave LaRondeRe: POV video and frame rates
by on Oct 14, 2009 at 9:06:18 pm

Okay, I guess I don't know what the term, "POV Camera" means.

I THOUGHT it meant, "a still camera that purportedly shoots video, like the Canon D5 Mark II".

Perhaps it means, "a still camera that takes still pictures at a pretty fast rate."

Is it something else? If so, what?

And if it's like that barely-tolerable Canon piece of junk, know that the Canon shoots at 30fps. Not 24 like film, not 23.976 like NTSC film, not 25 like PAL, not 29.97 like NTSC... it shoots 30.

Dave LaRonde
Sr. Promotion Producer
KCRG-TV (ABC) Cedar Rapids, IA


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Eric HansenRe: POV video and frame rates
by on Oct 14, 2009 at 9:25:29 pm

POV = Point of View Camera. these are small imagers, i've sometimes heard people call them lipstick cameras, that athletes mount on their helmets, bikes, surfboards, etc; to give the audience their point of view.

here is VIO's site: http://www.vio-pov.com/

since these cameras are marketed to the fans of these athletes as much as the athletes themselves, they are very inexpensive compared to pro options like the Iconix. the cheapest GoPro is $190. so in many cases you're dealing with similar resolution and quality as point and shoot cameras with video, or cell phones with video. this also means non-pro codecs such as the OpenDML JPEG i mentioned in the first post. not high quality stuff, but definitely a case of content being more compelling than image quality.

if anyone has any suggestions on how to deal with these non-standard codecs and their frame rate issues, please let me know. or if you have used these codecs/cameras and not run into these framerate issues, let me know that too. i used VIO footage for years and this is the first time i've encountered this issue. or maybe its the first time i've noticed it.

thanks

e


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Dave LaRondeRe: POV video and frame rates
by on Oct 14, 2009 at 9:50:20 pm

These cameras seem to be able to shoot at different frame rates. I hope you picked one instead of experimenting with frame rates. If not, you've got problems.

I'm a Mac guy, and I have never even HEARD of the Apple OpenDML JPEG codec. I'd bet the recording media on these gizmos isn't very long at all, so this mysterious codec may use some form of interframe (aka long-gop or temporal) compression. I'd change it to something well-known, because AE does not play nicely AT ALL with temporally-compressed video.

I'll guess you're on a Windows box, but even so, I'd use QT Pro to export a Quicktime Movie in the PNG codec... not a PNG sequence, but a Quicktime Movie using the PNG codec. At best quality, it's lossless, and the file sizes aren't all that stupefying.

Once that's done, try conforming again. Good luck trying to make it look like HD.

Dave LaRonde
Sr. Promotion Producer
KCRG-TV (ABC) Cedar Rapids, IA


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