[FFmpeg-user] Extracting frames from 59.94 FPS video - only every other frame is different

[Will Price]

Thank you all for your valuable insights.

It's a real shame that the GoPro does this without warning as it will make our lives more challenging. We need to compute the optical flow of the videos and without an easy method of determining whether frames are 'duplicated' or not we'll have to downsample the videos to 30FPS.

Thanks again,

--
Will Price | PhD student | Visual Information Laboratory | University of Bristol

On Dec 2 2017, at 3:55 am, Moritz Barsnick <barsnick at gmx.net> wrote:
> On Fri, Dec 01, 2017 at 21:33:32 +0000, Andy Furniss wrote:
> > Maybe it's intended by the camera eg. the early part is lower motion or
> > lower light level.
>
> Actually, googling for this issue gives a lot of hits, such as this:
> https://community.gopro.com/t5/Cameras/High-speed-video-frame-doubling-issues/td-p/15968
>
> So, yes, it's exposure, and you can turn "Auto Exposure" off.
>
> Moritz, no GoPro.
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