[FFmpeg-user] Output image sequence duplicate first image

[adam smith]

> On 20 Apr 2020, at 15:38, Edward Park <kumowoon1025 at gmail.com> wrote:
> 
> If this is accurate, it looks like you have asked it to produce 20 frames in 60 seconds, or 1/3 fps, or 1 frame every 3 seconds regardless of input framerate, whatever. It will drop frames, duplicate frames, do what is needed to keep 1/3 frames per second constant output. You've also specified that you want 10 frames total. at 1/3 fps that runs 30 seconds. I'm not sure why the first and second are always duplicates, it doesn't look like any frames were duplicated. (at 0.33fps if two frames were exactly the same when they weren't duplicated, maybe it was frozen in the source?)
> 
> Regards,
> Ted 
> 

Thanks Ted,
Thats exactly what I was hoping I had asked it for.
Create 20 image files per 60 seconds of source media up to a maximum total of 10 images.
So if the source was 15 seconds in duration I would get 5 images, anything 30 seconds if longer in duration I would get 10 images output spaced equally apart in time at a frequency of 1/3 fps from the start of the source.
These values are all variables at runtime so I might ask to create at a lower frequency with more or less total images.
Every single time I get a duplicate first image :(