[FFmpeg-user] Feature request: -number_range

[Michael Koch]

The option "-start_number_range" is only used when searching for the 
first image of a sequence. I propose to add a new option "-number_range" 
that specifies the number of trials if the next image in a sequence 
isn't found.
For example, when making a timelapse from hundreds of images, it may be 
necessary to exclude a few images from the sequence. But we can't simply 
delete these images, because ffmpeg will stop if the next image isn't 
found. Possible workarounds are duplicating one of the neighbor images, 
or renaming all subsequent images. With the proposed option ffmpeg would 
just skip the missing images.

Thanks,
Michael