Problem when using --grid 10x0 ... mode.

[GuguKatze]

I get this error using the following parameter (probably again an issue with --grid 10x0) ... I got no such errors with the same mp4 file but with a regular 3x3 or 5x4 grid ...

... it seems to be caused by input files not long enough for even a single thumbnail ... i.e. using "--interval 1m" but the input file only being 40 seconds long.

my $cmd = '/usr/local/bin/vcsi ' . $self->mp4;
$cmd .= ' --show-timestamp --width 1920 --grid 10x0 --interval 1m --grid-spacing 0 --background-color 000000';
$cmd .= ' --start-delay-percent 0 --end-delay-percent 1 --metadata-position hidden'; # see #75
$cmd .= ' --timestamp-font "/usr/share/fonts/truetype/dejavu/DejaVuSans.ttf"';
$cmd .= ' --timestamp-format '{H}:{M}'';
$cmd .= ' --timestamp-font-size 10 --timestamp-vertical-padding 2 --format jpg -o ' . $self->{'preview'};

Traceback (most recent call last):
  File "/usr/local/bin/vcsi", line 8, in <module>
    sys.exit(main())
  File "/usr/local/lib/python3.8/dist-packages/vcsi/__init__.py", line 3, in main
    vcsi.vcsi.main()
  File "/usr/local/lib/python3.8/dist-packages/vcsi/vcsi.py", line 1518, in main
    process_file(filename, args)
  File "/usr/local/lib/python3.8/dist-packages/vcsi/vcsi.py", line 1646, in process_file
    selected_frames, temp_frames = select_sharpest_images(media_info, media_capture, args)
  File "/usr/local/lib/python3.8/dist-packages/vcsi/vcsi.py", line 677, in select_sharpest_images
    selected_items = select_color_variety(selected_items, args.num_selected)
  File "/usr/local/lib/python3.8/dist-packages/vcsi/vcsi.py", line 686, in select_color_variety
    min_color = avg_color_sorted[0].avg_color
IndexError: list index out of range

[plambert]

I see this problem as well; it'd be really nice if we could have the option to, in this case, just grab a frame from the approximate middle of the video.