[FFmpeg-user] Combine 2 small GIF images to small animated GIF, fails with "Decoder (codec none) not found for input stream #0:0"

[Gyan Doshi]

GIFs have a dedicated demuxer and don't work via the image2 demuxer.

Try the concat demuxer, or ingest the two GIFs separately and use the 
concat filter.

Regards,
Gyan