Module input 

Structs

FrameSequence

A numbered copy of a frame list that ffmpeg can read on every platform.

Functions

collect_input_frames

Collect files from input_folder matching the optional pattern, in natural order (frame_2.png before frame_10.png). Defaults to *.png.

natural_cmp

Compare strings with digit runs compared as numbers: a2 < a10.

png_bytes_have_alpha

png_has_alpha for PNG bytes, e.g. the start of a PNG stream. The first few KB are enough: IHDR and tRNS come before the image data.

png_has_alpha

Whether a PNG file can hold transparency: an alpha channel (RGBA or gray + alpha) or a tRNS chunk. Returns false for anything that is not a readable PNG.