[meltedcapacitor]

Read again the proposal.

A top level thread scans the opcodes only to solve this, with no decoding and no writing, thus progressing faster in the stream than the child chunked decoding threads it progressively spawns.

Not as quick as a format with a chunk table, but faster than naive single core.

[seoaeu]

I did read your comment. You don’t have any explanation of how the top level scan can maintain the color index array for QOI_OP_INDEX chunks without doing any decoding.

[flohofwoe]

I bet you can split big images into smaller QOI encoded chunks and decode those in parallel.

QOI is simple enough to remix the file format as much as you want in your own encoder/decoder (that's actually the USP), it's not meant as a standardized image exchange format, just something that lives in your own asset pipeline.