Read PNG/JPG from stdin

[avidseeker]

avifenc supports reading jpg, png formats as files.

SYNOPSIS
       avifenc [options] input.[jpg|jpeg|png|y4m] output.avif

But not as file descriptors:

       --stdin
              Read y4m frames from stdin instead of files; no input filenames allowed, must set before
              offering output filename.

[maryla-uc]

Would adding a flag to specify the format of the input work for you?
I think it would be easier to implement than guessing the file format automatically (because you can't read a few bytes for format guessing then rewind the stream when using stdin).

[avidseeker]

Would adding a flag to specify the format of the input work for you?

Yes