Why don't you convert these ECM formats into BIN / CUE or using the Clone CD format such; IMG / CCD / SUB / CUE ( more recommended format for the PSX games, especially for the CDDA kind of files )
I knew that the ePSXe 1.90 and ahead can deal with that ECM kind of format. But unfortunately, these are for a file compression methods.
For a more better performance, without issues and better compatibilities, i highly recommend on to uncompress these files.
Too bad, it's been ages that i had ever done these kind of stuff, and i can't remember anything on where you can find that ECM kind of tools. But GOOGLE it's your friend ( you know )