https://somewes.com/frame-count/
Please note that the "console time" part is based off the NES + SNES framerate, so if you're using a platform that's different than that, I wouldn't concentrate on that part, I'd just look at the "video time" part.
I would recommend using vdub (virtualdub) with the mp4 plugin for framecounting and then just putting in the frames that you got into the somewes.com frame section. Sadly I cant give out links but you should find it pretty easy.
Effective immediately, any submissions using the SNES9x emulator will not be verified. The SMB1 mod team has concerns about its integrity due to its ability to overclock and remove lag frames, which may not be easily detectable. Additionally, we request that all BizHawk submissions avoid using the S