are you submitting these to a scoreboard like Twin Galaxies?
Otherwise, you might want to look into a capture card or software to capture the output of your emulators. Some versions of MAME have this built in.
Current MAME has avi file write. Can be processor-intensive, though. Fraps is a little better, though file size is about the same. I find it easier to record the INP, then use my phone, and directly upload via WIFI.
So, yeah, if you have a decent smart phone, just use that. Camera....what is that??