Use ffmpeg to convert multiple videos(in any path) to MP4. Output in the same filename in the current path.

convertToMP4.sh

#!/bin/bash

FILEPATH=""
for arg in $@
do
    FILEPATH="${FILEPATH}${arg}"
    if [[ -f $FILEPATH ]]; then
	echo "Converting $FILEPATH to mp4"
	FILENAME_W_EXTENSION=$(basename "$FILEPATH")
        FILENAME="${FILENAME_W_EXTENSION%.*}"
        ffmpeg -i "${FILEPATH}" -pix_fmt yuv420p "${FILENAME}.mp4"
	# clear $FILEPATH when success
	FILEPATH=""
    else
	# prepare space for next arg
	FILEPATH="${FILEPATH} "
    fi
done

Bug:
If an original filename has continuous spaces. It will not recognised as a file because the limitation of for arg in $@.
Please don't use continuous spaces, if you have to, use only 1 continuous space in your original files.