Bash function to convert subrip subtitle srt files to advanced sub station alpha subtitle file

ffmpeg.srt.to.ass.zsh

# ----------------------------------------------------
#  srt to ass script converter
#  
#   Usage: srt2ass $SRT_FILE
#
#   It will convert srt file into a default subs.ass
#
#   If you want to override font size (16)
#
#     srt2ass $SRT_FILE [FONT_SIZE]
#
#     [FONT_SIZE] should be positive numeric value
#
#.  Author: Jaziel Lopez <[email protected]>
# ----------------------------------------------------

function srt2ass() {

    local DESTINATION="subs.ass"

    local SOURCE="$1"
    local FONT_SIZE="$2"

    if [ -f "$SOURCE" ]; then

        if [ ! -s "$SOURCE" ]; then

            echo "$SOURCE is an empty file ... bye now"
            return 1
        fi

        if [ -z $FONT_SIZE ]; then
            FONT_SIZE=16
        fi

        if [[ ! "$FONT_SIZE" =~ ^[0-9]+$ ]]; then
            echo "$FONT_SIZE is not a valid number .. bye now"
            return 1
        fi

        ffmpeg -i $SOURCE $DESTINATION
        vim -c "%s/Arial,16/Arial,$FONT_SIZE/" -c "wq" "$DESTINATION"
        EXIT_CODE_VIM=$?

        if [[ $EXIT_CODE_VIM == 0 ]]; then
            echo "srt to ass file type conversion completed."
            echo "see generated file: $DESTINATION"
        fi

        return $EXIT_CODE_VIM
    fi
}