[FFmpeg-user] FFMPEG processing time

[Dzung Nguyen]

I have the following script, I have run it for a day but still doesn't
finish. The goal is a one hour video

1) Images --> videos:

ffmpeg -loop 1 -r 1 image.png -r 29.97 video1.mpg

2) Concatenate allsubvideos:

cat *.mpg >concat.mpg

3) Overlay with another video:

ffmpeg -i concat.mpg -i input2.webm"\
                                    " -filter_complex
\"color=c=black:size=1280x720 [base];"\
                                    " [0:v] setpts=PTS-STARTPTS,
scale=#{size_slide} [left];"\
                                    " [1:v] setpts=PTS-STARTPTS,
scale=#{size_webcam} [right];"\
                                    " [base][left]
overlay=shortest=1:x=0:y=39[tmp1];"\
                                    " [tmp1][right]
overlay=shortest=1:x=856:y=402\" -q:v 0 overlay.mpg")

This seems unable to finish even if I let it run for a day. What settings
should I change?