Video compression script

compress-video

#!/bin/bash

# Process command-line arguments
if [[ $# -eq 0 ]] || [[ "$1" == "--help" ]]; then
    echo "Usage: compress-video [OPTIONS] [FILENAMES...]"
    echo
    echo "Options:"
    echo "  --speed-2x     Output video at 2x speed"
    echo "  --size-half    Scale output to half size"
    echo "  --help         Display this help page"
    exit 0
fi

echo "1"

flag_speed2x=false
flag_half=false

# Array to hold file arguments
files=()

# Process command-line arguments
while [[ $# -gt 0 ]]; do
    echo "2"
    case "$1" in
        --speed-2x)
            flag_speed2x=true
            shift
            ;;
        --size-half)
            flag_half=true
            shift
            ;;
        *)
            # Add non-flag arguments to files array
            files+=("$1")
            shift
            ;;
    esac
done

echo $flag_speed2x
echo $flag_half

for f in "${files[@]}"
do
    echo "$f"
    if $flag_speed2x && $flag_half; then
        # The scaling to ceil(n/4)*2 is to ensure that the dimensions are
        # divisible by 2, which is required by the codec.
        ffmpeg -i "$f" -vf "scale=ceil(iw/4)*2:ceil(ih/4)*2,setpts=0.5*PTS" -af "atempo=2.0" "${f%.*}-2x-half.mp4"
    elif $flag_speed2x; then
        ffmpeg -i "$f" -vf "setpts=0.5*PTS" -af "atempo=2.0"  "${f%.*}-2x.mp4"
    elif $flag_half; then
        ffmpeg -i "$f" -vf "scale=ceil(iw/4)*2:ceil(ih/4)*2" "${f%.*}-half.mp4"
    else
        ffmpeg -i "$f" "${f%.*}-compressed.mp4"
    fi
done

Compression results:

2281519 May 28 18:49 screencap.mov              <-- Original file
 280541 Jun  6 12:35 screencap-compressed.mp4   <-- No size or speed change
 132959 Jun  6 12:35 screencap-half.mp4         <-- Half size
 145569 Jun  6 12:35 screencap-2x.mp4           <-- Double speed
  66790 Jun  6 12:35 screencap-2x-half.mp4      <-- Half size and double speed