gif.bash

#!/bin/bash
#
#         _/_/_/  _/_/_/  _/_/_/_/
#      _/          _/    _/
#     _/  _/_/    _/    _/_/_/
#    _/    _/    _/    _/
#     _/_/_/  _/_/_/  _/
#
#    Uses ffmpeg to generate
#    animated gifs from mov
#    files.

# TODO
# + delay/speed
# + choose dither

# Get the speed from the user (or default)
read -p "Enter fps[10]: " FPS
FPS=${FPS:-10}

read -p "Enter max colors[255]: " MAX_COLORS
MAX_COLORS=${MAX_COLORS:-255}

# Get the video size
GIF_ORIGINAL_SIZE=$(php -r '
$json = `/usr/local/bin/ffprobe -v quiet -print_format json -show_streams ~/Desktop/in.mov`;
$info = json_decode($json);
foreach($info->streams as $stream) {
  if (isset($stream->width)) {
    break;
  }
}
$width = $stream->width;
$height = $stream->height;
echo "$width:$height";')

# Get the size from the user (or match the original)
read -p "Enter size[$GIF_ORIGINAL_SIZE]: " GIF_SIZE
GIF_SIZE=${GIF_SIZE:-$GIF_ORIGINAL_SIZE}

ffmpeg -y -i ~/Desktop/in.mov -vf fps=$FPS,scale=$GIF_SIZE:flags=lanczos,palettegen=max_colors=$MAX_COLORS /tmp/palette.png
ffmpeg -i ~/Desktop/in.mov -i /tmp/palette.png -filter_complex "fps=$FPS,scale=$GIF_SIZE:flags=lanczos[x];[x][1:v]paletteuse=dither=none" ~/Desktop/out.gif
rm /tmp/palette.png