gif_to_mp4_1x.sh

#!/bin/bash

# gif_to_mp4_5x.sh
# Convert GIF to 5x speed MP4 using ffmpeg.

INPUT="$1"
BASENAME=$(basename "$INPUT" .gif)
SPEED=1
PTS=$(awk "BEGIN{print 1/$SPEED}")
WIDTH=1000  # Desired output width (px)

if [[ -z "$INPUT" ]]; then
  echo "❗ Usage: $0 input.gif"
  exit 1
fi

echo "🖼️  Input GIF: $INPUT"
echo "⚡ Speed: ${SPEED}x | Resize to width: ${WIDTH}px"

ffmpeg -i "$INPUT" -vf "setpts=${PTS}*PTS,scale=${WIDTH}:-2:flags=lanczos" \
-vcodec libx264 -pix_fmt yuv420p -crf 23 -preset slow -movflags +faststart \
"${BASENAME}_${SPEED}x.mp4"

echo "✅ Done: ${BASENAME}_${SPEED}x.mp4"