Reencoding mpvs to upload as discord clips

make-clips.sh

#!/usr/bin/env bash
# A script that reencodes mkvs to a target filetype for uploading to discord
current_datetime=$(date +%Y-%m-%d_%H-%M-%S)
output_dir="discord-sized/$current_datetime"

if [[ ! -d "$output_dir" ]]; then
  mkdir -p "$output_dir"
fi

reencoded_files=()
for file in *.mkv; do
  # Check if the file exists
  if [[ ! -f "$file" ]]; then
    echo "Error: File $file not found. Skipping."
    continue
  fi

  filename=$(basename "$file")
  filename="${filename%.*}"
  output_file="$output_dir/${filename}.mp4"

  target_mb=$((9 * 1024 * 1024))
  audio_bytes=$(ffprobe -v error -select_streams a:0 -show_entries packet=size -of default=nokey=1:noprint_wrappers=1 "$file" | awk '{s+=$1} END {print s}' )
  duration=$(ffprobe -v error -show_entries format=duration -of default=noprint_wrappers=1:nokey=1 "$file")
  video_kbps=$(echo "scale=0; (($target_mb - $audio_bytes) * 8 / $duration / 1024)" | bc)

  # Prevent video bitrate from being negative if audio is too large
  if ((video_kbps < 0)); then
    video_kbps=100
  fi

  # Perform two-pass encoding
  ffmpeg -y -i "$file" -c:v libx264 -b:v "${video_kbps}k" -pass 1 -an -f null /dev/null && \
  ffmpeg -y -i "$file" -c:v libx264 -b:v "${video_kbps}k" -pass 2 -c:a copy "$output_file"

  echo "Re-encoded: $file to $output_file"
  reencoded_files+=("$output_file")
done

echo "Finished processing all files, output:"
for encoded_file in "${reencoded_files[@]}"; do
  echo "$output_dir/$encoded_file"
done