#!/usr/bin/env bash
#
# checkmp4.sh <directory>
#
# Verifies all .mp4 files in the given directory ie checks if they are broken or not.
# Prints "OK" or "Not OK" for each file.
# Exit code is 0 if all files are OK, 1 if any are broken.

dir="$1"

if [ -z "$dir" ]; then
  echo "Usage: $0 <directory>"
  exit 2
fi

if [ ! -d "$dir" ]; then
  echo "Not a directory: $dir"
  exit 2
fi

bad=0

# loop through mp4 files (non-recursive)
# use `find "$dir" -type f -iname "*.mp4"` if you want recursive
shopt -s nullglob
for file in "$dir"/*.mp4 "$dir"/*.MP4; do
  [ -e "$file" ] || continue

  # --- Test 1: metadata sanity check ---
  ffprobe -v error -select_streams v:0 -show_entries stream=width,height,duration \
    -of csv=p=0 "$file" > /dev/null 2>&1
  probe_status=$?

  # --- Test 2: deep read/decode ---
  ffmpeg -v error -xerror -i "$file" -f null - -nostats > /dev/null 2>&1
  decode_status=$?

  if [ $probe_status -eq 0 ] && [ $decode_status -eq 0 ]; then
    echo "OK     $file"
  else
    echo "Not OK $file"
    bad=1
  fi
done
shopt -u nullglob

exit $bad