fix copy tag in reduce-bitrate by id3lib app

reduce_bitrate.sh

@@ -55,11 +55,8 @@ get_bitrate_kbps() {
 restore_metadata() {
     local source_file="$1"
     local target_file="$2"
-    local script_dir="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
-
-    # Use Python script with mutagen to properly copy all ID3 tags including multi-value fields
-    "$script_dir/copy_id3_tags.py" "$source_file" "$target_file" 2>/dev/null
 
+    id3cp "$source_file" "$target_file" >/dev/null 2>&1
     return $?
 }
 
@@ -138,8 +135,8 @@ if ! command -v ffprobe >/dev/null 2>&1 || ! command -v ffmpeg >/dev/null 2>&1;
     exit 1
 fi
 
-if ! python3 -c "import mutagen" 2>/dev/null; then
-    log_error "Python mutagen library not found. Please install python-mutagen (Arch) or python3-mutagen (Debian/Ubuntu)."
+if ! command -v id3cp >/dev/null 2>&1; then
+    log_error "id3cp not found. Please install id3lib (Arch: id3lib, Debian/Ubuntu: libid3-tools)."
     exit 1
 fi