ffmpeg convert pipeline

convert_pipe.sh

#!/usr/bin/env bash

# Usage Example: find ./*.{mp4,flv} -type f | parallel -j 2 --keep-order --line-buffer ./convert_pipe.sh {} {.}.mkv
# Please use git bash on windows

set -e
# Shell colors
NC='\e[0m' # No Color
DRY_RUN=0
INPUT=""
OUTPUT=""
SKIP_HEVC=0

# START: Parse arguments
for i in "$@"; do
  case $i in
  -d | --dry-run)
    DRY_RUN=1
    ;;
  -i=*| --input=*)
    INPUT="${i#*=}"
    ;;
  -o=*| --output=*)
    OUTPUT="${i#*=}"
    ;;
  -s| --skip-hevc)
    SKIP_HEVC=1
    ;;
  esac
done
# END: parse arguments

print_error() {
  local red='\e[31m'
  echo -e "${red}$1${NC}"
}

print_info() {
  local green='\e[32m'
  echo -e "${green}$1${NC}"
}

ask_to_exit() {
  read -n 1 -s -r -p "Press any key to exit."
  exit 1
}

detect_windows() {
  local uname
  uname=$(which uname) 2>/dev/null

  if [ "$uname" = "" ]; then
    print_error "${RED}Unable to detect system type. If you are on Windows, please use git bash.${NC}"
    ask_to_exit
  fi
}

is_hevc() {
  local codec
  codec=$(ffprobe -v error -select_streams v:0 -show_entries stream=codec_name -of default=nokey=1:noprint_wrappers=1 "${1}")
  if [ "${codec}" = "hevc" ]; then
    echo 1
  else
    echo 0
  fi
}

check_file_exist() {
  if [ -z "$1" ]; then
    print_error "Input file cannot be empty."
    ask_to_exit
  fi

  if [ ! -f "$1" ]; then
    print_error "File $1 does not exist."
    ask_to_exit
  fi
}

get_extension() {
  local ext="${1##*.}"
  if [ -z "$ext" ]; then
    print_error "Unable to get file extension from $1"
    ask_to_exit
  fi
  echo "$ext"
}

compute_temp_file() {
  local path="$1"
  local extension random_string
  extension="$(get_extension "$path")"
  # shellcheck disable=SC2002
  random_string="$(cat /dev/urandom | tr -dc 'a-zA-Z0-9' | fold -w 16 | head -n 1)"
  echo "/tmp/${random_string}.${extension}"
}

get_duration() {
  ffprobe -v error -show_entries format=duration -of default=noprint_wrappers=1:nokey=1 -sexagesimal "$1"
}

get_codec_type() {
  local type
  type="$(ffprobe -loglevel error -show_entries stream=codec_type -of default=nw=1 "$1")"
  if [ "codec_type=video" = "$(echo "$type" | grep video)" ]; then
    echo "video"
  elif [ "codec_type=audio" = "$(echo "$type" | grep audio)" ]; then
    echo "audio"
  else
    print_error "Unable to detect media type of $1"
    ask_to_exit
  fi
}

convert() {
  local input_file="$1"
  local output_file="$2"
  local default_video_params
  local default_audio_params
  local video_params=""
  local audio_params=""
  local command=""
  local type

  default_video_params="-c:v hevc_nvenc"
  default_video_params="${default_video_params} -rc vbr"
  default_video_params="${default_video_params} -preset:v slow"
  default_video_params="${default_video_params} -profile:v main10"
  default_video_params="${default_video_params} -level:v 6.2"
  default_video_params="${default_video_params} -tier:v high"

  default_audio_params="-c:a libopus"
  default_audio_params="${default_audio_params} -b:a 20k"
  default_audio_params="${default_audio_params} -vbr on"
  default_audio_params="${default_audio_params} -cutoff 8000"
  default_audio_params="${default_audio_params} -ac 1"
  default_audio_params="${default_audio_params} -apply_phase_inv 0"
  default_audio_params="${default_audio_params} -compression_level 10"
  default_audio_params="${default_audio_params} -application voip"
  default_audio_params="${default_audio_params} -frame_duration 60"

  type="$(get_codec_type "$input_file")"
  audio_params="$default_audio_params"
  if [ "video" = "$type" ]; then
    if [ "$(is_hevc "$input_file")" = "1" ]; then
      print_info "Input is already in hevc."
      video_params="-c:v copy"
    else
      video_params="$default_video_params"
    fi
  fi

  command="ffmpeg -hide_banner -i \"$input_file\""
  command="${command} ${audio_params} ${video_params} -y $output_file"
  if [ "0" = "$DRY_RUN" ]; then
    print_info "Start: $command"
    eval "$command"
  else
    print_info "Dry run: $command"
  fi
}

main() {
  local input_file output_file temp_file command
  input_file="$1"
  check_file_exist "$input_file"
  print_info "Input: $input_file"
  print_info "Duration: $(get_duration "$input_file")"

  if [ -z "$2" ]; then
    output_file="$input_file"
  else
    output_file="$2"
  fi
  print_info "Output: $output_file"
  temp_file=$(compute_temp_file "$output_file")
  print_info "Temp file: $temp_file"

  convert "$input_file" "$temp_file"

  command="mv \"$temp_file\" \"$output_file\""
  if [ "0" = "$DRY_RUN" ]; then
    print_info "$command"
    eval "$command"
  else
    print_info "Dry run: $command"
  fi
}

main "$INPUT" "$OUTPUT"

Mac version:

#!/bin/sh

# Usage Example: 
#   find ./*.{mp4,flv} -type f | parallel -j 2 --keep-order --line-buffer ./convert_pipe.sh {} {.}.mkv
#   ./convert_pipe.sh input.mp4 output.mp4

set -e

# Shell colors
RED='\033[0;31m'
GREEN='\033[32m'
NC='\033[0m' # No Color

echo "${GREEN}Input: $(realpath "$1")"
echo "${GREEN}Output: $(realpath "$2")"

INPUT_ENV=`ffprobe -v error -select_streams v:0 -show_entries stream=codec_name -of default=nokey=1:noprint_wrappers=1 "${1}"`
OUTPUT_EXT="${2##*.}"
TEMP_FILE=/tmp/"$(cat /dev/urandom | gtr -dc 'a-zA-Z0-9' | fold -w 16 | head -n 1)"."${OUTPUT_EXT}"

# validation
if [ "${OUTPUT_EXT}" = "" ]; then
  echo "${RED}Invalid output of ${2}, skipping ...${NC}"
  return 1
fi

if [ "${INPUT_ENV}" = "hevc" ]; then
  echo "${RED}Already in ${INPUT_ENV}, skipping ...${NC}"
  return 1
fi

echo "${GREEN}Start converting "$(basename "$1")" to temp file: ${TEMP_FILE}"
echo "${NC}"

ffmpeg -hide_banner \
  -i "${1}" \
  -c:v hevc_videotoolbox \
  -c:a libopus \
  -b:a 20k \
  -y \
  "${TEMP_FILE}"

mv "${TEMP_FILE}" "${2}"

if [ "${1}" != "${2}" ]; then
  rm -f "${1}"
  echo "${GREEN}Deleted source file" "$(realpath "$1")"
fi