dump-streams

#!/bin/bash

# SPDX-FileCopyrightText: 2021 - 2023 sudorook <daemon@nullcodon.com>
#
# SPDX-License-Identifier: GPL-3.0-or-later
#
# This program is free software: you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by the Free
# Software Foundation, either version 3 of the License, or (at your option)
# any later version.
#
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
# or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
# for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program. If not, see <https://www.gnu.org/licenses/>.

set -euo pipefail

ROOT="$(dirname "${0}")"

source "${ROOT}"/globals

! check_command ffmpeg ffprobe sed && exit 3

function get_stream_count {
  ffprobe -analyzeduration 1G -probesize 1G -v error -show_format file:"${1}" |
    sed -n "s/nb_streams=\([0-9]\+\)/\1/p" 2> /dev/null
}

function pick_container {
  local format
  local format_name
  local container_type

  format="$(ffprobe -analyzeduration 1G -probesize 1G -v error -show_format file:"${1}")"
  format_name="$(echo "${format}" | sed -n "s/^format_name=\(.*\)/\1/p")"

  if [[ "${format_name}" =~ matroska ]]; then
    container_type=mkv
  elif [[ "${format_name}" =~ mp4 ]]; then
    container_type=mp4
  else
    container_type=avi
  fi

  echo "${container_type}"
}

function dump_stream {
  local info
  local codec_name
  local codec_type
  local container
  local font_file
  local in
  in="$(basename "${1}")"
  local name=${in%.*}
  local idx="${2}"
  local out
  local cmd="ffmpeg -analyzeduration 1G -probesize 1G -v warning"

  info="$(ffprobe -analyzeduration 1G -probesize 1G -v error -show_entries stream -select_streams "${idx}" file:"${1}")"
  codec_name="$(echo "${info}" | sed -n "s/^codec_name=\(.*\)/\1/p")"
  codec_type="$(echo "${info}" | sed -n "s/^codec_type=\(.*\)/\1/p")"

  case "${codec_type}" in
    video)
      container="$(pick_container "${1}")"
      out="${name}_${idx}.${container}"
      cmd="${cmd} -i file:${1@Q} -map 0:${idx} -c copy file:${out@Q} -y"
      show_listitem "${cmd}"
      eval "${cmd}"
      return
      ;;
    subtitle)
      cmd="${cmd} -i file:${1@Q} -map 0:${idx}"
      case "${codec_name}" in
        ass)
          out="${name}_${idx}.ass"
          cmd="${cmd} -c copy file:${out@Q} -y"
          ;;
        dvd_subtitle)
          container="$(pick_container "${1}")"
          if [[ "${container}" = mp4 ]]; then
            out="${name}_${idx}.mp4"
          else
            out="${name}_${idx}.mkv"
          fi
          cmd="${cmd} -c copy file:${out@Q} -y"
          ;;
        mov_text | srt | subrip)
          out="${name}_${idx}.srt"
          cmd="${cmd} -c subrip file:${out@Q} -y"
          ;;
        hdmv_pgs_subtitle)
          out="${name}_${idx}.sup"
          cmd="${cmd} -c copy file:${out@Q} -y"
          ;;
        *)
          show_warning "Format ${codec_name@Q} not supported. Skipping."
          return
          ;;
      esac
      show_listitem "${cmd}"
      eval "${cmd}"
      return
      ;;
    audio)
      out="${name}_${idx}.${codec_name}"
      cmd="${cmd} -i file:${1@Q} -map 0:${idx} -c copy file:${out@Q} -y"
      show_listitem "${cmd}"
      eval "${cmd}"
      return
      ;;
    attachment)
      if [[ "${codec_name}" =~ ^[o|t]tf ]]; then
        mkdir -p "${name}_fonts"
        font_file="$(echo "${info}" | sed -n "s/^TAG:filename=\(.*\)/\1/p")"
        cmd="${cmd} -dump_attachment:${idx} \"\" -i file:${1@Q} -y"
        show_listitem "${cmd}"
        eval "${cmd}" || true # FIXME: override return false for attachments
        mv "${font_file}" "${name}_fonts"
      fi
      return
      ;;
  esac
}

#
# Main
#

if [ ${#} -eq 0 ]; then
  show_error "ERROR: No input given. Exiting."
  exit 3
fi

if [ ${#} -gt 1 ]; then
  show_warning "WARNING: skipping inputs ${*:2}."
fi

if ! [ -f "${1}" ]; then
  show_error "ERROR: invalid input ${1@Q}. Exiting."
  exit 3
fi

STREAM_N="$(get_stream_count "${1}")"
for i in $(seq 1 "${STREAM_N}"); do
  dump_stream "${1}" "$((i - 1))"
done