gear360video.sh

#!/usr/bin/env bash

# Script to stitch panoramic videos produced by Samsung Gear360.
# Could be adopted to use with other cameras after creating pto file
# (Hugin template)
#
# For help see:
# https://github.com/ultramango/gear360pano
#
# Names:
# dec, DEC, decoding - means video -> images
# enc, ENC, encoding - means stitched images -> video


#############
### Constants

# http://stackoverflow.com/questions/59895/can-a-bash-script-tell-which-directory-it-is-stored-in
DIR=$(dirname `which $0`)
FRAMESTEMPDIRSUFF="frames"
OUTTEMPDIRSUFF="out"
OUTDIR="$DIR/html/data"
# Options, default is the quality option, overridable by speed parameter
# Valid value is: 2-31, lower is better
FFMPEGQUALITYDEC="-q:v 2"
FFMPEGQUALITYENC="-c:v libx265 -crf 18"
IMAGETMPLDEC="image%05d.jpg"
IMAGETMPLENC="image%05d_pano.jpg"
PTOTMPL4096="gear360video4096.pto"
PTOTMPL3840="gear360video3840.pto"
PTOTMPL2560="gear360video2560.pto"
# This is a default, it will/should be overwritten anyway
PTOTMPL="$DIR/${PTOTMPL3840}"
TMPAUDIO="tmpaudio.aac"
TMPVIDEO="tmpvideo.mp4"
# Throttle parallel processing to give some room for other processes
# See: https://www.gnu.org/software/parallel/parallel_tutorial.html#Limiting-the-resources
PARALLELEXTRAOPTS="--load 99% --noswap --memfree 500M"
# Debug, yes = print debug messages
DEBUG="no"
# Global flag if temporary directories should be removed
CLEANUP="yes"


#############
### Functions

# Debug, arguments:
# 1. Text to print
print_debug() {
  if [ "$DEBUG" == "yes" ]; then
    echo "DEBUG: $@"
  fi
}

# Clean-up function
clean_up() {
  if [ "$CLEANUP" == "yes" ]; then
    echo "Removing temporary directories..."
    if [ -d "$FRAMESTEMPDIR" ]; then
      print_debug "Removing frames directory: $FRAMESTEMPDIR"
      rm -rf "$FRAMESTEMPDIR"
    fi
    if [ -d "$OUTTEMPDIR" ]; then
      print_debug "Removing output directory: $OUTTEMPDIR"
      rm -rf "$OUTTEMPDIR"
    fi
  else
    echo "Keeping temporary directories..."
    echo "Frames temp directory: $FRAMESTEMPDIR"
    echo "Output temp directory: $OUTTEMPDIR"
  fi
}

# Function to run a command and check the result
# http://stackoverflow.com/questions/5195607/checking-bash-exit-status-of-several-commands-efficiently
run_command() {
  # Remove empty arguments (it will confuse the executed command)
  local cmd=("$@")
  for i in "${!cmd[@]}"; do
    [ -n "${cmd[$i]}" ] || unset "cmd[$i]"
  done

  print_debug "Running command: " "${cmd[@]}"
  "${cmd[@]}"
  local status=$?
  if [ $status -ne 0 ]; then
    # We failed, inform the user and clean-up
    echo "Error while running $1" >&2
    if [ $1 != "notify-send" ]; then
       # Display error in a nice graphical popup if available
       run_command notify-send -a $0 "Error while running $1"
    fi
    clean_up
    exit 1
  fi
  return $status
}

# Print help for the user
print_help() {
  echo -e "\nSmall script to stitch raw panoramic videos."
  echo "Raw meaning two fisheye images side by side."
  echo -e "Script originally writen for Samsung Gear 360.\n"
  echo -e "Usage:\n$0 [options] infile [outfile]\n"
  echo "Where infile is a panoramic video file, output"
  echo "parameter is optional. Video file will be written"
  echo "to a file with appended _pano, ex.: dummy.mp4 will"
  echo -e "be stitched to dummy_pano.mp4.\n"
  echo "-o|--output DIR will set the output directory of panoramas"
  echo "                default: html/data"
  echo "-p|--parallel   use GNU Parallel to speed-up processing"
  echo "-s|--speed      optimise for speed (lower quality)"
  echo "-t|--temp DIR   set temporary directory (default: system's"
  echo "                temporary directory)"
  echo "-h|--help       prints this help"
}

check_preconditions() {
  # Check if we have the software to do it
  # http://stackoverflow.com/questions/592620/check-if-a-program-exists-from-a-bash-script
  local error=0

  type nona >/dev/null 2>&1 || { echo >&2 "Hugin required but it is not installed. Aborting."; exit 1; }
  type ffmpeg >/dev/null 2>&1 || { echo >&2 "ffmpeg required but it's not installed. Will abort."; error=1; }
  type multiblend >/dev/null 2>&1 || { echo >&2 "multiblend required but it's not installed. Will abort."; error=1; }

  # Use parallel? Check if we have it
  # https://stackoverflow.com/questions/3601515/how-to-check-if-a-variable-is-set-in-bash
  if [ ! -z "${USEPARALLEL+x}" ]; then
    type parallel >/dev/null 2>&1 || { echo >&2 "GNU Parallel use enabled but it's not installed. Will abort."; error=1; }
  fi

  if [ $error -ne 0 ]; then
    exit 1
  fi
}

######################
### "Main" starts here

# Check required argument(s)
if [ -z "${1+x}" ]; then
  print_help
  run_command notify-send -a $0 "Please provide an input file."
  exit 1
fi

# Process command line options. Source (modified):
# https://stackoverflow.com/questions/192249/how-do-i-parse-command-line-arguments-in-bash
while [[ $# -gt 0 ]]
do
key="$1"

case $key in
  -h|--help)
    print_help
    shift
    exit 0
    ;;
  -o|--output)
    OUTDIR="$2"
    if [ ! -d "$2" ]; then
      echo "Given output ($2) is not a directory, cannot continue"
      exit 1
    fi
    shift
    shift
    ;;
  -p|--parallel)
    # Switch to use parallel
    USEPARALLEL=1
    print_debug "Use of GNU Parallel enabled"
    shift
    ;;
  -t|--temp)
    if [ -d "$2" ]; then
      TEMPDIRPREFIX="$2"
    else
      echo "Given temporary ($2) is not a directory, using default"
    fi
    shift
    shift
    ;;
  -s|--speed)
    FFMPEGQUALITYDEC=""
    FFMPEGQUALITYENC="-c:v libx264 -preset ultrafast"
    shift
    ;;
  *)
    break
    ;;
esac
done

# Output name as second argument plus output directory
if [ -z "${2+x}" ]; then
  # If invoked by nautilus open-with, we need to remember the proper directory in the outname
  OUTNAME=$OUTDIR/`basename "${1%.*}"`_pano.mp4
  print_debug "Output filename: $OUTNAME"
else
  OUTNAME=$OUTDIR/`basename $2`
fi

# Check if software is installed
check_preconditions

# Start counting time
STARTTS=`date +%s`

# Handle temporary directories
if [ -n "$TEMPDIRPREFIX" ]; then
  # On some systems not using '-p .' (temp in current dir) might cause problems
  FRAMESTEMPDIR=`mktemp -d -p $TEMPDIRPREFIX`
  OUTTEMPDIR=`mktemp -d -p $TEMPDIRPREFIX`
else
  FRAMESTEMPDIR=`mktemp -d`
  OUTTEMPDIR=`mktemp -d`
fi

# Extract frames from video
run_command notify-send -a $0 "Starting panoramic video stitching..."
echo "Extracting frames from video (this might take a while)..."
# Note: anything in quotes will be treated as one single option
run_command "ffmpeg" "-y" "-i" "$1" $FFMPEGQUALITYDEC "$FRAMESTEMPDIR/$IMAGETMPLDEC"

# Detect video size (http://trac.ffmpeg.org/wiki/FFprobeTips)
eval $(ffprobe -v error -of flat=s=_ -select_streams v:0 -show_entries stream=height,width "$1")
SRCVIDEOSIZE=${streams_stream_0_width}:${streams_stream_0_height}
print_debug "Input video size: ${SRCVIDEOSIZE}"

# Detect video size and select appriopriate pto file
case $SRCVIDEOSIZE in
  4096:2048)
    PTOTMPL=$PTOTMPL4096
    ;;
  3840:1920)
    PTOTMPL=$PTOTMPL3840
    ;;
  2560:1280)
    PTOTMPL=$PTOTMPL2560
    ;;
  *)
    PTOTMPL=$PTOTMPL3840
    ;;
esac
print_debug "PTO template: ${PTOTMPL}"

# Stitch frames
export -f run_command print_debug clean_up
echo "Stitching frames..."
if [ -z "${USEPARALLEL+x}" ]; then
  # No parallel
  find $FRAMESTEMPDIR -type f -name '*.jpg' | xargs -Ipanofile bash -c "run_command \"$DIR/gear360pano.sh\" -r -m -o \"$OUTTEMPDIR\" \"panofile\" \"$PTOTMPL\""
else
  # Use parallel
  find $FRAMESTEMPDIR -type f -name '*.jpg' | parallel $PARALLELEXTRAOPTS --bar run_command "$DIR/gear360pano.sh" -r -m -o "$OUTTEMPDIR" {} "$PTOTMPL"
fi

# Put stitched frames together
echo "Recoding the video..."
# Detect source FPS (probe streams until some sane fps found, naive but should work)
for streamno in {0..5}; do
  SRCFPSSTR=`ffprobe -v fatal -of default=noprint_wrappers=1:nokey=1 -select_streams $streamno -show_entries stream=r_frame_rate "$1"`
  print_debug "Stream: $streamno FPS: $SRCFPSSTR"
  if [ $SRCFPSSTR != "0/0" ]; then
    break;
  fi
done
if [ $streamno -eq 5 ]; then
  print_debug "Couldn't find FPS, assuming 30000/1001"
  SRCFPSSTR="30000/1001"
fi

print_debug "Input video FPS: ${SRCFPSSTR}"

# Re-encode video back with stitched images
run_command ffmpeg -y -f image2 -framerate ${SRCFPSSTR} -i "$OUTTEMPDIR/$IMAGETMPLENC" -r "${SRCFPSSTR}" -s "${SRCVIDEOSIZE}" $FFMPEGQUALITYENC "$OUTTEMPDIR/$TMPVIDEO"

# Check if there's audio present (https://stackoverflow.com/questions/21446804/find-if-video-file-has-audio-present-in-it)
SRCHASAUDIO=`ffprobe -v fatal -of default=nw=1:nk=1 -show_streams -select_streams a -show_entries stream=codec_type "$1"`
print_debug "Input video has audio: ${SRCHASAUDIO}"

if [ -n "$SRCHASAUDIO" ]; then
  echo "Extracting audio..."
  run_command notify-send -a $0 "Extracting audio from source video..."
  run_command ffmpeg -y -i "$1" -vn -acodec copy "$OUTTEMPDIR/$TMPAUDIO"

  echo "Merging audio..."
  run_command notify-send -a $0 "Merging audio with final video..."
  run_command ffmpeg -y -i "$OUTTEMPDIR/$TMPVIDEO" -i "$OUTTEMPDIR/$TMPAUDIO" -c:v copy -c:a aac -strict experimental "$OUTNAME"
else
  print_debug "No audio detected (timelapse video?), continuing..."
  mv "$OUTTEMPDIR/$TMPVIDEO" "$OUTNAME"
fi

# Remove temporary directories
clean_up

# Inform user about the result
ENDTS=`date +%s`
RUNTIME=$((ENDTS-STARTTS))
echo Video written to $OUTNAME, took: $RUNTIME s
run_command notify-send -a $0 "'Conversion complete. Video written to $OUTNAME, took: $RUNTIME s'"
exit 0